This document defines key terms related to anatomy, physiology, and cell biology. It provides an overview of the organization of the human body from atoms to organ systems. Key points include: - Anatomy studies body structure, physiology studies functions, and pathology studies abnormalities. - The body is made of cells, tissues, organs, and systems organized into body cavities. - The human cell contains organelles like the nucleus, mitochondria, and endoplasmic reticulum, surrounded by a plasma membrane. - Cells divide through mitosis and meiosis to produce genetically identical or variant cells. - Substances move across the cell membrane through passive, active, or bulk transport processes.

1. ANATOMY
AND
PHYSIOLOGY

2. DEFINITION OF TERMS
 ANATOMY
• Is the study of the structure and
organization of the body and its parts.
 PHYSIOLOGY
• Physiology is the study of the functions
of the body and its parts.
 PATHOLOGY
• Is the study of abnormalities and how
they affect body functions and often
causing illness.

3. DEFINITION OF TERMS contd
 ATOM
• Is the smallest unit/particle of an
element which can exist as a stable
entity.
 ELEMENT
• Is a chemical substance whose atoms
are all of the same type.
 COMPOUND
• Is a chemical substance which contains
more than one type of atom.

4. DEFINITION OF TERMS contd
 MOLECULES
• Is the smallest unit of a compound that
contains two or more atoms chemically
combined.
 CELL
• Is the smallest functional unit of the
body.
 TISSIE
• Is a group of similar cells performing a
similar function.

5. DEFINITION OF TERMS contd
 ORGAN
• Is a structure formed of two or
more tissues that performs
specific functions.
 SYSTEM
• Is a combination of organs that
perform different functions.
 HOMEOSTASIS
• Is the maintenance of a
dynamically stable internal
environment.

6. ORGANIZATION OF THE BODY
 The body is organized in a
complex manner, its
structure and functions.
 It operates as a single entity
and is made up of a number
of operational parts that work
independently.

7. ORGANIZATION OF THE BODY
contd
 All the parts of the body
perform essential functions
for the well-being of an
individual.
 The integrated working of the
body parts ensures the ability
of the individual to survive.

8. SYSTEMS AND BODY DESIGN
 The body is organized in a complex
manner. i.e.
Atom.
Molecule
Cell
Tissue.
Organ
System
Human boby

9. ENVIRONMENT IN WHICH THE
BODY EXISTS.
 The body maintains its
own internal environment
which is different from the
external environment in
which it exists.

10. ENVIRONMENT IN WHICH THE
BODY EXISTS contd.
EXTERNAL ENVIRONMENT
- It surrounds the body and
provides
- Oxygen and nutrients required
by all cells of the body.
- Waste products of cell activities
are excreted into this
environment.

11. ENVIRONMENT IN WHICH THE
BODY EXISTS contd.
INTERNAL ENVIRONMENT
- It is the water-based
medium in which body cells
exist.

12. BODY CAVITIES AND THEIR
CONTENTS
 The body consists of two
major cavities;
•The dorsal cavity.
•The ventral cavity.

13. THE DORSAL CAVITY.
 It is made of two cavities
•The cranial cavity.
•Contains the brain
•The spinal cavity.
•Contains the spinal cord

14. THE VENTRAL CAVITY
 It has two main
compartments;

15. THE VENTRAL CAVITY
The thoracic cavity.
Contains;
lungs,
heart,
trachea,
oesophegus

16. THE VENTRAL CAVITY
• The abdominopelvic
cavity, which is further
divided into two cavities;

17. THE VENTRAL CAVITY contd
•The abdominal cavity,
Contains
Stomach
Intestines
Liver
Gall bladder
Spleen
Pancreas
Kidneys
 suprarenal glands

18. THE VENTRAL CAVITY contd
 The pelvic cavity
Contains
 Sigmoid colon
 Rectum
 Anus
 Some loops of small
intestines.
 Urinary bladder
 Lower part of the ureters
 Urethra.
 Reproductive organs

19. The pelvic cavity contd
In Females
•Uterus
•Uterine tubes
•Ovaries
•vagina

20. The pelvic cavity contd
 In Males
•Prostate gland
•Seminal vesicles
•Spermatic cord
•Vas deferens
•Ejaculatory duct

21. NOTE
CHIEF ORGANS OF THE BODY
The organs that are secured
in the body cavities and are
said to be chief organs of the
body include;
•The Brain.
•The lungs
•The heart
•Digestive organs

