Animal Transport Flashcards
What features does a transport system have?
A suitable transport medium to carry materials. A pump such as a heart for moving blood. Valves to maintain the flow in one direction.
What do you some systems have?
A respiratory pigment (which increases the volume of oxygen which can be transported). A system of vessels with a branching network to distribute the transport medium to all parts of the body.
What is an open circulatory system?
It’s when the blood isn’t held in blood vessels but it pays to tissue directly in the blood well held in a cavity called haemocoel.
What animal has an open circulatory system?
Insects
Describe the circulatory system of an insect?
They have a long dorsal tube shaped heart running the entire length of the body. It pumps a haemolymph via vessels which empty into tissue spaces called haemocoel at low pressure so materials can be exchanged between the blood and the cells. Blood return slowly to the heart with little control over circulation. Blood re-enters the heart via pause called ostria and the open circulation starts again.
What is a closed circulatory system?
It is when blood is transported in the blood vessels. The blood is pumped by small muscular heart at high-pressure. The cells are not in direct contact but are bathed in tissue fluid which can exist out of the capillary walls, the blood contains a respiratory pigment.
What is single circulatory
It’s when the blood moves through the heart once in its passage around the body.
Which animals have a single circulatory system?
Fish and earthworms
How does an earthworm circulatory system work?
The blood moves forward in the dorsal vessel and back in the ventral vessel. Five pairs of ‘pseudohearts’ thick and muscular blood vessels pump the blood from the dorsal vessel to the ventral vessel and keep it moving.
How does the fishes circulatory system work?
The ventricle of the heart pumps blood to the gills where the pressure falls oxygenated blood is carried to the tissues and the deoxygenated returned the atrium of the heart blood moves to the ventricle and the circulation starts again.
How does the fishes circulatory system work using a diagram?
Heart —> Gills —-> Body —-> Heart —->
What is a double circulatory system?
It is when the blood passes through the heart twice in it’s circuit around the body.
Which animals have a double circulatory system?
Mammals
How does a mammalian in the circulatory system work?
Blood is pumped by the heart at a high-pressure giving it a rapid flow to the blood vessels. Organs and not in direct contact with the blood but are bathed in tissue fluid which seeps out of the capillaries. Haemoglobin carries oxygen in the blood.
Why is the blood pumped through the heart twice?
As blood pressure decreases in the lungs, the pressure would be too low low to make efficient circulation to the rest of the body so the blood is returned to the heart in order to raise the pressure again so it can be pumped to the rest of the body.
Why is double circulatory system more efficient for mammals?
As they have a high metabolic rate and a high energy requirement their cells needs a large amount of oxygen and glucose and the removal of waste products. It is more efficient as oxygenated blood can be pumped around the body at high pressures.
What is the pulmonary circulation?
It is when the right side pumps deoxygenated blood to the lungs and once oxygenated it returns from the lungs to the left side of the heart. Heart —> Lungs —> Heart.
What is systemic circulation?
It serves the respiring tissue, the left side of the heart pumps the oxygenated blood to the tissues. The oxygenated blood from the body returns the right side of the heart. Heart —> Respiring tissue —> Heart
What are the three types of blood vessels?
Capillaries, veins and arteries
What is the three layers called found within arteries and veins?
Endothelium/ tunica intima, tunica media and tunica externa
What is the tunica intima layer?
It has endothelium which is one cell thick and is surrounded by a smooth flat lining reducing friction with a minimum resistance to blood flow.
What is the tunica media layer?
It contains elastic fibres and smooth muscle which is thicker in the arteries and veins. In the arteries the elastic fibres stretch to accommodate changes to blood flow and pressure as its pants on the heart. At a certain point the fibres recoil pushing blood to the artery this is felt as a pulse and helps sustain pressure. The contraction of this smooth muscle regulates blood flow and maintains blood pressure as blood is transported further from the heart.
What is the tunica externa layer?
The outermost layer contains collagen fibres which resist overstretching as well as help the vessel to withstand high pressure by the strong fibrous proteins.
What happens at the arteries?
High-pressure blood is taken away from the heart to other regions of the body.
