Homeostasis

Question 0

What is often the efferent of homeostasis?

Answer 0

The ANS

Question 1

What is the integrator of homeostasis?

Answer 1

The hypothalamus

Decides what efference does

Question 2

Where are the core temperature receptors?

Answer 2

The spinal cord, not the hypothalamus

Question 3

What do local temperature sensors cause release of?

Answer 3

Nitric Oxide (vasodilator, increasing surface flow)

Question 4

How does NO vasodilate?

Answer 4

Activate gaunyl cyclase –> convert GTP to cGMP –> affects potassium currents or MLK to cause relaxation

Increases blood flow

Question 5

What do core temp sensors send signals to in the CNS?

Answer 5

The sympathetic nervous system

Question 6

What are the two different types of sweating?

Answer 6

Adrenergic - nervous sweating (norepinephrine)

Cholinergic - eccrine, ACh release

Question 7

What is pyrogens?

Answer 7

Stimulates hypothalamus to make PGE2

Prostaglandins change the set point of temperature
So you treat by inhibiting prostiglandins

Question 8

What happens to hypothalamic temp set point?

Answer 8

Nothing, it is never changed

Receives sensors from else place

Question 9

What receptors are related to blood pressure regulation?

Answer 9

Baroreceptors

In corotid artery and aortic arch

Question 10

What is BP largely determined by?

Answer 10

Norepinephrine release from sympathetic nerves

Question 11

What is BP equation?

Answer 11

BP = cardiac output * total peripheral resistance

BP = HRStroke volumetotal peripheral resistance

Cardia output = HR*stroke volume

Question 12

What happens when sympathetic nerves stimulate Beta1 receptors?

Answer 12

Increase HR and Stroke volume (up cardiac output)

Question 13

What happens when sympathetic nerves stimulate alpha1 receptors?

Answer 13

Increase total peripheral resistance

Question 14

What is the other major input to BP?

Answer 14

Vagus nerve (parasympathetic)

Question 15

How does the vagus nerve affect BP?

Answer 15

Parasympathetic

Releases ACh which stimulate muscarinic receptors and LOWER HR

Question 16

What to Baroreceptors do?

Answer 16

Sense stretch in the carotid artery and aortic arch

Up BP, Up firing rate

Question 17

Where are impulses from the Baroreceptors carried to and by what?

Answer 17

Signals are carried to the solitary nucleus (medulla) by the Glossopharyngeal and vagus nerves

Question 18

How does the NTS lower BP?

Answer 18

By suppressing neurons in the rostral Ventrolateral area which normal excite the sympathetic NS

Question 19

What produces orthostatic hypotension?

Answer 19

Dehydration

Question 20

When do the Baroreceptors fire?

Answer 20

When BP is above 50mm

Question 21

Where is the pacemaker for breathing?

Answer 21

The pre-boetzinger area of Ventrolateral medulla

Question 22

What does the pre-boetzinger area of the Ventrolateral medulla do?

Answer 22

Stimulus C3-C5 (phrenic nerve) to innervate diaphragm

Question 23

What neurotransmitter is somatomotor or autonomic therefore stimulated on the diaphragm?

Answer 23

Acetylcholine on nicotinic receptor, sodium channel

Question 24

What is the main input into the pre-boetzinger area?

Answer 24

``` Parafacial respiratory center Sense CO2 (actually H) and excites the pre-boetzinger area ``` This also excites muscles involved in expiration

Question 25

Where does the H atom come from CO2?

Answer 25

Carbonic anhydrase

Question 26

What happens with lack of carbon dioxide sensors?

Answer 26

Ondine's curse Hypoventilation Forget to breath when sleep

Question 27

What is the path of breathing?

Answer 27

CO2 sense by Parafacial respiratory center --> stim of pre-boetzingers area --> stimulation of diaphragm through the phrenic nerve

Question 28

What part of urination is voluntary?

Answer 28

The external sphincter of skeletal muscle by | ACh stimulating nicotinic

Question 29

What is the internal sphincter and detrusor (wall) controlled by?

Answer 29

Parasympathetics ACh stimulating muscarinic

Question 30

What does bladder filling send signals to?

Answer 30

Prefrontal cortex --> normally suppresses voiding! no it doesn't

Question 31

How does urination happen?

Answer 31

Pontine micturition center activates the sacral cord to simulate preganglionic parasympathetics also does interneurons that stim motor neurons controlling the external sphincter

Question 32

How do you treat urination incontinence?

Answer 32

Anti muscarinic Muscarinic antagonist (Like atropine)

Question 33

What sensor has two neurons?

Answer 33

Temperature