Question

1. List the functional and structural characteristics of epithelial tissue. 2. Identify the different epithelia of the body, and describe the chief function(s) of each. 3. Distinguish exocrine from endocrine glands. 4. Explain how multicellular exocrine glands are classified. 5. Describe apical, lateral, and basal surface features of epithelia and epithelial cells. 6. Describe the features that are common to all connective tissues. 7. Identify the four main classes of connective tissue. 8. Differentiate between the different types of connective tissues in reference to the types of cells located within the tissue, and the structure and composition of the extracellular matrix, and the main function of each. 9. Discuss the structure and function of mucous, serous, and cutaneous membranes. 10. Briefly describe the three types of muscle tissue. 11. Distinguish the cell types found in nervous tissue. 12. Describe the inflammatory and repair processes by which tissues recover from injury. 13. Briefly describe the changes that occur in tissues with age.

Answer 1

1.List the functional and structural characteristics of epithelial tissue.

• Covers and lines body surfaces
• Acts as a selective barrier for diffusion
• Cells are densely packed together with minimal amount of intercellular substance.
• Main functions are: absorption, diffusion, secretion, excretion

2. Identify the different epithelia of the body, and describe the chief function(s) of each.

• Simple squamous epithelium:- its main function is diffusion
• Simple cuboidal epithelium:- its main function is absorption and secretion
• Simple columnar epithelium:- its main functions are absorption and secretion.
• Pseudostratified epithelium:- its main function is protection- they have ability to withstand wear &tear.

3. Distinguish exocrine from endocrine glands.

• Endocrine- manufacture and secrets their products into the blood(with out any ducts). The secretions include harmones.
• Exocrine- manufacturers and secrets their products out side the body(secretion through ducts). The secretions include- enzymes & metabolites.

4. Explain how multicellular exocrine glands are classified.

• Multicellular exocrine glands are classified by their shape of secretory parts and the arrangement of their ducts.
• A gland with one duct- simple gland. (Eg:- sweat glands)
• A gland with branched ducts- compound gland.(Eg:- salivary glands).

5. Describe apical, lateral, and basal surface features of epithelia and epithelial cells.

Epithelial tissues are composed of many cells closely join together by special cell junctions. Epithelial tissues have distinct apical &basal regions.

• Basal region:- it sites on a specialised boundary with the underlying connective tissue.
• Apical region:- certain epithelial cells has modifications associated with specific functions.
• Lateral surface features:- adhesion proteins in the plasma membrane of the adjacent cells link together in extracellular space. It has special cell junctions.

6. Describe the features that are common to all connective tissues.

• All connective tissue has 3 components:- cells-scattered throughout tissue, protein fibers, ground substance.
• Functions are:- storage, protection, support, transport.

7. Identify the four main classes of connective tissue.

Main classes are:-

• Connective tissue proper
• Cartilage
• Bone
• Blood

8. Differentiate between the different types of connective tissues in reference to the types of cells located within the tissue, and the structure and composition of the extracellular matrix, and the main function of each.

• Aeriolar connective tissue (loose)- gel like matrix, made up of 3 fiber like cells-(fibroblasts, macrophages, mast cells)(function:- wraps& cushions organs)
• Adipose tissue- veruy little matrix, closely packed. - made up of adipocytes.(function:- energy storage, insulates against heat loss)
• Reticular connective tissue:- loose network of reticular fibers.(function:- it forms loose framework and support other cell type)
• Dense regular connective tissue:- a few elastic fibres. Major cell type fibroblasts.(function:- withstand great tensile stress when pulling force is applied)
• Cartilage:- consists of collagen fibres. Main cell type chondocytes.(function:- support, resistant comprehensive stress)
• Bone(osseous tissue):- matrix is super hard containing collagen fibres.(function:- support and protects, store minerals)
• Blood:- Red and white blood cells in a fluid matrix called plasma.(function:- transport respiratory gases).

9. Discuss the structure and function of mucous, serous, and cutaneous membranes.

• Mucous membrane:- line all body cavities. Contains either stratified squamous epithelium or simple columnar epithelium (function:- absorption and secretion)
• Serous membrane:- it is a thin connective tissue composed of simple squamous epithelium.(function:- it reduces friction)
• Cutaneous membrane:- it consists of keratinized stratified squamous epithelium attached to connective tissue.(function:- it protects the body tissues and organs from physical damage).

10. Briefly describe the three types of muscle tissue.

• Skeletal muscle:- it is voluntary. These muscles attached to bones and responsible for their movement
• Cardiac muscle:- it is found in heart. It causes the muscle to beat even when away from the heart.
• Smooth muscle:- it is involuntary. It found in organs and enables functions such as digestion and respiration. It doesn't generate tension as much as skeletal muscle.

11. Distinguish the cell types found in nervous tissue.

1. Satellite cells:- support cell bodies in ganglia.
2. Schwann cells:- surround all axons of PNS
3. Oligodendrocyte:- myelinate CNS axon and add structural support
4. Astrocytes:- form blood brain barrier
5. Microglia
6. Ependymal cells:- associated with gray matter
7. Anaxonic:- mediates communicate between neurones.
8. Bipolar:- relay sensory information
9. Pseudo unipolar:- relay general sensory information.
10. Multipolar:- general motor neurones.