Lecture 20: Endocrine System - Pituitary and Adrenal Glands Flashcards
define “ex”
out
define “krinein”
to secrete
define “endo”
within
functions of exocrine glands
secrete secretions into ducts which carry the secretions out of glands into lumens of certain places of the body
functions of endocrine glands
secrete sectretions right into spaces around cells; the products are picked up and carried by bloodstream
purely endocrine system organs
pituitary, thyroid, parathyroid, adrenal, and pineal glands
define “hormon”
urge on
what are hormones?
chemical messengers that act on organs and normally regulate growth, reproduction, and metabolism
How long do hormones take to work?
Varies; some take seconds, minutes, or hours
how does the nervous system act?
By generating nerve impulses to activate or inhibit effector organs. Sometimes stimulates release of hormones.
How long do nerve impulses last?
effect in milliseconds, result short-lived
what do nerve impulses normally cause?
muscle contraction and secretion of fluids from certain glands
what glands are located in the brain
the hypothalamus, pituitary gland, and pineal gland
what glands are in the neck?
thyroid gland with four parathyroid glands behind it
what gland is in the chest?
thymus
what glands lie on top of the kidneys?
adrenal (suprarenal) glands
what lets cells pick what hormones they need
receptors (glycoproteins)
what happens when there is an excess of hormones?
number of receptors decrease
define “para”
near
define “auto”
self
where do paracrine hormones act?
cells right next to it without crossing the bloodstream
where do autocrine cells act?
on the cell that secreted them. Cancer cells love these.
where does the pituitary gland lie
sella turcica (“Turkish saddle”) at base of the brain, behind the optic chiasm
what controls the pituitary gland?
hypothalamus
what functions do the hypothalamus and pituitary gland manage?
stress, rage, flight-fight, body temperature, thirst, hunger, sexual activity, and in general, survival
2 parts of pituitary gland
anterior (75%), posterior (25%)
hormones from the anterior pituitary
- thyroid-stimulating hormone (TSH)
- follicle-stimulating (FSH) and luteinizing hormone (LH)
- Prolactin (PL)
- Adrenocorticotropic (ACTH)
- Melanocyte-stimulating (MSH)
- Human growth hormone (hGH or somatotropin)
what does TSH do?
makes the thyroid release hormones
FSH and LH function
release of estrogens and progestrones
prolactin (PL) function
production of milk
adrenocorticotropic (ACTH) function
release of adrenal cortical hormones
MSH function
increased skin pigmentation
hGH functions
body growth and metabolic processes
What is pituitary dwarfism
A person has low hGH levels in growth years, the bone-growth-plate closes before person achieves normal size. Organs stay small.
what is pituitary giantism
An oversecretion of hGH during growing years. It causes long bones and tallness and normal proportions
what is acromegaly
A functioning pituitary tumor in an normal adult. Bones in face, hands, and feet thicken; tongue, eyelids, and nose bigger. Pituitary tumor can cause tunnel vision
characteristics of posterior pituitary gland
- Does not synthesize hormones
- Will store and secrete two.
- Hormones from brain are stored here in packets
other names for whole, anterior, and posterior pituitary gland
whole: hypophysis
anterior: adenohypophysis
posterior: neurohypophysis
two hormones stored in the posterior pituitary gland
- oxytocin
2. antidiuretic hormone (ADH/vasopressin)
antidiuretic hormone
decrease urine production, increase reabsorption of kidneys. Alcohol inhibits this secretion
what type of gland are the adrenal glands?
retroperitoneal
3 zones of adrenal glands and their hormones
- mineralocorticoids; aldosterone (96%), plus water and electrolytes
- glucocorticoids; cortisol (hydrocortisone) for immune system, protein catabolism and lipolysis; anti-inflammatory, allergic reactions, slows wound repair
what is lipolysis
making triglycerides into fatty acids
what is protein catabolism
breakdown of proteins into amino acids
what is glucose formation
gluconeogenesis
what is Addison’s disease and the result
Disease: lack of adrenocortical.
Results: lethargy, low blood pressure, weight loss, anorexia, and low blood sugar
Cushing’s syndrome
Disease: Excessive adrenal cortical function.
Result: Spindly arms and legs, moon-face, buffalo hump on back, flushed skin, hypertension, osteoporosis, and decreased resistance to infection and stress
androgens
Masculinizing hormones. Lots adult male. Converted to estrogen in females after menopause
hormones made in or from the adrenal medulla
Makes chromaffin (“color affinity”) cells. Stimulates the release of epinephrine (adrenalin, 80%) and norepinephrine (noradrenalin, 20%)
what happens when there is a hypersecretion of pheochromocytoma, aka a tumor of the adrenal medulla?
paroxysmal hypertension, causing an extreme fight of flight response
