Ch. 15/16: Thalamus & Hypothalamus (2/2)

Question 1

Function of Dorsal Thalamus

Answer 1

Largest of 4 subdivisions and neurons project to all areas of the cortex (sensory). Some nuclei receive info from subcortical and cortical motor areas and send to cortex.

Question 2

Hypothalamus

Answer 2

Connected to forebrain, brainstem, and spinal cord, controls autonomic function

Question 3

Ventral Thalamus

Answer 3

subthalamic nuclei; connected to basal ganglia and functions in motor circuitry

Question 4

Epithalamus

Answer 4

Limbic system- habenula and pineal gland

Question 5

Association Nuclei

Answer 5

Anterior Thalamic Nuclei, Dorsomedial nucleus, lateral dorsal, Pulvinar, Lateral posterior.

Generally medial/anterior, memory and decision making

Question 6

Relay Nuclei

Answer 6

VPL, VMP, Lateral geniculate, medial geniculate, ventral anterior, ventral lateral

Sensory and motor information

Question 7

What myelinated axons surround the thalamus laterally (fibers that enter/leave subcortical white matter, associated with thalami reticular nucleus)

Answer 7

External medullary lamina

Question 8

What divides the thalamus into cell groups?

Answer 8

Internal Medullary Lamina, divides dorsal medial nucleus and anterior from the rest of the thalamus

Question 9

Thalamus processes _______ info and relays it to _____

Answer 9

sensory-motor info

nucleus

Question 10

Pulvinar processes ____ info

Answer 10

visual

Question 11

Ventral part of thalamus: the medial and lateral geniculate bodies

Answer 11

Medial Geniculate Body (auditory info)

Lateral Geniculate (sensory, gets ganglion inputs)

Question 12

3 generalizations about dorsal thalamus

Answer 12

1. All nuclei project to cortex
2. Projections are ipsilateral
3. No known projections between nuclei, expect TRN

Question 13

White matter that communicates between thalamus and cortex

Answer 13

Internal Capsule

Question 14

Subthalamus (ventral thalamus)

Answer 14

motor functions

Subthalamic nuclei: inputs from motor cortex and projects to substantia nigra and globus pallidus.

Subthalamus is below the dorsal thalamus. Has to do with motor functions. Connects with globus palladus

Question 15

Epithalamus

Answer 15

Pineal gland, habenular nuclei, stria medullaris thalami (which is fiber tract)

Question 16

Pineal Gland

Answer 16

receives info about visual stimuli (rhythmically produces melatonin (circadian over 24 hour period)

Question 17

Habenula

Answer 17

medial and lateral nuclei - part of limibic system. Role in processing rewards and addiction

Question 18

Hypothalamus: Functions

Answer 18

Homeostasis, Metabolism, Temperature, food intake, glucose, blood flow (blood volume, pressure, salinity, O2, glucose), reproductive activity, menstruation, stress, child birth, autonomic reflexes of brainstem and spinal cord, functions of various nuclei, periventricular zone has more specific nuclei, neuroendocrine function, Leptin in feeding around the arcuate/lateral hypothalamus.

Question 19

Olfactory info to hypothalamus —>

Answer 19

amygdala in median forebrain bundle involved in reproduction defense, feeding

Question 20

visual inputs

Answer 20

suprachiasmatic nucleus, circadian rhythems

Question 21

Visceral Sensations: Sensory info arises from nucleus of the ___ ___. Sensory info from cranial nerves ___ & ___.

Answer 21

solitary tract

cranial nerves 9 & 10

Question 22

Hypothalamus has 3 broad zones:

Answer 22

Periventricular zone: neurosecretory, Automatic nervous system (ANS)

Lateral/medial zones: motivation, sex, stress

Question 23

Hypothalamus EFFERENTS (output)

Answer 23

Endocrine system: neuroendocrine cells via pituitary
ANS: preautonomic cells via brain/spinal cord. Projections via medial forebrain bundle and dorsal longitudinal fasciculus.

