hypothalamus Flashcards
(86 cards)
1
Q
controls the autonomic nervous system and the endocrine system and thus indirectly controls body homeostasis
A
hypothalamus
2
Q
lies below the thalamus and forms the floor and the inferior part of the lateral walls of the third ventricle
A
hypothalamus
3
Q
Caudally, the hypothalamus merges into the ___ of the midbrain
A
tegmentum
4
Q
The lateral boundary of the hypothalamus is formed by the ___
A
internal capsule
5
Q
hypothalamus is seen to be related to the following structures, from anterior to posterior:
One tree makes dew VIP
A
- the optic chiasma
- tuber cinereum and the infundibulum
- mammillary bodies
- dorsomedial nucleus
- ventromedial nucleus
- infundibular (arcuate) nucleus
- posterior nucleus
6
Q
In the lateral zone, the following hypothalamic nuclei can be recognized, from anterior to posterior:
A
- preoptic nucleus
- suprachiasmatic nucleus
- supraoptic nucleus
- lateral nucleus
- tuberomammillary nucleus
- lateral tuberal nuclei
7
Q
General somatic sensation and gustatory and visceral sensations reach the hypothalamus through collateral branches of the lemniscal afferent fibers and the tractus solitarius and through the reticular formation
A
Somatic and visceral afferents
8
Q
leave the optic chiasma and pass to the suprachiasmatic nucleus
A
Visual afferents
9
Q
travels through the medial forebrain bundle
A
Olfaction
10
Q
have not been identified, but since auditory stimuli can influence the activities of the hypothalamus, they must exist.
A
Auditory afferents
11
Q
arise from the frontal lobe of the cerebral cortex and pass directly to the hypothalamus
A
Corticohypothalamic fibers
12
Q
pass from the hippocampus through the fornix to the mammillary body. Many neurophysiologists regard the hypothalamus as the main output pathway of the limbic system
A
Hippocampohypothalamic fibers
13
Q
pass from the amygdaloid complex to the hypothalamus through the stria terminalis and by a route that passes inferior to the lentiform nucleus
A
Amygdalohypothalamic fibers
14
Q
arise from the dorsomedial and midline thalamic nuclei.
A
Thalamohypothalamic fibers
15
Q
arise from the midbrain
A
Tegmental fibers
16
Q
- influence the peripheral neurons of the autonomic nervous system
- The hypothalamus is connected to the parasympathetic nuclei of the oculomotor, facial, glossopharyngeal, and vagus nerves in the brainstem.
A
Descending fibers to the brainstem and spinal cord
17
Q
- arises in the mammillary body and terminates in the anterior nucleus of the thalamus
- pathway is relayed to the cingulate gyrus
A
mammillothalamic tract
18
Q
arises from the mammillary body and terminates in the cells of the reticular formation in the tegmentum of the midbrain
A
mammillotegmental tract
19
Q
Multiple pathways to the ___
A
limbic system
20
Q
The hypothalamus is connected to the hypophysis cerebri (pituitary gland) by two pathways:
A
- nerve fibers that travel from the supraoptic and paraventricular nuclei to the posterior lobe of the hypophysis and
- long and short portal blood vessels that connect sinusoids in the median eminence and infundibulum with capillary plexuses in the anterior lobe of the hypophysis
21
Q
- synthesized in the nerve cells of the supraoptic and para- ventricular nuclei
- passed along the axons together with carrier proteins called neurophysins and are released at the axon terminals
A
vasopressin and oxytocin
22
Q
- antidiuretic hormone
- produced mainly in the nerve cells of the supraoptic nucleus
- cause vasoconstriction
- has an important antidiuretic function, causing an increased absorption of water in the distal convoluted tubules and collecting tubules of the kidney
A
vasopressin
23
Q
- produced mainly in the paraventricular nucleus
- stimulates the contraction of the smooth muscle of the uterus and causes contraction of the myoepithelial cells that surround the alveoli and ducts of the breast
A
oxytocin
24
Q
- stimulates labor contractions of the uterus
- when the baby suckles at the breast, a nervous reflex from the nipple stimulates the hypothalamus to produce more of the hormone.
