Neuroanatomy 17: Pituitary And Hypothalamus

Front 1

4 functions of hypothalamus

Back 1

homeostatic, endocrine, autonomic, limbic

Front 2

Anterior pituitary is derived from ...

Back 2

oral ectoderm (Rathke's pouch)

Front 3

Posterior pituitary is derived from ...

Back 3

neuro-ectoderm from ventricular system

Front 4

Which endocrine cells are located in the posterior pituitary?

Back 4

none, it just has axons that carry hormones from the hypothalamic endocrine regions (supraoptic and paraventricular)

Front 5

The hypothalamus is part of which brain region?

Back 5

diencephalon

Front 6

What is found beneath the sella turcica?

Back 6

sphenoid sinus

Front 7

What is the diaphragma sella?

Back 7

dura mater over the pituitary fossa

Front 8

The pituitary fossa has what on both sides of it?

Back 8

cavernous sinus

Front 9

Enlargement of the pituitary gland can compress what major nerve?

Back 9

optic nerve at the chiasm (causes bi-temporal hemianopia)

Front 10

Damage to the lateral hypothalamus will damage what bundle of nerve fibers?

Back 10

medial forebrain bundle

Front 11

What part of the hypothalamus is derived from the telencephalon?

Back 11

pre-optic area

Front 12

To regulate autonomic function, the hypothalamus sends fibers through what structure to get to pre-ganglionic autonomic nuclei?

Back 12

MFB (medial forebrain bundle) that runs across the lateral hypothalamus and dorsolateral brainstem

Front 13

2 pathways for communication between amygdala and hypothalamus?

Back 13

stria terminalis and ventral amygdalofugal pathway

Front 14

What is hypothalamic hamartoma?

Back 14

illustrates limbic-hypothalamic connection. lesions of hypothalamus lead to emotional incontinence

Front 15

Circadian rhythm is regulated by which hypothalamic nucleus?

Back 15

suprachiamastic

Front 16

A patient presents with insomnia and a brain lesion is found on an MRI of the hypothalamus. What part of the hypothalamus has this lesion?

Back 16

anterior hypothalamus. anterior hypothalamus contains the VLPO that puts you to sleep. if this is damaged, you can't sleep

Front 17

A patient presents with hypersomnia and a brain lesion is found on an MRI of the hypothalamus. What part of the hypothalamus has this lesion?

Back 17

posterior hypothalamus. posterior hypothalamus controls histaminergic neurons that keep you awake. if the neurons are damaged and don't release histamine to keep you awake, you sleep more. (hint: nyquil and benadryl are anti-histamine drugs, thats why they make you drowsy. they block the histamine from keeping you awake)

Front 18

An extremely obese patient has a brain lesion found on an MRI of the hypothalamus. What part of the hypothalamus has this lesion most likely?

Back 18

ventromedial hypothalamus. ventromedial hypothalamus is responsible for inhibiting appetite after a meal. if there is a lesion here you keep eating = obese

Front 19

An extremely skinny patient has a brain lesion found on an MRI of the hypothalamus. What part of the hypothalamus has this lesion most likely?

Back 19

lateral hypothalamus. this part controls hunger. if there is a lesion here, you are rarely hungry = anorexia

Front 20

Function of leptin

Back 20

bind Ob receptors in hypothalamus and signal inhibition of appetite. leptin deficiency = obese

Front 21

Function of Ghrelin

Back 21

from gastric mucosa to initiate hunger. obese people may have high Ghrelin

Front 22

A patient presents with extreme dehydration. An MRI shows a lesion in the hypothalamus. What part of the hypothalamus is most likely affected?

Back 22

Lateral hypothalamus lesions = less thirst = less water intake. Also anterior hypothalamus contains osmo-receptors to determine thirst. Also the supraoptic nuclei makes ADH, if this is damaged, then we have diabetes insipidus which leads to extreme thirst

Front 23

A patient presents with extreme heat intolerance. An MRI shows a lesion in the hypothalamus. What part of the hypothalamus is most likely affected?

Back 23

anterior hypothalamus will initiate mechanisms of heat dissipation. if the lesion is in the anterior region, the patient won't sweat or dissipate heat and will hate being in Florida and always overheat

Front 24

A patient presents with extreme cold intolerance. An MRI shows a lesion in the hypothalamus. What part of the hypothalamus is most likely affected?

Back 24

posterior hypothalamus control mechanisms for warming the body up (shivering, conserve heat). if the lesion is here, the patient will not be able to adjust homeostasis in the cold = cold intolerance

Front 25

A patient presents with extreme fluctuations in body temperature. An MRI shows a lesion in the hypothalamus. What part of the hypothalamus is most likely affected?

