Circulatory Shock, types and stages, compensatory mechanisms
Cell seminar
1.
2. Contents
Introduction to cell
History
Number and cell size
Cell type
Structure of cell
Cell membrane
Cytoplasm
Organelle in cytoplasm
Nucleus
Cell surface contact
Molecule movement
Endocytosis and Exocytosis
References
3. Cell
Cell-Structural and functional unit of
the living body.
Smallest living unit
Most of cells are
microscopic
4. Discovery of Cells
Robert Hooke (Mid 1600)
Coined term cell
First seen cork plant cell
(1889) Rudolf Virchow
“all cells come from cells”
5. Number
Unicellular(consist of a single cell)
-Bacteria, Virus
Multicellular – Human (Around 100 trillion
cells)
-Other animal
Amoeba proteus
6. Cell size
Most of cell are between 5-50μm in
diameter
Ex,RBC-7.5 μm
Columnar epithelial cells 20 μm tall
and 10 μm wide
Larger cells
Skeletal muscle cell
Neurons
10. Prokaryotic cell
First cell type on earth
Cell type of Bacteria and Archaea
No membrane bound nucleus
Nucleoid = region of DNA concentration
11. Eukaryotic cell
Organelles not bound by membranes
Nucleus bound by membrane
Fungi, Protists, Plant, and Animal cells
Possess many organelles
Animal cell
Plant cell
12.
13.
14. Structure of cell
Each cell is formed by cell body and
membrane
Cell membrane –Separate cell body from
the surrounding cell
Cell body -Cytoplasm
Nucleus
15. Cell membrane
Protective sheath enveloping the cell body
Separate intracellular and extracellular fluid
Permits exchange of some substance
Thickness- 75A to111A
Double layer of
Phospholipids & Proteins
16.
17.
18. lipid layer
Cell membrane-Bilayered component
Lipids are cholesterols and phospholipids
Phospholipids = Phosphrous and fatty acid
(Amino Phospholipid, Phosphetidyle Glycerol
Phosphetidyle Inositol)
Outer part- Hydrophilic
(soluble in water)
Inner part- Hydrophobic
(soluble in fat)
19. Significance of lipid layer
Forms semi-permeable membrane
Fat soluble substance can pass through it.
-O2, CO2 and alcohols
Barrier to water soluble materials
-Glucose, Urea, Electrolytes
22. Significance of protein layer
Integral proteins- Structural Integrity
Channels(formed by integral protein)
Diffusion of water soluble substance
Glucose, Electrolytes
Receptors protein
Receptor for hormones and
neurotransmitter
Recognize certain chemicals
Carrier protein
-Transport of substance(active or passive)
Act as antigen
-act as antigen and provide antibody
formation
24. Carbohydrate
Attached to protein or lipid
Significance- Negatively charged
-Glucocalyx of neighboring cell
help in tight fixation.
-Receptor for some hormone
-Contain specific antigen(RBC-blood group
antigen)
25. Cytoplasm
Viscous fluid containing organelles
Interconnected filaments & fibers
Organelles
Fluid= Cytosol
Various particles
(Different shape and size)
-Proteins, Carbohydrate,
lipids and Electrolytes.
200mg/ml of protein
High K +
low Ca+2 low Na+
26. Cytoskeleton
Filaments & Fibers
Made of 3 fiber types
◦ Microfilaments
◦ Microtubules
◦ Intermediate filaments
3 functions:
◦ Mechanical support
◦ Anchor organelles
◦ Help move substances
Transport
Shape of cell
Actin and myosin
Shape of cell
27. A = actin, IF = intermediate filament, MT = microtubule
28. Organelle in Cytoplasm
Organelle caries out various functions
Two type-
Bound by limiting membrane
Endoplasmic reticulum
Golgi apparatus
lysome, Peroxisome
Mitochondria
Not bounded by limiting membrane
Chromosome, Ribosome
Microfilaments, Microtubules
29. Endoplasmic Reticulum
Network of tubular and micrsomal
vesicular structure
Outer side-Limiting Membrane
Inner side- Endoplasmic Matrix(lumen)
Helps to move substances within cells
Two types
◦ Rough endoplasmic reticulum
◦ Smooth endoplasmic reticulum
30. Rough endoplasmic reticulum
Ribosomes are attached to surface
◦ Manufacture proteins
◦ Not all ribosomes attached to rough ER
May modify proteins from ribosome
Protein pass through membrane and
accumulate in cisternae.
