3.1.2 transport in animals

characteristics of circulatory systems:
-_______ medium eg. haemolymph
-______ to transport medium
-________ to move fluid around

liquid transport, vessels, pumping mechanism

blood is not contained within blood vessels but is pumped directly into body cavities

open circulatory system

lood is pumped around the body always contained in a network of blood vessels

closed circulatory system

blood passes through the heart once during a complete circuit of the body

single circulatory system

blood passes through the heart twice during a complete circuit of the body

double circulatory system

nsect circulatory system
_____ system
-____heart pumps _______into the _____ vessel
-haemolymph surrounds the organs
-haemolymph renters the heart via the ___
-oxygen is delivered directly to the tissue so this system is only needed deliver/remove nutrients and waste

open , tubular, haemolymph, dorsal, ostia

fish circulatory system
_____ system
-deoxygenated blood is pumped to the ___ from the heart
-gas exchange occurs in the gills
-oxygenated blood flows through ____ to the rest of the body

single closed, gills, capillaries

mammal circulatory system
type: ___ ___
-blood on the ____ side of the heart travels to the lungs
-gas exchange occurs at the lungs
-blood returns to the ___ side of the heart and is pumped through the body through blood vessels
-blood returns to the right side of the heart

double closed, right, left

advantages of double circulation
-maintains _____ blood pressure and average speed of flow
-this helps to maintain a ____ concentration gradient which allows for efficient exchange

higher, steeper

carry oxygenated blood away from the heart to the body, except the pulmonary artery which carries deoxygenated blood form the heart to the lungs and umbilical artery

arteries

-blood is the arteries in under a _____ pressure
-______ enable arteries to withstand the force of blood and stretch to take a larger blood vol and return to original length
-_____ limits the stretch of the arteries
-lining of the artery, _______, is smooth so blood flows easily over it

high, elastic fibres, collagen, endothelium

link arteries and capillaries

arterioles

-more _ and less ___ than arteries, as they have little pulse surge
-_____; smooth muscle contracts to constrict the vessel and prevents blood flowing in the capillary bed
-_____; smooth muscle relaxes to constrict the vessel and allows blood flowing in the capillary bed

smooth muscle, elastin, vasoconstriction, vasodilation

microscopic blood vessels that link the arterioles and the venules

capillaries

capilaries
-___is small so erythrocyte have to travel in single file
-surface exchange occurs here
-large SA
-total cross-sectional area of capillaries is ____ than the arteriole suppling it, so slower movement of blood means more time of the exchange of materials
-walls are a single _____ cell thick
-gaps between endothelial cells that make up the lumen are relatively large, except the junctions between nervous cells

lumen, greater, endothelial

small veins that carry blood from the capillaries into larger veins

venules

carry deoxygenated blood away from the cell towards the heart, except the pulmonary vein which carries oxygenated blood form the lungs to the heart and umbilical vein which carries oxygenated blood form the placenta to the fetus

veins

veins
-blood is at a low pressure in the blood
-walls contain lots of ___ and little
-the lumen is very _ and the endothelium is smooth to allow blood to flow smoothly
-contain valves to prevent the backflow of blood one-way valves-flaps/infolding in the inner lining of the vein and only open when blood if flowing in one way
-larger veins run between large, active muscles so when the muscle contract they squeeze the veins, forcing blood towards the ___. the valves prevent backflow when the muscle ____
-breathing movements act as a ___, the pressure change and squeezing actions move blood in the veins in the chest and abdomen towards the heart

collagen, elastic fibre, wide, heart, relax, pump

the pressure created by water in an enclosed system

hydrostatic pressure

the tendency of water to move into the blood by osmosis as a result of the plasma proteins

oncotic pressure

maintains osmotic potential of blood

albumin

important in blood clotting

fibrinogen

involved in transport and immune system

globulins

fragments of megakaryocytes, which are in the red bone marrow

platelets

tissue fluid
-large plasma proteins have an osmotic effect as they give the blood in the capillaries a ___ solute potential, so ___ water potential; this causes water to move into the blood in the capillaries from the surrounding fluid

high, low

tissue fluid
-as blood flows through the capillaries it is still under presure from the surge of blood that occurs when the heart contracts
-the hydrostatic pressure is __ than the oncotic pressure so fluid is squeezed out of the capillaries
-this fluid fills in the spaces between the cells and is called tissue fluid and has the same composition as ____
-as blood moves through the capillaries towards the venous system the hydrostatic pressure ___, the oncotic pressure stays the same
-the oncotic pressure is ___ than the hydrostatic pressure so water moves back into the capillaries as it reaches the venous end of the capillaries

