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52 Cards in this Set
- Front
- Back
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Excretory system |
regulation of - BP - blood osmolarity - acid-base balance - removal of nitrogenous wastes Consists of... - kidneys -ureters - bladder - urethra |
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Kidney structure |
- cortex: outer most layers - medulla: within cortex - renal hilum: deep slit in the center of its medial surface (renal artery, vein, and ureter enter and exit through this) - Renal pelvis: spans entire width of renal hilum |
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Urine pathway |
kidneys (nephron) --> renal pelvis --> ureter --> bladder --> urethra |
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portal system |
- 2 capillary beds in series through which blood must travel before returning to the heart |
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afferent arterioles (kidney) |
- renal artery --> medulla --> cortex as an afferent arteriole |
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glomeruli |
- highly convoluted capillary tufts derived from afferent arterioles |
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efferent arterioles (kidney) |
- after blood passes through glomerulus the efferent arterioles form the vasa recta |
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vasa recta |
- cappilary bed formed by the efferent arterioles that surround the loop of henle |
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Bowmans capsule |
- cup like structure around the glomerulus - leads to a long tubule of proximal tubule --> descending and ascending limbs of the loop of henle --> distal convoluted tubule --> collecting duct |
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detrusor muscle |
- muscular lining of the bladder - contracts by parasympathetic parasympathetic activity |
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internal urethral sphincter |
- smooth muscle - normal state = contracted - involuntary control |
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external urethral sphincter |
- skeletal muscle - voluntary control |
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micturition relfex |
- full bladder --> stretch receptors tell nervous system that the bladder needs emptying --> parasympathetic neurons fire --> detrustor muscle contracts --> internal sphincter relaxes |
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filtration (kidney) |
- filtrate is collected into bowmans capsule through starlings forces - net flow = blood to nephron = glomerulus to bowmans space - filtrate does not contain cells or proteins because they are too large - remaining blood in glomerulus --> efferent arterioles --> vasa recta - fliter about 180L a day ** movement of solutes from blood to filtrate at bowmans capsule** |
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secretion (kidney) |
- secretes salts, acids, bases, and urea into the tubule by active or passive transport - directly related to the needs of the body at the time - mechanism for excreting wastes that are too large to pass through glomerular pores **movement of solutes from blood to filtrate anywhere besides bowmans capsule** |
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Reabsorption (kidney) |
- compounds previously filtered or secreted may be taken back up for use - usually glucose, amino acids, or vitamins ** movement of solutes from filtrate to blood ** |
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proximal convoluted tubule (PCT) |
- 1st entry of filtrate - amino acids, glucose, water-soluble vitamins, salts (70% of sodium) are reabsorbed with water -secretes waste products (hydrogen ions, potassium ions, ammonia, and urea) - "Dump the HUNK"l |
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descending limb of the loop of henle |
- PCT --> descending loop of henle (deep into medulla) - permeable to water only - water flows out at it goes deeper into the medulla (high osmolarity) - leads into the ascending loop |
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countercurrent multiplied system |
- created by vasa recta and nephron - flow of filtrate in loop is opposite of the flow of blood thru the vasa recta - allows filtrate to be exposed to hypertonic blood that allows for maximal reabsorption of water |
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ascending loop of henle |
- only permeable to salts - impermeable to water - salts concen. decreases at the limb rises therefore salts are removed from filtrate |
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diluting segment |
- thicker portion between the inner and outer medulla of the loop of henle - cells lining tube are larger -contain large amounts of mitochondria which allows for reabsorption of Na and Cl by active transport - produces urine more dilute than the blood |
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results of loop of henle |
- slight degree of filtrate dilution - reduction of filtrate volume - shows net reabsoprtion of a large volume of water |
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Distal convoluted tubule (DCT) |
- responds to aldosterone (promotes sodium reabsorption) - releases water, concentrating urine, decreasing volume - site of waste product secretionc |
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collecting duct |
