learning outcomes

Question 1

De ne the term ‘epithelium’ and describe the basic functions of epithelial surfaces, those covering the body and lining internal structures.

Answer 1

Primary function: Covers surfaces, separates compartments and allows cells to communicate. 
Secondary function: 
-absorption-microvilli
-movement-cilia
-gas diffusion-thin
-wear and tear- regeneration
-glands 
-cell-cell communication- cell junctions

Question 2

Describe the types of surface epithelia and explain how the structural properties of each correlates with its functions.

Answer 2

SIMPLE:

• squamous: irregular and flat. e.g. capillaries-thin so allow good diffusion
• cuboidal: same width and length.
• columnar: greater length than width. e.g. lining of digestive tract- help remove microbes when ciliated.

STRATIFIED:

• squamous: many layers, fewer as you get closer to surface
• cuboidal/columnar: 2 layers
• Transitional: waterproof and toxic resistant
• pseudostratified: seems like not every cell is connected to basement membrane but it is

Question 3

Describe the epithelial components of the liver and kidney.

Answer 3

Liver:

• Cells are hepatocytes
• organised in rows between blood vessels
• functions include secretion
• support epithelial cells found in bile ducts

Kidney:

• Functions include blood filtration
• support cells line blood vessels and renal pelvis which reduces urine toxicity

Question 4

Consider the consequences of abnormal function of covering and lining epithelia.

Answer 4

• Over/under secretion

- Over/under proliferation

Question 5

Define the term ‘gland’ and describe the basic functions of glandular epithelium.

Answer 5

A single or multi cellular group of secretory epithelial cells.
Involved in secretion of proteoglycans and water-mucosal or proteins.

Question 6

define exocrine and endocrine and give an example of each

Answer 6

Endocrine releases into the blood

Exocrine releases onto surface e.g. sweat gland.

Question 7

consider the problems associated with abnormal glandular function?

Answer 7

over-production: pituitary giantism
under-production: pituitary dwarfism
Secretion: mucus too thick- traps sperm-infertile

Question 8

De ne the term ‘connective tissue’ and describe its basic functions.

Answer 8

Tissue made up of fibres ( elastin and collagen), ground substance and tissue fluid.

Question 9

Describe the matrix, fibre and cellular components of connective tissue and explain the function of each.

Answer 9

fibres:
COLLAGEN- very tensile, 19 different types
ELASTIN- can stretch 1.5 its length, what makes aorta yellow
Ground substance: proteogycans and glycoproteins.
Tissue fluid: loose, dense regular or dense irregular

Question 10

onsider the consequences of abnormal function of connective tissues

Answer 10

Blood/bone marrow problems- leukemia
cartilage- tears
bone- osteoporosis