53 Questions
How is thirst affected by decreases in extracellular fluid (ECF) volume?
Stimulates thirst through a pathway independent of increased plasma osmolality
What is the role of angiotensin II in the hypothalamic regulation of thirst?
Acts on the subfornical organ to stimulate thirst-related neural areas
What stimulates renin secretion and leads to an increase in angiotensin II levels?
Hypovolemia
Which specialized receptor area in the diencephalon is stimulated by angiotensin II to affect thirst?
Subfornical organ
What is one factor that contributes to an increase in liquid intake during eating?
Gastrointestinal hormone action on the hypothalamus
What happens when the sensation of thirst is obtunded?
Patients stop drinking adequate amounts of fluid
What contributes to most cases of hypernatremia?
Simple dehydration in patients with psychoses or hypothalamic disease
Why does high protein intake lead to large amounts of water required to maintain hydration?
Products of protein metabolism cause an osmotic diuresis
What is the main function of vasopressin mentioned in the text?
Promoting water retention by the kidney
Where are vasopressin-secreting neurons found, according to the text?
Hypothalamus
What are the types of vasopressin receptors mentioned in the text?
V1A, V1B, V2
What is the physiological consequence of vasopressin's action on the kidney according to the text?
Decreased urine volume and concentration
Which term is commonly used to refer to the chemical agents secreted by the hypothalamus into the portal hypophysial vessels?
Hypophysiotropic hormones
Which hormone is now generally known as gonadotropin-releasing hormone (GnRH)?
Luteinizing hormone–releasing hormone (LHRH)
What is the modern term used for Growth hormone–inhibiting hormone (GIH)?
Somatostatin
Which of the following polypeptides found in the hypothalamus stimulates prolactin secretion?
VIP
Where do most of the supraoptic fibers end in the hypothalamus?
Posterior lobe
From where do sympathetic nerve fibers reach the anterior lobe of the pituitary gland?
Capsule
What forms a direct vascular link between the hypothalamus and the anterior pituitary?
Portal hypophysial vessels
What is a characteristic of the circulatory system connecting the hypothalamus and anterior pituitary, as described in the text?
Bypasses the heart
What is the primary role of the hypothalamus in regulating the endocrine system?
Regulating emotional behavior
How does the posterior pituitary gland connect to the hypothalamus?
Through neural connections
In embryological terms, from where does the posterior pituitary gland originate?
Wall of the third ventricle
What is the composition of the posterior pituitary?
Mainly consists of axon endings from specific nuclei
What is the main effect of vasopressin on the kidney, as described in the text?
Increasing the permeability of the collecting ducts
Where else in the body, besides the hypothalamus, are vasopressin and oxytocin found according to the text?
Adrenal cortex
Which receptors are involved in the actions of vasopressin, as mentioned in the text?
V1A, V1B, V2
What is one of the roles of vasopressin-secreting neurons found in the suprachiasmatic nuclei?
Controlling cardiovascular functions
What is the physiologic role of hCRH-RII according to the text?
It is involved in receptor internalization in corticotropes
Which type of hormones do NOT have known binding proteins according to the text?
Vasopressin
In most mammals, which hormones are secreted by the posterior pituitary gland?
Vasopressin and oxytocin
What is the main physiological consequence of oxytocin's action according to the text?
Promoting lactation and uterine contractions
What is the physiologic role of CRH-binding protein in the peripheral circulation?
Inactivating CRH
In most mammals, what are the hormones secreted by the posterior pituitary gland?
Vasopressin and oxytocin
Where is hCRH-RII primarily found?
Many parts of the brain
What is the main physiological action of vasopressin?
Increasing urine concentration
Which part of the body does oxytocin primarily act on?
Breasts and uterus
The hypothalamus regulates emotional and instinctual behavior independently of the limbic system.
False
The posterior pituitary arises from the floor of the fourth ventricle.
False
Vasopressin and oxytocin primarily act on the adrenal glands.
False
The anterior pituitary is directly connected to the hypothalamus via neural connections.
False
Hemorrhage can lead to decreased drinking even if plasma osmolality remains unchanged.
False
Renin secretion is decreased by hypovolemia, resulting in a decrease in circulating angiotensin II.
False
The subfornical organ is not involved in the stimulation of neural areas related to thirst.
False
The organum vasculosum of the lamina terminalis (OVLT) is not affected by angiotensin II according to some evidences.
False
Thirst response to hypovolemia is completely blocked by drugs that block the action of angiotensin II.
False
High protein intake causes a decrease in the amounts of water required to maintain hydration.
False
Patients with psychoses or hypothalamic disease always increase their water intake when their thirst mechanism is stimulated.
False
An increase in plasma osmolality occurs as food is absorbed, contributing to a learned response of increased liquid intake during eating.
True
Hypophysiotropic hormones are commonly known as releasing and inhibiting factors.
False
Prolactin-releasing hormone (PRH) has been confirmed to exist according to the text.
False
VIP is one of the hypothalamic polypeptides that stimulate prolactin secretion.
True
Luteinizing hormone–releasing hormone (LHRH) is generally known as corticotropin-releasing hormone (CRH).
False
Explore the role of hypothalamic regulation in the secretion and function of vasopressin and oxytocin in the endocrine system. Learn about the locations and functions of vasopressin-secreting neurons and the significance of vasopressin and oxytocin in cardiovascular control.
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