A
oxytocin
25
The releasing hormones stimulate the production and release of
adrenocorticotropic hormone (ACTH)
- follicle-stimulating hormone (FSH)
- luteinizing hormone (LH)
- thyrotropic hormone or thyroid-stimulating hormone (TSH)
- and growth hormone (GH)
26
the release of inhibiting hormones inhibits the release of the
melanocyte-stimulating hormone (MSH) and luteotropic hormone (LTH)
27
The hypothalamus has a controlling influence on the ___ and appears to integrate the autonomic and neuroendocrine systems, thus preserving body homeostasis
autonomic nervous system
28
- Electrical stimulation of the anterior hypothalamic area and the preoptic area influence ___
- lowering of the blood pressure, slowing of the heart rate, contraction of the bladder, increased motility of the gastrointestinal tract, increased acidity of the gastric juice, salivation, and pupillary constriction
parasympathetic responses
29
- Stimulation of the posterior and lateral nuclei causes ___
- elevation of blood pressure, acceleration of the heart rate, cessation of peristalsis in the gastrointestinal tract, pupillary dilation, and hyperglycemia
sympathetic responses
30
- The nerve cells of the hypothalamic nuclei, by producing the releasing factors or release-inhibiting factors
- control the hormone production of the anterior lobe of the hypophysis
endorcrine control
31
- of the hypothalamus controls those mechanisms that dissipate heat loss
- dilatation of skin blood vessels and sweating, which lower the body temperature.
anterior portion
32
Stimulation of the ___ of the hypothalamus results in vasoconstriction of the skin blood vessels and inhibition of sweating; there also may be shivering, in which the skeletal muscles produce heat
posterior portion
33
- Stimulation of the ___ of the hypothalamus initiates the feeling of hunger and results in an increase in food intake
- hunger center
- Bilateral destruction of this center results in anorexia, with the consequent loss in body weight
lateral region
34
- satiety center
- Stimulation of the ___ of the hypothalamus inhibits eating and reduces food intake
- Bilateral destruction of the satiety center produces an uncontrolled voracious appetite, causing extreme obesity
medial region
35
- stimulation of other areas in the ___ of the hypothalamus causes an immediate increase in the desire to drink water
- thirst center
lateral region
36
function of the hypothalamus, the limbic system, and the prefrontal cortex
emotion & behavior
37
Stimulation of the ___ may cause the symptoms and signs of rage, whereas lesions of these areas may lead to passivity
lateral hypothalamic nuclei
38
Stimulation of the ___ may cause passivity, whereas lesions of this nucleus may lead to rage
ventromedial nucleus
39
The hypothalamus controls many ___, including body temperature, adrenocortical activity, eosinophil count, and renal secretion.
circadian rhythms
40
Lesions of the ___ of the hypothalamus seriously interfere with the rhythm of sleeping and waking
anterior part
41
receives afferent fibers from the retina, appears to play an important role in controlling the biologic rhythms.
suprachiasmatic nucleus
42
- Viscera and somatic structures
- Hypothalamic nuclei
Medial and spinal lemnisci, tractus solitarius, reticular formation
43
- Retina
- Suprachiasmatic nucleus
Visual fibers
44
- Olfactory mucous membrane
- Hypothalamic nuclei
Medial forebrain bundle
45
- Inner ear
- Hypothalamic nuclei
Auditory fibers
46
- Frontal lobe of cerebral cortex
- Hypothalamic nuclei
Corticohypothalamic fibers
47
- Hippocampus
- Nuclei of mammillary body
Hippocampohypothalamic fibers; possibly main output pathway of limbic system
48
- Amygdaloid complex
- Hypothalamic nuclei
Amygdalohypothalamic fibers
49
- Dorsomedial and midline nuclei of thalamus
- Hypothalamic nuclei
Thalamohypothalamic fibers
50
- Tegmentum of midbrain
- Hypothalamic nuclei
Tegmental fibers
51
- Preoptic, anterior, posterior, and lateral nuclei of hypothalamus
- Craniosacral parasympathetic and thoracolumbar sympathetic outflows
Descending fibers in reticular formation to brainstem and spinal cord
52
- Nuclei of mammillary body
- Anterior nucleus of thalamus; relayed to cingulate gyrus
Mammillothalamic tract
53
- Nuclei of mammillary body
- Reticular formation in tegmentum of midbrain
Mammillotegmental tract
54
- Hypothalamic nuclei
- Limbic system
Multiple pathways
55
The nuclei of the hypothalamus are divided by
an imaginary plane formed by the columns of the fornix and the mammillothalamic tract into ___ and ___ groups
medial; lateral
56
The ___ is absent in the median eminence of the hypothalamus, thus permitting the neurons to sample the chemical content of the plasma directly.
