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85 Cards in this Set
- Front
- Back
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List four functions of the Hypothalamus:
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Maintains homeosasis:
-temp -food and water intake -balance -circadian rhythm |
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What 3 systems influence the hypothalamus?
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-ANS
-Endocrine -Limbic |
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What forms the anterior border of the hypothalamus, along with the anterior commisure?
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Lamina terminalis
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What is the most comon location for hypothalamic brain tumors?
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Anterior commisure/lamina terminalis
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What does an anterior hypothalamic brain tumor do?
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Disrupts parasympathetic commands, resulting in unopposed sympathetic function.
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How does a patient with an anterior hypothalamic lesion present?
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All sympathetic is increased (heart rate, hypetension, etc)
-a lesion here disrupts visual function by putting pressure on optic chiasm resulting in biltemporal hemianopsoa or unilateral nasal hemianopsia |
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What makes up the posterior boundary of the hypothalamus?
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Mamillary bodies (adjacent to mesencephalon)
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What happens if the posterior boundary of the hypothalamus is dirupted?
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Confusion, loss of short-term/long-term memory, disrupts limbic or emotion thoughts and functions.
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How can you tell if there is a tumor in the medial part of the hypothalamus?
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The medial portion is the 3rd ventricle, so look for assymtery on MRI
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What is the lateral border of the hypothalamus?
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Internal capsule
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What is the tuber cinereum?
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The raised portion of the hypothalamus that surrounds the infundibulum (including the median eminence)
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Which hypothalamic nuclei are the main recipients of the hippocampus?
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Mamillary bodies
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How do mamillary bodies receive projections from the hippocampus?
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Hippo----->fornix----->mammillary------>anterior thalamic nucleus (mammilothalamic tract)
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What is the "fornix" of the amygdala?
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stria terminalis
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Where else does the stria terminalis project to, besides the hypothalamus?
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septal nucleus
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Which hypothalamic nucleus can be called the "sleep center"?
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anterior hypothalamic nucleus
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What does stimulation of the anterior hypothalamic nucleus do?
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increases parasympathetic activity
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Which part of the anterior hypothalamic nucleus regulates sex functions?
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preoptic area
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What info does the anterior hypo nuc receive?
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Olfactory info, input from amygdala and septum.
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Which hypo nucleus prevents overheating?
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anterior hypo nuc
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What is Kallman's syndome:
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anosmia and lack of gonad developement
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How does Kallman's syndrome develope?
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Destruction of cells that release LHRH (anterior hypothalamic nucleus)
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Which nucleus produces oxytocin and vasopressin? Which is the major product?
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Oxytocin is mostly produced, by the paraventricular nucleus.
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Which nucleus produces oxytocin and vasopressin, mostly vasopressin?
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Supraoptic nucleus.
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Which nucleus makes you jet-lagged due to Circadian rhythms?
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suprachiasmatic nucleus
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What is the stalk of the pituitary gland called?
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Infundibulum
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What part of the hypothalamus is the infundibulum surrounded by?
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The tuber cinereum (aka: median eminence)
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What is siginificant about the infundibulum?
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It is the site where inhbiting and releasing factors are released into the portal system.
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What hormone inhibits prolactin release?
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Dopamine (NOT A PEPTIDE)
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What is the venous drainage of the infundibulum?
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PORTAL VEINS
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How can the portal veins surrounded the stalk of the pituitary be damaged during birth?
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Because its a portal system, there is a watershed area which can result in loss of hormonal control during hypovolemia becasue it bursts from high pressure.
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Stimulation of which part of the hypothalamus induces eating?
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Lateral hypothalamus. A lesion here would cause you to stop eating (starve).
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How does Leptin inhibit eating?
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Binds to OB receptors on Hypothalamus (lateral).
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What part of the hypothalamus causes you to stop eating?
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medial hypothalamus. Lesion would cause you to overeat.
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Stimulation of which part of the hypothalamus increases sympathetic activity?
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posterior
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Which part of the hypothalamus increases parasympathetic activity?
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anterior
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Stimulation of which part of they hypothalamus causes waking and heat conservation?
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posterior
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A lesion at the posterior hypothalamus would result in what symptoms?
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piokilothermia (los of heart regulation)
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The limibic system is part of which area of the hypothalamus?
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anterior hypo
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What structure tells us what is dangerous?
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Amygdala
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What part of the frontal lobe acts as an afferent pathway to the Hypo?
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Limbic system
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How does the Hypo send efferent information to the frontal lobe?
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To the limbic system outside of the hypothalamus.
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What is the output of the limbic system?
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The Hypothalamus.
limibc-->Hypo------>limbic------> |
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Which part of the brain is responsible for planning and decision making?
