H&n A9: Hypothalamus And Pituitary Lecture 9

Front 1

Location of hypothalamus

Back 1

Inferior to thalamus, anterior to midbrain/cerebellum, forms lateral wall of 3rd ventricle.

Front 2

What hangs from the inferior extent of the hypothalamus?

Back 2

Pituitary, by the infundibulum. It sits in the sella turcica (depression in sphenoid bone of the skull)

Front 3

What are the 8 main functions of the hypothalamus?

Back 3

1) Temperature regulation
2) Emotion
3) Hunger
4) Memory
5) Sexuality
6) Sleep
7) Blood pressure
8) Maintenance of balance between parasympathetic and sympathetic systems

Front 4

What part of the hypothalamus deals with heat regulation? Where do the fibers go? What is the end result? Damage to this area results in?

Back 4

Anterior hypothalamus - heat regulation. Lowers body temperature when outside body temperature raises.

Fibers:

1) synapse in reticular formation
2) OR go to brainstem/spinal cord, stimulate sympathetic nervous system, voluntary musculature, cardiac/respiratory centers in medulla

End result - reduced body temp

Damage - can't keep body temp low when outside temp rises, person overheats (heat stroke)

Front 5

What part of the hypothalamus deals with cold regulation? What happens if this part is damaged? What factors can affect this system?

Back 5

Posterior hypothalamus. Efferent pathways are the same as heat regulation. Damage - person's core temp dangerously drops in cold environments. Alcohol and age can affect.

Front 6

What emotions does the hypothalamus have control over, and how does it control these emotions? What is the most powerful evoker of memories, emotions, and sexuality?

Back 6

Anger, fear, well-being. Interacts with limbic system/visual/auditory/olfactory system.

Olfactory.

Front 7

What part of the hypothalamus controls hunger?

Back 7

Ventral median nucleus - helps you feel satiated

Lateral hypothalamic area - controls appetite, maintains it

Front 8

What part of the hypothalamus deals with memories?

Back 8

Mammillary bodies - important for retention of short-term anterograde memories

Front 9

What part of the hypothalamus is associated with sexuality?

Back 9

Medial preoptic nucleus - male behavior

Ventromedial nucleus - female behavior

Front 10

4 parts of the pituitary from the histologic categorization:

What parts are not present in humans?

Back 10

1) Pars distalis
2) Pars nervosa
3) Pars tuberalist
4) Pars intemedia

No pars tuberalis in humans, intermedia is minimal

Front 11

What are the parts of the pituitary from the embryologic categorization?

Back 11

Neurohypophysis - pars nervosa + infudibulum

Adenohypophysis - pars distalis, pars intermedia, pars tuberalis

Front 12

What are the parts of the pituitary from the anatomic categorization?

Back 12

Anterior pituitary - pars distalis, pars tuberalis

Posterior pituitary - pars intermedia, pars nervosa, infundibular stalk

Front 13

Where does the pars nervosa get its hormones from?

Back 13

NO hormones produced by the cells in the pars nervosa. Get hormones from paraventricular and supraoptic nuclei from the hypothalamus, which travel down hypothalamic/hypophyseal tract in axons that terminate in pars nervosa.

Front 14

What are the two major hormones secreted into the pars nervosa?

Back 14

ADH (retains fluid/salt by decreasing urine excretion) and oxytocin (stimulates uterine contractions, milk ejection during pregnancy)

Front 15

What are Herring Bodies? Where are they found?

Back 15

Axons of the neuroendocrine system stained with secretions of hormones. Found in the pars nervosa

Front 16

What part of the pituitary makes up the majority of the adenohypophysis? What are the three major cell types in the adenohypophysis, and what do they do?

Back 16

Pars distalis.

Folliculostellate - don't produce/store hormones. Thought to suport cells that form interconnecting matrix that holds the glands together.

Chromophils - basophils (FLAT), acidophils (PG) - produce hormones

Chromophobes - stem cells or exhausted hormone producing cells.

Front 17

How do the anterior pituitary and hypothalamus connect?

Back 17

Portal blood system (they are not directly connected). Hormones can travel from hypothalamus to anterior pituitary, and hormones from anterior pituitary can travel back to hypothalamus to exert negative feedback.

Front 18

What are the hormones secreted in the portal blood system to the anterior pituitary? What are the functions of these hormones?

Back 18

FLATPeG.

BASOPHILS:

FSH - female - growth of ovarian follices/oocytes. Males - growth/development of sperm. Controlled by GnRH (hypothalamus)

LH - female - ovulation, estrogen production. Male - testosterone production. Controlled by GnRH (hypothalamus)

ACTH - stimulates adrenal glands to produce hormones. Controlled by ACTH stimulating hormone (hypothalamus)

TSH - stimulates thyroid hormone production from thyroid. Controlled by thyroid hormone stimulating hormone (hypothalamus)

ACIDOPHILS:

Prolactin - breast development and milk ejection - controlled by prolactin inhibitory hormone (hypothalamus)

Growth hormone - stimulates body growth - controlled by growth hormone inhibitory hormone (hypothalamus)

Front 19

What are the globus pallidus and substantia nigra responsible for?

Back 19

Modulating motor function. Send fibers down to the dorsal tegmental nuclei of the midbrain

Front 20

Where does Rathke's pouch originate? What two pars is it found in between?

Back 20

In the stomadeum (primitive mouth). Pars distalis and pars intermedia.

Front 21

What type of diabetes do you get if you don't secrete ADH?

Back 21

Diabetes insipidus

Front 22

What are the specific types of chromophils and where are they found?

What are the other cell types in the pars distalis?

Back 22

Pars distalis.

1) Basophils - produce FLAT (FSH, LSH, ACTH, TSH)

2) Acidophils - produce PG (prolactin, growth hormone )

Other types - chromophobes (degranulated cells/stem cells) and folliculstellate cells (may help support parenchymal cells)

Front 23

What kind of hormones act on basophils? Acidophils? (Stimulating or inhibiting?)

Back 23

Stimulating hormones work on basophils, inhibitory work on acidophils.

Front 24

What does acromegaly usually result from? What is it?

Back 24

Usually results from pituitary tumor, can cause gigantism if it occurs before puberty. Results in enlarged bones (hands, feet, jaws), organs.

Front 25

What is the reticular system? How do the globus pallidus and substantia nigra control this?

Back 25

Bunch of nuclei scattered throughout the brainstem, activates everything else motor. It's activated by the hypothalamus, with input from globus pallidus and substantia nigra that send fibers down to deep and dorsal tegmental nuclei of the midbrain.

Front 26

What disease can you get from lack of secretion of ADH?

Back 26

Diabetes insipidus