Module 5

Question 1

Adaptations of the Proximal convoluted tubule for selective reabsorption

Answer 1

1) Epithelial cells contain mitochondria to produce ATP
2) Epithelial cells contain microvilli - increase SA:V
3) Contain numerous and variety of cotransport proteins
4) Short diffusion pathway in one epithelial cell

Question 2

role of loop of henle

Answer 2

Ascending limb actively transports Na+ out into medulla - decrease water potential in medulla
Water moves down potential gradient from descending limb into medulla ( only descending limb permeable to water)

Question 3

Specialised features of the pre synaptic bulb

Answer 3

Many mitochondria
Lots SER (packages neurotransmitter into vesicles)
Large no. of vesicles
lots calcium ion channels

Question 4

What is acetycholineesterase

Answer 4

found in synaptic cleft, breaks down acetylcholine to ethanoic acid and choline

Question 5

What is spatial summation

Answer 5

Action potentials arrive from several pre-synaptuc neurones

Question 6

What is temporal summation

Answer 6

Several action potentials from one pre-synaptic neurone

Question 7

What does becoming habituated to a stimulus mean

Answer 7

Repeated stimulation caused synapse to run out of vesicles containing neurotransmitter, syanpse fatigued