Hypothalamus - Friedman - Exam 1

Question 1

Four major functions of the hypothalamus:

Answer 1

HEAL

Homeostasis

Endocrine

Autonomic

Limbic (bodily expression)

Question 2

The hypothalamus has two different kinds of outputs. One is a ___ output, which comes from the ___ gland. The other is the ___ output, which goes to an array of different systems, such as the brain system, motor systems, ANS, spinal cord, forebrain and limbic structures.

Answer 2

The hypothalamus has two different kinds of outputs. One is a humeral output, which comes from the pit. gland. The other is the neural output, which goes to an array of different systems, such as the brain system, motor systems, ANS, spinal cord, forebrain and limbic structures.

Question 3

The hypothalamus is the ventral portion of the __

Answer 3

Diencephalon

Question 4

The hypothalamus, like the thalamus is a set of nuclei. Almost all the nuclei participate in multiple functions.

The ___, ___ and ___ nuclei project to the rest of the hypothalamus.

The __, ___ and ___ nuclei are integrative nuclei and have outputs to the pituitary.

__, __, ___ and __ nuclei are integrative nuclei have have neural outputs to the brainstem and forebrain.

Answer 4

The hypothalamus, like the thalamus is a set of nuclei. Almost all the nuclei participate in multiple functions.

The pre-optic, suprachiasmatic, arcuate nuclei project to the rest of the hypothalamus.

The paraventricular, arcuate and ventromedial nuclei are integrative nuclei and have outputs to the pituitary.

Lateral, paraventricular, dorsomedial, and posterior nuclei are integrative nuclei have have neural outputs to the brainstem and forebrain.

Question 5

The ___ nucleus produces 7 or 8 NT’s that go to different places

Answer 5

paraventricular

Question 6

The hypothalamus integrates the forebrain (mainly the limbic system) inputs with the brainstem spinal cord. It gets its visceral sensory inputs via the __ nerve, __ nerve via the nucleus solitarious track. There is a big projection from the nucleus solitarious track to the hypothalamus. Some of it goes to the lateral parabrachial nucleus and then to the hypothalamus.

The outputs back to the brainstem are all about autonomic nervous system control. They project to the nuclei that are part of the autonomic nervous system (cranial nerve nuclei, and others) and it also projects directly to the spinal cord.

Answer 6

The hypothalamus integrates the forebrain (mainly the limbic system) inputs with the brainstem spinal cord. It gets its visceral sensory inputs via the IX nerve and X nerve via the nucleus solitarious track. There is a big projection from the nucleus solitarious track to the hypothalamus. Some of it goes to the lateral parabrachial nucleus then to the hypothalamus.

The outputs back to the brainstem are all about autonomic nervous system control. They project to the nuclei that are part of the autonomic nervous system (cranial nerve nuclei, and others) and it also projects directly to the spinal cord.

Question 7

The brainstem mediates an array of reflexes that help keep our bodies working properly. The ___ controls how these reflexes work. These are typically controlled simply by sensory input from different types of receptors. Because of its __ inputs, the hypothalamus is able to modify homeostatic reflex activity in based on the emotional and cognitive environment

Answer 7

The brainstem mediates an array of reflexes that help keep our bodies working properly. The hypothalamus controls how these reflexes work. These are typically controlled simply by sensory input from different types of receptors. Because of its limbic inputs, the hypothalamus is able to modify homeostatic reflex activity in based on the emotional and cognitive environment

Question 8

Visceral sensory information is relayed largely by the ___ nerve to the nucleus of the ___ tract. There are direct projections from the NTS (solitary tract) to the ___, and other, indirect projections, through the ___ nucleus. There is also a __-___ tract that carries pain info among other things.

Answer 8

Visceral sensory information is relayed largely by the vagus nerve to the nucleus of the solitary tract. There are direct projections from the NTS to the hypothalamus, and other, indirect projections, through the parabrachial nucleus. There is also a spino-hypothalamic tract that carries pain info among other things.

