topic 3B: mass transport in animals Flashcards

Question

Describe the equation for cardiac output

Answer 1

CARDIAC OUTPUT (volume of blood pumped out of heart per min) = STROKE VOLUME (volume of blood pumped in each heart beat) x HEART RATE (number of beats per min)

Answer 2

Function – carry blood AWAY from heart at HIGH PRESSURE THICK smooth MUSCLE tissue: Can CONTRACT and CONTROL AND MAINTAINS AND WITHSTAND BLOOD FLOW AND PRESSUSRE THICK ELASTIC tissue: Can STRETCH as ventricles contract and RECOIL as ventricles relax, to reduce PRESSURE SURGES AND EVEN OUT blood pressure AND MAINTAINS HIGH PRESSURE THICK wall: WITHSTANDS high pressure / prevents BURSTING SMOOTH AND FOLDED endothelium: Reduces FRICTION and can stretch NARROW lumen: INCREASES AND MAINTAINS high pressure

Answer 3

Function – (division of arteries to smaller vessels which can) DIRECT BLOOD TO DIFFERENT CAPILLARIES AND TISSUE ● THICKER smooth MUSCLE layer than arteries ○ CONTRACTS → NARROWS lumen (VASOCONSTRICTION) → REDUCES BLOOD FLOW to capillaries ○ RELAXES → WIDENS lumen (VASODILATION) → INCREASES BLOOD FLOW to capillaries ● THINNER ELASTIC layer → pressure surges are lower (as further from heart / ventricles)

Answer 4

FUNCTION - allow efficient EXCHANGE of substances between blood and tissue fluid (EXCHANGE SURFACE) Wall is a THIN (one cell) layer of endothelial cells: Reduces DIFFUSION DISTANCE Capillary bed - LARGE NETWORK of branched capillaries: Increases SURFACE AREA for diffusion SMALL DIAMETER and narrow lumen: REDUCES BLOOD FLOW RATE so more TIME for diffusion PORES in walls between cells: Allow larger substances through

Answer 5

FUNCTION– carry blood BACK TO HEART at LOWER PRESSURE ● WIDER LUMER than arteries → less resistance to blood flow ● VERY LITTLE elastic and muscle tissue → blood pressure lower ● VALVES → prevent BACKFLOW of lood

Answer 6

At the ARTERIOLE END of capillaries: 1. HIGHER BLOOD AND HYDROSTATIC PRESSURE inside capillaries (due to contraction of VENTRICLES) than tissue fluid (so net outward force) 2. FORCING water (and dissolved substances) out of capillaries 3. LARGE PLASMA PROTEINS remain in capillary

Answer 7

At the VENULE END of capillaries: 1. Hydrostatic pressure REDUCES as fluid leaves capillary (also due to friction) 2. (Due to water loss) an INCREASING CONCENTRATION of plasma proteins LOWERS WATER POTENTIAL in capillary below that of tissue fluid 3. Water enters capillaries from tissue fluid by OSMOSIS down a WATER POTENTIAL GRADIENT 4. Excess water taken up by LYMPH CAPILLARIES and returned to circulatory system through veins

Answer 8

● LOW concentration of PROTEIN in blood plasma ○ Water potential in capillary not as low → WATER POTENTIAL GRADIENT is REDUCED ○ So MORE tissue fluid FORMED at arteriole end and LESS WATER ABSORBED at venule end by osmosis ○ LYMPH system may not be able to drain excess fast enough ● High BLOOD pressure (eg. caused by HIGH SALT CONCENTRATION ) → high HYDROSTATIC pressure ○ INCREASES OUTWARD PRESSURE from arteriole end AND REDUCES INWARD PRESSURE at venule end ○ So MORE tissue fluid FORMED at arteriole end and LESS WATER ABSORBED at venule end by osmosis ○ LYMPH system may not be able to drain excess fast enough

Answer 9

● An aspect of a person’s LIFESTYLE or substances in a person’s BODY AND ENVIRONMENT ● That have been shown to be linked to an INCREASED RATE OF DISEASE ● Examples - age, diet high in salt or saturated fat, smoking, lack of exercise, genes

Answer 10

● COVER any CUTS with a waterproof dressing ● When using a SCALPEL, cut AWAY from body onto a HARD surface ● When using a SCALPEL, use a SHARP blade ● When using a SCALPEL, CARRY with blade protected / pointing DOWN ● Wear disposable GLOVES and DISINFECT HANDS / wash with SOAP ● DISINFECT surfaces / equipment ● Safe DISPOSAL - put gloves / paper towels / organ in a separate BAG / BIN to dispose ● If poisonous chemicals / toxins involved, work in a well VENTILATED environment

Answer 11

● Morally wrong to kill animals just for dissection ● So use animals for dissection that have ALREADY BEEN KILLED (humanely) for meat

Answer 12

1. Add a drop of WATER to glass slide 2. Obtain a THIN section of specimen and place on slide 3. STAIN (eg. with iodine / potassium iodide to view starch) 4. Lower COVERSLIP at ANGLE using MOUNTED NEEDLE without trapping air bubbles

Answer 13

-Look SIMILAR to specimen / image - draw parts to the same SCALE / relative size -NO SKETCHING - only CLEAR, CONTINOUS lines -NO SHADING / hatching -Include a MAGNIFICATION SCALE (eg. x 400) -LABEL with straight, UNCROSSED LINES

topic 3B: mass transport in animals Flashcards

(37 cards)