Mass Transport In Mammals Flashcards
Mass transport in animals
Mass flow, the bulk movement of substances through transport systems
Transport systems linked with specialist exchange system, maintain con grad
Transport systems in mammals
Larger organisms cannot exchange materials sufficiently across surface
Need exchange surfaces, eg alveoli in lungs
Required to take material between cells, exchange surface
What do transport systems in mammals rely on?
SA:V
How active the organism is
Features of a transport system
Medium to carry medium across
Medium needs to be moved in bulk over large distance
Closed system of tubular vessel containing medium
Mechanism for moving transport medium, eg, muscular contractions of heart
Circulatory system in mammals
Double circulatory system
Important to maintain high body temp and high rate of metabolism
Material exchange takes place by diffusion, over large SA, short distances, steep diffusion gradient
Vessels in systemic circulation
Hepatic artery and vein
Hepatic portal vein (from stomach)
Renal artery and vein
Vessels in pulmonary circulation
Superior vena cava
Pulmonary artery
Pulmonary vein
Aorta
Blood vessels
Arteries Arteriolar Capillaries Venues Veins
Structure of blood vessels
Tough outer layer Muscle layer Elastic layer Endothelium (caps only have E and L) Lumen
Function of veins, ventures
Blood to heart from body Thin collagen walls Low pressure Large lumen, reduce flow resistance Valves to prevent backflow Low pressure blood Deoxygenated blood except pulmonary vein
Function of capillaries
Allow diffusion of materials between blood and tissues
Very thin permeable walls, 1 cell thick, material exchange
V small lumen, short diffusion pathway for material exchange
No valves
BP falls in capillaries
Changes from oxygenated to deoxygenated
Function of arteries, arterioles
Carry blood from heart to body Thick walls, smooth elastic layers, restrict high pressure Muscle layer aids pumping Small lumen No valves except in pul artery, aorta High BP Oxygenated except in pul art
Arterial movement
Expand during systole Recoil during diastole Arterioles, more muscular, vasoconstriction, close off cap beds Vasodilation, opens up cap beds Changes occur under control of medulla
Venous movement
Leg contractions help blood move up against gravity
DVT caused by lack of movement
Tissue/ Interstitial fluid
Contains glucose, amino acids, fatty acids, salts, oxygen. No AA
Similar to plasma
Supplies substances to tissues
Recieves waste, CO2
Tissue fluid moves into and around cells, diffusion
Hydrostatic pressure
Hydrostatic pressure of tissue fluid out caps, prevents outward fluid movement
Water potential in cap beds
Lower WP of blood due to plasma proteins
Pulls water back into blood within capillaries
Blood composition
55% plasma
1% WBC
44% RBC
Hematocrit can change
Tissue fluid formation
High hydrostatic pressure in arterioles end of cap, blood plasma squeezed out cap
Cell proteins too big
Tissue fluid formed, material exchanged from fluid to cel by 4 methods of transport
Low hydrostatic pressure at venous end, lost too much plasma, plasma back into caps
Water enters caps by osmosis
NOt all plasma returns, drains into lymph vessels in cap beds
Waste diffuses into caps
Lymph, similar to tissue fluid, move digestive product fats
Narrowing of vessels pushes fluid out of vessels, ultrafiltration
Lymphatic system
Made up of system of lymph vessels along veins
Lead to heart, lymph drains back into blood system at superior vena cava
Helped by muscle contractions like in veins
Vessels also absorb fats from small intestines from lacteals
Networks in various places, lymph nodes
Swollen if more WBC needed to fight infection
