11.7-11.10 Flashcards
Peptide hormones
produced in rough ER, made of amino acids connected by peptide bonds.
Actions: bind to cell surface receptors because they cannot pass through cell membrane, indirect stimulation through secondary messengers
G protein coupled receptors
cell surface receptors that initiate secondary response after binding to peptide hormone. G protein dissociates into alpha beta gamma subunits
Receptor Tyrosine Kinases
cell receptor that dimerizes and initiated secondary messenger responses. Cross phosphorylate eeachother and vitiate secondary messenger
steroid hormones
produced in smooth ER, 4 ringed.
Action: needs protein carrier to travel through blood because it is lipophilic. Freely crosses cell membrane and binds to receptors in cytoplasm or nucleus to form molecule-receptor complexes that bind to DNA and influence gene transcription. Direct stimulation.
amino acid hormones
produced in rough ER, similar to peptide and steroid
hypothalamus
maintains body homeostasis
Pituitary gland (location)
under hypothalamus and made of 2 lobes
Posterior pituitary
releases anti-dieuretic hormone, which increases water retention. also releases oxytocin which causes urine contractions during child birth and milk for breastfeeding
Anterior pituitary
made of glandular tissue and releases its own hormones
hypothalamic releasing hormones
1) GnRH- stimulated production of FSH, LH
2) TRH- release of thyroid stimulating hormone
3) CRH- release of adrenocorticotropic hormone
4) GRH- release of growth hormone
hypothalamic inhibitory hormones
inhibit the release of hormones
Tropic
target other endocrine glands for further hormone release (FSH, LH, ACTH (stimulates release of glucocorticoids to fight stress) ,TSH (stimulates T3+ T4 production)
Direct hormones
Target organs directly for effect (prolactin, Growth hormone)
Pineal Gland
produces melatonin which regulates circadian rhythm
thyroid gland hormones
1) T3- released in response to TSH and increases metabolism, negative feedback with TSH
2) T4- less potent than T3 but more stable, same function
3) calcitonin
hypothyroidism
under-secretion of t3+t4, reduced metabolism
hyperthyroidism
over secretion of t3+t4, increased metabolism which results in enlargement of thyroid gland
Pancreas endocrine cells
1) alpha cells- secrete glucagon in response to low glucose, raises glucose through stimulating liver and fat tissue
2) Beta- secrete insulin in response to high blood glucose
3) delta- secrete somatostatin, which inhibits growth hormone. Inhibits secretion of glucagon and insulin
Adrenal gland
has outer cortex and inner medulla
cortex functions
deals with long term stress, stimulated by ACTH, releases steroid hormones, raises blood glucose(glucocorticoid) to fuel long term stress, increases blood volume and pressure(mineralcorticoids), produces small amount of male sex hormones
Adrenal Medulla
short term stress, sympathetic nervous system, releases amino acid derived hormones, increases blood flow
Amylase
breaks down starch into maltose in the mouth when chewing
epiglottis
blocks trachea to prevent choking
cardiac sphincter
where the food enters the stomach
Gastrin functions
1) stimulates parietal cells to release acidic gastric juice
2) stimulates chief cells to secrete gastric lipase and pepsinogen which is converted to pepsin.
Pepsin
Cleaves peptide bonds, breaks down proteins
small intestine parts
“DJ EYE” duodenum (digestion), jejunum, and ileum (absorption)
cholecystokinin (CCK)
released by small intestine, slows gastric emptying, stimulates pancreas to release digestive enzymes+ tells gall bladder to release bile into duodenum
Bile
emulsifies fats, produced by liver and stored in gall bladder
Pancreas functions
secretes HCO3-, pancreatic amylases, and proteases. Converts trypsinogen into trypsin, and eventually converts chymotrypsinogen into chymotrypsin
Liver functions
1) blood maintenance- stores blood, detoxifies blood, destroys erythrocytes and bacteria, kupfer cells eat bacteria and break down hemoglobin
2) glucose metabolism:
glycogenesis- conversion of glucose into glycogen
glucogenolysis- glycogen converted to glucose
glucuoneogenesis- glycerol+amino acids into glucose when glycogen stores are depleted
3) protein metabolism- synthesis plasma proteins from Amino acids, converts ammonia into urea
cecum
where water and mineral absorption occur
colon
where water absorption is completed
rectum
where feces is stored
3 main functions of large intestin
1) water absorption
2) mineral absorption ‘
3) vitamin production and absorption. Bacteria produce vitamins B and K
makeup of kidney
cortex (where blood enters), medulla, pelvis (where filtrate exits kidney)
Nephron
single functional unit of kidney
filtration through kindey
at renal corpuscle, consists of glomerulus and Bowmans capsule. blood enters afferent arteriole into glomerulus to form fenestrations which allow small substances to be filtered into Bowmans capsule/ large ones stay in blood. exits via efferent arteriole
Why aren’t blood and proteins in blood?
too big to get through glomerulus
reabsorption
water+ solutes body needs are reabsorbed into blood, Loop of Henle, descends into medulla and has selective permeability. Water is absorbed into blood as filtrate travels down descending limb(filtrate more concentrated) and solutes are reabsorbed as filtrate travels up ascending limb
secretion
transfer of solutions from blood vasculature into nephron tubule filtrate. Occurs at distal convoluted tubule and proximal convoluted tubule
Excretion
filtrate travels from nephrons > collection duct > renal pelvis> ureter.
Ureter
connects kidney to bladder where urine is stored
Renin angiotensin aldosteron system
1) juxtaglomerular cells- detects changes in blood pressure and sodium levels, when BP and sodium is low, cells release renin
2) renin- acts on angiotensinogen to activate angiotensin I which gets converted to angiotensin II which is an active hormone
Angiotensin 2
stimulates additional aldosterone release form adrenal gland cortex, increases NA+ absorption from proximal tubule, vasoconstrictor, makes individual more thirsty so they drink more and increase blood liquid volume
Aldosterone
minercortoroid produced by adrenal cortex, increases salt and water reabsorption
anti-dieuretic
posterior pituitary upon stimulation from hypothalamus. Vassopressin is involved
Atrial natriuretic peptide
produced by atrial cells because of increased blood volume and pressure
3 layers of skin
epidermis, dermis, hypodermis
layers of epidermis
“come lets get some beers”
1) stratum corner- corneocytes (dead keratinocytes) outermost, protective layer
2) Stratum Lucidum- dead keratinocytes that are not fully differentiated into corneocytes, found on hands and feet 3) Stratum Granusolum- keratinocytes secrete lamellar bodies to form water barrier
4) Stratum Spinosum- important for strength (desomosomes) and immunity
5) Stratum Basale- precursor kaertinocyte stem cells proliferate here, where light tough sensation and melanin synthesis occurs. UV protection
Dermis
supports and cushions against injury, 2 layers (papillary- thin and high SA) and (reticular dermis- deeper, thin and dense). contains blood vessels
Eccrine glands
sweat glands important for thermoregulation
Apocrine
located at specific sites and secrete into hair follicle, produce ear wax to milk
hypodermis
deepest layer, contains nerves and blood vessels, main function is fat storage
