Basics of anatomy and physiology, cell, tissues, membranes and glands

1. UNIT 1
ANATOMY
&
PHYSIOLOGY
By
Mr. Johny Kutty Joseph
Asstt. Professor
SMVDCoN

2. Anatomy – It is the study of structure and
shape of body and its parts & their
relationships to one another. The term
anatomy comes from the Greek words
meaning to cut (tomy) apart (ana).
Gross anatomy( macroscopic anatomy) – the
study of large, easily observable
structures (by naked eye), such as the
heart or bone.
Microscopic anatomy (cytology, histology) –
the study of very small structures, where
a magnifying lens or microscope is
needed.

3. Physiology – the study of how the body and
its parts work or function physio =nature
, logy = the study of.
Like anatomy , physiology has many
subdivisions.
For example, neurophysiology explains the
working of the nervous system , and
cardiac physiology studies the function of
the heart.

4. Levels of Structural Organization
The human body exhibits 7 levels of
structural complexity :
1-Chemical level : The simplest level of
structural ladder .At this level atoms
combine to form molecules such as water,
sugar, & proteins. Every material thing in
the universe including human body
consists atoms and thus molecules.
2- Organelle Level: Chemical structures may
get organized to form larger units called
cells; the smallest units of living things. It
is a structure that can perform a specific
function.
Eg. Mitochondria (produce ATP/Enzyme), ER,
Golgi Apparatus

5. 3 - Cellular Level: cells are the smallest
structural units that possess and exhibit
the basic characteristics of a living matter.
An adult human body consists of
100000000000000 cells. (100K billion).
They perform different functions and
hence differentiated accordingly.
4- Tissue level : The next higher level;
groups of similar cells that have a common
function along with matrix, the
intracellular substannces. (4 basic types
such as epithelial, connective, muscle and
nervous issues.) these are fabrics of the
body.

6. 5- Organ level: An organ is a structure
composed of 2 or more tissue types that
performs a specific function . Heart is and
example of organ. Muscle and connective
tissue give shape and helps pumping,
epithelial tissue forms the inner lining,
nervous tissue control the pumping
mechanism.
6- System Level: The most complex unit
of the Body. It is a group of organs that
work together to accomplish a common
purpose

7. (each organ has its own job to do)
(Cardiovascular System includes the
organs such as heart, arteries, veins,
capillaries, etc.)
7- Organism level , represents the highest
level of structural organization ( total of
11 organ systems). It is the living human
organism. It has well coordinated systems
and can survive independently and can
perform many activities with the capacity
of maintenance and repair.

9. The human body has 11 systems
1-INTEGUMENTARY
ORGANS
 Skin
FUNCTIONS
 Waterproofs, cushions,
protects deeper tissue
 Excretes salts & urea; pain,
pressure
 Regulates body temp;
synthesize vitamin D

10. 2-SKELETAL
ORGANS
 Bones, cartilages,
ligaments, joints
FUNCTIONS
 Protects & supports body
organs
 Framework for muscles &
movement
 Hemato-poiesis; store
minerals

11. 3- MUSCULAR
ORGANS
 Skeletal muscle, muscles
(attached to bone)
FUNCTIONS
 Contraction & mobility
(locomotion)
 Facial expression, posture
 Produce body heat

12. 4- NERVOUS
ORGANS
 Brain, spinal cord, nerves,
& sensory receptors
FUNCTIONS
 Fast-acting central control
system
 Responds to
external/internal stimuli
via nerve impulses
(electrical messages)

13. 5- ENDOCRINE
ORGANS
 Pituitary, thyroid,
parathyroids, adrenals,
thymus, pancreas, pineal,
ovaries, testes…..etc.
FUNCTIONS
 Slow -acting control system
 Glands produce hormones
that regulate growth,
reproduction, metabolism,….
etc.

14. 6- Circulatory
ORGANS
 Heart, blood vessels,
capillaries &blood
FUNCTIONS
 Carries O2 nutrients,
hormones, & other
substances to and from
tissue cells
 White blood cells protect
against bacteria, toxins,
tumors

15. 7- LYMPHATIC
ORGANS
 Lymphatic vessels, lymph
nodes, spleen, tonsils
FUNCTIONS
 Complements circulatory
system by returning
leaked fluid back to blood
vessels
 Cleanses the blood;
involved in immunity

16. 8- RESPIRATORY
ORGANS
 Nasal cavity, pharynx,
larynx, trachea,
bronchi, & lungs
FUNCTIONS
 Keeps blood supplied
with O2 & removes CO2
 Carries out gas
exchanges through air
sacs in lungs

17. 9- DIGESTIVE
ORGANS
 Oral cavity, esophagus,
stomach, small intestine,
large intestine, rectum,
anus (liver & pancreas)
FUNCTIONS
 Breaks food down into
absorbable units that enter
the blood; indigestible food
eliminated as feces

18. 10- URINARY (EXCRETORY)
ORGANS
 Kidney, ureter, urinary
bladder, urethra
FUNCTIONS
 Eliminates nitrogenous
waste from the body
(urea & uric acid)
 Regulates water,
electrolytes, & acid-base
balance of the blood

19. 11- REPRODUCTIVE
ORGANS
 Male: Seminal vesicles, prostate,
penis, vas deferens, testis,
scrotum
 Female: Ovaries, mammary
glands, uterus, vagina, uterine
tube
FUNCTIONS
 Primary function for both sexes is
to produce offspring
 Male – testes produce sperm &
male sex hormones
 Female – ovaries produce eggs &
female sex hormones; mammary
glands for nourishment

20. Body Cavities
There are two sets of internal
body cavities called the dorsal
and ventral body cavities.
These cavities are closed to the
outside.
1. Dorsal Body Cavity: Which
protects the fragile nervous
system organs has two
subdivisions. The cranial
cavity, in the skull, encases
the brain.
Contd…..

21. Body Cavities
The vertebral, or spinal,
cavity, which runs within the
bony vertebral column,
encloses the delicate spinal
cord. The cranial and spinal
cavities are continuous with
one another
2- Ventral Body Cavity
The more anterior and larger
of the closed body cavities is
the ventral body cavity .It
has two major subdivisions,
the thoracic and the
abdomino-pelvic cavities.

22. Body Cavities
Thoracic cavity includes lungs,
esophagus, thymus, aorta, heart
etc… It houses internal organs
collectively called the viscera
They are separated by the
diaphragm, a dome-shaped
muscle important in breathing.
The abdominopelvic cavity, as its
name suggests, has two parts
not physically separated by a
muscular or membrane wall.
The inferior part, the pelvic
cavity, lies in the bony pelvis .

23. Body Cavities
It mainly includes;
Abdominal Cavity:
liver, gallbladder,
stomach, pancreas,
spleen, kidneys etc.
Pelvic Cavity: Urinary
bladder,
Reproductive
organs, intestine
(parts) & rectum.

24. Anatomical Position
Standing erect
Feet parallel
Arms hanging at the sides
Palms facing forward
Anatomical position – body is erect with
the feet parallel and the arms hanging
at the sides with the palms facing
forward. (It’s important to note
throughout this course, most
terminology refers to this position
regardless of the position the body
happens to be in at the time)

25. Directional terms
 Superior (cranial or cephalad): toward the
head end or upper part of a structure or
body;
 Inferior (caudal): away from the head end
or toward the lower part of a structure or
body;
 Anterior (ventral) – toward or at the front
of the body;
 Posterior (dorsal) – toward or at the
backside of the body;
 Medial – toward or at the midline of the
body;
 Lateral – away from the midline of the
body;

26. Directional terms
 Proximal – close to the origin of the body part
or the point of attachment of a limb to the
body trunk.
 Distal – farther from the origin of a body or the
point of attachment of a limb to the body
trunk.
 Superficial (external) – toward or at the body
surface.
 Deep (internal) – away from the body surface;
more internal.
 Central: Near to the centre. (CNS)
 Peripheral: Near to the boundary of the Body.
(PNS)
 Medullary: inner region or core of an organ.
 Cortical: Outer region or outer layer of an
organ.

