Download Tissue level of organization

Tissue level of Organization
Lecture content:
1. Types of Tissue:
2. Cell Junctions
3. Epithelial tissue
4. Connective tissue
5. Muscle tissue
6. Nervous tissue
1. Types of tissue:
a.
b.
c.
d.
Epithelial tissue
Connective tissue
Muscle tissue
Nervous tissue
2. Cell Junction;
i.
Functions: a. Form tight seal in between cells
b. Anchor cells
c. Acts as channels for ions and mol.
ii.
Types:
a.
b.
c.
d.
e.
Tight junctions
Adherence junction
Desmosomes
Hemidesmosome
Gap junction (Intercalated disc)
3. Epithelial tissue:
i.
General character:
-Cells are densely packed
-has apical and basal surface
-Basal surface adhere to basement membrane
-It is avascular (no blood supply)
-constantly renew and repair itself
-Functions as protection, filtration, secretion and absorption
ii.
Types: (classification)
a. According to layers: -simple epithelium
-Stratified
b. According to cell shape: - squamous epithelium
- Cuboidal epithelium
- Columnar epithelium
4. Connective tissue
a. General character and functions:
-They are of various forms
-Binds and support body tissue
-Acts as a transport system
-Site of storage of energy
b. Components of connective tissue:
i.
ii.
iii.
iv.
v.
vi.
Fibroblast
Macrophage
Plasma cell
Mast cell
Adipocyte
Nutrophil & Eosinophil
c. Classification (Mature connective tissue):
-Loose connective tissue
-Dense connective tissue
-Cartilage
-Bone tissue
-Blood tissue
-Lymph
5. Muscle tissue:
a. Types: i. Skeletal muscle
ii.Smooth muscle
iii.Cardiac muscle
b. Skeletal muscle:
-shows striations under microscope
-called Voluntary muscle
-Long cylindrical in shape
-Has peripheral multiple nuclei
-arranged parallel to each other
-Contract only when stimulated
c. Cardiac muscle:
-Striated and involuntary muscle
-They are branched
-one central nucleus in each cell
-Intercalated disc connect all cells. Acts as a syncytium
-Syncytium provides route for quick conduction of
cardiac action potential
d. Smooth muscle:
-Located at the wall of the hollow organ
-spindle shaped cell with one central nucleus
-non-striated and involuntary muscle
-They are self excitable
--contraction of smooth muscle causes : move the along intestine
narrows the diameter of blood vessels
6. Nervous tissue:
a. Neurons: -structural and functional unit of nervous system
-Consists of cell body and processes(dendrites & axons)
-Cell body contains nucleus and organelles