Transport in animals

    Master this deck with 89 terms through effective study methods.

    Imported from Quizlet

    Created by @jbf

    Why do large organisms require transport systems

    The metabolic demands of large organisms means diffusion over the long distance isn't enough to fuel them

    What's an open circulatory system

    Few vessels to contain the transport medium. It is pumped straight from the heart into the body cavity of the animal called the haemocoel. In the haemocoel there is low pressure and it comes not direct contact with the tissues. It returns through an open ended vessel

    Where are these open circulatory systems found

    Found in invertebrate animals including insects

    What is insect blood called and how does it flow around the body

    Haemolymph. It can't maintain a steep concentration gradient for efficient diffusion. It doesn't carry any oxygen or carbon dioxide. Flows back to the heart which stretches across the thorax and abdomen

    What are closed circulatory systems

    The blood is enclosed in blood vessels and doesn't come into direct contact with the cells. The amount of blood flowing to a particular tissue can be controlled by narrowing or widening blood vessels and flows under high pressure

    What is a single closed circulatory system

    Single closed circulatory systems are found in fish. The blood flows through the heart around the body and back to the heart. Blood flows through 2 capillaries before going to the heart so blood pressure is low

    Why do fish have a particularly efficient single circulation system

    They have a countercurrent gaseous exchange in their gills which lets them take in lots of oxygen from water.

    What allows fish to be so active

    The efficient counter current system alongside their low metabolic demands as their body weight is supported by water and they don't maintain their own body temperature

    Why do birds and mammals require double closed circulatory systems

    They maintain their body temperature and are active.

    Describe the double closed circulatory systems

    Blood is pumped from the heart to the lungs to pick up oxygen and unload carbon dioxide and then returns to the heart Blood flows through the heart and is pumped to the rest of the body before returning

    What are the 3 components used in blood vessels

    Elastic fibres- composed of elastic and can stretch and recoil Collagen- provides structural stability Smooth muscle- can contract or relax to change the size of the lumen

    What are the two arteries that carry deoxygenated blood

    pulmonary and umbillical arteries

    What do the elastic fibres do in arteries

    They stretch when blood is pumped out of the heart andim between contracts they recoil and rerun to their original length which helps to maintain blood pressure and smooth out the blood flow

    What are arterioles

    Link the arteries and capillaries

    Describe the structure of an artery

    Have a narrow lumen and a smooth endothelium layer to allow blood to pass over it, then an elastic layer, then a muscle layer and then a collagen layer

    Describe the structure of an arteriole

    Have more smooth muscle and less elastin in the cells as they have little pulse surges and can construct and dilate to alter blood flow to specific organs

    What's it called when an arteriole prevents blood from flowing to a capillary bed

    Vasoconstriction

    What's it called when an arteriole widens to allow blood flowing to a capillary bed

    Vasodilation

    What happens to the proportion of elastic fibres as the blood vessels get further from the heart

    Decreases as greater pressure closer to the heart so more elastic fibres needed to stretch during systole and recoil during diastole to even blood flow

    What happens to the proportions of collagen in blood vessels further away from the heart

    Decreases as less collagen needed for support as the blood pressure is lower

    What happens to the proportion of smooth muscle in blood vessels further from the heart

    Aorta has the least then a medium sized artery has more as more involved in vaso construction/dilation and an arteriole has more proportionally but less overall

    What are capillaries

    Microscopic, one cell-thick vessels that connect arterioles and venules

    Describe the blood entering the capillaries from arterioles

    Oxygenated

    Describe blood entering capillaries from venules

    Deoxygenated

    How are capillaries adapted do their role

    Very large surface area for diffusion of substances The total cross-sections area of the capillaries is larger then the arteriole so blood flood flow is slower and more time for diffusion of materials The walls are a single endothelial cell thick

    What are the two veins that carry oxygenated blood

    pulmonary and umbilical veins

    What are the names of the two main veinscarryingdepxygenated blood back to the heart

    Inferior vena cava and superior vena cava

    What's the blood pressure like in veins

    they have no pulse surge and its much lower

    what is the structure of a vein

    they have little elastic fibres and lots of collagen and the vessels have a wide lumen and a smooth lining called the endothelium

    explain how a one-way valve works

    these are flaps of the inner lining of the vein and when blood flows in the direction of the heart the valves open to let blood flow but if it flows backwards they close

    how do muscles help blood flow in veins

    many of the bigger veins run between the big muscles in the body like arms and legs. When they contract they squeeze the veinns forcing the blood towards the heart

    How do breathing movements help blood flow in veins

    The breathing movements of the chest act like a pump. The pressure changes and the squeezing actions move blood in the veins of the chest towards the heart

    What is the name of the valve inbetween the left atria and left ventricle

    bicuspid valve

    What keeps the atrioventricular valves from turning inside-out from the pressure

    Tendinous cords

    What's the name of the valve in between the right atria and right ventricle

    tricuspid valve

    What is the name of the valve between the major arteries in the heart and the ventricles

    semi-lunar valves

    How long does a heart-beat last in an adult

    0.8 seconds

    What is diastole

    the heart relaxes. The atria and ventricles fill with blood and the pressure starts to build. The pressure in the arteries is it a minimum