Back 25

bilateral posterior hypothalamus lesions cause poikilothermia= no regulation of temperature. the heat conserving regions in the posterior are damaged and descending fibers from the anterior (for heat dissipation) are damaged

Front 26

Why do bilateral posterior hypothalamus lesions lead to poikilothermia?

Back 26

the heat conserving regions in the posterior are damaged and descending fibers from the anterior (for heat dissipation) are damaged

Front 27

6 hormones of the anterior pituitary

Back 27

FSH, LH, GH, TSH, Prolactin, ACTH

Front 28

2 posterior pituitary hormones

Back 28

ADH, Oxytocin

Front 29

Hypothalamus releases regulatory hormones to the anterior pituitary via what system?

Back 29

hypophysial portal system

Front 30

What affect does dopamine have as a hormone?

Back 30

inhibits prolactin secretion

Front 31

Where is ADH MOSTLY made?

Back 31

supraoptic nuclei of hypothalamus. not made in the posterior pituitary!

Front 32

Where is oxytocin MOSTLY made?

Back 32

paraventricular nuclei of hypothalamus. not made in the posterior pituitary!

Front 33

Cortisol has a negative feedback inhibition on what 2 hormones?

Back 33

CRH (from hypothalamus) and ACTH (from ant. pituitary)

Front 34

A patient presents with a prolactin secreting tumor. What drug might we prescribe to him?

Back 34

dopamine or a dopamine agonist (bromocriptine)

Front 35

A patient is diagnosed with Cushing's SYNDROME. What is the endocrine problem here?

Back 35

generic glucocorticoid (cortisol) excess. Cushing's DISEASE is different because it specifically refers to an ACTH secreting tumor as the cause of glucocorticoid excess

Front 36

A patient is diagnoses with Cushing's DISEASE. What is the endocrine problem here?

Back 36

an ACTH secreting tumor is causing glucocorticoid (Cortisol) excess

Front 37

A patient presents with a "moon-face" and extreme immune suppression. What is a likely diagnosis?

Back 37

Cushing's Syndrome or Cushing's Disease

Front 38

A patient is suspected of having an ACTH secreting tumor (Cushing's Disease). A dexamethasone suppression test is given. Describe the test and what results would confirm Cushing's disease.

Back 38

dexamethasone is a strong cortisol agonist. by giving it, we are checking to see if cortisol/ACTH levels fall due to the negative feedback loop that should be working. if cortisol levels stay high, however, we would further suspect Cushing's DISEASE (ACTH secreting tumor) because a tumor doesn't care about the negative feedback, its just gonna keep secreting ACTH to make more cortisol

Front 39

A patient presents with extreme sweating and goiter. TSH levels are very high. What is causing this problem most likely?

Back 39

TSH secreting adenoma leading to hyperthyroidism

Front 40

A patient presents with extreme sweating and high metabolic rate. TSH levels are very low. What is causing this problem most likely?

Back 40

Grave's disease. antibodies are stimulating the thyroid gland to constantly produce T4/T3. the excess hormones feedback and keep TSH levels low.

Front 41

A patient presents with extreme lethargy and weight gain. What lab results would we expect in a thyroid function test if there was a rare hypothalamus lesion causing this?

Back 41

low TRH = low TSH = low T4/T3

Front 42

A patient is peeing uncontrollably and there is no glucose in the urine. What drug would you give him?

Back 42

vasopressin (ADH) to treat diabetes insipidus

Front 43

A patient is peeing uncontrollably and there is no glucose in the urine. There are high levels of ADH in the blood though. What is your diagnosis?

Back 43

nephrogenic diabetes insipidus. ADH is made normally, but kidneys have a defect in using it = high ADH due to feedback

Front 44

A patient excretes small amounts of extremely concentrated urine. What is the diagnosis?

Back 44

SIADH. high ADH secretion

Front 45

A patient excretes small amounts of extremely concentrated urine. What might we expect to see in a metabolic panel regarding his blood-sodium levels?

Back 45

low Na in the blood because he is excreting very concentrated urine

Front 46

A patient excretes small amounts of extremely concentrated urine. What drug can we give him?

Back 46

vaprisol to block ADH

Front 47

What is panhypopituitarism?

Back 47

deficiency of all pituitary hormones

Front 48

What is pituitary apoplexy?

Back 48

hemorrhage of pituitary tumor leading to panhypopituitarism

Front 49

A patient presents with uncontrollable giggling and emotional outbursts. Where is there a lesion in the hypothalamus most likely?

Back 49

stria terminalis or ventral amygdalofugal pathway. the hypothalamic/limbic interaction is damaged in someway