Human Anatomy and Physiology Laboratory Manual, Cat Version: Endocrine System notes Flashcards
What does the endocrine system do
It coordinates all of the body systems by the use of hormones produced by endocrine cells
What is a hormone
A mediator molecule that is released in one part of the body and regulates its local or a distant environment
How do hormones move
Most enter interstitial fluid and then the blood stream.
What are the organs in the endocrine system?
Pituitary, thyroid, parathyroid, adrenal, and pineal glands.
What five cells secrete seven hormones?
Somatotroph's, Thryotroph's, Gonadotroph, Lactotroph, and Corticotroph
What are autocrine hormones
Local hormones that are secreted and bind to the same cell
What are paracrine hormones
Local hormones that are secreted into interstitial fluid and act on nearby cells
What are the two chemical classes of hormones
Lipid soluble - bind to receptors in cytoplasm or nucleus of cell. Consist of steroid hormones, thyroid hormones, and nitric oxide
Water soluble - bind to receptors on surface of cell. Include amine hormones, peptide and protein hormones, and eicosanoid hormones
What are the 7 hormones that the AP releases
hGH, TSH, PRL, FSH, LH, ACTH, MSH
Does the Posterior pituitary synthesize hormones? Explain
No, but neurosecretory cells release oxytocin and ADH from their axon terminals
What does oxytocin do
It targets smooth muscle in the uterus and breasts. Stimulates uterine contractions, and milk let down
What does ADH do
Targets the kidneys and sweat glands to minimize water loss. Also causes arterioles to constrict, increasing blood pressure
What are the physiological processes of the endocrine hormones
Balance body fluids, regulate metabolism and energy, direct rate of growth and development, exert control during stress, and oversee reproductive mechanisms
How is the AP connected to the hypothalamus
By blood vessels that form a portal system called the hypophyseal portal system
What do somatotroph cells release
hGH (human growth hormone) stimulates secretion of growth factors that promote growth
What do thyrophroph cells release
TSH (thyroid stimulating hormone) stimulates synthesis and secretion of thyroid hormones
What do lactrotroph cells release
PRL (prolactin) stimulates breast growth and development of mammary glands
What do gonadotroph cells release
FSH (follicle stimulating hormone) stimulates secretion of estrogen and maturation of sex cells and production of testosterone.
Also releases LH (leutinizing hormone) which stimulates secretion of estrogen and progesterone and trigger ovulation
What do corticotroph cells release
ACTH (adrenocroticotropic hormone) which stimulates release of corticosteroids which plays a role in stress response and circadium rhythm.
MSH (Melanocyte stimulating hormone) which stimulates production of melanin. Also signals to the brain have effects on appetite and sexual arousal
What is most of the thyroid gland composed of
What is TGB (thyroglobulin)
Stored in thyroid follicles. Releases T3 and T4 hormones
What do T3 and T4 do
Increase metabolism, body temp, blood pressure, and reduce cholesterol.
What is calcitonin (CT)
This is produced by parafollicular cells of thyroid gland and decreases calcium in blood
What does the parathyroid gland do
Regulates calcium, magnesium, and phosphate ions in the blood
What does the adrenal cortex do
Secretes steroid hormones. Has three zones: Zona glomerulosa, zona fasciculata, and zone retiularis
What does the adrenal medulla do
Secretes chromaffin cells. Epinephrine (80%) and norepinephrine (20%)
What is the renin-angiotensin-aldosterone system
Important endocrine component of autoregulation. Renin is released when blood volume falls. It is converted into agniotensin II which raises BP by vasoconstriction and secretes aldosterone which increases BV/BP
What are glucocorticoids
They regulate metabolism by promoting breakdown of proteins and fats to form glucose.
What type of gland is the pancreas
An endocrine and exocrine.
What is acini
Clusters of exocrine cells of the pancreas. Distributed among acini are clusters of endocrine tissue called pancreatic islets
What do the alpha cells of the pancreatic islet secrete
What do the beta cells of the pancreatic islet secrete
What do the delta cells of the pancreatic islet secrete
What do the F cells of the pancreatic islet secrete
What do the ovaries produce
Estrogen, progesterone, relaxin, and inhibin
What do the testes produce
What does the pineal gland produce
What is general adaptation syndrome
The bodily changes happening in an extremely stressful situation
What are the three stages of GAS?
Alarm reaction, resistance reaction, and exhaustion
The flight or fight response
Lasts longer than alarm reaction, sustains you after running, jumping, etc.
Body's reserves become so depleted that they cannot sustain resistance, and you want sleep/rest
- Decrease thyroid hormones
- Decrease growth hormones
- Increase PTH, which takes calcium from bone and puts in into blood
- No change in epinephrine/norepinephrine
- Decrease sex hormones