Question 24

Hypothalamic AFFERENTS (inputs)

Answer 24

Ascending sensory signals from brainstem/spinal cord

Descending afferents from cortex/limbic system

Hippocampus via fornix and amygdala via stria terminalis

Question 25

Supraoptic nucleus and paraventricular nucleus

Answer 25

Hypothalamus water/electrolyte balance, vasopressin lactation, and partuition, oxytocin

Question 26

Paraventricular

Answer 26

Hypothalamus Stress

Question 27

Arcuate and paraventricular nuclei

Answer 27

Hypothalamus hypothalamic releasing factors, arcuate-leptin-regulator of body fat and food intake

Question 28

Ventromedial and dorsomedial

Answer 28

Hypothalamus Growth hormone, hunger

Question 29

Suprachiasmatic

Answer 29

Circadian clock

Question 30

Anterior and preoptic areas

Answer 30

Regulation of sexual behavior, sleep regulation, temperature regulation

Question 31

Anterior and posterior nuclei

Answer 31

Temperature regulation

Question 32

Dorsal and posterior nuclei

Answer 32

Activation of sympathetic nervous system/adrenal medulla

Question 33

Lateral hypothalamus

Answer 33

Thirst

Question 34

Hypothalamus connections, in anterior/posterior pituitary where they release ______ into circulation that control various homeostatic functions.

Answer 34

Hormones

Question 35

Hypothalamus connects to limbic system via ____

Answer 35

Fornix

Question 36

Hypothalamus connects to what two areas of the brainstem and what do they do?

Answer 36

Reticular formation and medullary centers Cardiovascular, respitory, and gastrointestinal processes

Question 37

Vasopressin

Answer 37

Water/electrolyte balance

Question 38

Oxytocin

Answer 38

lactation, physical contact (positive), possible treatment for autism

Question 39

Circumventricular Organ Functions

Answer 39

Vasopressin release Response to hypovolemia (decrease blood volume, hemorrhage) Kidney secretion of Renin Activation of vasopressin neurons (SON & PVN, asynchronous burst generation) Water retention in kidney

Question 40

Circumventricular Organ: specific process. Adaptive behaviors for water conservation (excrete NaCl)

Answer 40

Blood pressure down, Kidney secretes renin Renin breaks down angiotensinogen produced by liver into angiotensin 2. Also activates cells in lateral hypothalamus, produces thirst and motivates drinking behavior (AV3V, OVLT)

Question 41

Angiotensin 2 effects

Answer 41

Kidney/blood vessel--> increase blood pressure Subfornical Organ --> Activates vasopressin neurons Lateral Hypothalamus --> Produces thirst and motivates drinking behavior (AV3V, OVLT) Once water intake increases, vasopressin levels decrease and dilute urine is excreted.

Question 42

Posterior pituitary: Neuropophysis

Answer 42

``` Hypothalamus outcropping (part of the brain) Hormone secretion into general blood stream ``` Cells in superoptic/paraventricular nuclei project down and release O/V into general circulation (Magnacellular cells)

Question 43

Anterior Lobe: Adenohypophysis

Answer 43

Controlled by releasing hormone cells in hypothalamic terminals in median eminence, portable blood vessels, pituitary hormone release into general circulation.

Question 44

Follicle stimulating Hormone

Answer 44

ovulation and spermatogenesis

Question 45

Luteinizing hormone

Answer 45

sperm and ovarian maturation

Question 46

Thyroid stimulating hormone

Answer 46

Thyroxin secretion (metabolism)

Question 47

ACTH

Answer 47

cortisol secretion

Question 48

Growth hormone

Answer 48

protein synthesis

Question 49

Prolactin

Answer 49

growth and milk secretion

Question 50

Regulation of adrenal glands under stress

Answer 50

Parvocellular neurons release corticotropin, releasing hormone into the portal circulation, travels to anterior pituitary to release ACTH travels to the adrenal cortex to release cortisol.