22. REGIONS OF THE ABDOMINAL
CAVITY
 This region is divided into six
portions.
 DRAW A DIAGRAM TO SHOW

23. SYSTEMS OF THE BODY
 These include;
•The locomotor system
•The nervous system
•Cardiovascular system
•Skin and organs of special
senses
•Blood (haemopoietic
system)

24. SYSTEMS OF THE BODY contd
•Respiratory system
•Digestive system
•Endocrine system
•Urinary system
•Reproductive system

25. DEFINITION OF TERMS USED IN
ANATOMICAL DESCRIPTION
 Midline – middle line (imaginary)
 Anterior – towards front of body or
limbs
 Posterior – towards back of body or
limbs
 Median – in the middle
 Medial – side nearest the midline of
body
 Lateral – side away from the midline

26. DEFINITION OF TERMS USED IN
ANATOMICAL DESCRIPTION contd
 Superior – structure nearest to head.
 Inferior – structure further below the
head
 Proximal – nearer to the point of
attachment.
 Distal – far from a point of
attachment.

27. THE PLANES OF THE BODY
There are three main planes of
the body. These planes lie at
right angles to each other.
•Transverse or Horizontal plane.
•Sagittal or medial plane.
•Coronal or Front plane.

28. THE HUMAN CELL
DEFINITION
It is smallest functional unit of the
body.
- It can not be seen by naked eyes,
but by use of a microscope.

29. HUMAN CELL contd
The cell consists of a plasma
membrane inside which there
are a number of organelles
floating in a watery fluid called
CYTOSOL.
ORGANELLES are small
structures with highly specialized
functions, many of which are
contained within a membrane

30. HUMAN CELL contd
The organelles found
in the human cell
include the following;
•Nucleus
•Mitochondria
•Ribosomes

31. Organelles contd
•Endoplasmic Reticulum
Rough and
Smooth.
•Golgi apparatus
•Lysosomes
•Microfilaments
•Microtubules.

32. HUMAN CELL
DRAW THE CELL

33. CELL/PLASMA MEMBRANE
 It is the outer covering of the cell.
 It is permeable
 It consists of two layers of
phospholipids (fatty substances) with
some protein embedded in them.
DRAW a section to show the two layers

34. CELL/PLASMA MEMBRANE contd
 The two layers of
phospholipids are also
referred to as
phospholipids bilayer.
 Each of the phospholipid
layers is made of
molecules that consist of;
•A head and
•A tail.

35. CELL/PLASMA MEMBRANE contd
 The Head is hydrophilic (water
loving) and is said to be electrically
charged.
 The Tail is hydrophobic (water
hating) and has no charge.

36. ORGANELLES
NUCLEUS
•It is the largest organelle.
•It is surrounded by a
plasma membrane
•It contains the body’s
genetic material which
directs the activities of the
cell.

37. NUCLEUS contd
 The genetic material found
in the nucleus is built from
DNA and protein called
Histones coiled together
forming a network of fine
threads called Chromatin

38. NUCLEUS contd
 Chromatin resembles tiny
strings of beads.
 During cell division, the
chromatin replicates and
becomes more tightly
coiled forming
Chromosomes

39. NUCLEUS contd
NOTE
Every cell in the body
has a nucleus.
Skeletal muscle cells
contain several nuclei
Erythrocytes (RBCs)
do not have nuclus.

40. MITOCHONDRIA (Power house)
 Are sausage shaped
structures in the
cytoplasm.
 They generate energy for
the cell.

41. RIBOSOMES
 Are tiny granules
 They synthesize proteins
for use within the cell

42. ENDOPLASMIC RETICULUM (ER)
 Is a series of
interconnecting
membranous canals in the
cytoplasm.
 There are two types of ER;
•Smooth ER and
•Rough ER

43. ENDOPLASMIC RETICULUM (ER)
contd
SMOOTH ER.
 It synthesizes lipids and
steroid hormones.
 It is associated with the
detoxification of some drugs.

44. ENDOPLASMIC RETICULUM (ER)
contd
ROUGH ER.
 It is studded with ribosomes.
 It is a site of synthesis of
proteins that are exported
(extruded) from the cells to
be used by other cells.

45. GOLGI APPARATUS
 It consists of stacks of closely
folded flattened membranous
sacs.
 It is present in all cells.
 It packages and stores
proteins synthesized in the
Rough ER into vesicles called
Secretory granules

46. LYSOSOMES
 Are one type of secretory granules
from the golgi apparatus.
 They contain a variety of enzymes
involved in breaking down fragments
of organelles and large molecules
(e.g. RNA, DNA, CHOs, proteins)
inside the cell into smaller particles.
These particles are either recycled or
extruded from the cell as waste
materials.

