Test 2: Pituitary and Hypothalamus

Question 1

Diabetes insipidus can be caused by?

Treatment?

Answer 1

Damage to stalk of the pituitary from trauma

treat with synthetic ADH (vasopressin)

Question 2

Suprachiasmatic nucleus

1. Function
2. Lesion here causes

Answer 2

1. Circadian rhythm
2. loss of circadian rhythm

Question 3

Supraoptic/paraventricular nuclei

1. Function
2. Lesion results in

Answer 3

1. Increased blood volume, pressure and metabolism
2. Diabetes insipidus, treat with ADH

Question 4

Lateral hypothalamic nucleus

1. Function
2. Lesion results in

Answer 4

1. Increased feeding
2. decreased feeding

To become more lateral (wide) activate the lateral hypothalamus

Question 5

Ventromedial nucleus

1. Function
2. Lesion results in

Answer 5

1. Decreased feeding
2. increased feeding

Question 6

Dorsomedial nucleus

1. Function
2. Lesion results in

Answer 6

1. Sham rage
2. Decreaesd aggression and feeding

Question 7

Mamillary body

1. Function
2. Lesion results in

Answer 7

1. Unknown fx
2. short term memory isn’t processed into long term memroy= **anterograde amnesia **

Question 8

This is associated with thiamine deficiency and alcoholism.

Answer 8

Korsakoff syndrome= degradation of mammillary bodies (anterograde amnesia), hippocampus, and dorsomedial thalamic nucleus. Fornix carries projections from hippocampus to hypothalamus.

Question 9

You’re having a conversation with the patient. He has been in the hospital for 3 days. You ask him what he did yesterday, and he tells you he went to the park. What’s going on?

Answer 9

CONFABULATION! patient doesn’t remember so his brain fills in the gaps.

Question 10

Damage to hypothalamospinal fibers

Answer 10

Horner’s syndrome on ipsilateral side. This is seriosuly in every chapter we’ve covered. I’d make sure you understand it.

Question 11

**Polyuria, polydipsia, are characteristic of ____ which is caused by ____. _____ is responsible for those symptoms. **

Answer 11

Characteristic of diabetes insipidus caused by damage to the **supraoptic or paraventricular nucleus or **supraoptic hypophysial tract. **LOW ADH causes the symptoms.

Question 12

When does the ____ realease ADH?

Answer 12

The posterior pituitary releases ADH in response to hypovolemia.

Question 13

Bitemporal hemianopia can be caused by?

Answer 13

Pituitary tumor. A pituitary tumor can damage the optic nerve, chiasm or tract.

Question 14

How are pituitary tumors characterized? Names some examples.

Answer 14

1. Secreting tumors- make too much hormones= prolactin. non secretory tumors= undetected until size compresses something.
2. Size: Microadenomas <1cm vs Macroadenomas>1cm
3. Invasiveness- can invade dura or sphenoid bone

Question 15

Visual disturbances and headaches are common in patients with?

Answer 15

**Non secreteing ** pituitary tumor that compress on optic chiasm or hypothalamus.

Question 16

Gigantism

Answer 16

• excess growth hormone BEFORE closure of epiphseal plates
• extremely tall, muscles have a lot of CT instead of muscles

Question 17

Acromegaly

• Cause
• Sx
• secondary problems.

Answer 17

• excess GH **AFTER **closure of epiphyseal plates
• enlargement of digits, elongation of face, malocclusion of jaw and gaps in lower teeth. Bulbous nose, thick lips, large hands and feet. Mastoid and front sinuses bulge.
• 2^o= cardiomegaly leading to cardiac failure, hypertension, DM

Question 18

Thyrotropin tumors

Answer 18

abnormal CV function and tremor. Headaches, visual distrubrnaces and parasellar CN dysfunction in the following order: abducens, oculomotor, trochlear.

Question 19

What cranial nerves can be compromised from pituituary growth?

Answer 19

Parasellar cranial nerves= 3,4,6

Medial–> lateral: abducens, oculomotor, trochlear.

Question 20

Cushings disease

Answer 20

• CRH or ACTH cause overproduction of cortisol.
• Sx: truncal obesity, moon faces, facial hisutism (hair), buffulo hump, purple to violet stria (compared to pale white)
• Hyperpigmentation, easy bruising, hypertension, osteopenia, emotional lability

Question 21

Hyperprolactinemia

• What is it
• Pathological?
• associated sx?

