Exchange

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and lined with goblet cells and ciliated epithelium Inspiration blood • wax cuticle upper epidermis 2 palisade mesophyll air Space 7 Spongy Mesophyll stoma guard cell gas as exchange system goblet cells- line the trachea and bronchi and release mucus to trap small particles Ciliated epithelium- traps large particles macrophages- bacterial Scavengers lower epidermis 1 wax cuticle lie between the ribs blood allows gases to diffuse throughout the leaf and 7 есте contact with expiration into mesophyll cells The mechanism. of breathing air when air When air pressure of the atmosphere is forced into the lungs- inspiration pressure inside the lungs, air is forced out of the lungs-expiration The pressure changes are caused by the movement of these muscles: - diaphragm - internal intercostal muscles - external intercostal muscles large surface area for rapid diffusion 50 many stomata short diffusion pathway bronchi-2 divisions of the trachea; has some cartilage; has Ciliated epithelium, goblet cells and macrophages bronchioles-branching subdivisions of bronchi; has little cartilage; Smooth muscle controls air flow ·alvedi - tiny air sacs with collagen and elastic fibres which allow them to stretch with air and spring back to expel air; moist inner Surface to prevent drying; large surface area; Steep diffusion gradient; Surfactant prevents surfaces sticking is greater than the air greater than the air pressure inside pressure of the atmosphere the lungs, CU >diaphragm muscles contract, making it go flat active process- uses energy 2. maltose external pintercostal muscles, internal contract lipid molecule Digestion 0 Interested ribs pulled upwards and outwards, increasing the the volume thorax Muscles relax caused a reduction in pressure Gair is forced into lungs + ♦ diaphragm muscles pushed relax So it up by the abdomen I largely passive- doesn't require much energy › internal intercostal 1. Salivary amylase and pancreatic amylase-hydrolyse glycosidic bonds starch into maltose Maltase bile Salts of proteins. ooto external muscles contract intercostal muscles relax ribs move downwards and inwards, decreasing the volume of the thorax Gincreases pressure is hydrolysed to a-glucose by of lipids Gair is forced "out of lungs Exchange of gases in the lungs Adaptations of the alvedi for faster diffusion of gases: - red blood cells are slowed as they pass through pulmonary capillaries, allowing more time for diffusion - red blood cells flattered against capillary walls, reducing diffusion distance between alvedar air and RBCS -thin alveoli and capillary walls-thin diffusion pathway area large surface -concentration gradient is maintained with breathing/ventilation and blood circulation Enzymes and digestion Digestion of Carbohydrates (starch) Digestion 1. lipids monoglycerides (glycerol with by lipases to form fatty acids and 2. to speed up the action of lipases by increasing the surface of the lipids, bile salts break them up into are a tiny droplets called micelles by emulsification tidal pulmonary ventilation = volume rate (am ³) (dm ³ min) how much b volume air is taken in of air peptide peptide bonds and out of the lungs in a given time normally taken in at each breath at rest Structure of ileum. -villi and microvilli- large surface area of the breathing rate a 1. endopeptidases-hydrolyse 2. exopeptidases - hydrolyse bonds inside on the peptide molecules formed by endopeptidases to release dipeptides and Absorption of the products of digestion 00 (min) b number of breaths taken 1 minute, normally between 12 and 20 breaths in 0 healthy adult in the lining of the ileum. 3. di peptidases- hydrolyse the bond between two amino acids in a dipeptide, found in ileum lining polypeptide terminal amino acids of the single EN amino acids one cell thick thin diffusion pathway good blood supply -maintains concentration and amino acids Absorption of triglycerides 1. micelles diffuse into 2. transported to form Chylomicrons 3. chylomicrons move out of the cell 4. they enter lyruphatic capillaries called lacteals monosaccharides are gradient arbsorbed by diffusion and break down, releasing monoglycerides and fatty acids epithelial cells the exocytosis and then. endoplasmic reticulum and made into triglycerides again pass which into co-transport the easily blood and