27. Examples:
 The navel is inferior to the breastbone
 The heart is posterior to the breastbone
 The arms are lateral to the chest
 The elbow is proximal to the wrist
 The skin is superficial to the skeleton
 The forehead is superior to the nose
 The breastbone is anterior to the spine
 The heart is medial to the arm
 The armpit is intermediate between the breastbone and
the shoulder
 The knee is distal to the thigh
 The lungs are deep to the rib cage

28. Body planes and sections
A section is a cut made along a plane
 Sagittal – cut made along the lengthwise or
longitudinal plane of the body dividing it into
left and right parts
 Midsagittal (median) plane – right and left
parts are of equal size
 Frontal (coronal) plane – cut made along a
lengthwise plane that divides the body into
anterior and posterior parts
 Transverse plane (cross section) – cut made
along a horizontal plane dividing the body or
organ into superior and inferior parts

29. Planes
 Sagittal Plane –
divides body into
right and left parts.
 Midsagittal =median
plane –divides
body into two equal
halves.

30. Planes
 Frontal = coronal
plane – divides body
into anterior and
posterior parts

31. Planes
 Transverse plane =
cross
Section= horizontal
section divides into
upper and lower
parts

32. Abdominopelvic Regions and Quadrants
Because the abdominopelvic cavity is large and
contains several organs, it helps to divide it into smaller
areas for study.
One division method, used primarily by anatomists,
uses two transverse and two parasagittal planes. These
planes, divide the cavity into nine regions :
-The umbilical region is the centermost region deep to
and surrounding the umbilicus (navel).

33. Abdominopelvic Regions

34. -The epigastric region is located superior to the umbilical region
(epi = upon, above; gastri = belly).
-The hypogastric (pubic) region is located inferior to the
umbilical region (hypo = below).
-The right and left iliac, or inguinal, regions (ing′gwĭ-nal) are
located lateral to the hypogastric region (iliac = superior part of
the hip bone).
-The right and left lumbar regions lie lateral to the umbilical
region (lumbus = loin).
-The right and left hypochondriac regions flank the epigastric
region laterally (chondro = cartilage).

35. Life Span considerations
1.Every organ regardless of location and function
undergoes change over the years.
2.Maturity refers to a fully operational body.
3.Atrophy is the term used to describe the wasting
effects of advancing age.
4.Developmental processes.
5.Aging processes.
6.Autopoiesis is the process of self organizing & self
maintenance.

36. Questions.
1.What is gross anatomy?
2.What is Cytology?
3.Define physiology?
4.Define Autopoiesis?
5.What is bilateral symmetry? What are the terms used to
denominate this?
6.Locate mediastinum?
7.What is the anatomical position of the heart?
8.Explain the abdominal regions?
9.What is sagittal plane?
10.What is viscera?
11.Name the organs of circulatory system.
12.Name the organs of endocrine system

37. STRUCTURE OFSTRUCTURE OF
HUMAN CELLHUMAN CELL
BY:BY:
MR. JOHNY KUTTY JOSEPHMR. JOHNY KUTTY JOSEPH
ASSTT. PROFESSOR, SMVDCONASSTT. PROFESSOR, SMVDCON

38. INTRODUCTIONINTRODUCTION
• The cell is the basic unit of structure and function in living
things. Cells vary in their shape size, and arrangements but all
cells have similar components, each with a particular function.
• Around 100 trillion of cells make up human body.
• All human cell are microscopic in size, shape and function.
• The diameter range from 7.5um micrometer (RBC) to 150 um
(ovum).
• Cell is defined as the fundamental living unit of any organism.
• Cell is important to produce energy for metabolism (all chemical
reactions within a cell)
• Cell can mutate (change genetically) as a result of accidental
changes in its genetic material (DNA).
• Cytology: the study of the structure and functions of cells.

39. TYPES OF CELLSTYPES OF CELLS
Prokaryotic Cells
• Do not have structures surrounded by membranes
• They have few internal structures
• One-celled organisms, bacteria.
• Genetic material is present in the Nucleoid
Eukaryotic cells
• Possess a membrane-bound nucleus
• Are more complex than prokaryotic cells
• It functions within the membranes and has many
organelles
• It has a cytoskeleton.
• It is present in most plants and animals.

40. TYPES OF CELLSTYPES OF CELLS
1. Nerve Cells: Sensitive Surface, Long
Extensions, It Detect Changes In External
Environment.
2. Muscle Cells: Elongated, Threadlike
Structures Containing Fibers For Force And
Contraction To Allow Movement.
3. RBC: Contains Haemoglobin, Transportation
Of Oxygen.
4. Gland Cells: Contain Sacs That Release
Secretion To Outside The Cell Such As
Hormones, Enzymes Etc.
5. Immune Cells: Capacity To Engulf Other
Cells Such As Bacteria And Cancer Cells And
Produce Antibodies.s.

41. STRUCTURE OF CELLSTRUCTURE OF CELL

42. CELL STRUCTURECELL STRUCTURE
THE CELL (PLASMA) MEMBRANE: the cell membraneTHE CELL (PLASMA) MEMBRANE: the cell membrane
is a thin, dynamic membrane that encloses the cell andis a thin, dynamic membrane that encloses the cell and
controls what enters and leaves the cell.controls what enters and leaves the cell.
Fluid mosaic model:Fluid mosaic model: composed of a double layercomposed of a double layer
(bilayer) of phospholipid molecules with many protein(bilayer) of phospholipid molecules with many protein
molecules dispersed within it;molecules dispersed within it;
The surfaces of the membrane are "hydrophilic" due toThe surfaces of the membrane are "hydrophilic" due to
the polar phosphate heads;the polar phosphate heads;
The internal portion of the membrane is "hydrophobic"The internal portion of the membrane is "hydrophobic"
due to the non-polar fatty acid tails;due to the non-polar fatty acid tails;
Cholesterol is the bounding factor of all theseCholesterol is the bounding factor of all these
phospholipid molecules.phospholipid molecules.

43. PLASMA MEMBRANEPLASMA MEMBRANE

44. FUNCTION OF PLASMA MEMBRANEFUNCTION OF PLASMA MEMBRANE
• Serves as boundary of the cell.Serves as boundary of the cell.
• Serve as markers that identify the cells.Serve as markers that identify the cells. Cell recognition proteins-Cell recognition proteins-
allow cell to recognize other cellsallow cell to recognize other cells
• Play significant role in transportation of molecules through gatesPlay significant role in transportation of molecules through gates
made of proteins.made of proteins.
• Some IMPs (intra membrane proteins) connect the cell membrane toSome IMPs (intra membrane proteins) connect the cell membrane to
another membrane to form large tissue.another membrane to form large tissue.
Membrane proteinsMembrane proteins
• Some membrane proteins have carbohydrates attached to them,Some membrane proteins have carbohydrates attached to them,
forming glycoproteins that act as identification markersforming glycoproteins that act as identification markers
• Some membrane proteins are receptors that react to specificSome membrane proteins are receptors that react to specific
chemicals, sometimes permitting a process called signalchemicals, sometimes permitting a process called signal
transduction (carry across the messages) such as hormones.transduction (carry across the messages) such as hormones.

45. CYTOPLASMCYTOPLASM
• Is a gel-like matrix of water, enzymes, nutrients,Is a gel-like matrix of water, enzymes, nutrients,
wastes, and gases and contains cell structureswastes, and gases and contains cell structures
(organelles).(organelles).
• Fluid around the organelles called cytosol.Fluid around the organelles called cytosol.
• Most of the cells metabolic reactions occur in theMost of the cells metabolic reactions occur in the
cytoplasm.cytoplasm.
• It contains both membranous and non-It contains both membranous and non-
membranous organelles.membranous organelles.

46. ENDOPLASMIC RETICULUMENDOPLASMIC RETICULUM
It is a network of interconnected parallel
membranes (maze), that is continuous with the
nuclear membrane; there are two types;
Rough Endoplasmic Reticulum (RER)
•ER studded with small granules called ribosomes
•This ribosomes give an appearance of sandpaper.

47. ENDOPLASMIC RETICULUMENDOPLASMIC RETICULUM
• A new polypeptide strands (amino acids) are
released from the ribosomes which forms the
protein in combination with others.
• The main function of RER is protein synthesis.
• This further moves to Golgi apparatus and some
leaves the cell.

