Osmoregulation – lecture 9
1. How many are true,
a. The osmotic exchanges in an animal can be divided as obligatory and regulated
b. Defecation is a controlled osmotic exchange
c. Active epithelial transport help regulate homeostasis.
d. Mucus, cornified epithelium and cuticle are three layersof integuments found in animals
A is correct.
B is incorrect because defecation is controlled osmotic exchange
C is correct!
2. how many are true,
a. cornification is a well seen mechanism throughout the animal kingdom in acting as an
3. how many are true about the characteristics of transport epithelia,
a. Large supply of mitochondrial to supply ATP and ER to produce transporter proteins
b. Have a polarity
c. Tightly held together by gap junctions
d. Variety of cell composition
A is incorrect. There is a large supply of ATP, to energize the tranpsorters, but not ER
B is correct. There is an apical and basolateral domain. Which give different distributions of
C is incorrect! Not GAP. But TIGHT.
D is correct!. Example lumen cells
4. How many are true,
a. Epithelial cells are connected by tight junctions which can be leaky or tight’
b. Leaky tight junctions leads to transcellular transport, and tight tight juctions leads to
c. Salt glands in reptiles secretes an hyposmotic solution of Na Cal.
d. In salt glands, NaK ATPase is found in the apical membrane and NaK2Cl transporter
recycles the K and Na used for the passive pump.
i. 1 ii. 2