endo Flashcards
- All glandular tissue derived from?
- contains specialized cells that?
- embryologically derived from epithelium
- glandular epithelium contains specialized cells that synthesize, store and secrete chemical substances
Exocrine vs Endocrine glands
- Exocrine: release secretions into ducts that carry secretions to the body surface
- sweat, mammary, salivary
- Endocrine: ductless, hormones are released into bloodstream that will bind only to garget cells with receptors
Endocrine Glands: release secetions into? then to? then to? ex?
- released into sinusoids (large, extracellular spaces)
- sinusoids pass secretions to capillaries
- circulatory system carries secretions to intended target site (as well as rest of body(
- thyroid, pituitary, adrenal/suprarenal
Endocrine System: collection of …that? integrates? functions together with?
Neuroendocrinology: brain/hormones? similarities between nerve and gland cells?
Nervous vs Endocrine system: responses
- NS: responses are highly specific and act over the short term
- ES: responses that affect many different tissues and organs simultaneously, and act over a longer duration
NS vs ES: responses generated by? signals are?
- NS: by neurons, signals are electrical impulses conducted along axons
- chemical messengers conduct impulse between neurons
- ES: hormones, signals are chemical substances released by endocrine glands
- circulate in bloodstream throughout the body
What is a hormone? produced by? travels? acts on?
- chemical messenger
- produced and secreted by endocrine cell/tissue
- travels through circulatory system to reach other tissues
- acts upon specific target cells w/i tissue
Hormones: bind to? what determines response? sensitivity?
- hormones bind to specific cellular receptors
- presence/absence of receptor determines cell’s response to homrone
- changing number of receptors changes cell’s sensitivity to the hormone
Pituitary Gland - ant vs post aka? gland or not?
- Anterior lobe = adenohypophysis
- true gland
- Posterior lobe = neurohypophysis
- extensions of hypothalamus
Ant Pit: 7 hormones?
- Human Growth Hormone, hGH: stimulates body growth and metabolism
- TSH: controls thyroid gland function
- FSH, LH: control secretion of sex hormones, production of gametes
- Prolactin: milk production, sexual gratification, frowth factor
- Adrenocorticotropic ACTH: controls hormone secretion by adrenal cortex
- Melanocyte MSH: stimulates melanin secretion
Posterior Pit: 2 hormones?
- ADH, antidiuretic hormone aka vasopressin: regulates urine concentration, regulates blood pressure
Control of Hormone Release: ant pit? post pit?
- hypothalamus secreates releasing hypophyseotropic factors that act on cells of the ant pit
- hormones of the post pit are produced in the supraoptica dn paraventricular nuclei of the hypothalamus: these neurons extend inferiorly to end at the post pit, releasing oxytocin and ADH
Production of Thyroid Hormones - precursor? iodine? conversion? secretion?
- follicle cells secrete hormone precursor thyroglobulin into follicle cavity (colloid)
- iodine is attached to thyroglobulin in cavity
- when stimulated by TSH, follicle cells convert thyroglobulin into T4 and T3
- follicle cells secrete T3/4 into connective tissue between follicles
- hormones picked up by capillaries
- hyroid homrones regulate metabolism
Parafollicular Cells (Thyroid) - aka? produce? function?
- “next to” follicle cells - C cells - C thyrocytes
- produce calcitonin
- function in calicum regulation: decrease conc in body fuilds
Calcitonin
Parathyroid glands - where? secrete? function
- 4 embedded in thyroid
- parathyroid hormone, calcium regulation
Parathyroid hormone - from where? does what?
- parathyroid gland
- increases Ca in body fluids
- decreases Ca deposition in bone: so gets osteoclasts to break down bone
- reduces urinary excretion of Ca
Adrenal/Suprarenal Glands - cortex vs medulla?
- cortex = outside, from epithelium
- medulla< inside, autonomic ganglion derived from neural tissue (like post pit)
Adrenal Cortex - 3 hormones?
- mineralocorticoids: aldosterone
- glucocorticoids: cortisol
- androgens
Mineralocorticoids - from where? ex? does what?
- from adrenal cortex
- aldosterone
- increases renal absorption of Na and H2O
- decreases renal abosrption of K
Glucocorticoids - from where? ex? does what?
- from adrenal cortex, cortisol
- stimulates protein, lipid and carbohydrate metabolism
- anti inflammatory
Androgens - from where? does what?
- adrenal cortex
- stimulates frowth of axillary and pubic hair
- stimulates libido
Epi and Norepi - from where? does what?
- adrenal medulla
- aka adrenaline, noradrenaline (also neuroT)
- flight or fight response
- increase cardia output, blood pressure
- increase blood glucose for energy
- effect release of lipds from adipose tissue
Pancreas - two types of glands? 3 cell types and secretions?
- mostly exocrine, some endocrine islets
- alpha for glucagon
- beta for insulin, most abundant
- delta for somatostatin
Glucagon - from? does what?
- pancreas
- stimulates glucose synthesis
- elevates blood glucose
- mobilizes lipid reserves
Insulin - from ? does what?
- pancreas
- stimulates lipi and glycogen synthesis and storage
- stimulates glucose uptake by cells
- decreaes blood glucose levels
Somatostatin - from? what?
- pancreas: like a switch
- inhibits production and secretion of both glucagon and insulin
Diabetes Mellitus - inability to ? 2 signs? result in ? two types %?
- inability to produce or use insulin
- elevation of blood glucose levels aka hyperglycemia, excretion of glucose in urine
- results in cardiovasular problems, vision problems
- type I - 10%
- type II - 90%
Type I - what? insulin levels/dependency? age?
- autoimmune disease that destroys insulin secreting cells of islets
- marked reduction of insulin levels
- insulin dependent diabetes
- any age, but more common 5 - 20
Type II - combination of? what’s wrong? insulin dependency? correlation with? management?
- combination of insulin resistance and insulin secretory defects
- target cells become less sensitive to insulin: can’t use the insulin you make because of resistance - downregulation of receptors
- non-insulin dependent diabetes
- correlates with age and obesity
- diet, exercise, weight loss
Pineal Gland - role? secretion?
- unclear physiological role
- secretes melatonin: regulates biological clock
- increases during night, decreases during day
- sleep wake cycle - cicadian rhythm
Thymus - where? function?
- mediastium, just posterior to sternum
- produces T-lymphocytes: cell-mediated immunity
- secretes thymic hormones: promote proliferation and maturation of T-lymphoctes
Gastrointestinal Tract hormones
- over 20 different hormones
- regulate activity of GI tract and digestive glands
- most act locally
Kidney hormones
- erythropoeitin: increases RBC production
- renin: increases blood pressure
Heart hormones
- atrial natriuretic peptide: made in wall of atria, counteracts renin
- decreases blood pressure by suppresing ADH, aldosterone so stimulates water/salt loss at kidneys
Adipose Tissue hormone
- leptins
- appetite suppressant
