Water and Ion Physiology I

Question 1

What is the Internal Milieu

Answer 1

the eternal fluid environments which are separated from the external envoirments via epithelial barrier

Question 2

Conformers

Answer 2

Internal conditions similar to that of the external conditions

Question 3

Regulators

Answer 3

Maintain a constant internal environment regardless of their external environment

Question 4

how to terrestrial animals prevent water loss

Answer 4

body covering which resists the passive water loss to the air this varies over many different species

Keratinocytes differentiate to form a thickened external layer containing keratin

The amniotes (mammals, birds, and reptiles) have a specialization of the integument, the stratum corneum, which creates a highly water-proof layer on the skin

The integument of insects, the cuticle (made of chitin), is highly hydrophobic and forms exoskeleton

Question 5

organs involved in water/ion homeostasis

Answer 5

kidneys in invertebrates
fish use there gills and guy
birds and reptiles have specialized salt glands

Question 6

What is the function of kidneys in mammals

Answer 6

1. Regulation of plasma volume
2. regulation of plasma osmolarity
3. regulation of plasma osmolarity
4. regulation of acids base status
5. excretion of metabolic waste
6. regulation of red blood cell levels
7. production of renal hormones
8. production of glucose

Question 7

Urinary system in mammals

Answer 7

2 kidneys
2 ureters
bladder
urethra

Question 8

control of the bladder

Answer 8

the bladder is controlled via the PSNS and SNS

when filling the PSNS is active relaxing the detrusor muscle and the SNS becomes active when contraction of the urethral sphincters is needed

Question 9

The Micturition reflex

Answer 9

filling of the bladder until it reaches its capacity

induced by stretch receptors and can be overridden in teens/adults

Question 10

The Nephron

Answer 10

A individual kidney tubule is or a nephron is the basic functional unit of the kidney

Question 11

What is a renal tubule

Answer 11

A component of the Nephron which is in essence a single winding tube along which urine flows and gets modified via diffusion(intestines for urine)

Question 12

the portal system

Answer 12

blood supplied to the kidneys enters through a portal system where first the blood travels through the glomerulus and afferent artirole then travels to either peritubular capillaries or vasa recta

Question 13

The 3 main transport processes

Answer 13

1. Glomerular filtration
2. Tubular reabsorption
3. Tubular Secretion

Question 14

Glomerular filtration

Answer 14

Driven by hydrostatic and osmotic pressure gradients

Question 15

Tubular reabsorption

Answer 15

Passive diffusion of water and ions as well as some active transport

Question 16

Tubular secretion

Answer 16

active transport

Question 17

Filtration rate +secretion Rate-reabsorption rate = ?

Answer 17

Excretion

Question 18

what happens to glucose absorption when its levels are elevated

Answer 18

If the [glucose] exceeds the reabsorption capacity it will remain in the urine excreted as the tubules can reabsorb only a certain amount