Question 9

The hypothalamus controls the autonomic nervous system via connections in the brainstem. The most important brainstem ANS reflex centers include the periaqueductal Gray (PAG), rostral ventrolateral medulla (RVLM), dorsal motor nucleus of the vagus (DMNX), nucleus ambiguus, and raphe nuclei. All of these project to the __ __.

The __ is a noradrenergic cell (NE releasing) group that projects to the intermediolateral cell column in the thoracic cord. It controls ____ output.

Answer 9

The hypothalamus controls the autonomic nervous system via connections in the brainstem. The most important brainstem ANS reflex centers include the periaqueductal Gray (PAG), rostral ventrolateral medulla (RVLM), dorsal motor nucleus of the vagus (DMNX), nucleus ambiguus, and raphe nuclei. All of these project to the spinal cord. The RVLM is a noradrenergic cell group that projects to the intermediolateral cell column in the thoracic cord. It controls sympathetic output.

Question 10

Answer 10

The hypothalamus controls the autonomic nervous system via connections in the brainstem. The most important brainstem ANS reflex centers include the periaqueductal Gray (PAG), rostral ventrolateral medulla (RVLM), dorsal motor nucleus of the vagus (DMNX), nucleus ambiguus, and raphe nuclei. All of these project to the spinal cord. The RVLM is a noradrenergic cell group that projects to the intermediolateral cell column in the thoracic cord. It controls sympathetic output.

Visceral sensory information is relayed largely by the vagus nerve to the nucleus of the solitary tract. There are direct projections from the NTS to the hypothalamus, and other, indirect projections, through the parabrachial nucleus. There is also a spino-hypothalamic tract that carries pain info among other things.

Question 11

The hypothalamus moniters the blood. It moniters the blood through some things called ___ organs. There are places where there is a break in the BBB, and, since capillaries are fennestraed, the neurons that are there can actually sample the blood. In addition to that, some of the neurons within the nuclei are sensitive to different parts of the ECF.

The ___ moniters blood osmolarity, Na+ levels and circulating pyrogens. The ___ moniters blood osmolarity and many hormones. The ___ ___ moniters toxins/vomiting, and many hormones.

Which circumventricular organs sample hormones?

Which circumventricular organs sample blood osmolarity?

Which circumventricular organ moniters toxins/vomiting?

Which circumventricular organ moniters Na+ levels?

Which one, out of SFO, OVLT, and AP do NOT moniter blood osmolarity?

Answer 11

The hypothalamus moniters the blood. It moniters the blood through some things called circumventricular organs. There are places where there is a break in the BBB, and, since capillaries are fennestraed, the neurons that are there can actually sample the blood. In addition to that, some of the neurons within the nuclei are sensitive to different parts of the ECF.

The OVLT (organum vasculosum of lamina terminalis) moniters blood osmolarity, Na+ levels and circulating pyrogens. The SFO (subfornical organ) moniters blood osmolarity and many hormones. The area postrema moniters toxins/vomiting, and many hormones.

Which circumventricular organs sample hormones? –> SFO and area postrema

Which circumventricular organs sample blood osmolarity? –> both SFO and OVLT

Which circumventricular organ moniters toxins/vomiting? –> area postrema (AP also samples hormones

Which circumventricular organ moniters Na+ levels?

–> OVLT (OVLT also samples blood osmolarity and circulating pyrogens)

Which one, out of SFO, OVLT, and AP do NOT moniter blood osmolarity? –> AP does not moniter blood osmolarity. It only moniters many hormones and toxins/vomiting.

Question 12

The hypothalamus is involved in homeostatic control of survival functions such as:

C - TEAS

Answer 12

Cardivascular: HR and BP, Na+ and H2O balance

Temperature regulation

Energy balance

Activity cycles

Sexual functioning

Question 13

There are thermoreceptors in the skin, deep organs and on preoptic neurons of the hypothalamus. These are the core of the temperature regulating system, but the hypothalamus also receives information about:

Nutritional status

Energy needs

Developmental stage

Emotional and motivational status

Endogenous pyrogens

These inputs modulate the response of the hypothalamus to thermoreceptor input

Control of cutaneous blood flow, skeletal muscle activity and sweating are the main mechanisms of thermoregulation

