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22 Cards in this Set
- Front
- Back
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Heat Exchange |
Body size: surface area- volume ration Body shape: surface area for heat loss Adaptions e.g. ear size, nose size |
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Behavioural and physiological adaptions to aid exchange |
Kidney structure adaptation-produce less urine Large amounts of high energy foods Thick layers of fur when hibernating Spending time in water |
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Gas exchange in single-celled organisms |
Diffusion through cell-surface membrane Large surface area Short diffusion pathway |
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Gas exchange in fish |
Gills: gill filaments and lamellae (surface area)- lots of blood capillaries (speed up diffusion) Counter current: water and blood flow opposite to each other- maintains concentration gradient across whole gill |
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Gas exchange in dicotyledonous plants
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Mesophyll cells Large surface area- special pores in epidermis called Stomata- can open to allow exchange- guard cells control |
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Gas exchange in insects |
Moves in through spiracles Trachae- microscopic air-filled pipes branch into tracheoles-thin permeable walls- respiring cells Insect uses rythmic abdominal movements |
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Control of Water Loss
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Close spiracles Waxy Cuticles Stomata sunk in pits- reduce gradient Layer of 'hairs'- trap water vapour Curled leaves Reduced number of stomata |
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Gas exchange in humans |
Trachea- Bronchus- Bronchioles- Alveoli- Capillaries Thin exchange surface- one cell thick Largesurface area- millions of alveoli Steep conc. gradient- Flow of blood and ventilation |
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Ventilation |
Inspiration- external intercostal and diaphragm muscles contract- rigcage upwards and outwards- volume of thoracic cavity increases so lung pressure decreases Expiration- external intercostal and diaphragm relax- ribcage moves in and down (dome) volume decrease pressure increase |
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Lung disease |
Tuberculosis: bacteria- reduce tidal volume- Fibrosis: scar tissue-tidal volume decrease-FVC decrease Asthma: bronchioles tighten, FEV reduced Emphysema: break down elastin- gaseous exchange decreases |
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Digestive Enzymes |
Amylase: breakdown starch- glycosidic bonds-maltose Lipase: Lipids to monoglycerides and fatty acids- hydrolise ester bonds- pancreas to s. intestine Endopeptisases:hydrolise peptide bonds inside Exopeptidases:hydrolise peptide at ends (bile salts emulsify lipids) |
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Absorption
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Monosaccharides: glucose & galactose absorbed by active transport-sodium ions via cotransporter Fructose- facilitated diffusion Monoglycerides: micelles help release- lipid soluble so can diffuse Amino acids- co transport with sodium ions which actively transport |
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Haemoglobin |
Protein that carries Oxygen Oxygen+haemoglobin=oxyhaemoglobin(in lungs) Called loading/association Oxygen leaves haemoglobin- disassociation or unloading |
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Affinity and Partial Pressure |
Partial pressure (pO2) is Oxygen concentration Affinity is tendancy of molecule to bind with O2 High PO2 = high affinity (e.g. alveoli in lungs) Low PO2= low affinity (e.g. respiring tissue) |
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Dissociation Curves |
S-shape: difficulty bonding at the start- curve flattens because near saturation
Low Oxygen: high affinity bc need Oxygen- left High activity: high Oxygen demand low affinity- right Size: small= high Oxygen demand low affinity-right |
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Circulatory System |
Pulmonary artery: heart to lungs Pulmonary vein: lungs to heart Aorta: heart to body Vena Cava: body to heart Renal artery: body to kidney Renal vein: kidneys to vena cava |
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Arteries, arterioles and veins |
Arteries: Heart to Body- thick muscle, elastic tissue (pressure), Oxygenated - Pulmonary artery exception Arterioles: mainly circular muscle, small vessels Veins: wide lumen, low pressure, little elastic or muscle, valves (backflow), deoxygenated- pulmonary exception |
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Tissue Fluid |
Pressure filtration Arteriole end: high hydrostatic pressure fluid-capillaries to tissue cells- plasma too big Venule end: low hydrostatic pressure water potential lower outside, 95% osmosis in 5% into lymphatic system, lymph, skeletal movement |
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Cardiac Cyle |
Vetricles relax, atria contract, AV valves open Ventricles contract, atria relax, SL valves open Ventricles relax, atria relax, AV valves open Blood flows back in |
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Cardiovascular disease |
Atheroma: damage to endothelium, white blood cells, lipids make fatty streaks-plaque Aneurysm: weaken artery, blood pushes inner layers balloon swelling, haemorrhage Thrombosis: atheroma rupture, rough surface, accumulation, blood clot Myocardial infarction: coronary artery blocked, no oxgyen |
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Xylem |
Transpiration (evaporation) Water evaporates from leaves at the top Tension pulls water into leaf Cohesion pulls water upwards Water enters stem through roots |
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Phloem |
Mass Flow Hypothesis
Source: Active transport loads solutes from companion cells- lowers water potential-water enters by osmosis Sink: Solutes removed from phloem,increase water potential, osmosis out, low pressure Flow:pressure gradient from source to sink, solutes used at sink or stored |