- responsive to aldosterone and ADH - increase in permeability --> increase water absorption --> increased concen. of urine - if body is hydrated, the CD will be impermeable to salt and water - ADH and aldosterone act to increase reabsorption of water for water retention CD --> renal pelvis --> ureter --> bladder |
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aldosterone |
- steroid hormone - alters ability of DT and collecting duct to reabsorb sodium and therefore water - increase K+ and H+ excretion - secreted by the adrenal cortex in response to low BP by... juxtaglomerulaar cells --> secretes renin --> cleaves angiotensinogen (liver protein) --> angiotensin 1 --> angiotensin-converting enzyme (in lungs) --> angiotensin 2 --> promotes release of aldosterone |
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Antidiurectic Hormone |
- "ADH or Vasopressin" - peptide hormone synthesized by hypothalamus and released by the posterior pituitary in response to high blood osmolarity - alters permeability of collecting duct allows more water reabsorption (leaky cell junctions) |
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osmotic pressure |
- "sucking" pressure that draws water into the vasculature caused by all dissolved particles |
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oncotic pressure |
- osmotic pressure that is attributed to dissolved proteins specifically |
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bicarbonate buffer system |
- regulates blood pH by selectively increasing or decreasing the secretion of H+ and bicarbonate CO2 + H2O <--> H2CO3 <--> H+ + HCO3- |
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skin |
- "integument" - largest organ in our bodies - major component of nonspecific immune defense - hypodermis, dermis, and epidermis |
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epidermis |
- contains layers called strata - deepest --> out = stratum basale, stratum spinosum, stratum granulosum, stratum lucidum, stratum corneum - "Come Lets Get Sun Burned" (inner to outer) |
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Stratum Basale |
- outermost layer of epidermis - contains stem cells - responsiblke for proliferation of keratinocytes (produces keratin) |
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stratum spinosum |
- epidermis - cells become connected to eachother - site of langerhans cells |
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stratum granulosum |
-epidermis - keratinocytes die and lose nuclei |
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stratum lucidum |
- epidermis - present in think hairless skin (sole of foot, palms) - nearly transparent |
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stratum corneum |
- inner most layer of epidermis - contains dozens of layers of keratinocytes to form a barrier that prevents invasions of pathogens - helps prevent loss of fluids and salt |
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keratin |
- produced by keratinocytes - resistant to damage and provides protection against injury, water, and pathogens |
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melanocytes |
- dervied from neural crest cells - found in stratum basale - produce melanin - protects the skin from DNA damage caused by UV rays |
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langerhans cells |
- special macrophages in stratum spinosum - present antigens to T-cells to activate immune system |
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Dermis |
Upper layer: papillary layer = loose connective tissue Lower layer: reticular layer - contains sweat glands, blood vessels, hair follicles, and sensory receptors |
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Merkel cellls (discs) |
- in dermis - cells connected to sensory neurons - responsible for deep pressure and texture sensation |
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free nerve endings |
- dermis - part of sensory nerve organs that respond to pain |
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Meissners corpuscles |
- dermis - respond to light touch |
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ruffini endings |
- dermis - respond to stretch |
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pacinian corpuscles |
- dermis - respond to deep pressure and vibration |
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hypodermis |
- layer of connective tissue that connects the skin to the rest of the body - contains fat and fibrous tissue |
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thermoregulation |
- achieved by sweating, piloerection, vasodilation, and vasoconstriction |
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sweating |
- cooling mech - controlled by ANS - evap of water from skin to absorb body heat |
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vasodilation |
- maximizs heat loss - brings large amt of blood to the skin - accelerate the evaporation of sweat by maximizing the heat energy available for the liquid-gas phase change |
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arrector pili |
- contract causing the hairs of the skin to stand up - helps trap a layer of heated air near the skin |
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shivering |
-skeletal muscles contract rapidly - requires ATP to convert into thermal energy |
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white/brown fat |
white: fat just below the skin to insulate the body Brown: more heat energy is released as fuel is burned b/c of less efficient electron transport chain (found mostly in infants) |