blood—brain barrier
57
The hypothalamus receives many afferent fibers from the viscera via the ___
reticular formation
58
The nerve cells of the hypothalamus produce releasing and release-inhibiting hormones that control the production of various hormones in the anterior lobe of the ___
hypophysis
59
The hypothalamus brings about the physical changes associated with ___, such as increased heart rate and flushing or pallor of the skin
emotion
60
The nerve cells of the supraoptic and paraventricular nuclei produce the hormones ___ and ___
vasopressin; oxytocin
61
It carries releasing hormones and release-inhibiting hormones to the secretory cells of the anterior lobe of the hypophysis
hypophyseal portal system
62
lies in the center of the limbic system
hypothalamus
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located between the lamina terminalis and the optic chiasma
preoptic area
64
plays an important role in controlling circadian rhythms
suprachiasmatic nucleus
65
controls the lower autonomic centers by means of pathways through the reticular formation
hypothalamus
66
stimulates the contraction of the smooth muscle of the uterus
Oxytocin
67
The hormones travel in the axons of the hypothalamohypophyseal tract with protein carriers called ___
neurophysins
68
___ stimulates the distal convoluted tubules and collecting tubules of the kidney, causing increased absorption of water from the urine
Vasopressin
69
circular series of pathways linking the cingulate gyrus to the hippocampal formation to the mammillary bodies to the anterior thalamic nucleus, with a return flow back to the cingulate gyrus
Papez circuit
70
stimulates growth of the body and, particularly, the long bones
Growth hormone (GH)
71
GH release is controlled by ___
growth hormone–releasing hormone
72
- GH can also be inhibited by ___
- widely distributed throughout the central nervous system (CNS) but is present in dense quantities in the preoptic region and anterior hypothalamus
growth hormone– inhibiting hormone (somatostatin)
73
- controlled by thyrotropin-releasing hormone (TRH)
- located principally in the periventricular region and adjoining areas of the hypothalamus
- released from axon terminals located in the median eminence into the portal system
Thyroid-stimulating hormone (TSH)
74
controls the release of steroid hormones, such as cortisol, in the adrenal cortex
Adrenocorticotropic hormone (ACTH)
75
- ACTH is controlled by
- synthesized in the paraventricular, supraoptic, and arcuate nuclei, as well as outside the hypothalamus, enters the portal system from axon terminals in the median eminence
- stimulates the release of beta-endorphin from the anterior pituitary
corticotropin-releasing hormone (CRH)
76
include follicle-stimulating hormone and luteinizing hormone (LH)
Gonadotropic Hormones
77
facilitates growth of follicles and oocytes
follicle-stimulating hormone
78
critical for induction of ovulation and formulation of the corpus luteum
luteinizing hormone (LH)
79
Follicle-stimulating hormone & LH hormones are controlled by ___
gonadotropin-releasing hormone (GnRH)
80
- synthesized in the arcuate nucleus of the hypothalamus and acts as a neuromodulator of GnRH-containing neurons
- stimulates feeding behavior
neuropeptide Y
81
- released from the anterior pituitary by prolactin-releasing factor and causes growth of the mammary glands in women prior to and following birth
Prolactin
82
Synthesized in the paraventricular nucleus and released
in the posterior pituitary
Oxytocin
83
An experiment was conducted in cats to determine the effects of stimulation of the medial amygdala on the activity of medial hypothalamic neurons. After determining that stimulation of the medial amygdala powerfully excited medial amygdaloid neurons, the investigator sought to further test the relationship between these regions by destroying the major pathway that links these two regions and then test- ing to see whether stimulation of the medial amygdala no longer affected medial hypothalamic neuronal activity. The most likely pathway that was destroyed by the investigator was the
Stria terminalis
84
Lesions of the medial hypothalamus will result in
Hyperphagia
85
A lesion of the lateral hypothalamus is discovered after an examination in which a magnetic resonance imaging scan was done. Which of the following disorders would likely be present, and which pathway would most likely be damaged?
Aphagia—medial forebrain bundle
86
Surgical lesions designed to reduce blood pressure and manifestations of violent and related emotional responses in schizophrenic patients have been made in the
Posterior medial hypothalamus