Answer 13

There are thermoreceptors in the skin, deep organs and on preoptic neurons of the hypothalamus. These are the core of the temperature regulating system, but the hypothalamus also receives information about:

Nutritional status

Energy needs

Developmental stage

Emotional and motivational status

Endogenous pyrogens

These inputs modulate the response of the hypothalamus to thermoreceptor input

Control of cutaneous blood flow, skeletal muscle activity and sweating are the main mechanisms of thermoregulation

Question 14

Hypothalamus controls temperature. It is able to moniter brain temp, skin temp, visceral organ temp, because there are temp. receptors in all those places.

They all give input mainly to the __-__ area of the ___, which projects to other areas in the ___.

The outputs are first to the ANS, which makes changes in arteriole diameter, sweat glands, muscle and fat. These are short-term changes.

Long-term changes include: release of __ which changes metabolism and also behavior

Answer 14

Hypothalamus controls temperature. It is able to moniter brain temp, skin temp, visceral organ temp, because there are temp. receptors in all those places.

They all give input mainly to the pre-optic area of the hypothalamus, which projects to other areas in the hypothalamus.

The outputs are first to the ANS, which makes changes in arterioles, sweat glands, muscle and fat. This is a short-term change.

Long-term changes include: release of TSH which changes metabolism and also behavior

Question 15

Pre-optic, suprachiasmatic, arcuate nuclei, are all input target areas, and project to the ___.

Answer 15

Pre-optic, suprachiasmatic, arcuate nuclei, are all input target areas, and project to the hypothalamus.

Mnemonic: pre-opt students are super characteristic are over arching overachievers that are hypo-tall (short) because they study all day.

Question 16

Paraventricular, ventromedial nuclei, arcuate are ___ centers and have outputs to the ___.

The parents that are viscious, very motherly, and over arching overachievers send their music kids to the orchestra pit and force them to integrate with others.

Answer 16

Paraventricular, ventromedial nuclei, arcuate are integrative centers and have outputs to the pituitary gland.

The parents that are viscious, very motherly, and over arching overachievers send their music kids to the orchestra pit and force them to integrate with others.

Question 17

Lateral, paraventricular, dorsomedial, posterior nuclei are integrative centers and have outputs to the__ and __.

Later on, the parents that are viscous end up delivering mail and post to the brainstem and forebrain.

Answer 17

Lateral, paraventricular, dorsomedial, posterior nuclei are integrative centers and have outputs to the brainstem and forebrain.

Later on, the parents that are viscous end up delivering mail and post to the brainstem and forebrain.

Question 18

Our circadian cycles are linked to the light/dark cycle through ___ nucleus.

The ___ nucleus receives direct input from the ___, projects to other nuclei in the hypothalamus, and literally entrains the entire body to the light-dark cycle established by the sun through these connections.

Answer 18

Our circadian cycles are linked to the light/dark cycle through suprachiasmatic nucleus.

The suprachiasmatic nucleus receives direct input from the retina, projects to other nuclei in the hypothalamus, and literally entrains the entire body to the light-dark cycle established by the sun through these connections.

Question 19

All eating behavior is determined by the ___. Cognitive, limbic and metabolic influences regulate eating.

___ stimulates eating,

___ (from pancreas) GLP-1, PYY and other peptides like leptin inhibit eating. That is, they elicit satiety.

Limbic control of eating is driven by the pleasure derived from eating. Eating turns on the brain reward system, which is an important learning and survival circuit. But certain foods, especially those high in sugar, fat and salt are especially good at activating this system.

These foods are said to have high hedonic value. Ghrelin makes the system more responsive to food (that’s why you like food more when you’re hungry).

Answer 19

All eating behavior is determined by the ___. Cognitive, limbic and metabolic influences regulate eating.

Ghrelin stimulates eating,

Insulin (from pancreas) GLP-1, PYY and other peptides like leptin inhibit eating. That is, they elicit satiety.

Limbic control of eating is driven by the pleasure derived from eating. Eating turns on the brain reward system, which is an important learning and survival circuit. But certain foods, especially those high in sugar, fat and salt are especially good at activating this system.