    What is the term for when the atria contracts

    Atrial systole

    What is the name for when the ventricles contract

    ventricular systole

    Describe systole

    Atriole systole occurs closely followed by ventricular systole and pressure inside the heart increases dramatically. blood is forced out of the right side of the heart to the lungs and from the left side to the main body. The volume and pressure in the heart are low but in the arteries at a maximum

    how do you get the lub- dub sound in a heart beat

    the lub sound comes from when the atrioventricular valves close during the beginning of ventricular systole and the dub sound comes from the semi-lunar valves closing when the ventricles relaxw

    what does myogenic mean in the heart

    the heart is able to make its own rhythm independent of any electrical signals

    what does the sino-atrial node stimulate

    the walls of the atria to contract

    What picks up the wave of excitation from the sino-atrial node

    the atrio-ventricular node (AVN)

    Why is there a slight pause before the AVN passes on the electrical signal

    To make sure the atria have stopped contracting by the time the ventricles contract

    what picks up the wave of excitation from the AVN

    the bundle of His

    What is the budle of His made out of

    Conductive tissue called Purkyne fibres

    how do you monitor the electrical control of the heart

    An electro-cardiogram

    What is Tachycardia

    when your resting heart rate is too quick (above 100bpm)

    What is Bradycardia

    When your resting heart rate is too slow (below 60bpm)

    What is an ectopic heartbeat

    An extra or 1 less heartbeat that is out of the normal rhythm. Most people have one per day. Irregular

    What is atrial fibrillation?

    irregular rapid heart beat. When the atria contract a lot and the ventricles much less frequently

    What is the composition of blood

    made of plasma- carries all the components like glucose and amino acids and fibrinogen, globulins. Transports red and white blood cells and platelets

    What are platelets made from and where are they made

    made up of megakaryocutes found in the red bone marrow, used in clotting

    what is the name for red blood cells

    erythrocytes

    what is the name for white blood cells

    leucocytes

    name some large plasma proteins

    albumin which has a role in osmotic effect

    what is oncotic pressure

    the large plasma proteins gives the blood in the capillaries a low water potential compared with the surrounding fluid. As a result water has a tendency to move into the blood of the capillaries

    what is the standard oncotic pressure

    -3.3 kPa

    what is hydrostatic pressure

    when blood flows through the blood vessels and is under pressure from the surge of blood that occurs when the heart contracts and is forced outwards

    what is the standard hydrostatic pressure at the arterial end of the capillaries

    4.6 kPa

    what is the standard hydrostatic pressure at the venous end of the capillaries

    2.3 kPa

    What is the net movement of fluid in the arterial end of the capillaries

    the hydrostatic pressure is stronger then the oncotic pressure so fluid moves out to form tissue fluid

    What is the net movement of fluid in the venous end of the capillaries

    Fluid has moved out of the vessels and a pulse is completely gone so now oncotic pressure is higher then hydrostatic pressure so fluid moves back into the capillaries

    what is tissue fluid

    the fluid that fills the spaces between the cells and has the same composition as plasma, without red blood cells and plasma proteins

    What is lymph

    10% of tissue fluid doesn't return to the capillaries and drain into a system of lymphatic capillaries.

    What's the composition of lymph

    Similar in composition to tissue fluid but with fewer nutrients and has fatty acids

    how is lymph moved in lymph vessels

    through he squeezing of the body muscles and there are one-way valves to stop backflow

    What are lymph nodes?

    lymph nodes filter out debris and bacteria from the lymph which are destroyed the immune system. Lymphocytes also build up here and make antibodies

    What is the reaction between haemoglobin and oxygen

    Hb + 402 -> Hb08

    what substances do arterial blood contain

    it has large proteins, erythrocytes and neutrophils

    What substances do tissue fluids have

    has no large proteins or erythrocytes but has neutrophills

    what substances do lymph have

    has no erythrocytes or large proteins but has neutrophills

    What happens when carbon dioxide reacts with oxygen

    C02 + H20 <--> H2C03 Carbonic acid is made

    What enzyme catalyses the breakdown of carbonic acid

    carbonic anhydrase

    What does carbonic acid turn into

    H2C03 -> H+ +HC03-

    Why is it bad if carbonic acid is in the blood

    it denatures the blood proteins

    What happens when hydrogen ions bond with haemoglobin

    Hb + H+ <--> HHB Haemoglobinic acid This causes the release of oxygen from haemoglobin

    So what happens to the relative amounts of oxygen released with different concentrations of C02

    More C02 causes more oxygen to be released which is useful during exercise

    What's the structure of Myoglobin

    found in two forms Oxymyglobin Deoxymyglobin

    Describe the Bohr effect

    At high levels of carbon dioxide the percentage saturation of haemoglobin with oxygen is lower because more oxygen is released.

    What's the oxygen association curve graph with the Bohr effect look like

    more to the right and further down

    What is myoglobin

    pigment that stores oxygen in muscles. Always more saturated with oxygen than haemoglobin

    What is foetal haemoglobin

    The foetus needs oxygen from maternal haemoglobin. It diffuses from maternal blood to foetus via placenta. Foetal haemoglobin has a higher Affinity or association potential.

    what is the name for HC03-

    hydrogen carbonate

    Why is it crucial that the foetal haemoglobin is different to the adult haemoglobin

    Foetus gains oxygen from the mother across the placenta The partial pressure oxygen in the placenta is low Maternal haemoglobin releases oxygen Foetal haemoglobin has a higher affinity for oxygen Maintains a diffusion gradient

    Why do foetuses have to make a switch to adult haemoglobin

    Oxygen would not be released readily enough Because affinity of foetal haemoglobin would be too high

    What is the oxygen association curve of foetal haemoglobin vs adult haemoglobin

    Foetal haemoglobin is more to the left so it has a higher affinity to oxygen