Diencephalon and Hypothalamus

Question 1

Composition of epithalamus

Answer 1

pineal body, habenular nuclei, and caudal commissure

Question 2

Function of epithalamus

Answer 2

linked to the limbic system, regulates reproductive functions and secretes melatonin, which is concerned with biological timing including sleep induction

Question 3

Function of subthalamus

Answer 3

movement-focusing function selecting wanted and suppressing unwanted movements.
involved in generation of rhythmic movements

Question 4

Composition of thalamus

Answer 4

lateral geniculate nucleus (vision)

medial geniculate nucleus (hearing)

Question 5

Function of thalamus

Answer 5

receives sensory input from all sensory pathways except olfaction and relays that information to cerebral cortex

Question 6

Function of hypothalamus

Answer 6

regulate homeostasis
controls hormone release by the pituitary gland
integrates autonomic function
generates behaviors involved in rage, aggression, escape (via interconnections w/ limbic system)

Question 7

Function of supraoptic nucleus

Answer 7

produces antidiuretic hormone

Question 8

Functions of paraventricular nucleus

Answer 8

produce oxytocin

Question 9

Functions of suprachiasmatic nucleus

Answer 9

circadian rhythm role

Question 10

Function of mamillary region

Answer 10

plays a role in memory

Question 11

Afferent inputs to the hypothalamus

Answer 11

nucleus of solitary tract
limbic system
retina
blood

Question 12

Efferent projections from the hypothalamus

Answer 12

neural signals to autonomic nervous system
neural signal to limbic system
endocrine signals to pituitary gland

Question 13

How does the hypothalamus control the endocrine system? (2 routes)

Answer 13

1. directly by secretion of neuroendocrine products into the general circulation
2. indirectly by secretion of releasing factors into the local hypophyseal portal venous plexus

Question 14

Direct effects of endocrine system (2 things)

Answer 14

secretion of oxytocin and vasopressin into the circulation

Question 15

Function of oxytocin

Answer 15

• acts on uterine smooth muscle to stimulate myometrial contractions and accelerates parturition
• activates milk letdown reflex in response to suckling

Question 16

Function of vasopressin

Answer 16

increase reabsorption of water in the kidney

Question 17

Diabetes insipidus

Answer 17

disorder of water balance in which there is loss of control of water excretion due to a failure of production, transport, or release of ADH into the blood stream from the neurohypophysis

Question 18

Hyperadrenocorticoidism (Cushing’s disease)

Answer 18

Excess adrenocorticotropic hormone

Symptoms: extremely hungry, poor hair coat, obesity, muscle weakness, and lethargy

Question 19

Control of autonomic nervous system (2 things)

Answer 19

stimulate rostral hypothalamus = parasympathetic responses

stimulate caudal hypothalamus = sympathetic responses

Question 20

Temperature regulation (2 things)

Answer 20

rostral hypothalamus = heat loss center; panting, vasodilation, sweating
caudal hypothalamus = heat conservation center; shivering and vasoconstriction