These foods are said to have high hedonic value. Ghrelin makes the system more responsive to food (that’s why you like food more when you’re hungry).

Question 20

____ disorders often have endocrine and/or autonomic symptoms. These can be caused by destructive lesions such as in trauma, as well as space occupying lesions (neo-plasms, cysts).

Answer 20

Hypothalamic disorder often hae endocrine and/or autonomic symptoms. These can be caused by destructive lesions such as in trauma, as well as space occupying lesions (neo-plasms, cysts).

Question 21

Vasopressin and Oxytocin are the two hormones released by the __ ___.

The hormones release by the anterior pituitary are:

FLAT PIG

F- FSH
L- LH
A- ACTH
T- TSH

P- Prolactin
I - (ignore)
G- GH

Answer 21

Vasopressin and oxytocin are the two hormones released by the posterior pituitary gland.

Ant. pit releases:

FLAT PIG

F- FSH
L- LH
A- ACTH
T- TSH

P- Prolactin
I - (ignore)
G- GH

Question 22

The pituitary gland has __ lobes.

The ___ lobe contains axon terminals

A.hormones released directly into blood supply

B.act directly on tissues

B.Anterior lobe contains cells (tropes) that synthesize hormones

A.Activated by hypothalamic releasing hormones

B.Release “tropic” hormones that act on glands and tissues

Answer 22

A.Posterior lobe contains axon terminals

A.hormones released directly into blood supply

B.act directly on tissues

B.Anterior lobe contains cells (tropes) that synthesize hormones

A.Activated by hypothalamic releasing hormones

B.Release “tropic” hormones that act on glands and tissues

Question 23

Vasopressin synthesizing neurons are osmoreceptors. They sample the ECF.

Increased osmolarity increases firing rate and therefore releases ___ from the __ __. The ___ acts on the __ __ in the kidney to increase water reabsorption.

Answer 23

Vasopressin synthesizing neurons are osmoreceptors. They sample the ECF.

Increased osmolarity increases firing rate and therefore releases vasopressin from the posterior pituitary gland. The vasopressin acts on the collecting ducts in the kidney to increase water reabsorption.

Question 24

The ___ (aka ___ lobe) lobe contains axon terminals. Hormones are released directly into the blood supply and acts on tissues. The ___ lobe contains cells (tropes) that synthesize hormones.

Answer 24

The posterior (aka neural lobe) lobe contains axon terminals. Hormones are released directly into the blood supply and acts on tissues. The anterior lobe contains cells (tropes) that synthesize hormones.

Question 25

Vasopressin and oxytocin are the two post. pit hormones. They are synthesized by the ___ and __ nuclei, and are released directly from the axon terminals in the posterior pit.

Answer 25

Vasopressin and oxytocin are the two post. pit hormones. They are synthesized by the paraventricular and supraoptic nuclei, and are released directly from the axon terminals in the posterior pit.

Question 26

____ enhances uterine contractility (via ___ nerve), stimulates milk ejection from gland to duct. It encourages pro-social behavior such as in pair bonding, copulaton, mother infan bonding. It also improves mood.

Answer 26

Oxytocin enhances uterine contractility (via vagus nerve), stimulates milk ejection from gland to duct. It encourages pro-social behavior such as in pair bonding, copulaton, mother infan bonding. It also improves mood.

Question 27

Ant. pit releases hormones to control endocrine function. All of these are controlled by feedback. For example, if there is too much thyroid hormone, the hormone will inhibit the __ ___ and also the ___ so that it stops releasing/synthesizing more hormone.

Answer 27

Ant. pit releases hormones to control endocrine function. All of these are controlled by feedback. For example, if there is too much thyroid hormone, the hormone will inhibit the ant. pit and also the hypothalamus so that it stops releasing/synthesizing more hormone.

