Transport in animals Flashcards
What is a single circulatory system and what animal has it?
The blood only passes through the heart once. Fish.
What is a double circulatory system and what animal has it?
Blood passes through the heart twice. Human.
Where does the blood travel in a fishes circulatory system?
The heart pumps, the blood to the gills to pick up the oxygen and then to the rest of the body
Where does the blood travel in the human circulatory system?
The right side of the heart pumps blood to the lungs, and the left side of the heart pumps blood to the rest of the body.
What is the name for the side of the heart that sends blood to the lungs?
Pulmonary
What is the name for the side of the heart that sends blood to the body?
Systemic
What is an advantage of the mamillan double circulatory system?
The heart can pump the blood from the lungs to the rest of the body, making the blood travel faster
What is a closed circulatory system and what has it?
The blood is enclosed inside blood vessels. All vertebrates (fish and mammals).
What is an open circulatory system and what has it?
Blood isn’t enclosed in blood vessels and flows freely through the body cavity. Invertebrates (insects).
What are the three steps of an open circulatory system?
1) heart pumps blood into arteries and branch out into capillaries
2) oxygen and glucose diffuse from blood to body cells
3) veins take the blood back to the heart
What are the three steps of a closed circulatory system?
1) the heart is segmented and contracts in a wave starting from the back into a single main artery
2) the artery opens up into the body cavity
3) the blood flows around the insects organs, gradually making its way back to the heart through valves
What are the five types of blood vessels?
Arteries, arterioles, capillaries, venules and veins
What do arteries do?
Carry blood from the heart to the rest of the body
What are arteries structure?
Thick walls, muscular, have elastic tissue to stretch and recoil as the heart beats
What are arterioles?
Smaller branches of arteries
What are arterioles structure?
Much smaller than arteries, layer of smooth muscle, but less elastic tissue
What are capillaries?
The smallest blood vessels that are branches of capillaries
What do capillaries do? How?
The site of diffusion because their walls are once cell thick
What are venules?
Join together to form veins
What is the structure of venules?
Very thin walls with some muscles cells
What do veins do?
Take blood back to the heart
What is the structure of veins?
Wider lumen and contain valves to stop backflow of blood and have little elastic and muscle tissue
What is tissue fluid?
Fluid that surrounds tissue cells
Where does the blood flow in a capillary bed?
From the arterioles, through the tissue, to the venule
How is tissue fluid formed?
Hydrostatic pressure inside the capillary is higher than the hydrostatic pressure in the tissue fluid. This pressure forces water and other small molecules out of the capillary, forming tissue fluid.
Where does excess tissue fluid drain?
Lymph vessels
What are lymph vessels?
Carry excess tissue fluid to the chest where it is returned to the blood near the heart
What doesn’t tissue fluid and lymph have?
Red blood cells and platelets
Describe the pathway of oxygenated blood in the heart
In through the pulmonary veins, into the left atrium, through the AV valve, into the left ventricle, through the semi-lunar valve and up the aorta to the body
Describe the pathway of deoxygenated blood in the heart.
In through the superior and inferior vena cava, into the right atrium, through the AV valve, into the right ventricle, through the semi lunar valve and up out the pulmonary artery to the lungs
What do valves in the heart do?
Prevent blood from flowing the wrong way
How do the valves open and close in the heart?
If there’s pressure behind the valve it is forced open, if there is pressure in front of the valve, it is forced shut
What is the large vein looking structure that spans across the top of the heart?
The coronary artery
What are the 3 constantly repeated steps in the cardiac cycle?
1) ventricles relax and atria contract
2) ventricles contract and atria relax
3) ventricles relax and atria relax
What does an electrocardiograph (ECG) do?
Records the electrical activity of the heart
What is the structure of one full heartbeat on an ECG?
P,Q,R,S and T
What is P wave caused by on ECG?
Contraction of the atria
What is the QRS complex caused by on an ECG?
Contraction of the ventricles
What is the T wave caused by on an ECG?
Relaxation of the ventricles
What does the height of the wave on an ECG indicate?
The strength of the electrical charge
What is the term for a heartbeat that is too fast?
Tachychardia
What is the term for a heartbeat with an early contraction of the atria?
Ectopic heartbeat
What is the term for an irregular heartbeat?
Fibrillation
What is oxygen carried round the body as?
Oxyheamoglobin
What is haemoglobin? What is its structure?
A large protein with a quaternary structure
How many oxygen molecules can haemoglobin carry?
4
What does the oxygen join to in haemoglobin?
The iron
What is the partial pressure of oxygen?
A measure of oxygen concentration
What does the greater concentration of dissolved oxygen in cells mean?
The higher the partial pressure
When does oxygen load onto haemoglobin?
When there is a high partial pressure of oxygen
When does oxyhemoglobin unload its oxygen?
When there’s a lower partial pressure
Where does oxygen enter the blood capillaries?
At the alveoli in the lungs
What happens when cells respire?
They use up oxygen and lower the partial pressure
What is dissociation? Give an example.
When a molecule is broken into smaller parts. Oxygen dissociating from haemoglobin.
What shape is the dissociation curve for affinity of oxygen?
S shape
What type of haemoglobin has the highest affinity for oxygen?
Fetal haemoglobin
How does a fetus get oxygen?
From its mothers blood across the placenta
How does CO2 concentration affect oxygen unloading?
Haemoglobin gives up its oxygen more readily at higher parola pressures of CO2
What does CO2 from respiring tissues react with? What does this form?
Water to form carbonic acid
What is the formation of carbonic acid catalysed by?
Carbonic anhydrase
What happens when carbonic acid dissociates?
Hydrogen and hydrogen carbonate ions are released
What do H+ ions do?
Cause oxyhemoglobin to unload and forms haemoglobinic acid
What maintains the balance it charge between the RBC? What is it?
The chloride shift. It maintains the balance of charge between a red blood cell and the plasma.
What does myogenic mean?
Heart (cardiac) muscle that can contract and relax without receiving signals from the nerves
What does the SAN do?
Sets the rhythm of the heartbeat by sending out electrical waves
What does the AVN do?
Passes on the waves to the bundle of His
What is the bundle of His?
Group of muscle fibres that conduct the waves to the muscles in the ventricle walls
What is the purkyne tissue?
Carries the waves into the walls of ventricles causing them to contract simultaneous from the bottom up