31. Smooth Endoplasmic
Reticulum
No attached ribosomes
Various enzymes are present on outer
surface
Enzymes- Metabolic process of cell
33. Significance of Smooth Endoplasmic
Reticulum
Carbohydrate metabolism
Synthesis of non protein substance
◦ Cholesterol
◦ Steroid hormones
◦ Sebum
Catabolism of toxic substance
Cooperate with rough endoplasmic reticulum
and Golgi apparatus to synthesize new cell
membrane.
Specialized type
In skeletal muscle-sarcoplasmic reticulum
34. Golgi Apparatus or Golgi
Body
Present in all cell except Red Blood Cell
Situated near nucleus
Consist of 5 to 8 membranous sac
The Sacs are flattened and called as
Cisternae
35. Function of Golgi Body
Processing and delivering the protein
molecule to different parts of the cell.
Protein synthesized from endoplasmic reticulum
Transported in the form of Reticular Vesicle
To Golgi Body where it is processed and sorted out
Packed in the form of Secretory Granules, Secretory
Vesicles
Vesicles delivered by golgi body leave the cell
by exocytosis.
lysosomal Vesicles
36.
37. Lysosomes
Vesicular organelle
80 to 800nm in diameter
Have thickest covering membrane
Many small granules present in lysosomes
Contain digestive enzymes(hydrolytic
enzyme)
More than 40 different type of hydroxylases
All enzyme- lysozymes
38. Functions
◦ Digests protein, carbohydrate, Lipid,
nucleic acids
◦ Destruction of bacteria and other foreign
body.
◦ Removal of unwanted cell in embryo
◦ Break down old cell parts
◦ When bacteria enter into the cell
lysosomes rupture and immediately digest
the invaded bacteria or foreign body.
39. Lysosomal storage disease
Enzymes are defective because of gene
Materials that they normally degrade will
accumulate within late endosomes and lysosomes.
e.g. Tay-Sachs disease
Hurler's Syndrome: Failure to metabolize certain
mucopolysaccharides causes the accumulation of
large amounts of matrix within connective
tissue, which distorts the growth of many parts of
the body.
41. Function of peroxisome
Hydrogen peroxide is produced by
poisons or alcohol
(ethanol and formaldehyde)
Peroxisome ruptures when hydrogen
peroxide is formed in cell.
Oxidases destroys hydrogen peroxide
Also destroy other enzymes necessary
for its production
Gluconeogenesis from fats and
degradation of purine and fat.
43. Mitochondria
Rod shaped, oval shaped structure
Diameter - 0.5 to 1 μm
Bilayered membranous organelle
Outer layer- Smooth
Inner layer- Series of shelf like projection
-Cristae
(provide large surface area)
Contain RNA and DNA
44. Principle source of chemical energy in
most of the cells
Enzymes are located in mitochondrial
matrix and inner mitochondrial matrix.
45. Function
Break down fuel molecules (cellular
respiration)
Glucose
Fatty acids
Production of energy by catabolism of
digested food particles
Stored in the form of ATP molecules
So It is power house of cell
Energy released by breakdown of ATP
molecule
When needed
Mitochondria contain enzymes for citric acid
46. Mitochondria are distributed within a cell
according to regional energy
requirements
-Near the base of cilia
-Near basal domain of cells of proximal
convulated tubules
-Proximal end of flagellum
Genetic diseases of mitochondria affect
perticular tissues
Ex. Mitochondrial myopathies
Mitochondrial neuropathies
47. Ribosomes
It is granular structure
Diameter of 15 to 20 nm
Contain 65%RNA and 35% Protein
Some ribosomes remain free in
cytoplasm
Function of free ribosome
Synthesis of protein from amino acid
Synthesis of protein part of
hemoglobin
Protein molecules of peroxisome
48.