high, higher, plasma, decreases, higher

filtration pressure

hydrostatic pressure - oncotic pressure

lymph
-tissue fluid that leaves the blood vessel that drains into lymph capillaries
-similar to plasma composition but with less O2 and nutrients and contains___that have been absorbed from the small intestine
-lymph ___ join up to form larger vessels through which lymph is transported through the squeezing of ___ and have valves to avoid the backflow of lymph
-lymph returns to the blood in the veins
-lymphocytes build up in the ___ to produce antibodies
-lymph node intercept bacteria and debris from lymph and ingested them by phagocytes
-enlarged lymph nodes are a sign the body is fighting of a pathogen

amino acids, capillaries, muscles, lymph nodes

-deoxygenated blood enters the heart from the upper body + head from the ____ vena cava and the from the lower body from the ____ vena cava
-the atria have ___ muscular walls
-as the pressure builds up the atrio-ventricular valve opens, allowing blood to pass into the ___ ventricle
-when both atrium and ventricle are filled with blood, the atrium ___, forcing all the blood into the right ventricle, stretching the ventricle walls
-as the right ventricle starts to contract, the ___ valve closes, preventing the backflow of blood to the atrium
-the ____ cords make sure the valves are not turned inside out by the pressure exerted
-right ventricle contracts fully and deoxygenated blood is pumped through ___ valves into the ___

superior, inferior, thin, right, contracts, tricuspid, tendinous, semilunar, pulmonary artery

-oxygenated blood enters from the ___
-as pressure builds in the atrium, the ___ valve opens and blood flows into the left ventricle
-left ventricle fills with oxygenated blood and once the atrium and ventricle are full, the atrium ___ forcing all the blood into the left ventricle
-left ventricle contracts (tricuspid valve close to prevent the backflow of blood) and pumps oxygenated blood through semilunar valves into the ___ and around the body
-muscular wall on the left side is ___ than the right as a higher force is needed to overcome the resistance of the aorta and arteria systems to move blood

pulmonary vein, biscupid, contracts, aorta, thicker

the events in a single heartbeat

cardiac cycle

the heart relaxes, the atria and ventricles fill with blood

diastole

the atria contract then the ventricles

systole

cardiac output

heart rate x stroke volume

cardiac muscle is ____-it has its own rhythm which prevents the body wasting resources maintain the basic heart rate

myogenic

region of the heart that initiates a wave f excitation that triggers the contraction of the heart
-causes the atria to contract
-a layer of non-conducting tissue prevents the excitation passing directly to the ventricles

sino-atrial mode

recording of the electrical activity of the heart by measuring tiny electrical differences in the skin

electrocardiogram

-heartbeat is very rapid, over 100bpm
-often normal due to exercise, fever, fear or anger
-abnormal due to problems in the electrical control of the heart and many need medication or surgery

tachycardia

-heart rate slows down, below 60bpm
-training make the heart beat more slowly and efficiently
-severe cases can be serious and may need an artificial pacemaker

bradycardia

-an example of arrhythmia, which means an abnormal rhythm of the heart
-rapid electrical impulses are generated in the atria
-they contract very fact but didn't contract properly and only some impulses are passed on to the ventricles
-heart doesn't pump blood very effectively

atrial fibrillation

-extra heartbeats that are out of normal rhythm
-usually normal, most people experience at least 1 a day
-if frequent can be linked to serious conditions

ectopic heartbeat

-small change in partial pressure of O2 make a ___ difference to the saturation of haemoglobin with O2 as the change in shape of haemoglobin means O2 molecules are added more ____

larger, rapidly

catalyses the reaction between CO2 and H20 to form carbonic acid dissociates to form hydrogen carbonate ions and hydrogen ions

carbonic anhydrase

-negative hydrogen carbonate ions move __ of erythrocytes into the plasma by diffusion and negatively charged chloride ions move ___ erythrocytes to maintain the ___ balance of the cell

out, into, electrical

-acts as a buffer and prevents changes in the pH by accepting free hydrogen ions in a reversible reaction

haemoglobinic acid

effect of carbon dioxide
-as the partial pressure of CO2 ___, haemoglobin O2 more easily, known as the Bohr affect as a result
-active tissues with a partial pressure of CO2, haemoglobin give up O2 more readily
-lungs where CO2 is lower, O2 bind to haemoglobin-lungs where CO2 is lower, O2 bind to haemoglobin molecules easily

rises, gives up, high

fetal haemoglobin
-oxygenated blood from the mother runs close to the deoxygenated fetal blood in the placenta
-if the blood of the fetus had the same affinity for O2, little O2 would be transferred to the blood of the fetus
-fetal haemoglobin has a ___ affinity of O2 than adult haemoglobin

higher

stimulates the ventricles to contract after imposing a slight delay to ensure atrial contraction is complete
-imposes a slight delay before stimulating the bundle of His
-His are a bundle of conducting tissue made up of Purkyne fibres which penetrate through the septum between the ventricles

atrio-ventricular node