Chapter 8: Transport In Mammals Flashcards
Why do mammals need efficient transport systems?
Animals perform greater activities like muscle contraction and nervous impulses and therefore have a higher demand for oxygen.
What is the physiological reason for why larger animals need complex transport systems?
They have lower surface area to volume ratios
What are the different reasons for why a metabolically active cell might need might need an efficient transport system?
To supply oxygen for respiration, nutrients for metabolic processes and for the removal of wast products.
What is the cardiovascular system?
It is the system that pumps blood around mammals, composed of a heart and blood vessels that remain in a closed system.
What is systemic circulation?
Is is the circulation of blood around the body from the aorta to the vena cava. Systemic circulation excludes the pulmonary circulation which goes through the lungs.
What is the carotid artery?
They are blood vessels in the neck that supply the brain and head with blood.
What is the jugular vein?
It is a paired venous structure that collects blood from the brain, superficial regions of the face and brings it to the right atrium.
What is the subclavian artery?
It is the blood vessel that supplies the thorax (head, shoulder, neck and arms) with blood.
What is the subclavian vein?
It is the blood vessel that drains blood from the upper extremities.
What is the aorta?
It is the main blood vessel that carries blood away from the heart.
what is the pulmonary artery?
It is the main artery that carries deoxygenated blood away from the heart to the lungs in order to get oxygenated.
What is the hepatic artery?
is supplies oxygenated blood to the liver, pylorus of the stomach, duodenum, pancreas and the gall bladder.
What is the renal artery?
It is the artery that carried blood away from the heart tot he kidneys in order for it to get filtered.
What is the mesenteric artery?
It is the artery that takes blood to the major portion of the GIT, going through the mesentery.
What is the iliac artery?
It carries blood to the lower limbs
What is the iliac vein?
Carries blood away from the the lower limbs
What is the Renal Vein?
It is the vein that carries blood away from the kidneys after filtration back to the the heart.
What is the hepatic portal vein?
Is the vein that conveys blood to the liver from the spleen stomach, stomach, pancreas and intestine.
What is the hepatic vein?
The hepatic veins are the veins that drain de-oxygenated blood from the liver into the inferior vena cava
What is the vena cava?
It is the main vein that brings back deoxygenated blood to the heart.
What is the pulmonary vein?
it is the vein that brings back oxygenated blood from the lungs to the heart.
What does the pulmonary circulation mean?
It involves the pulmonary artery and pulmonary vein that would bring blood to the lungs
What does the term ‘Double Circulation’ mean?
It is the combination of the pulmonary circulation and the systemic circulation where the blood flows through the hear twice in one circulation.
What is the basic difference between arteries and veins?
Arteries carry blood away from the heart and veins carry blood towards the heart.
Name the three layer that an artery is composed of.
- The Endothelium (tunica intima)
- Tunica media
- Tunica Externa
Describe the composition of the three layer of the heart.
Tunica intima: Made of squamous epithelial cells that are arranged in a jigsaw fashion that reduces friction.
Tunica Media: Made of smooth muscle, collagen anf elastic fibres
Tunica Externa: Elastic fibres and collagen fibres
Why is the arteries really thick and elastic?
So that it can carry blood at high pressures
What are the dimensions of the Aorta?
2.5 cm diameter
2 mm thick wall
Describe the composition of the tunica media the further away web go from the heart.
The tunica media usually just has elastic fibres that allow stretching.
however, the further away we go from the heart, the more muscle fibre we have.
How the arteries smoothen the flow of blood?
The blood is pumped in pulses where the walls stretch to reduce the pressure and then recoil to increase the pressure to push it down.
How do the arteries reduce the likelihood of bursting?
the stretching and recoiling maintain the pressure from the the aorta.
What is the role of the arterioles?
It regulates the volume of blood flowing into the tissues based on the demand by dilating and constricting.
What allows the dilation and constriction of the arterioles?
The presence of smooth muscle.
Describe and explain the changes in blood pressure from the arteries to the arterioles?
Blood pressure drops from the arteries to the arterioles due to the increased SA: Volume ratio.
What are capillaries?
They are tiny blood vessels that go near the tissue to supply nutrients by forming capillary beds around the tissue.
How are the capillaries adapted to get as close to the tissue as possible?
They are made of only endothelial cells that allows blood to be brought as close to the tissue as possible.
What is the function of the endothelial gaps in the capillaries?
They allow components of blood to seep through into the spaces between the cell.
How is blood returned back to to the heart?
The capillaries will join to form venules that will eventually join to form veins, that will eventually reach the heart via the vena cava.
Why do vein have really thin tunica media?
Because the blood pressure in the veins is really low.
How does the the veins flow blood back to the heart if the pressure is really low?
The veins form semilunar valves that form on the endothelium the pump the blood back to the heart.