Biology 3 Flashcards
Learn Organ System Physiology
The kidneys (Excretory system)
Excrete liquid and solute waste (excess water, salt, nitrogenous waste)
Maintain pH
Osmolarity and blood pressure
Glomerulus
Fenestratedcapillarybedthatstrainstheblood, allowingfluids,ions,andmoleculestheapproximatesizeofglucoseofsmallertopassthroughintoBowman’scapsule.
Bloodcellsandlargerbloodcomponentsremainwithinthecapillariesandexitviatheefferent
arteriolewhicheventuallyemptiesintotherenalvein.
Bowman’s Capsule
Spherical enclosure that captures filtrate and funnels it to the proximal convoluted tubule
Proximal convoluted tubule (PCT)
SectionofthenephronbetweenBowman’scapsuleandthedescendinglimboftheLoopofHenle.AlongthePCTsodium isreabsorbedviaactivetransportandglucoseisreabsorbedviasecondaryactivetransport
throughasymporteridenticaltotheoneusedtoabsorbglucosefromthesmallintestine.Water
followsthesolutesviafacilitateddiffusion.However,becausewaterandsolutesarereabsorbed
inthesameratio,thefiltrateremainsisotonic(i.e.,thevolumeoffiltratedecreases,butits
concentrationremainsconstant).
Descending loop of Henle
Travels into the very hypertonic medulla. Impermeable to salts, but very permeable to water. Water flows out of the filtrate, concentrating the urine.
Ascending loop of henle
Carries filtrate out of the medulla and into the cortex. This portion of the loop is impermeable to water and actively transports ions out of the filtrate and into the medulla. This continuous dumping of salts into medulla account for its hypertonicity. At the top, filtrate is less concentrated due to the removal of ions.
Distal convoluted tubule (DCT)
Section of nephron between ascending loop and collecting duct. Passes directly by the opening of Bowman’s capsule where the juxtaglomerular apparatus is located.
The DCT regulates calcium, hydrogen, and sodium concentrations (focus on sodium reabsorption regulated by aldosterone)
Reabsorbs calcium as a response to parathyroid hormone.
Juxtaglomerular apparatus
Detects decreased blood pressure in the afferent arteriole, it secretes Renin, setting into motion the renin-angiotensin pathway, which increases blood volume and blood pressure (negative feedback).
Collecting duct
Carries filtrate through medulla towards renal pelvis. Becomes very permeable to water in response to ADH
Respiratory System
Gas exchange. Oxygen diffuses down its concentration gradient into the blood, and CO2 diffuses down its concentration gradient out of the blood and back into the lungs.
Tidal volume
Volume of air that enters and exits the lungs during an average, unforced respiration.
Inspiratory reserve volume (IRV) and Expiratory reserve volume (ERV)
Volume of additional air that can be exhaled or inhaled after a normal, unforced expiration or inhalation.
Residual volume
Amount of air left in the lungs after a forced, maximal exhalation.
Vital capacity
Total amount of air the lungs can hold at maximum inflation, MINUS residual volume
Diaphragm
Moves DOWN when it is FLEXED, moves UP when it is RELAXED.
Moves DOWN during inhalation, moves UP during exhalation.
Hemoglobin
Quarternary protein made of four protein chains, two alpha and two beta. Each protein has an Fe-containing “heme” group at its center, which can hold one O2 molecule.
Oxygen dissociation curves:
% Hb Saturation vs pO2
Right Shift: Increased [H+], [CO2], temp, or BPG
Left Shift: Decreased [H+], [CO2], temp, or BPG
How CO2 is carried in the blood
CO2 + H2O –> HCO3- + H+
Cardiovascular system
Deliver oxygen and nutrients to the cells and tissues of body.
Electrical System of the Heart
Electrical signal originates from the SA node (sinoatrial node), then spreads across both atria to the AV node (atrioventricular), there is a pause for the ventricles to fill, then from the AV node it travels down the bundle of His, then up through the Purnkinje fibers.
Sympathetic and Parasympathetic effect on heart rate and blood pressure
Sympathetic activity INCREASES HR AND BP
Parasympathetic activity DECREASES HR AND BP
Blood
Transport nutrients, gases, waste products and hormones to and from cells; regulate extracellular environment, help maintain homeostasis; repair injuries, protect the body from foreign bodies (antigens).
All blood cells develop from stem cells in the bone marrow, process called HEMATOPOIESIS.