47. MICROFILAMENTS
 Are tiny strands of proteins
 They provide structural
support and maintain the
characteristic shape of the
cell.

48. MICROTUBULES
 Are contractile protein
structures in the cytoplasm.
 They are responsible for
•Movement of the cell
•Movement of organelles within
the cell

49. CELL DIVISION
 There are two types of cell division;
• Mitosis
• Meiosis

50. MITOSIS
 Is a process by which the
contents of the eukaryotic
nucleus are separated into two
genetically identical packages.

51. MITOSIS contd.
 This involves a series of changes
in which there is a
rearrangement of centrioles and
chromosomes in different
phases/stages namely;
• Prophase.
• Metaphase.
• Anaphase.
• Telephase.

52. PROPHASE
 Is the first stage of mitosis.
 Centrosme divides and
centrioles migrate to opposite
poles of cell attached to
spindles.
 Chromatin material forms
into well defined
chromosomes.

53. METAPHASE
 Nuclear membrane
fragments.
 Chromosomes align
themselves at the centre of
the nucleus and are attached
to the spindles.

54. ANAPHASE
 Chromosomes are tightly
stretched.
 As centrioles draw further apart
each chromosome splits into two
chromosomes.
 The chromosomes then move
towards opposite poles of the
cell.

55. TELEPHASE
 A new nuclear membrane forms
around each set of chromosomes.
 Spindle fibres disappear.
 Cytoplasm and cell membrane begin
to constrict.
 Finally, the cell splits into two
identical cells.
 The clearly defined chromosomes
fade and become a mass of scattered
threads again

56. MEIOSIS
 Is a process by which a
diploid nucleus divides twice
to produce four haploid nuclei
 Is a process of cell division
that occurs in the formation
of reproductive cells
(gametes; ova and
spermatozoa).

57. MEIOSIS
 In this type of division, four
daughter cells are formed.

58. MEIOSIS contd.
 Each daughter cell formed
has only 23 chromosomes.
This is referred to as haploid.
 A full complement of 46
chromosomes that occurs
when ovum is fertilized is
referred to as diploid.

59. MUTATION
 Change in the characteristics
of an organism when its
genetic make-up is altered.

60. MUTATION contd
 Mutation may cause;
• No significant change in the
cell function.

61. MUTATION contd
• Modification of cell function
that many cause physiological
abnormality but does not
prevent cell growth and
multiplication. E.g.
Inborn errors of metabolism.
Defective blood clotting
• Death of the cell.

62. TRANSPORT OF
SUBSTANCES ACROSS CELL
MEMBRANE

63. TYPES OF TRANSPORT
 Transport of substances
across the membrane is of
three types
•Passive transport.
•Active transport.
•Bulk transport.

64. PASSIVE TRANSPORT
 Occurs when substances can cross
plasma and organelles (semi-
permeable) membranes and move
down the concentration gradient
(downhill) without using energy.
 Processes involved in passive
transport include;
• Diffusion
• Facilitated diffusion.
• Osmosis.

65. DIFFUSION
What is it?

66. FACILITATED DIFFUSION
 This passive process is
utilized by some substances
that are unable to diffuse
through the semi-permeable
membrane unaided eg.
•Glucose.
•Amino acids.

67. FACILITATED DIFFUSION
 Specialized protein carrier
molecules in the membrane have
specific sites that attract and
bind substances to be
transported like lock and key
mechanism
 The carrier then changes its
shape and deposit the
substances on the other side of
the membrane.

68. OSMOSIS
What is it?

69. ACTIVE TRANSPORT
 This is transport of
substances up their
concentration gradients
(uphill), i.e. from low to high
concentration.

70. ACTIVE TRANSPORT contd.
 Chemical energy in form of
ATP drives specialized protein
carrier molecules that
transport substance across
the membrane in either
direction.
NB: Carrier sites are specific,
can only be used by one
substance.

71. BULK TRANSPORT
 This involves transfer of
larger particles. e.g. cell
fragments, foreign
materials,microbes etc.
 Transfer of particles to large
to cross cell membranes
occur by;
•phagocytosis

72. BULK TRANSPORT contd.
 Particles are engulfed by
extensions of the cytoplasm
which enclose them, forming
a membrane-bound vacuole.
 Extrusion of waste materials
by the reverse process
through the plasma
membrane is called
exocytosis

73. THE END
THANKS