B9 transport in animals Flashcards
describe the circulatory system
- system of blood vessels
- with a pump and valves
- to ensure one-way flow of blood
describe the single circulation of a fish
- blood flows from heart to gills for oxygenation
- from gills to rest of body
- single circulation: blood glows thru heart only once
describe the double circulation of a mammal
blood follows two circuits
- pulmonary: blood flows from heart to lungs for oxygenation then back to heart
- systemic: blood flows from heart to other parts of body then back to heart
advantages of double circulation
higher blood pressure:
- o2 and glucose supplied rapidly to cells, co2 and water removed quickly from them
- blood can be supplied to distant parts of large animals
how is the activity of the heart monitored
- ECG (electrocardiogram)
- pulse rate
- listening to sounds of valves closing
do veins have a pulse? why
- no
- their walls do not expand/contract
stages of heartbeat
- Atrial and Ventricular diastole
- Atrial systole
- Ventricular systole
effect of exercise on hr and why
- hr increases with exercise
- increased energy from aerobic respiration needed by muscle cells
- more glucose and oxygen must be supplied by blood to respiring cells, increase rate at which co2 and water (waste products) removed
describe coronary heart disease
- blockage of coronary arteries
- unable to supply oxygen rich blood to heart muscles
- cardiac muscles cannot produce enough energy for contraction
risk factors for CHD
- diet
- lack of exercise
- stress
- smoking
- genetic predisposition
- age
- sex
explain how to prevent CHD
balanced diet
- consume all nutrients needed by body in correct amounts to maintain health
- wide variety of food, eat less animal fat
exercise
- prevent excessive weight gain
- decrease bp
- reduce stress
structure of arteries
- thick, muscular wall
- narrow lumen
structure of veins
- thin wall
- wide lumen
- valves
structure of capillaries
- one cell thick wall
- tiny lumen
relate structure of arteries to pressure of blood transported
- elastic tissues make flow of blood smoother
- thick walls to withstand high bp
- narrow lumen to maintain high bp
relate structure of veins to pressure of blood transported
- large lumen, thin walls due to low bp
- wide lumen reduces resistance to blood
- veins to prevent backflow
explain how structure of capillaries related to functions
- thin wall for short diffusion distance
function of capillaries
allow exchange of materials between blood and body cells
components of blood
- red blood cells
- white blood cells
- platelets
- plasma
function of red blood cells
- transporting oxygen
- haemoglobin (protein) combines with oxygen
function of white blood cells
- ingest and destroy pathogens (phagocytosis)
- production of antibodies
function of platelets
- clotting of blood
function of plasma
transport of
- blood cells
- ions
- nutrients
- urea
- hormones
- co2
function of lymphocytes
antibody production
function of phagocytes
engulfing pathogens by phagocytosis
role of blood clotting
- prevent blood loss
- prevent entry of pathogens