Question 28

Neural input to the hypothalamus can be translated into endocrine responses

Some hypothalamic nuclei can produce hormones that are transported by axons to the ___ pituitary where they are released directly into the blood stream

Other hypothalamic nuclei can produce releasing or inhibiting factors that are released into the portal hypophyseal circulation. The portal hypophyseal system is a portal system of veins that carry hormones from capillary beds in the hypothalamus to capillary beds in the anterior pituitary gland. In the anterior pituitary gland, these factors indirectly stimulate or inhibit endocrine cells to release hormones into the systemic blood stream

Circulating hormones can in turn regulate hypothalamic function via feedback loops

Answer 28

Neural input to the hypothalamus can be translated into endocrine responses

Some hypothalamic nuclei can produce hormones that are transported by axons to the posterior pituitary where they are released directly into the blood stream

Other hypothalamic nuclei can produce releasing or inhibiting factors that are released into the portal hypophyseal circulation. The portal hypophyseal system is a portal system of veins that carry hormones from capillary beds in the hypothalamus to capillary beds in the anterior pituitary gland. In the anterior pituitary gland, these factors indirectly stimulate or inhibit endocrine cells to release hormones into the systemic blood stream

Circulating hormones can in turn regulate hypothalamic function via feedback loops

Question 29

Releasing hormones are small peptides released by hypothalamic neurons that are found in the ___ nucleus, ___ nucleus and __-___ nucleus.

These are mostly small neurons so they are caleld parvocellular neurons. When they get finally to to eh ant pit, the stimulate gene ___and release __product (tropic homrones).

Answer 29

Releasing hormones are small peptides released by hypothalamic neurons that are found in paraventricular nucleus, arcuate nucleus and medial pre-optic nucleus. These are mostly small neurons so they are caleld parvocellular neurons. When they get finally to the ant. pit, the stimulate gene expression and release gene product (tropic homrones).

Question 30

One of the really important hypothalamic system is the one that responds to stress: the ___ axis. It consists of the hypothalamus, which is under the control (in this case) of the limbic system. So, there is limbic input to the ____ nucleus, which releases ___, which causes the ___ pit. to release ACTH. ACTH causes the adrenals to release ___, which is the major stress hormone. In the short term, cortisol is good for us in terms of responding to stress. In the long term, it is bad for us.

Answer 30

One of the really important hypothalamic system is the one that responds to stress: the HPA axis. It consists of the hypothalamus, which is under the control (in this case) of the limbic system. So, there is limbic input to the paraventricular nucleus, which releases CRH (cortisol stimulating hormone), which causes the ant. pit. to release ACTH. ACTH causes the adrenals to release cortisol, which is the major stress hormone. In the short term, cortisol is good for us in terms of responding to stress. In the long term, it is bad for us.

Question 31

Pit. tumors may produce endorcine symptoms.

Adenomas secrete ____. Pit. tumors can also cause visual symptoms

Answer 31

Pit. tumors may produce endorcine symptoms.

Adenomas secrete hormones. Pit. tumors can also cause visual symptoms

Question 32

Answer 32

Question 33

How does the hypothalamus ineract with the ant. pit?

What types of hormones does the hypothalamus release to the ant. pit? What does the ant. pit do in response?

Answer 33

The hypothalamus interacts with the hypophyseal portal system.

This system is a capillary system. Little BV’s that flow between hypothalamus and pit. gland secrete hormones into the system.

Hormones:

GNRH released by the hypothalamus is going to go down to the ant. pit and will stimulate the release of FSH and LH. These hormones travel to the gonads and stimulate them to release their hormones.

CRTH stimulates the ant. pit’s release of ACTH. ACTH goes down to the adrenal gland, and stimulates them to release cortisol.

The ant. pit also release TRH. TRH goes down to the ant. pit and stimulates it to release TSH. TSH goes to the thyroid to release T3 and T4.

GHRH is the hypothalamus’s signal to the ant pit. to release GH which stimualte growth

Prolactin-inhibtiory factor (PIF) is a little different. it is constantly being released. When it is stopped being released, it is signalled to prolactin (for milk production).

FLAT PEG

“FLAT” - FSH, LA, ACTH, and TSH, are the TROPIC HORMONES.

PEG - Prolacting, (endorphins), GH (goes right to the bone), are the DIRECT HORMONES…stimulate parts of body directly).