48. SMOOTH ENDIOLASMIC RETICULUM
It lacks Ribosome.
It’s a continuation of RER.
It continues the process of protein synthesis started in RER
It synthesizes other molecules such as phospholipids &
cholesterol. And these are synthesized to form plasma
membrane.
Some SER enzymes helps to destroy toxins such as drugs.
It also stores calcium to maintain low concentration in cell.
It also helps in other membrane protein synthesis and then
transported to plasma membrane.

49. RIBOSOMERIBOSOME
• Every cell contains thousand of ribosome's and
many of them attached to the RER and some lie
free in the cytoplasm.
• Each ribosome is non-membranous structure,
made of two pieces large unit and small unit and
each subunit composed of rRNA (ribosomal RNA).
• Other types of RNA includes mRNA & tRNA.
(Messenger RNA & transport RNA)

50. RIBOSOME
• Function: protein synthesis. They are generally
called as protein factories because they are the
molecular machines that translate the genetic
code to make protein.
• Ribosome are temporary structures since they get
shed off after the formation of new polypeptide
strand.
• Protein released from there are not mature, need
further processing in Golgi complex before they
are able to perform their function within or
outside the cell.

51. GOLGI APPARATUS
1.1. Flattened membranous sacs (cisternae).Flattened membranous sacs (cisternae).
2.2. Arranged in stacks ("stack of pancakes")Arranged in stacks ("stack of pancakes")
associated with many vesicles (membrane boundassociated with many vesicles (membrane bound
sacs containing proteins); located near to thesacs containing proteins); located near to the
nucleus.nucleus.
3.3. It was first noticed by Italian biologist CamilloIt was first noticed by Italian biologist Camillo
Golgi.Golgi.
4.4. It helps in processing and packaging proteinIt helps in processing and packaging protein
molecules for export from the cell.molecules for export from the cell.

52. GOLGI APPARATUS
1.1. Protein is synthesized by Ribosome, then it movesProtein is synthesized by Ribosome, then it moves
to ER where it is packaged by tiny membranousto ER where it is packaged by tiny membranous
bubbles, then theses bubbles are moved to Golgibubbles, then theses bubbles are moved to Golgi
complex where it undergo chemical alteration bycomplex where it undergo chemical alteration by
enzymes present over there. Eg. Glycoproteinenzymes present over there. Eg. Glycoprotein
(protein + carbohydrate)(protein + carbohydrate)
2.2. It is then pinched off to another vesicle till plasmaIt is then pinched off to another vesicle till plasma
membrane.membrane.
3.3. At plasma membrane it is secreted outside theAt plasma membrane it is secreted outside the
cell.cell.

53. LYSOSOME
1. They are vesicles that have pinched off from the Golgi
apparatus.
2. The size vary according to the stage of activity.
3. Spherical membranous sacs containing digestive enzymes;
4. "Suicide sacs" which destroy anything the cell no longer
wants or needs. Eg. Proteins, bacteria etc. The break down
residuals can be reused by body. Eg. Amino acids
5. Autolysis is the process by which worn cell parts are
digested by autophagy.
6. They are also called digestive bags, cellular garbage
disposals.

54. PROTEASOMESPROTEASOMES
It is another misfolded protein destroying organelle in the
cell.
It is hallow cylindrical, made up by three protein sub units.
It is founded through out the cytoplasm.
Unlike Lysosomes it destroys the un needed protein one by
one.
The absence of proper functioning of Proteasomes can
cause severe illness such as parkinsonism because the
improperly formed/folded protein can damage the cell.

55. PEROXISOMES
It is another type of vesicle containing enzymes that is
present in some cells and is also pinched off from SER.
Often seen in kidney and liver
Function = detoxification of harmful or toxic
substances (ie. Alcohol)
It contains enzymes such as Peroxidase and Catalase
which are important in detoxification reactions involving
hydrogen peroxide. Its name is also derived from the
same.

56. MITOCHONDRIA
A highly organized molecular structure though too small.
The walls consist of two membranes.
• Kidney-shaped organelle whose inner membrane is folded
into shelf-like partitions called cristae;
• ATP (Adenosine Triphosphate) is embedded in the inner
membrane of mitochondria.
• Mitochondria extract energy from the food molecules and
build ATP.

57. MITOCHONDRIA
• ATP molecules leave mitochondria and break apart to
release energy for various chemical reactions in the cell.
• Thus each mitochondria acts as tiny power plants/power
house of the cell.
• Each mitochondria has its own DNA molecule which
enables them to divide and reproduce genetically and can
also make own enzymes.
• The number of mitochondria in a cell is directionally
proportional to its level of function. A liver cell contains
almost 1000 mitochondria and sperm contains 25
mitochondria.

58. NUCLEUSNUCLEUS
The central core, control center or "brain" of the cell.
The largest organelle of the cell and It is filled with
nucleoplasm.
Nuclear membrane (or nuclear envelope) is a double
membrane that separates the contents of the
nucleus from the cytoplasm; it is selectively
permeable.
At various point, these two membranes are perforated
and these are called nuclear pore. It helps in
transportation in and out of the nucleus.

59. NUCLEUSNUCLEUS
It possess DNA molecules which continuously move around
and perform its functions.
Human cell contains 46 chromosomes.
All the chromosomes contain DNA molecules and some
protein molecules.
Chromatin is the material which makes DNA.
The DNA molecules contain the master code for making all
RNA and enzymes and other proteins.
There is a prominent structure called nucleolus in the
nucleus but it does not have DNA but has RNA. The main
function of the nucleolus is production of rRNA to form
Ribosomes.

60. THE CYTOSKELETON
Gives mechanical support to the cell, It is also involved in
cell motility, which utilizes motor proteins.
Cell fibers, Centrosomes, Molecular Motors, Centrioles are
the part of Cytoskeleton.
Is a network of fibers extending throughout the cytoplasm
Fibers appear to support the endoplasmic reticulum,
mitochondria, and “free” ribosome.
It forms a fence to prevent free floating movement of
embedded proteins.

61. THE CAVEOLAE
It Is Newly Invented Cell Organelle
They Are Tiny Caves or Caveolae
They Are Tiny Indenations Of The Plasm Membrane.
They Are The Transportaors Of Lipids And Proteins.
It Can Also Cause Heart Disease And Stroke, Diabetes,
Cancer, etc, Because It Attracts LDLs (CD36/bad
cholestrol) and gets combined to it which is transported
through cell and Get Accumulated Along With Blood
Vessels. As the accumulation takes place blood vessel
narrow and it obstructs blood flow

62. CELL MEMBRANE SURFACE MODIFICATIONS
/CELL EXTENSIONSSCilia / CiliumCilia / Cilium
A. Short, hair-like cellular extensions (eyelashes);A. Short, hair-like cellular extensions (eyelashes);
B. Help move substances through passageways;B. Help move substances through passageways;
C. Located in lining of respiratory tract & fallopian tube.C. Located in lining of respiratory tract & fallopian tube.
FlagellaFlagella
A. Tail-like projection;A. Tail-like projection;
B. Only one per cell in humans;B. Only one per cell in humans;
C. Aids in cellC. Aids in cell locomotionlocomotion;;
D. Sperm cell.D. Sperm cell.
MicrovilliMicrovilli::
A. Small finger-like extensions of the external surface of the cellA. Small finger-like extensions of the external surface of the cell
membrane;membrane;
B. Function = toB. Function = to increase surface areaincrease surface area..
C. Located in the lining of the digestive tract.C. Located in the lining of the digestive tract.

63. CELL CONNECTIONS
The tissue and organs must be held together
hence they are well connected.
Desmosomes: They are also called as spot welds
that hold adjacent cells. It act as an adhesive
belt. These are anchored internally by
intermediate filaments of cytoskeleton.