Answer 21

• Galactorrhea= milk production
• Normal during pregnancy.
• Can also cause amenorrhea (which can be occur independently of this from low body fat)

Question 22

Pituitary tumors account for ____ of brain tumors.

Answer 22

12%. When found later in life, it’s usually an accident and they weren’t doing anything bad.

Question 23

1. What is a pituitary pathway that is tonically inhibited?
2. How is that inhibition reversed?

Answer 23

1. Prolactin production is tonically inhibited by **prolactin inhibiting factor. **Inhibition stops during pregnancy, birth and nursing.
2. Suckling reflex stimulates PRF (Prolactin releasing factor) and prolactin production.

Question 24

Differential diagnosis for hyperprolactinemia.

Answer 24

• hypothyroidism
• drug use
• In men it is accompanied by decreased libido, impotency or infertility

Question 25

Most commmon pathologic cause of infertility in men?

Answer 25

PRF hypersecretory tumor

Question 26

Excessive FSH affect? What are the symptoms?

Answer 26

No effect in men or post-menopausal women Exessive FSH in pre-men= shut down menstrual cycle.

Question 27

Excessive LH secretion

Answer 27

precocious puberty in males and disruption of normal period in females

Question 28

Most common symptoms of **gonadotroph ademonas** that raise attention?

Answer 28

visual impairment, headaches and sometimes diplopia **FROM MASS EFFECT= **compression of CN III from lateral extension of tumor.

Question 29

Where should i put a lesion to make *someone* realize what it's like to be always cold? (body temperature decrease, inhibition of symp NS)

Answer 29

lesion in caudolateral hypothalamus

Question 30

Aortic arch and carotid sinus are considered _______ receptors. They sense _______ . What is the reflex and pathway?

Answer 30

**Baroreceptor reflex, **they are EXTRINSIC receptors. low BP==\> info to neurons of solitary nucleus==\>activation of dorsal vagal nucleus ==\> terminal ganglia of hear to increaseforce of contraction and HR (opposite effect if high BP)

Question 31

Where does the solitary nucleus project to indirectly affect dorsal vagal nucleus?

Answer 31

paraventricular, dorsomedial and lateral hypothalamic nuclei which project to dorsal vagal nucleus.

Question 32

I just found out we have our second interview on Thursday, making my blood boil. What does my body do?

Answer 32

Neurons in rostral hypothalamus respond to hot blood==\> sweating and cutaneous vasodilation.

Question 33

I'm in the anatomy lab= SUPER EFFING COLD. What's my body doing?

Answer 33

**Cold blood** activates **caudal hypothalamus==\> **cutaneous vasoconstriction (heat conservation) and shivering (heat production) Vasocontriction mediate by **autonomic pathways** Shivering= **reticulospinal pathways. **

Question 34

1. What's different about the water balance reflex compared to baroreceptor? 2. Where are the "sensory/afferent" neurons? Efferent limb?

Answer 34

1. **Neurohumoral= **efferent part is hormone (ADH) rather than neural. 2. Osmolarity sensed by **osmolartiy sensitive neurons ** in the **anterior hypothalamus ** near the preoptic and paraventricular nuclei===\> neurons IN the preoptic and paraventricular nucleus neurons make ADH (in response to ant pituitary)

Question 35

1. Low blood osmolarity causes? 2. High blood osmolarity causes?

Answer 35

1. Low osmolarity= Less ADH= decreased renal reabsorption in collecting tubules 2. High osmolarity= high ADH= increase reabosorption in collecting tubules.

Question 36

What hormone when oversecreted can cause **hyponatrimia? **

Answer 36

**ADH (ADH secreting tumor) **

Question 37

Sx of hyperthyroidisms? Causes?

Answer 37

Caused by excess TSH= increased T3/T4==\> **sweating, insomina, tremor, weight loss, heat sensitivity. **

Question 38

What should I do to get insomnia so I can maybe pass this damn test?

Answer 38

Lesion in the **ventrolateral preoptic nucleus=** less inhibition to tuberomamillary nucleus= HISTAMINE OVERPRODUCTION. remember **anti histamines ** make you sleeepppyyy

Question 39

Why does this person keep falling asleep mid sentence?

Answer 39

**narcolepsy** Orexin neurons in lateral hypothalamus STIMULATES tuberommammilary nucleus= Histamine release. Lesion to orexin neurons= less histamine= sleepiness.

Question 40

What sort of lesion would inhibit pituitary function?

Answer 40

Lesion in hypothalamus blocks transport of endocrine factors==\> adverse affect on pituitary fx.