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Frontal lobes. Hypothalamus sends this info vai limbic
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How is a danger signal sent?
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A danger signal from the senses activates the reticular formation, which activates the hypothalamus, which activates the limbic (efferent).
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What parts of the temporal lobe are afferent pathways to the Hypothalamus?
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septal nuclei, amygdala, hippocampus.
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The temporal lobe is responsible for what actions?
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memory and emotion of fear and represion of violent behaviors. This is again, the limibic input to the hypo
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What part of the brainstem and spinal cord acts as the afferent pathway for the hypothalamus?
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medial forebrain bundle from the brainstem RETICULAR FORMATION.
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The nucleus solitarios is an example of what kind of pathway to the hypothalamus?
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Afferent (part of brainstem/s.c.)
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Afferent input from the cortex:
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mammilothalamic loop
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How does the retina input to the hypothalamus?
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Retina------>suprachiasmatic nucleus for circadian rhythms.
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What input tells you when to go to sleep, when to eat, etc. Body timings.
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Suprachiasmatic nucleus
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What monitors oxygen and carbon dioxide, as well as taste receptors?
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solitary tract
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Which projection comes from the brainstem to the hypothalamus to deal with pain and reticular function?
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the dorsal longitudinal fasciculus.
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What makes up the dorsal longitudinal fasciculus?
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periaqueductla gray, reticular formation dorsal columsn, and medial lemniscal system.
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How can the hypothalamus inhhibit pain signals?
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by the produciton of beta-endorphin. This stops pain signals at the periaqueductal gray , spinal cord, and substantia gelatinosa.
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Why don't afferent/efferent pathway fibers show up well with myelin stains?
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All the fibers are thinly myelinated.
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What mediates efferent info from the hypothalamus to autonomic preganglionics (sacral spinal cord)?
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dorsal longitudinal fasciculus
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Where is Beta-endorphin produced and where does it project to?
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produced in the dorsal longitudinal fasiculus and projects to the periaqueductal gray of the midbrain.
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What mediates projections to the brain stem reticular formation (mesencepaln, pons, medulla) from the hypothalamus?
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memmillotegmental tract
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What mediates projections from the lateral and preoptic hypothalamus to the habenula?
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stria medularis
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What part of the pituitary gland responds to hypothalamic releasing hormones?
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adenohypophysis
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WHat does the adenohypophysis do?
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produces and releases hormones into the blood system.
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What does the neurohypophysis store?
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ADH & oxytocin
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Where are ADh and oxytocin produced?
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suproptic and paraventricular nuclei of the hypothalamus
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Prohormones of ADH & Oxytocin are made in the soma and transported in the axon, what happens during their transportation?
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they are converted into the active hormone, accompanied by neurophsin I (oxytocin) or neurophysin II (vasopressin)
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The axons of ADH and oxytocin form what tract?
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superopticohypophyseal tract.
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Destruction of what, will cause diabetes insipids?
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destruction of superopticohypophyseal tract.
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When is the most common time during developement to get a tumor that results in D.I.?
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puberty
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What are the effects of a tumor on the axon of the superopticohypophyseal tract?
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inability to regulate the body's hormone levels and autonomic system. disruption of cognition and vision.
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What inhibits cells in the hypothalamus from releasing?
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short loop (pituitary) or ultra short loop (median eminence)
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The neurohypophysis receives axons from which hypothalamic nuclei?
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praventricular and supraoptic
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a prohormone traveling down the axon that is converted to oxytocin is accompanied by what else?
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neurophysi I
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What monitors blood volume or blood hormones?
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subfornial organs of the hypothalamus
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Where are the circumventricular organs located?
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around the pineal gland, median eminence, lamina terminalis, neurohypophysis, IV ventricle.
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Why are circumventricular organs an important site for infeciton or hemmorhage?
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because of the reduced blood brain barrier
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petechial hemmorhage in the brain is......
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ok
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petechial hemmorhage in the retina is...
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child abuse (strangulation)
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What disease causes lack of concentrated urine due to damage of the hypothalamus/pituitary?
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Diabets insipius
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What kind of tumor arises form glandular epithelial cells in the anterior pituitary and results in a bitemporal hemianopsia?
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pituitary adenoma
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What is the presentation of pituitary adenoma?
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prolactenoma, bitemporal heminaopsia (pressure on optic chiasm), weight gain, dcreased libido.
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How do you treat prolactenoma?
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dopamine
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What does the face of pituitary adenoma patients look like?
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round, "moon" face
fat middle, spindly extremities, buffalo hump, bruise easily |
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What disease is due to increased levels of growth hormone?
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acromegaly
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What is pituitary apoplexy?
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hemorrhage that destroys the pituitary gland associated with tumors. results in visual problems, headache, drowsy, confused, COMA
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