64. Gap Junctions: It form when
membrane channels of adjacent plasm
membrane connect each other. It also
allows chemical substance to pass
between the cells. They form
gaps/tunnels that join the cytoplasm
of two cells and also fuse plasma
membrane into a single structure. Eg.
Heart
Tight Junction: Impermeable
junction that encircles the cell &
prevents leakage. The membrane
proteins are well stuck. It is present in
those places where it is important to
control the passage of substances. Eg.
Intestine, Blood Brain Barrier, Skin
etc.
CELL CONNECTIONS

65. Cell Physiology
Transport Across the Plasma
Membrane
Moving of substances across the cell is necessary for
survival.
Membrane transport mechanisms are labelled into
two
There are mainly two types of transport
Passive Transport and Active Transport
Passive process does not require any energy
expenditure or activity of the cell membrane; the
particles move by energy that that they already have.
Active processes do require metabolic energy by the
cell.

66. Passive Transport
Diffusion.
Random mixing of particles in solution.
Substances move from area of higher concentration to
lower concentration through a membrane.
Particles eventually become evenly distributed -
Equilibrium reached.
It occurs down a concentration gradient.
There are two types of diffusion
Simple diffusion:
Facilitated Diffusion

67. Simple diffusion:
When molecules pass directly through membrane it
is called simple diffusion.
Facilitated Diffusion:
• It is call channel mediated or carrier mediated
transport.
• Channel mediated passive transport is diffusion
of particles through a membrane by means of
channel structures in the membrane; move down
their concentration gradient. Diffusion of sodium
ions into nerve cells during nerve impulse
• Carrier mediated passive transport is diffusion
through membrane by means of carrier
structures in the membrane ; move down their
concentration gradient.
• Diffusion of glucose molecules into most cells.

68. Diffusion Through the Plasma
Membrane

69. Facilitated diffusion
• Channel mediated passive transport: passage through
protein tunnels or membrane channels:
• Passage through appropriate channels such as
sodium and chloride.
• They are also called gated channels. Aquaporins are
recently discovered channels that can pass water
molecules faster than diffusion.
• Carrier mediated passive transport: Occurs through
transporter called membrane carrier.
• The carrier structure attracts a solute to a binding
site, changes its shape and then release into the
other side of the membrane.
• These are reversible actions.

70. Osmosis
 A special case of diffusion is called osmosis.
 Passive process
 Diffusion of water across a selectively permeable
membrane from high concentration of water
( low solute) to lower concentration of water
( High solute)
 No movement of substances.
 Osmotic pressure: water pressure that develops
in a solution as a result of osmosis is called
osmotic pressure.
 Potential osmotic pressure is the maximum
osmotic pressure that could be developed.
 The concept of osmosis and osmotic pressure is
very important as it decides the homeostasis of
the human body.

71. Membrane Permeability on Osmosis

72. Tonicity
It describes how a solution affects cell volume.
1.Hypertonic Solution: Higher solute pressure or
low water solution, solution with more solutes.
Blood cells shrink and crenate. Eg. 10D,5D, DNS,
etc.
2.Hypotonic low solute pressure or high water
solution, solution with less solutes, Blood cells
swell up and hemolyse. 5D
3.Isotonic Solution is a fluid that has the same
potential osmotic pressure as a cell is said to have.
Iso=same, tonic=pressure, both solutions have
similar concentrations of solutes, Cell size is
unchanged, NS

73. Tonicity

74. Filtration
Another important passive process.
Passing of water and solutes through a
membrane by the force of hydrostatic pressure.
It is a force of a fluid pushing against a surface.
It occurs from a area of high hydrostatic pressure
to an area of low hydrostatic pressure.

75. Active transport process
Active transport - movement of a substance from a lower
concentration to a higher concentration using a carrier
and energy.
Transport by pumps.
1.Membrane transporters called membrane pumps carry
out a transport process in which cellular energy is used.
2.Movement against concentration gradient.
3.Molecules move uphill by pump mechanisms.
4.Calcium pumps: it pumps the calcium ions from the
intra cellular region to other compartments or to outside
the cells.
5.Sodium potassium pump operates across plasma
membrane. Potassium into the cell and sodium to outside
the cell. Both are done by same transporter sodium-
pottassium adenosine triphosphate.

77. Transport by vesicles
A form of active transport. Transport of large
particles across the plasma membrane also
require expenditure of metabolic energy. There
are two Types :
1. Endo-cytosis; the plasma membrane traps
some extracellular material and brings into cell.
In this the major activity is done by
cytoskeleton. The cytoskeleton pulls the
membrane inward thus forming a vesicle. It also
pushes the edges to t close the vesicle. There are
two basic form of endo-cytosis;
1. Phago-cytosis
2. Pino-cytosis

78. Phago-cytosis
Only a few body cells are capable
Ex. WBC (macrophages , neutrophils )
Particle binds to plasma membrane
Pseudopods (temporary projection of cytoplasm) extend
and surround particle forming phago-some
Phago-some fuses with Lyso-somes which destroy
invader.

79. Pinocytosis
Also called cellular drinking
most body cells carry out process
especially absorptive cells in intestines and kidneys
tiny droplets of extracellular fluid taken into cell
lysosomes fuse and degrade particles into smaller
useable particles

80. Exocytosis
• Releases materials form a cell to external area;
large molecules such as protein that cannot be
passed through plasma membrane.
• All cells carry out process
• Secretary cells: release digestive enzymes,
hormones, mucus, or other secretions
• Nerve cells: release neurotransmitters
• vesicles fuse with plasma membrane and release
contents into extracellular fluid.

81. Homeostasis
Describes the body’s ability to
maintain relatively stable internal
conditions even though the outside
world is continuously changing
The literal translation of homeostasis is
“unchanging,”( homeo= the same,
stasis=standing-still)
An American Psychologist Walter B
Cannon suggested the name of
homeostasis.

82. Importance of Homeostasis
1. Body should maintain constant conditions
about temperature, pressure, oxygen, etc.
2. The absence of constancy in body can
cause death.
3. every regulatory mechanisms of the body
consists of homeostatic mechanism.
Set Point:
1. The normal reading or range of normal is
called the set point or set point range.
Eg: Blood glucose: 80-120mg/dl
Body temperature: 370
C / 980
F

83. Homeostatic Control Mechanisms
Communication within the body is essential for
homeostasis. Human body is like a bag of fluid that
is separated from the external environment.
Communication is accomplished chiefly by the
nervous and endocrine systems, which use neural
electrical impulses or blood borne hormones,
respectively, as information carriers.
Regardless of the factor being regulated (the
variable) all homeostatic control mechanisms have
at least four interdependent components .

84. The first component, the receptor or sensor,
is some type of sensor that monitors the
environment and responds to changes, called
stimuli, by sending information (input) to the
control centre by creating afferent signal.
The second component, the control center or
integration centre. Input flows from the receptor
to the control center along the so-called afferent
pathway. The control center, analyzes the input
it receives and then determines the appropriate
response or course of action. The control centre
may give command to effector or may send signal
to higher centres.

85. The third component, the Effector,
provides the means of response (output) to
the stimulus. Information flows from the
control center to the effector along the
efferent pathway. The results of the
response. Eg.body temperature, heart rate,
blood pressure, etc.
Then feed back ( fourth component) to
influence the stimulus, either depressing it
(negative feedback) so that the whole control
mechanism is shut off or enhancing it
(positive feedback) so that the reaction
continues at an even faster rate.

87. Homeostatic functions of the Body;
1. Integumentary: Separate internal environment
from external providing stability.
2.Skeletal: Supports and protects movement,
store minerals which is moved to internal fluid on
demand.
3. Nervous: Regulation of homeostasis, by sending
signals.
4. Endocrine: Regulation of homeostasis, by
signaling hormones that travel across.
5. Cardiovascular: Maintains internal constancy of
oxygen, water, hormones, wastes and heat.

88. Homeostatic functions of the Body;
6. Lymphatic: maintains constant fluid pressure
by draining excess fluid from tissues.
7. Immune: Defends from harmful agents.
8.Respiratory: Maintains stable oxygen and carbon
dioxide by proper gas exchange.
9. Digestive: Maintains constant nutrient level.
10. Urinary: Maintains low level of wastes and
regulates pH of the internal environment.
11. Reproductive: Passes genetic code to offspring
to maintain homeostasis.