49. Nucleus
Control center of cell
3 to 10 μm in diameter
Double membrane
(Nuclear membrane)
Contains
◦ Nucleoplasm
◦ Nucleolus
50. Nuclear membrane
Double layered, porous in nature
Communicate with cytoplasm
Outer layer continuous as endoplasmic
reticulum
Inner space forms lumen of endoplasmic
reticulum
Pores- Guarded by protein
- Diameter 80nm to 100nm
52. Nucleoplasm
Gel like substance
Contain DNA
Called as
chromatin
One or more in each nucleus
Contain RNA and some proteins
RNA synthesized by 5 pairs of
chromosome
Condensed to form subunit of ribosome
Subunit travel to cytoplasm through pore
Fusion of subunits lead to formation of
Ribosome
Nucleol
i
53. Function of Nucleus
Control center for all activity of cell
It sends genetic information in the form
of DNA to cytoplasm for synthesis of
specific enzymes
Enzymes are responsible for various
metabolic reactions.
Genes present in the nucleus controls
cell division.
The hereditary information is stored in
the nucleus and transferred from
one generation to next.
54.
55. Cell surface contact
Two type
-General adhesive contact
calcium dependent
calcium independent
-Specialized contact
56. General adhesive contact
Calcium dependent adhesion molecule
Cadherins
selectins
Integrins
Calcium independent adhesion
molecule
Most are transmembrane proteins
N-CAMs
I-CAMs
57. Specialized Adhesive Contacts
Occluding Junction( Tight junction )
-Tight junction is made up of ridges
-Ridges have two halves which are in
close contact
- provide strength and stability
-prevent movement of ions and protein
Desmosomes
Hemidesmosomes
58. Communicating junction(gap junction)
Cytoplasm of two cells is connected by
channels
Diameter of channel 3 nm
Passage of Ions, Glucose, Amino acid
Rapid propagation of action potential
Connexon
59. Molecule Movement & Cells
Passive Transport
Active Transport
Endocytosis
(phagocytosis & pinocytosis)
Exocytosis
60. Passive Transport
No energy required
Move due to gradient
◦ differences in
concentration, pressure, charge
Move to equalize gradient
◦ High concentration moves toward low
concentration.
61. Types of Passive Transport
1. Diffusion
2. Osmosis
3. Facilitated diffusion
62. Diffusion
Molecules move to
equalize concentration
Osmosis
Special form of diffusion
Fluid flows from lower solute
concentration
Often involves movement of water
◦ Into cell
◦ Out of cell
63. Solution Differences & Cells
Solvent + Solute = Solution
Hypotonic
◦ Solutes in cell more than outside
◦ Outside solvent will flow into cell
Isotonic
◦ Solutes equal inside & out of cell
Hypertonic
◦ Solutes greater outside cell
◦ Fluid will flow out of cell
64.
65. Facilitated Diffusion
Differentially permeable membrane
Channels (are specific) help molecule
or ions enter or leave the cell
Channels usually are transport
proteins
(aquaporins facilitate the movement of
water)
No energy is used
66. Process of Facilitated Transport
Protein binds with molecule
Shape of protein changes
Molecule moves across membrane
68. Endocytosis
Movement of large material
◦ Particles
◦ Organisms
◦ Large molecules
Movement is into the cells
Types of
Endocytosis
◦ Bulk-phase (nonspecific)
◦ Receptor-mediated (specific)
69. Process of Endocytosis
Plasma membrane surrounds material
Edges of membrane meet together
Membranes fuse to form vesicle
71. References
Grey’s textbook of human anatomy
40th edition
Guyton and Hall textbook of medical
physiology 12th edition
Ganong’s textbook of medical physiology 21st
edition
Human physiology volume-1,Dr. C.C
Chatterjee
Text book of human histology, Inderbir singh
http://www.biologymad.com/resources
http://biology.about.com/od/molecularbiology
http://rarediseases.about.com/od/raredisease
sz/a/030505.htm