9. Transport in animals Flashcards
Describe the circulatory system
a system of blood vessels with a pump and valves to ensure one-way flow of blood
Describe the single circulation of a fish
Describe the double circulation of a mammal
A system in which blood passes through the heart only once on one complete circuit of the body.
A system in which blood passes through the heart twice on one complete circuit of the body.
Evidence of a double circulatory system.
Heart has, two sides;
Blood must flow through the heart twice in one complete circuit of the body;
Pulmonary and systemic circuits- circuits from heart to lungs and from heart to rest of body ;
advantages of a double circulatory system
- oxygenated and deoxygenated blood, are kept separated by septum- do not mix
- ensures efficient supply of oxygen to, body ;
- ensures efficient supply of (named) nutrients (to, body ;
- low(er) pressure in, pulmonary, artery / circuit ;
- to prevents damage to (capillaries in the) lungs ;
- allows more time for gas exchange ;
- allows high(er) pressure (in body) ;
- to ensure efficient, blood supply to (rest of) body ;
- to allow filtration in kidneys (for excretion) ;
- to allow / maintain, a high, metabolic rate / rate of respiration ;
Pathway of blood in circulatory system
Right Atrium
Tricuspid Valve
Right Ventricle
Semilunar Valve
Pulmonary Artery
Lungs- Capillaries
Pulmonary Vein
Left Atrium
Bicuspid Valve
Left Ventricle
Semilunar Valve
Aorta
Explain the relative thickness of:
(a) the muscle walls of the left and right ventricles
(b) the muscle walls of the atria compared to those of the ventricles
(c) septum role
(d) functioning of heart
ventricles- thicker muscle walls- generate higher pressure- pump blood out of body
LV thicker- higher pressure- to entire body
RV- thinner- lower pressure- to lungs
separates the left side and the right side of the heart / separates right atria and ventricle from the left atria and ventricle ;
keep deoxygenated blood and oxygenated blood separate ;
contraction of muscles of the atria and ventricles and the action of the valves
Activity of the heart may be monitored by
ECG, pulse rate and listening to sounds of valves closing
Effect of physical activity on the heart rate
frequency of heat beats increases because exercising muscles require more energy for muscle contraction
more respiration
faster blood flow to muscles
supply oxygen and remove carbon dioxide produced by anaerobic respiration
Describe coronary heart disease and possible risk factors
blockage of coronary arteries
diet, lack of exercise, stress, smoking, genetic predisposition,
age and sex
Structure of arteries & veins
thick, strong wall- withstand high pressure
elastic tissue- to stretch and recoil with force of blood
narrow lumen- maintain high pressure
wide lumen- provide less resistance for blood flow
large lumen- to carry more volume of blood
presence of valves- prevent backflow of blood to ensure blood flows in one direction
Function and structure & adaptations of capillaries
thin, wall/ epithelium;
for efficient, diffusion/gas exchange ;
small, diameter/ lumen;
idea that many capillaries can fit into tissues / capillaries reach (every cell)
throughout the body /relative size to red blood cell ;
extensive network ;
large surface for diffusion ;
capillary cells have pores ;
to allow substances to pass in and out of the blood easily
function- take oxygen, nutrients and other materials to all the cells in the body and take away their waste materials.
All the blood vessels in our body with associated organs
(a) heart- vena cava, aorta, pulmonary artery and pulmonary vein
(b) lungs- pulmonary artery and pulmonary vein
(c) kidney- renal artery and renal vein
(d) liver- hepatic artery, hepatic veins and hepatic portal vein- SI to liver
Functions of the following components of blood
a) red blood cells- transporting oxygen, including the role of haemoglobin
(b) white blood cells- phagocytosis and antibody production
(c) platelets- clotting
(d) plasma- transport of blood cells, ions, nutrients, urea, hormones and carbon dioxide
(a) lymphocytes – antibody production
(b) phagocytes – engulfing pathogens by phagocytosis
Structure and adaptations of RBC, WBC- both
red blood cell:
biconcave disc - increased SA for oxygen diffusion
no nucleus - more space for haemoglobin
smaller size to squeeze through capillaries supplying oxygen to every cell
lymphocyte:
little cytoplasm / large(r) nucleus / nucleus fills most of the cell ;
phagocyte:
lobed / irregular-shaped / C-shaped nucleus
Role and process of blood clotting
preventing blood loss and the entry of pathogens
When an injury causes a blood vessel wall to break, platelets are activated.
release a substance that converts soluble fibrinogen to insoluble fibrin.
forms a mesh (trapping red blood cells) / forms scab