89.  Homeostatic control mechanisms are
two:
Negative feedback mechanisms – the
net effect of the response to the
stimulus is the shut off of the original
stimulus or to reduce its intensity
E.g. – body temp, blood chemical
levels
Positive feedback mechanisms – tend
to increase the original disturbance
(stimulus) and push the variable
farther from its original value
E.g. – Ovulation, blood clotting

90. Negative Feedback Mechanisms
In these systems, the output shuts off the
original stimulus or reduces its intensity. These
mechanisms cause the variable to change in a
direction opposite to that of the initial change,
returning it to its “ideal” value; thus the name
“negative” feedback mechanisms.

91. A good example of a nonbiological negative feedback
system is a home heating system connected to a
temperature-sensing thermostat . If the thermostat is set
at 20°C (68°F), the heating system (effector) is triggered
ON when the house temperature drops below that
setting. As the furnace produces heat and warms the air,
the temperature rises, and when it reaches 20°C or
slightly higher, the thermostat triggers the furnace OFF.
This process results in a cycling of “furnace-ON” and
“furnace-OFF” so that the temperature in the house stays
very near the desired temperature of 20°C.
Your body “thermostat,” located in a part of your brain
called the hypothalamus, operates in a similar fashion.

92. Another example occurs when body temperature
increases above set point as may happen when
exercising. The hypothalamus receives feedback from
temperature sensors and responds by reacting on sweat
glands to release the heat.
When body temperature decreases below the setpoint
value the response is to shiver and produce heat thus
returning to normal body temperature.
Another example for the negative loop is maintaining
oxygen and carbon dioxide in the blood. As our muscles
work they consume large amount of oxygen from the
blood to produce energy. This is sensed by the blood
receptors and initiates respiratory system to increases
the rate and depth of breathing.

93. Sweating to cool down the body
1. When your body is hot, sweat glands are
stimulated to release sweat.
2. The liquid sweat turns into a gas (it evaporates)
3. To do this, it needs heat.
4. It gets that heat from your skin. As your skin
loses heat, it cools down.
Vasodilation to cool down the body
1. Your blood carries most of the heat energy
around your body.
2. There are capillaries underneath your skin that
can be filled with blood if you get too hot.
3. This brings the blood closer to the surface of the
skin so more heat can be lost.
4. This is why you look red when you are hot!

94. Vasoconstriction to warm up the body
1.This is the opposite of vasodilation
2. The capillaries underneath your skin get
constricted (shut off).
3. This takes the blood away from the surface of
the skin so less heat can be lost.
Piloerection to warm up the body
1. This is when the hairs on your skin “stand
up” .
2. It is sometimes called “goose bumps” or
“chicken skin”!
3. The hairs trap a layer of air next to the skin
which is then warmed by the body heat
4. The air becomes an insulating layer.

95. Controlling Glucose levels
Your cells also need an exact level of
glucose in the blood.
Glucose moves into the cells for cellular
respiration
Excess glucose gets turned into glycogen in
the liver
This is regulated by 2 hormones (chemicals)
from the pancreas called:
Insulin
Glucagon

96. Positive Feedback Mechanisms
In positive feedback mechanisms, the result or response
enhances the original stimulus so that the activity (output) is
accelerated. This feedback mechanism is “positive” because the
change that occurs proceeds in the same direction as the initial
disturbance, causing the variable to deviate further and further
from its original value or range.
In contrast to negative feedback controls, which maintain
many physiological functions or keep blood chemicals within
narrow ranges, positive feedback mechanisms usually control
infrequent events that do not require continuous adjustments.
However, TWO familiar examples of their use as homeostatic
mechanisms are the enhancement of labor contractions during birth
and blood clotting.

97. As delivery begins the baby is pushed from the
womb, into birth canal. Stretch receptors in the
reproductive wall sense these increased stretch
caused by the movement of the baby. It triggers
pituitary gland and secrete oxytocin. Oxytocin
stimulate stronger contactions and this push the
baby ahead. It gets stronger and stronger till the
baby is delivered.
During the process of blood clotting the clotting
factors arrive at the site of bleeding and
coagulation takes place, blood loss is arrested,
hence is hypo-volemic shock prevented.
Another example is process of ovulation

98. Homeostatic Imbalance
Homeostasis is so important that most disease can
be regarded as a result of its disturbance, a condition
called homeostatic imbalance. As we age, our body’s
control systems become less efficient, and our internal
environment becomes less and less stable. These events
increase our risk for illness and produce the changes we
associate with aging.
The body has different set points. During the period of
infection people suffer from fever (increased temperature)
but no sweating occurs because the set point is modified
in order to kill the bacteria as immunity increases with
temperature.
Role of circadian rhythm (Body Clock)

99. Levels of Homeostatic Control:
1.Intracellular Control: these mechanisms operate at
the cell level. They regulate the functions of the cell
often by means of genes and enzymes.
2.Intrinsic level: these mechanisms operate at the
tissue and organ level. Functioning of the heart such as
contraction and stretching is an example for this.
3.Extrinsic level: it operates at the system and
organism level. Eg. Nervous regulation.

100. Meiosis
1.Takes place in the Gametes of an organism
2.People have a Chromosome count of 46
3.When an egg joins a sperm the count must stay
at 46 to remain human, So, the egg can only have
23 chromosomes, and the sperm can only have
23 chromosomes
4.But, the integrity of the organism must be
maintained.
5.4 daughter cells produced
6.Each daughter cell has half the chromosomes of
the parent
7.2 sets of cell division involved

101. Mitosis occurs only in somatic
cells
• Gametes are not diploid (2n)
• Instead, they are haploid (n)
What about sex cells?
Called gametes
Eggs and sperm
Produced in ovaries or testes

102. Our haploid (n) number is 23
So our eggs and sperm have how many
chromosomes?
Half the number
Why?

103. Fertilization is the union of an egg
and a sperm
If the egg and sperm were
both diploid, what would the
fertilized egg (zygote) be?
It would have been a genetic
mess.

104. Note how mitosis and meiosis
differ:
• Number of divisions?
• Number of chromosomes?
• Number of products?

105. At the end of
Meiosis the
individual
Gamete cell
has divided
from one cell
to four.
Males produce
4 viable
sperm.
Females
produce 1
viable egg and
3 non
functioning
polar bodies.

107. SPERMATOGENESIS
OOGENESIS

108. Crossing over
When does it occur?
Only during Prophase of
Meiosis 1
Homologous chromosomes get
together in temporary tetrads
Overlap (cross over) and trade their DNA
Why is this a good thing to do,
generally?

109. Cell Reproduction
Cells reproduce by splitting themselves into two
separate daughter cells.
Splitting of plasma membrane and cytoplasm into two
is called cytokinesis.
The cells are divided equally with equal amount of
cytoplasm and organelles.
The equal division of DNA is necessary for the life of
cells and it is called Mitosis.

110. Cell Division
Also known as
Mitosis
Takes place in
Regular Body Cells
Keeps Cells Living
and Growing

111. Phases of Mitosis

112. Mitosis
The Basic Phases
of a Cell’s Life:
•Interphase
•Prophase
•Metaphase
•Anaphase
•Telophase
•Cytokinesis

113. Interphase
The longest stage
of a Cell’s life
The time spent
between divisions
Produces all
materials required
for growth
Preparation for
division

114. Prophase
1. The nucleolus disappears and the nuclear membrane
breaks apart.
2. The chromatids coil up densely and chromosomes
become visible.
3. The spindle apparatus forms and attaches to the
centromeres of the chromosomes. Two chromatids joined
by a chromatid.
4. The centrosomes move away to opposite poles.
5. Aster fibers radiating from each centrosomes anchor the
spindle at each pole.

115. Metaphase
1. It is otherwise called as position changing phase.
2. The Nuclear Membrane is completely gone
3. The duplicated chromosomes line up along the cell's equator.
4. The cytoskeleton moves the chromosomes into an orderly
pattern.
5. One chromatid of each chromosomes faces one pole of he cell,
and its identitical chromatid at the opposite pole.
6. Become attached to spindle fibres by centromeres

116. Anaphase
1.It is otherwise called as apart phase.
2.Diploid sets of daughter chromosomes separate
3.The centromeres split to form two chromosomes each
consisting of a single DNA molecule.
4.They are pushed and pulled toward opposite poles of
the cell by the spindle fibers
5.One set of DNA molecule at each pole of the cell.
6.Cytokinesis become apparent.