Describe the structure of an artery?
It has thick muscular walls to withstand high pressure from the heart with a narrow lumen maintaining the pressure. It contains several elastic tissues in its walls allowing it to stretch to accommodate the surge of blood from the ventricles and to recoil maintaining pressure. They can branch into vessels called arterioles which further subdivide into capillaries these can adjust the diameter to adjust the supply of blood in a certain area by contracting and relaxing the smooth muscle. The smooth endothelium reduces friction.
What is the function of the capillaries?
They provide exchange between respiring cells and materials.
What is the structure of a capillary?
They form a vast network which penetrates all tissues and organs of the body. A capillary wall is one endothelium cells thick with no elastic tissue providing a smooth diffusion pathway for exchange. The lumen has a small diameter which causes friction with the walls slowing the blood flow down low speed down in Hances the ability to exchange materials. The small gaps between the cells make the walls permeable to water and salt. In the last number provides a large surface area for exchange.
What is the purpose of veins?
They return low-pressure blood to the heart from the lungs and respiring cells.
What is the structure of a vein?
It has a thin wall and a wider lumen as it aids in returning low-pressure blood to the heart.
The outer layer is made of collagen resisting stretching with little elastic tissue in a tunica media as less as needed as the pressure is low.
For veins above the heart blood travels back by gravity. It moves other veins high-pressure from the surrounding muscles.
They have semilunar valves along the length ensuring flow in one direction preventing back flow.
Blood in the veins has no influence from the heart contractions. Blood from organs below the heart goes there by the venous pumped produced by the action of skeletal muscle. Negative pressure in the thorax produced during inspiration.
What can faulty valves cause ?
Heart failure and varicose veins
Where is the highest pressure of blood?
When the blood leaves the heart
What type of contraction causes a rhythmic rise and fall in pressure?
Ventricular contraction
What happens in terms of pressure in the arterioles?
There is a drop in pressure as they have a large total surface area and narrow lumen. The drop also depends on whether they are dilated or constricted
What is the pressure like in capillaries?
They have low pressure as they have a large total cross-sectional area with a greater resistance to bloodflow. The pores can cause leakage from the capillaries to the tissues causing even further drop.
What is the pressure like in the veins?
Its is low and non rhythmic, so muscles massage the veins to aid the returning of blood.
What is what happened at the Vena cava?
Blood is returned from all organs apart from the lungs..
What happened at the pulmonary vein?
Blood is returned from the lungs.
What happens at the left atrium?
Receives blood from the lungs and pushes it to the ventricle.
What happens at the atrioventricular valve?
It stops blood from flowing back into the atrium during ventricle systole.
What happened at the left ventricle?
It receives blood from a trim and push it to the body.
What happens at the semilunar valves?
It stops blood from flowing to ventricle when it relaxes.
What is the function of the aorta?
It distributes blood to all organs except the lungs.
What is the function of the pulmonary artery?
Distribute blood to the lungs
What is the function of the pulmonary valves?
Stops blood from flowing back into the ventricle as it relaxes.
What happens in the right ventricle?
Blood is received from the atrium and pushes it to the lungs.
The tricuspid (atrioventricular )valve is found on what side?
Right
The bicuspid valve is found on what side?
Left
What is the heart?
It is two separate pumps, 4 chambers which are used both pulmonary and systemic circulatory systems. The atria is thin walled chambers which collect the blood, artrium are found above the thick walled chambers called the ventricles this allows complete separation between oxygenated and deoxygenated blood.
What is the heart made from?
It consists of cardiac muscle which never tires with myogenic contraction (it can contract and relax rhythmically on its own accord). The heart rate can be modified by nervous and hormonal stimulation.
Which side has a high-pressure atrium or ventricle?
The ventricle side has high pressure because it has a thicker muscle wall as it needs to pump blood to respiring cells around the body whereas the atrium only has to pump blood to the ventricle with a thin muscular wall.
Which ventricle has high pressure?
The left ventricle has the highest pressure as it has to pump blood through the aorta to the rest of the body to respiring cells and muscle wall is three times thicker than the right ventricle muscle wall which only has to pump blood to the lungs.
