Hypothalamus/Pituitary Flashcards Preview

Physiology Exam 2 Endocrine (Shelby) > Hypothalamus/Pituitary > Flashcards

Flashcards in Hypothalamus/Pituitary Deck (35)
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1
Q

In prediabetes, oxytocin increases peripheral glucose uptake by a ________ mechanism, but not via the insulin receptor pathway

A

GLUT-4

2
Q

During intraaxonal transport of precursor ADH and oxytocin, what is it cleaved into?

A

ADH/ oxytocin
Neurophysin
terminal glycoprotein

3
Q

Is BNP more abundant in the ventricle or atria

A

ventricle

4
Q

Where are ADH and oxytocin synthesized

A

hypothalamic neuronal cell bodes (magnocellular neurons)

5
Q

What are the neurons involved in signal transmission from hypothalamus to anterior pituitary

A

Parvicellular neurons

6
Q

ADH binds to which neurophysin?

Oxytocin bind to which neurophysin?

A
ADH = NP 2
oxytocin = NP 1
7
Q

ADH and oxytocin are co-secreted with

A

neurophysins

8
Q

Is oxytocin more abundant in the ventricle or atria

A

3-4x more abundant in the atria

9
Q

What are the neurons involved in signal transmission from hypothalamus to posterior pituitary

A

magnocellular neurons

10
Q

How are ADH and oxytocin transported?

A

in axons with neurophysins

11
Q

Oxytocin regulates cardiac function by modulating the ____________ system and inotropicity

A

parasympathetic

12
Q

Releasing hormones regulate the secretion of ____________ from cell types of the anterior pituitary

A

tropic hormones

13
Q

What is the role of neurophysin?

A

carrier proteins that prevent diffusion of hormones (oxytocin and ADH) out of axons

14
Q

A decrease in blood volume of _____% elicits an increase ADH release

A

8-10%!!

15
Q

Magnocellular neurons of the hypothalamus project their axons down the ___________ and terminate in the _________ where they release their hormones into a _________

A

infundibular process
posterior lobe
capillary bed

16
Q

Is ANP more abundant in the ventricle or atria

A

more abundant in the atria

17
Q

What is the effect of oxytocin in the peripheral arterioles

A

oxytocin induces NO-dependent vasodilation, decreasing BP and resistance to blood flow.

18
Q

What is the plasma half-life of ADH and oxytocin

A

short! ~ 8 min

19
Q

The result of ADH release is an increase in _____ and a decrease in ______ with low urine output

A

plasma volume

osmolarity

20
Q

Oxytocin effects on blood pressure:

Oxytocin is released from the posterior pituitary into the plasma, where it can bind to receptors in the:

A

vasculature
kidney
cardiac tissue

21
Q

What are the two types of oxytocin that exist in the heart

A

pituitary oxytocin

local oxytocin

22
Q

In cardiac muscle, oxytocin binds to receptors resulting in:

A

synthesis and release of ANP and NO

negative inotropic and chronotropic effects

23
Q

Oxytocin stimulates _____, _______, ______ and _____via RENAL oxytocin receptors

A

diuresis
natriuresis
kaliuresis
decreased plasma volume

24
Q

ADH targets the kidney by acting on a ____ receptor

A

v2

25
Q

Hormones of the Posterior pituitary

A
oxytocin 
arginine vasopressin (ADH)
26
Q

Other than plasma osmolarity, ADH release can be stimulated by

A

a decrease in blood volume or blood pressure

not as sensitive!

27
Q

Small changes in plasma osmolarity above a threshold of __________ mOsm/L produce an increase in ADH release before stimulation of _______

A

280-284

thirst

28
Q

What classification of hormone are the two hormones of the posterior pituitary (oxytocin and ADH)

A

neuropeptides

29
Q

ADH acts on the _____ receptor to induce vasoconstriction

A

V1

30
Q

Activation of peripheral aortic baroreceptors in response to stimuli (blood volume, HTN, etc) within the ____________________ results in activation of the _________________ which in turn induces synthesis of ________________ in the hypothalamic parvicelluar neurons (PVN) and supraoptic nuclei (SON)

A

nucleus tractus solitarius (NTS)
oxytocinergic neurones (Otn)
Oxytocin (OT)

31
Q

Increased levels of plasma oxytocin (or increased OTn) results in a reduction of _______ which leads to a decreased production of ________

A
corticotropin RF (CRF)
cortisol
32
Q

Hormones of the anterior pituitary

A
ACTH (adrenocorticotropic hormone)
GH (growth hormone) 
TSH (thyroid-stimulating hormone) 
PRL (prolactin)  
LH (luteinizing hormone) 
FSH (follicle-stimulating hormone)
33
Q

Parvicellular neurosecretory neurons of the hypothalamus project axons to the ________ where they secrete _____ which flow down the pituitary stalk in the hypothalamo-hypophyseal portal vessels to the _____`

A

median eminence
releasing hormones
anterior pituitary

34
Q

Oxytocin causes ANP/BNP release fro cardiomyocyte and _____, in turn, stimulates the release of ________

A

ANP

nitric oxide from vascular endothelium

35
Q

Oxytocin’s vasodilatory effect on peripheral arterioles through NO is enhanced in the presence of

A

estrogen