117. Telophase
1.It is the end phase of mitosis.
2.DNA is returned to original form and location.
3.The nuclear membrane and nucleoli (nucleus) reform
4.DNA elongate back into the chromatin form.
5.Protein synthesis is not possible without this coiling.
6.Cytokinesis takes place: The final stage of Mitosis. The
cytoplasm, organelles, and nuclear material are evenly split and
two new cells are formed.

118. The two new cells – each exactly like the
other – are called Daughter Cells

119. Quick Review:
The following slides are drawings of the
stages of Mitosis.

120. A B C
D E
Quick Review – Place Cells in Mitosis Order

121. Quick Review:
Identify What
happens in each
phase of Mitosis:
Prophase
Metaphase
Anaphase
Telophase
Interphase

122. Why Do Cells Divide?
1. The larger a cell becomes, the more demands
the cell places on it's DNA.
2. The bigger the cell gets the harder it becomes
to move food and waste across the membrane
3. This happens because the surface area and
volume ratio does not stay the same as the
cell size increases.
4. As a cell gets bigger there comes a time when
its surface area is not large enough to meet the
demands of the cell's volume and the cell stops
growing.

123. 123
• Tissue - group of cells similar structure and function
along with similar extracellular substances between
the cells
• Histology – microscopic study of tissue structure,
Histo- = tissue, -ology = study
• Glands: a specialized cell, group of cells, or organ of
endothelial origin that selectively removes materials
from the blood, concentrates or alters them, and
secretes them for further use in the body or for
elimination from the body
• Membranes: a thin sheet or layer of tissue that is
part of a plant or an animal's body

124. Development
Growth
Aging
Trauma
Disease
124

125. Epithelial tissues
 Epi = on + thele = covering or lining
Connective tissues
Muscle tissues
Nervous tissues
125

126. 126
• Covers internal and external body surfaces
• Skin, digestive tract, respiratory passages, and
blood vessels, pleural, pericardial, peritoneal.
• Comprises major tissue of glands
• Membranous epithelium is oftenly called as surface
epithelium.

127. Consists mostly of
cells with very little
extracellular material
(matrix or ECM)
Lacks blood vessels
Gases, nutrients, &
waste diffuse across
basement membrane
Cells attached to
underlying tissue
Free membrane is not
touching any other
cells
127

128. 128
 Protect underlying structures; Skin & oral cavity
; It is relatively tough and impermeable.
Barrier: Skin keeps water in/out, prevents entrance
of toxins & microorganisms
Sensory function: Epithelial tissues are adapted for
sensory functions such as skin, nose, eye, ear etc.
Exchange of substances: O2 & CO2 diffused through
lung epithelia between air and blood.
Secretion: Sweat glands, mucous glands, pancreas,
Secretion of hormones, mucous, sweat, digestive
juices.
Absorption: Carrier molecules in intestine absorb
nutrients (vitamins, ions, food molecules)
Excretion: The unique epithelial cells of kidney
makes the excretion through urine.
Functions of Epithelial Tissue

129. 129
Based on membrane:
1. Membranous epithelium.
2. Glandular epithelium.
Based on shape:
1. Squamous
2. Cuboidal
3. Columnar
Based on layers present
1. Simple
2. Stratified

130. 1) Simple squamous epithelia (lungs)
2) Simple cuboidal epithelia
3) Simple columnar epithelia
4) Pseudostratified columnar epithelia (w/cilia)
(trachea)
5) Stratified squamous epithelia
6) Transitional epithelium (bladder)
130

131. 131
• Single layer of thin, flat
cells
• Line blood vessels,
lymphatic vessels,
heart, alveoli, kidney
tubules, serous
membranes
• The main functions are
Diffusion, filtration, anti-
friction, secretion,
absorption

132.  Single layer of cube-
shaped cells, some
with microvilli or
cilia
 Kidney tubules,
glands/ducts, brain,
bronchioles, ovary
surface
 Secretion,
absorption,
movement of
particles
132

133.  Single layer of tall,
narrow cells, some
with cilia/microvilli
 Lining of stomach,
intestines, glands,
ducts, bronchioles,
auditory tubes, uterus,
uterine tubes
 Secretion, absorption,
movement of
particles/oocytes
133

134.  Single layer of cells, some
tall and thin, others not,
nuclei at different levels,
appear stratified, almost
always ciliated
 Lining of nasal cavity,
nasal sinuses, auditory
tubes, pharynx, trachea,
bronchi
 Synthesis/secretion
(Goblet cells)/ movement
of mucus
 Though it looks like
stratified, it has only a
single layer irregularly
shaped.
134

135. 1. Stratified squamous epithelium: multiple layer,
flat cells, keratinized seen in skin and non
keratinized seen in vagina, mouth etc. (Kertain =
a fibre)
2. Stratified cuboidal epithelium: protective
function, more than one row, seen in pharynx,
epiglottis.
3. Startified columnar epithelium: protection, seen
in male urethra and mucus line of anus.
135

136.  Stratified cells appear
cuboidal when not
stretched and
squamous when
stretched
 Lining of bladder,
ureters, superior
urethra: urothelium
 Deals with changing
volume of fluid in an
organ, protects from
urine contact
136

137. • Epithelium for
secretory activity
• They may function as
unicellular gland or
multi-cellular glands.
• Exocrine glands
(saliva secreted to
ducts) and Endocrine
glands (no ducts,
pitutary etc passes the
hormones directly into
the blood.)
137

138. Cell Layers & Cell Shapes
 Single layers – control passage of materials
through epithelium
 Gas diffusion across lung alveoli
 Fluid filtration across kidney membranes
 Gland secretion
 Nutrient absorption in intestines
 Multiple layers – protect underlying tissues
 Damaged cells replaced by underlying cells
 Protect from abrasion (ex: skin, anal canal, vagina)
138

139. Cell Layers & Cell Shapes, continued
 Flat/thin (squamous) – diffusion, filtration
 Diffusion in lung alveoli
 Fluid filtration in kidney tubules
 Cuboidal/columnar – secretion, absorption;
contain more organelles
 Secretory vesicles (mucus) in stomach lining
 Mucus protects against digestive enzymes and acid
 Secretion/absorption in kidney tubules made
possible by ATP production by multiple
mitochondria
 Active transport of molecules into/out of kidney
139

140. Free Cell Surfaces
 Smooth – reduces friction
 blood vessel lining – smooth blood flow
 Microvilli – increase cell surface area; cells
involved in absorption or secretion
 Small intestine lining
 Cilia – propel materials along cell’s surface
 Nasal cavity/trachea – moves dust and other
materials to back of throat (swallowed/cough up)
 Goblet cells secrete mucus to entrap the “junk”
140

141. 141
Connective Tissue
• The most abundant and widely distributed tissue in
the body
• Multiple types, appearances and functions
• Relatively few cells in extracellular matrix (think:
fruit “peices in Fruit salad”)
• Protein fibers
• Ground substance
– Fluid

142. Three types of protein fibers: A connective tissue
comprise of any of the three fibres.
 Collagen fibers: Rope-like; resist stretching
 Reticular fibers: Fine, short collagen fibers;
branched for support
 Elastic fibers: Coiled; stretch and recoil to original
shape
 Ground substance – combination of proteins and
other molecules. Varies from fluid to semisolid to
solid
 Proteoglycans – protein / polysaccharide complex
that traps water.
142

143.  Based on function:
 Blast (germ) – produce matrix
 Cyte (cell) – cells maintain it
 Clast (break) – cells break down for remodeling
 Osteoblast (osteo-bone) – form bone
 Osteocyte – maintain bone
 Osteoclast – break down bone
 Macrophage (makros-large + phago-to eat) – large,
mobile cells that ingest foreign substances found in
connective tissue
 Mast Cells – nonmotile cells that release chemicals
that promote inflammation
143

144. 144

Enclose organs and separate organs and tissues from one
another

Liver, kidney; muscles, blood vessels, nerves

Connect tissue to each other

Tendons – muscles to bone & Ligaments – bone to bone

Support and movement

Bones, cartilage, joints

Storage

Fat stores energy; bone stores calcium

Cushion and insulation

Fat cushions/protects/insulates (heat)

Transportation

Blood transports gases, nutrients, enzymes, hormones,
immune cells

Protection

Immune & blood cells protect against toxins/tissue
injury; bones protect underlying structures.

