A&P 2: Chapter 16 Endocrine system Review
The pathway to release of neurohormones follows a series of steps. The correct pathway for the neurohormone ADH from synthesis to release
1. Synthesis 2. ADH synthesis supraoptic neurons 3. Transport in tract in infundibulum 4. Storage in axon termini in posterior pituitary 5. Action potentials arrive at the axon terminals 6. Release into blood
In which of the following mechanisms of hormone action do intracellular calcium ions act as a final mediator?
PIP2-calcium signaling mechanism
site into which releasing hormones or inhibiting hormones are secreted
Primary capillary plexus
site that receives the blood and hormones from the primary plexus and into which hormones like GH, TSH, and ACTH are secreted
Secondary capillary plexus
Axon termini of posterior pituitary
Stores neurohormones ADH and oxytocin and site of release of neurohormones into the blood capillary supplied by the inferior hypophyseal artery.
supplies the primary plexus
Superior hypophyseal artery
Which of the following homeostatic imbalances results from hyposecretion of growth hormone?
pituitary dwarfism
Oxytocin ________.
release is an example of a positive feedback control mechanism ; Oxytocin is produced by the hypothalamus.
Humoral Stimuli
secrete their hormones in direct response to changing blood levels of certain critical ions and nutrients. Example: stimulus: Low Ca in capillary blood response: parathyroid glands secrete PTH which then increases Ca
Tract in infundibulum:
transports neurohormones to termini in posterior pituitary/hypophysis.
Trace a releasing hormone from its synthesis through its pathway to stimulation of anterior pituitary hormones. Begin with the site of releasing hormone or inhibiting hormone synthesis
1. Synthesis 2. Hypothalamic neurons secrete hormones, RHs or IHs 3.Hypothalamic hormones move into primary capillary plexus 4. Hypothalamic hormones flow in blood through portal veins 5. Stimulation or inhibition of hormone secretion by anterior pituitary 6. Hormones secreted into the secondary plexus 7. Release into blood
Cushing's syndrome and aldosteronism have the same effects on ______
Blood pressure; Cushing's syndrome results from excessive exposure to the hormone cortisol. Cortisol increases blood pressure by increasing the sensitivity of the blood vessels to epinephrine and norepinephrine. Aldosteronism occurs due to oversecretion of aldosterone. One function of aldosterone is to indirectly stimulate the reabsorbtion of water from the kidney tubule cells into the systemic circulation. This process increases blood volume and thus blood pressure.
Steroid hormones are synthesized from __________.
Cholesterol
Aldosteronism will cause ______.
Decreased secretion of renin; Aldosteronism is due to oversecretion of aldosterone. The kidneys release renin, which is converted into angiotensin II which stimulates aldosterone release.
When it becomes necessary to enlist the fight-or-flight response, a hormone that is released during the alarm phase of the general adaptation syndrome is ________.
Epinephrine
True or False: Down-regulation involves the loss of receptors and prevents the target cells from overreacting to persistently high hormone levels.
True
True or false: Oxytocin is a strong stimulant of uterine contractions.
True
Neural Stimuli
Hormone release caused by neural input Example: stimulus: action potentials in preganglionic sympathetic fibers to adrenal medulla response: adrenal medulla cells secrete epinephrine & norepinephrine
Which of the following is a hormone produced by the posterior pituitary?
Hormones known as posterior pituitary hormones are synthesized by the hypothalamus, and include oxytocin and antidiuretic hormone. ADH
blood vessels of hypophyseal portal system that join two capillary beds
Hypophyseal portal veins
location of synthesis of releasing hormones (RH), like GHRH, TRH, CRH, GnRH; or inhibiting hormones (IH), like GHIH, PIH
Hypothalamus neurons
Antagonism
When one hormone opposes the action of another hormone, the interaction is called __________.
Which of the following triggers the release of glucagon?
a decrease in blood glucose levels
What hormone is released by the anterior pituitary to target the adrenal cortex when we are under stress?
adrenocorticotropic hormone (ACTH)
Which of the following hormones stimulates gamete (sperm or egg) production?
follicle-stimulating hormone
Similar for DM1 & DM2
glucose levels remain higher than normal.
Homeostasis Pathway that occurs when blood glucose levels fall
1. Low blood glucose 2. Cells in the pancreas 3. Glucagon 4. Liver Cells: Target cells 5. Response: Glycogen breakdown; glucose released into blood
What happens when Blood glucose becomes high
1. Pancreas releases insulin 2. Insulin binds to receptors on target cells 3. Cells take in glucose 4. Blood glucose returns to normal
Which of the following adrenal gland homeostatic imbalances is characterized by persistent elevated blood glucose levels, dramatic losses in muscle and bone protein, and water and salt retention, leading to hypertension and edema?
Cushing's disease; Cushing's syndrome is characterized by persistent elevated blood glucose levels, dramatic losses in muscle and bone protein, and water and salt retention, leading to hypertension and edema.
True or False : The anterior pituitary is known as the "master endocrine gland" because it controls the hypothalamus.
False; The anterior pituitary is known as the "master endocrine gland" because it controls the hypothalamus.
What is the specific order of zones in adrenal gland
From top to bottom: Zona glomerulosa, Zona fasciculata, Zona reticularis The Outer side from top to bottom Cortex & Medulla; medulla looks like a brain
Body cells that respond to insulin include
Liver cells, as well as most other cells of the body.
What cells in the body respond to glucagon by breaking down glycogen and releasing glucose?
Liver cells.
Paraventricular nuclei of hypothalamus:
Nuclei located in a more inferior location that synthesizes mainly the neurohormone ADH
Supraoptic nuclei of hypothalamus
Nuclei located in a more inferior location that synthesizes mainly the neurohormone ADH
A liver cell responds to insulin by
Taking in glucose and converting it to glycogen
Which of the following occurs within a negative feedback system?
Target organ effects inhibit further hormone release.
When blood glucose levels are low
The pancreas releases glucagon, which eventually causes blood glucose levels to increase.
When blood glucose levels are high
The pancreas releases insulin.
The body's tendency to maintain relatively constant internal conditions is called
homeostasis.
Hormonal stimulus
hormone release caused by another hormone (a tropic hormone) Example: stimulus: hormones from hypothalamus response: anterior pituitary gland secretes hormones that stimulate other endocrine glands to secrete hormones
What type of stimulation controls parathyroid release?
humoral
Which of the following conditions, if left untreated, progresses to respiratory paralysis and death?
hypoparathyroidism
Which hormone is involved in diabetes mellitus (DM)?
insulin; not enough insulin produced
Any given hormone will influence the activity of __________.
its target cells
Which of the following would result from hypoparathyroidism?
neurons become more excitable and tingling sensations
Type 1 DM
no insulin is produced.
Which of the following is NOT one of the three major types of stimuli to trigger endocrine glands to manufacture and release their hormones?
permissive stimuli
Type 2 DM
target cells do not respond normally to insulin.