Chapter 26- Endocrine Glands Flashcards
What is prolactin and its main function?
PRL- non tropic
Stimulates and maintains milk production
Operates on a positive feedback loop
ANTERIOR PITUITARY
What is thyroid stimulating hormone?
TSH- tropic
Causes thyroid to create thyroid hormone
ANTERIOR PITUITARY
What is adrenocorticotropic hormone?
ACTH- tropic
Stimulates adrenal cortex to secrete hormones
ANTERIOR PITUITARY
What is released by the hypothalamus to control the pituitary gland?
Secrete releasing hormones
What is gonadotropic hormone?
Follicle stimulating hormone- FSH
Regulates activity of gonads
Stimulates follicle cells and evolvement to secrete estrogen and develop ovaries (female)
Stimulates sperm development (male)
Luteinizing hormone- LH
Triggers ovulation and releases eggs (female)
Stimulates testosterone production (male)
Can the posterior pituitary create the hormones it secretes?
No. Unlike the anterior pituitary, the posterior pituitary can only store hormones then release
What is growth hormones main function?
GH (non tropic)
General metabolic hormone
Causes amino acids to build into proteins
Causes fats to break down into energy
ANTERIOR PITUITARY
What controls the anterior pituitary?
The hypothalamus responds to sensory information by secrete releasing hormones
Will stimulate or inhibit hormone production in pituitary
Links nervous system and endocrine system through pituitary
What is antidiuretic hormone and what is its purpose?
ADH
Inhibits urine production, helps body retain water
Causes vasoconstriction of blood vessels, increasing blood pressure (large amounts)
If not working can cause diabetes insipidus
POSTERIOR PITUITARY
What is oxytocin and what is its purpose?
OT
causes milk ejection (positive feedback) triggered by feeding infant
Stimulates contraction of uterine muscles during birth (positive feedback) triggered by uterine stretching
POSTERIOR PITUITARY
What are the two hormones produces by the thyroid gland?
Thyroid hormone
Calcitonin
What is thyroid hormone and what is its purpose?
Divided into two types of iodine containing hormones
T4- inactive in blood- stored and secreted by thyroid gland
T3- active state- converted from t4 at target destination to produce metabolic effect
Regulates metabolic rate
Regulates body temp
Controls cell growth
THYROID GLAND
What happens if we have a lack of iodine?
Pituitary sends thyroid stimulating hormone (TSH) to thyroid, but thyroid does not have the iodine required to produce t4.
Pituitary keeps sending TSH, since no change occurs
Thyroid gets inflamed and no longer functions properly- goiter
What is calcitonin and what is its purpose?
Decreases blood calcium levels by increasing osteoblasts
THYROID GLAND
What is parathyroid hormone and what is its purpose?
PTH
Antagonist to calcitonin
Stimulates osteoclasts to remove calcium from bone
Stimulates kidneys and intestines to absorb more calcium
PARATHYROID GLAND
What are the two important parts of the adrenal glands and what tissues are they made up of?
Adrenal cortex- endocrine tissue. Stimulates by ACTH
Adrenal medulla- neural tissue. Stimulates by SNS
What are the three layers of the adrenal cortex?
Zona glomerulosa
Zona fasciculata
Zona reticularis
What hormones does the Zona Glomerulosa secrete and what is their purpose?
Mineralocorticoids-
Aldosterone- maintains sodium homeostasis by causing reabsorption of sodium.
Absorption of sodium> reabsorption of water> blood vol increases> blood pressure increases
Ultimately regulates mineral content and electrolytes in body and regulates blood pressure.
What is the fast acting loop that increases blood pressure? How does it work?
Renin-Angiotensin-Aldosterone System (RAAS)
Low BP signals kidney to release Renin (enzyme)
Renin activates Angiotensin, which then activates angiotensin II, which stimulates adrenal cortex
Adrenal cortex secretes aldosterone to increase water retention and increase BP
What is are the hormones secreted by the Zona Fasciculata and what are their purpose?
Glucocorticoids- most importantly cortisol
Stimulated in response to ACTH released by anterior pituitary
Regulates long term stress response, accelerates lipid catabolism
Secreted in response to stress as a way of increasing glucose availability for fight or flight
Constant flow of cortisol> increased glucose> obesity, diabetes etc
What hormones are secreted by the Zona reticularis and what is their purpose?
Gonadocorticoids-
sex hormones
Androgen- males
Estrogen- female
What hormones does the adrenal medulla secrete and what are their purpose?
Catecholamines-
Epinephrine(Epi)
Norepinephrine (NE)
Short term stress response- stimulated by sympathetic nervous system
- increase heart rate
- increase blood pressure
- increase glucose levels
- dilate lung passageways
Do both long term and short term stress responses both operate out of the pituitary?
No.
Short term stress is handled by epinephrine- released by nervous message sent by hypothalamus directly
Long term stress is detected by hypothalamus, sent to pituitary, then sent to adrenal gland which secretes aldosterone( increased blood volume and BP) or cortisol (increased glucose level)
-other effects of long term stress include
Increased heart rate, dilated pupils, blood redirected from skin and digestion to skeletal muscle, brain, and heart, and dilated trachea
What is the endocrine portion of the pancreas and what does it secrete?
Islets of langerhans
Insulin (from beta cells)- increase blood glucose
Glucagon (from alpha cells)- decrease blood glucose
Where is the thymus and what is its purpose?
Located I’m mediastinum (large in children- deteriorates with age)
Produces THYMOSIN- matures white blood cells and develops immune system
Where is the pineal gland and what does it secrete?
Found in brain- (near hypothalamus)
Produces MELATONIN
- establishes sleep cycle and biological clock
What is the purpose of testes and what hormone do they produce?
-produce male sex cells and sperm
Produces testosterone
- responsible for growth and maintenance of male sexual characteristics
- deep voice, hair growth, enlarged skeletal muscles, increased bone growth and density
- growth and maturation of reproductive system
What are the two hormones produces by the ovaries and what do they do?
Progesterone- (secreted by corpus luteum)
- promotes pregnancy(maintains uterine lining)
- acts with estrogen to start menstruation
- placenta produces progesterone
- prepares body for lactation
Estrogen (secreted by Ovarian follicular cells)
- promotes development and maintenance of female sex characteristics
- increased hair, fat at hips, breasts, and widening at the hips
- prepares uterus for egg
- maintains pregnancy
What is the hormone secreted in some parts of the small intestine and stomach?
Gastric- increases HCL which aids with digestion
What is the hormone in the kidney that increases red blood cell production?
Erythropoietin (EPO)
What is the hormone produced by the heart?
Atrial natriuretic hormone (ANH)
-promotes loss of sodium and water from body to decrease blood pressure