145. 1. Fibrous tissue
Loose fibrous (Areolar)
Adipose
Reticular
Dense
2. Bone tissue
Compact
Cancellous
3. Cartilage
Hyaline
Fibrocartilage
Elastic
4. Blood
145

146.  Composition: ECM has
fibroblasts, other cells, collagen,
fluid-filled spaces. It is also called
areolar tissue.
 Functions: I is loose because it is
stretchable. It forms thin
membranes between organs and
binds them (loose packing
material)
 Locations: widely distributed,
between glands, muscles, nerves,
attaches skin to tissues,
superficial layer of dermis
 The matrix contains fibroblasts,
macrophages (Phagocytosis), mast
cells (secrete molecules like
histamine and it act as chemical
mediators.)
146

147.  Composition: very little ECM
(has collagen and elastic fibers);
large adipocytes filled with
lipid/fat cells. Less fibroblasts,
macrophages & Mast cells.
 Functions: Stores fat, (both white
fat and brown fat) energy source
(at some times), thermal
insulator, protection/ packing
material
 Locations: Beneath the skin, in
breasts, within bones, in loose
connective tissues, around
organs (kidneys and heart)
147

148. A three dimensional web net work
It forms the framework of spleen, lymph-
nodes and bone marrow.
Helps in producing blood cells.
Helps in defence against microorganisms.
Phagocytosis is also a function.
148

149.  Composition: ECM mostly
collagen (made by
fibroblasts), arranged in
regular, parallel rows.
 Functions: withstands
pulling forces, resists
stretching in direction of
fibers orientation. It also
forms the dermis and outer
capsule of the kidney.
 Locations: tendons,
ligaments, dermis of skin,
organ capsules
149

150.  Composition: ECM
collagen and elastic
fibers; orientation varies
 Functions: stretches
and recoils; strength in
direction of fiber
orientation
 Locations: arterial
walls, vertebral
ligaments, dorsal neck,
vocal cords
150

151.  Chondrocytes (cartilage cells) inside
lacunae (small spaces)
 Matrix composition (ECM):
 Collagen – flexibility & strength
 Water (trapped by proteoglycans) – rigidity and
flexibility
 No blood vessels – slow healing, can’t bring
cells/nutrients
 Three types:
 Hyaline cartilage
 Elastic cartilage
 Fibrocartilage
151

152. 152

153. 153

154.  Composition: solid matrix,
small evenly distributed
collagen fibers, transparent
matrix, chondrocytes (a type
of cell) in lacunae (small
bone opening)
 Functions: supports
structures, some flexibility,
forms smooth joint surfaces
 Locations: costal cartilages
of ribs, respiratory cartilage
rings, nasal cartilages, bone
ends, epiphyseal (growth)
plates, embryonic skeleton
154

155.  Composition: similar to
hyaline, numerous collagen
fibrous arranged in thick
bundles. The strongest
cartilage.
 Functions: somewhat
flexible, withstands great
pressure, connects
structures under great
pressure
 Locations: intervertebral
disks, pubic symphysis,
articulating cartilage of
some joints (knee, TMJ)
155

156.  Composition: similar to
hyaline cartilage,
abundant elastic fibers
 Functions: rigidity, more
flexibility than hyaline
(elastic fibers recoil to
original shape)
 Locations: external ears,
epiglottis, auditory tubes
156

157.  Composition: hard, mineralized matrix,
made of osseous tissue. The mature bone
cells are called osteocytes.
 Functions: strength, support, protects
organs, muscle/ligament attachments,
movement (joints) Red bone marrow
produce new blood cells.
 Locations: all bones of body
 There are two types;
 Compact bone tissue: hard shell of the
bone. The basic structure is called osteon.
The bone matrix is called lamellae.
 Cancellous (Spongy) bone tissue: present
inside the bone. The thin beams are called
trabeculae.
157

158. 158

159.  Composition: blood cells in a fluid
matrix (plasma). It exists in a liquid
state and contains neither ground
substances nor fibers. The whole
blood is divided into matrix called
plasma and formed elements called
blood cells. Three types of blood
cells RBC, WBCand thrombocytes.
 Functions: transportation (O2, CO2,
hormones, nutrients, waste, etc.),
protect from infection, temperature
regulation.
 Locations: in blood vessels and
heart, produced by red bone
marrow, WBCs leave blood vessels
and enter tissues.
159

160.  General features:
 Can contract wit the help of
Contractile proteins
 Enables movement of the
structures that are attached
to them
 Three (3) types of muscle tissue:
 skeletal
 smooth
 Cardiac
They are also classified as
striated (have cross striations
visible on microscopic slides of
tissue) and non striated (that
do not have strips)
160

161.  Composition: striated
muscle fibers , large,
cylindrical cells that have
many nuclei near periphery
 Functions: body
movement, voluntary
control, swallowing, heat
production
 Locations: attached to
bone, eyeball muscles,
upper third of Oesophagus
161

162.  Composition: cylindrical
cells, striated, single
nucleus, branched and
connected with
intercalated disks
 Functions: pump blood,
involuntary control
 Locations: heart
162

163.  Composition: cells tapered
at each end, not striated,
single nucleus. Otherwise
called as visceral muscle
tissue.
 Functions: regulates
organ size, forces fluid
through tubes, regulates
amount of light entering
eye, “goose bumps”,
involuntary control
 Locations: walls of hollow
organs and tubes
(stomach, intestine, blood
vessels), eye
163

164.  Forms brain, spinal cord, peripheral nerves
 Functions:
 Conscious control of skeletal muscles
 Unconscious control of cardiac muscles
 Self and environmental awareness
 Emotions
 Reasoning skills
 Memory
 Action potentials = electrical signals
responsible for communication between
neurons and other cells
164

165.  Neurons = conducts action
potentials (A.P.’s)
 Cell body = contains
nucleus, site of general cell
functions
 Dendrite = conduct nerve
impulse toward cell body
 Axon = conducts nerve
impulse away from cell
body
 Neuroglia = surrounding
support cells which nourish,
protect, insulate the neurons.
165

166. Thin sheet/layer of tissue covering a
structure or lining a cavity
Made of epithelium & connective tissue
Types:
 Mucous membranes
 Serous membranes
 Skin/cutaneous membranes
 Synovial membranes
 Periosteum
166

167. Mucous
Serous
Synovial
167

168.  Structure: various types of epithelia resting on a thick layer of
connective tissue
 Locations: line cavities that opening to outside of body
(digestive, respiratory, excretory, reproductive tracts)
 Mucous glands secrete mucus
 Functions:
 Protection – oral cavity (stratified squamous epithelium)
 Absorption – intestine (simple columnar epithelium)
 Secretion – mucus and digestive enzymes in intestine
168

169. Structure: simple squamous epithelium
resting on delicate layer of loose
connective tissue
Locations: line trunk cavities, cover
organs
Mucous glands secrete serous fluid onto
membrane surface
Function: prevent damage from
abrasion between organs in thoracic and
abdominopelvic cavities
169

170. Pleural membranes – lungs
 Pleurisy – inflammation of pleural membranes
Pericardial membranes – heart
 Pericarditis – inflammation of pericardium
Peritoneal membranes –
abdominopelvic
 Peritonitis – inflammation of peritoneum
170

171.  Skin/cutaneous membranes
 Stratified squamous epithelium &
dense connective tissue
 Skin
 Synovial membranes
 Connective tissue
 Line joint cavities
 Periosteum
 Connective tissue
 Surrounds bone
171

172.  Gland – multicellular structure secreting
substance onto a surface, into a cavity, or into
the blood
 Exocrine gland (exo-outside + krino-to separate): glands
with ducts; secretions pass through ducts onto a
surface or into an organ
 Simple – ducts w/o branches
 Compound – ducts w/ branches
 Tubular – tubes
 Acinus/alveolus – saclike
 Endocrine gland (endo-within): glands w/o ducts
 Hormones are secreted into blood
172

