Homeostasis - Trachte

Question 1

What signals result from cold temperatures?

Answer 1

Skin increases noreprinephrine release which vasoconstricts to reduce blood blow

CNS increases sympathetic to decrease skin blood flow

Question 2

How is fever caused?

Answer 2

Pyrogen (IL-1, IL-6, or TNF) stimulates the hypthalamus to oroduce PGE –> causing shivering and icnreased metabolic rate

Question 3

Why do post-menopausal women have hot flashes?

Answer 3

For some reason, postmenopausal women have an extremely narrow thermoregulatory zone.
Why? I dunno

Question 4

Sympathetic nerves interact with which receptors to regulate blood pressure?

Answer 4

Beta1 receptors
–> Stimulate heart rate and increase stroke volume
Alpha1 Receptors
–> Increase arterial resistance

Question 5

How does the parasympathetic system affect blood pressure?

Answer 5

Parasympathetic:

The vagus nerve constantly releases ACh that slows down heart rate thru muscarinic receptors

Question 6

Stretch receptors to sense blood pressure are located in the arotic arch and carotid arteries. What nerves carries their signal AND toward what nucleus?

Answer 6

impulses are carried by glossopharyngeal and vagus nerves to the medulla, terminating in the nucleus tractus solitarius

Question 7

The respiratory pacemaker is in Pre-Boetzinger area of ventrolateral medulla
What nerve innervates the diaphragm?
What type of nerve is it?
What is the neurotransmitter?
What is the receptor stimulated on the diaphragm?

Answer 7

What nerve innervates the diaphragm? - Phrenic
What type of nerve is it? - Somatomotor
What is the neurotransmitter? - ACh
What is the receptor stimulated on the diaphragm? - Nicotinic

Question 8

What does the prefacial respiratory center do?

What happens if it doesn’t work?

Answer 8

Parafacial respiratory center senses CO2 (actually H+) and excites the Pre-Boetzinger area

Parafacial respiratory center also directly excites muscles involved in active expiration (abdominals)

Lack of carbon dioxide sensors leads to hypoventilation while sleeping - BAD!

Question 9

Quick and easy of micturation:

Answer 9

Pontine micturition center activates the sacral cord to stimulate preganglionic parasympathetic nerves
also activates inhibitory interneurons influencing motoneurons innervating the external urethral sphincter

net result is relaxation of external (voluntary) sphincter and contraction of the urinary bladder via parasympathetic nerves