173. Development of Tissues
The four major tissues of the body appear early in the embryonic
stage, within first two weeks after conception. There forms three
germ layer from which the entire human being is developed.
They are
a.Endoderm
b.Mesoderm
c.Ectoderm
Each germ layer become differentiated to form specific tissues
and this process is called histogenesis.
Ectoderm: Skin, tooth, eye, ear, nose, facial bones, skeletal
muscles, brain & spinal cord, sensory neurons.
Mesoderm: dermis of skin, circulatory system, glands, kidneys,
muscles, bones
Endoderm: GI, Lungs, liver, pancreas, thyroid, thymus, tonsils etc.
173

174. Inflammation
 In response to tissue damage
 Viral/bacterial infections
 Trauma
 Functions:
 Mobilize body’s defences
 Destroy microorganisms, foreign materials, damaged
cells
 “Pave way” for tissue repair
Symptoms of inflammation
 Redness, Heat, Swelling, Pain, Disturbance of function
* Inflammation is beneficial, though painful!
174

175. Inflammatory Response
 Mediators of inflammation cause dilation 
permeability of blood vessels (redness/heat)
 Bring blood and important substances to site
 Edema = swelling (water, proteins, etc.) of tissues
 Fibrin = protein that “walls off” site; keeps
infection from spreading
 Neutrophils ingest bacteria (phagocytic WBC)
 Macrophage ingest tissue debris
 Pus = mixture of dead neutrophils, cells, fluid
175

176. Inflammation is
adaptive:
 Inflammation warns person
from further injury:
 Pain
 Limitation of movement
(edema)
 Tissue destruction
Fibroclast (cells break
down for re-modeling)
migrate to damaged
tissue and digest
176

177. Tissue Repair: Regeneration of injured tissue
by parenchymal cells of the same type or
replacement by connective tissue. It is the
process of Substitution of viable cells for dead
cells
 Completely regeneration: Regeneration of injured
tissue by parenchymal cells of the same type.
Regeneration: same type of cells takes place of
previous cells; same function
 Fibrous repair: Replacement by connective tissue
Scar: different type of tissue develops; forms scars; loss
of some function. Fibroclast lays down fibrin and forms
scar tissue
 Type of tissue repair is determined by:
 Wound severity
 Tissue types involved

178. Proliferative Potential
 Labile cells - Epidermis, mucosal epithelium,
GI tract epithelium etc
 Skin, mucous membranes
 Divide continuously through life
 Stable cells - Hepatocytes, renal tubular
epithelium, pancreatic acini Stable cells
 Don’t actively divide, but can after injury
 Connective tissue, glands (liver, pancreas)
 Permanent cells - Nerve cells, cardiac
myocytes, skeletal muscles.
 Little to no ability to divide
 If killed, replaced by connective tissue
 Recover from limited damage (axon of neuron)

179. Tissue Repair
 Repair, sometimes called healing, refers to the
restoration of tissue architecture and function after
an injury. Critical to the survival of an organism is
the ability to repair the damage, toxic insults and
inflammation.
Hence, the inflammatory response to microbes and
injured tissues not only serves to eliminate these
dangers but also sets into motion the process of
repair.
 Regeneration. Some tissues are able to replace the
damaged components and essentially return to a
normal state; this process is called regeneration.
 Regeneration occurs by proliferation of cells that
survive the injury. However, mammals have a limited
capacity to regenerate damaged tissues and organs, and
only some components of most tissues are able to fully restore
themselves.

180.  Connective tissue deposition (scar formation). If the
injured tissues are incapable of complete restitution,
or if the supporting structures of the tissue are
severely damaged, repair occurs by the laying
down of connective (fibrous) tissue, a process that
may result in scar formation.
Although the fibrous scar is not normal, it provides
enough structural stability that the injured tissue is
usually able to function.
The term fibrosis is most often used to describe the
extensive deposition of collagen that occurs in the
lungs, liver, kidney, and other organs as a
consequence of chronic inflammation, or in the
myocardium after extensive ischemic necrosis
(infarction).
If fibrosis develops in a tissue space occupied by an
inflammatory exudate, it is called organization (as in
organizing pneumonia affecting the lung)

181. Review steps of tissue repair:
 Clot (fibrin)
 Scab (seal)
 Blood vessel dilation
Fibroclast-clean up
 Fibrin “walls off”
 Epithelium replaced
 Scab sloughs
 Fibroblasts form granulation
tissue
 Wound contracture
181

182. It’s tough getting old…
 Tissue changes with age:
  neurons and  muscle cells
  visual acuity, smell, taste, touch
  in functional capacities of respiratory and
cardiovascular systems
 Slower cell division means slower healing
  flexibility (irregular collagen fibers in tendons &
ligaments)
  elasticity (elastic fibers bind to Ca2+
, becoming
brittle) – makes skin wrinkled too 
 Atherosclerosis – plaques in blood vessels
182

183. An example of scar formation where the
damaged tissues are not able to get
completely repaired due to old age any
other reason and hence scar is formed to
fill the vacuum.

184. Healing by First Intention
 When the injury involves only the epithelial layer,
the principal mechanism of repair is epithelial
regeneration, also called primary union or healing
by first intention.
 One of the simplest examples of this type of wound
repair is the healing of a clean, uninfected surgical
incision approximated by surgical sutures.
 Incision causes only focal disruption of epithelial
basement membrane continuity and death of
relatively few epithelial and connective tissue cells.
 The repair consists of three connected processes:
inflammation, proliferation of epithelial and other
cells, and maturation of the connective tissue scar.

185. Healing by Second
Intention
 When cell or tissue loss is more extensive,
such as in large wounds, abscesses,
ulceration, and ischemic necrosis (infarction)
in parenchymal organs, the repair process
involves a combination of regeneration and
scarring.
 In healing of skin wounds by second
intention, also known as healing by
secondary union and, the inflammatory
reaction is more intense, there is
development of abundant granulation tissue,
accumulation of ECM and formation of a
large scar, and wound contraction by the
action of myofibroblasts.

186. Factors That Influence Tissue Repair
 Infection is clinically one of the most important
causes of delay in healing; it prolongs inflammation
and potentially increases the local tissue injury.
 Diabetes is a metabolic disease that compromises
tissue repair for many reasons, and is one of the
most important systemic causes of abnormal wound
healing.
 Nutritional status has profound effects on repair;
protein deficiency, for example, and particularly
vitamin C deficiency, inhibits collagen synthesis and
retards healing.
 Glucocorticoids (steroids) have well-documented
anti-inflammatory effects, and their administration
may result in weakness of the scar due to inhibition
of TGF-β production and diminished fibrosis.

187.  Mechanical factors such as increased local pressure
or torsion may cause wounds to pull apart, or
dehisce.
 Poor perfusion, due either to arteriosclerosis and
diabetes or to obstructed venous drainage (e.g., in
varicose veins), also impairs healing.
 Foreign bodies such as fragments of steel, glass, or
even bone impede healing.
 The type and extent of tissue injury affects the
subsequent repair. Complete restoration can occur
only in tissues composed of stable and labile cells;
even then, extensive injury will probably result in
incomplete tissue regeneration and at least partial
loss of function. Injury to tissues composed of
permanent cells must inevitably result in scarring
with, at most, attempts at functional compensation
by the remaining viable elements. Such is the case
with healing of a myocardial infarct.

188.  The location of the injury and the character of
the tissue in which the injury occurs are also
important.
 For example, inflammation arising in tissue
spaces (e.g., pleural, peritoneal, synovial
cavities) develops extensive exudates.
 Subsequent repair may occur by digestion of
the exudate, initiated by the proteolytic
enzymes of leukocytes and resorption of the
liquefied exudate. This is called resolution, and
in the absence of cellular necrosis, normal
tissue architecture is generally restored.
 However, in the setting of larger accumulations,
the exudate undergoes organization:
granulation tissue grows into the exudate, and
a fibrous scar ultimately forms.

189. THANK
YOU