Animal Transport

Eduqas biology

Why dont single-celled organisms need a transport system?

-SA:V is high

-short distrances to travel

-low metabolic needsWhat

What is insect circulatory system?

open, with a dorsal, tube shaped heart and a fluid filled cavity

How does circulation in insects happen

Blood is pumped at low pressure into the haemocoel where it bathes the tissue directly for exchange of materials

Blood slowly returns to the heart and then is pushed forward tp the head where open circulation starts again

circulation system in earthworms

organs are not in direct contact with the blood but are bathed by tissue fluid. Respiratory gases are transported in the blood, aided by a pigment. has dorsal and ventral vessels running the length of the body, running the length of the body, connected by the 5 pseudohearts which pump the blood

single system

where blood passes through then heart once

double system

where blood passes throigh the heart twice and there re seperated systemic body and pulmonary systems

Three layers in blood vessels

-tough collagen

-elastic muscular layer to sustain pressure

-endothelium which is smooth to reduce friction

Arteries

thick walls to resist high pressure. They are able to adjust diameter to adjust blood supply and blood pressure

label artery and vein

veins

thinner muscle layer than arteries

-larger diameter than arteries

-reduced pressure compared to arteries

valves to flow in one direction only

capillaries

-walls are one layer thick and permeable

-small diameter

friction in walls slow down blood flow

-many capillaries in a bed for a large total crosssectional area, which further reduces blood flow

-low velocity to enhance ability to exchnage materials with surrounding tissue

-gaps that allow exchange of material

capillary

heart

cardiac muscle

intercolated discs, branched, faintly striated. MYOGENIC

the cardiac cycle

1- diastole, atria and ventricles relax and blood enters heart

2- atrial systole, atria contract and ventricle react, blood enters ventricle

3-ventricular systole, ventricle contracts and blood is forced out of heart.

more detailed heargt

How does the heart contract

the SAN sends a wave of excitation across the atria causing them to contract at the same time

This is prevented from spreading to the ventricles by a thin layer of connective tissue

Instead it spreads via the atrioventricular node, through the bundle of His to the apex of the ventricle . This branches into the Purkinje fibres which carry the wave of excitation through the ventricle muscle .

What does LVEDV mean

left ventricular end diastoli volume (volume of blood in the ventricle at the end of filling)

What does LVP mean

left ventricular pressure

LVESV

left ventricular end systolic volume (volume of blood in the ventricle at the end of emptying)

graphs

What are electrocardiograms

the electrical activity through the heart can be detected using electrodes

What does a ECT wave (healthy) look like

What does the P wave on an ECG show

the depolarisation of the atria during atrial systole

What does QRS wave on an ECG show

the spread of depolarisation through the ventricles resulting in ventricular systole

What does the T wave in an ECG diagram show

the repolarization of the ventricles during ventricular siastole

Where is blood pressure the highest and what does ti show

in the aorta and main arteries, showing rhythmic rise and fall corresponding to ventricukar contraction

Why does blood pressure drop as it moves away from the heart?

friction between blood cells and vessel walls as blood flows further from the heart

How do arterioles and capilleries affect blood flow?

large total surface area and narrow bore create high resistance. Lowers aortic pressur and slows down blood flow.

Whats the relationship between blood velocity, pressure and capillary beds?

velocity is directly related to pressure

Return flow to the heart

non-rhythmic. Pressure in veins is low but can be increased by the massaging effect of the muscles

red blood cells

erythrocytes

white blood cells

leucocytes

1-Granulocytes- granular cytoplasm and lobved nucleis. Phagocytic

2-agranulocytes- clear cytoplasm and spherical nuclei. produce antibodies

adaptations of Erythrocytes

-biconcave discs- large SA:V, flexible to pass through capilleries

-Haemoglobin- carries 12x more oxygen

-no nuceleus- more volume for Hb

Haemoglobin structure

4 subunits of a polypeptiude chain surrounding a haem gorup

Each haem group can carry one oxygen molecule

What is Partial Pressure of oxygen

a measure of oxyge concentrations.

21 kPA (atmospheric pressure = 100kPa)

What is an oxygen dissasociation curve

shows relationship between oxygen tension in surrounding environment and oxygen saturation in haemoglobin

Describe an oxygen dissociation graph

The curve is S-shaped. It is harder for the first o2 to join and it joins slower. When it loads/associates a conformational change in the haemoglobin shape occurs. This gives it a higher affinity for the next to oxygen to load, causing the steep section of the graph. Called positive cooperativity

It is more difficult for the last oxygen to load.

at low partial pressure haemoglobin has a low affinity for oxygen

Foetal haemoglobin

Lies to the left- showing it has a greater affinity for oxygen

The Bohr effect (oxygen dissasociation curve)

in hight CO2 the curve shifts to the right so Hb more readily gives up its O2. (UNLOADsS in Low CO2 it shifts to the left, LOADING oxygen mroe readily.

In active tissues there is more respiration = more CO2 = tissues need more oxygen = more unloading

Opposite in lungs

LLAMA haemoglobin adaptation

at high altitude there is a drop in atmospheric prssure so ppO2 is less. This means the haemoglobin must have a high affinity for oxygen and curve shifts to the left

LUGWORM haemoglobin adaptations

They burrow in the sand. ppO2 in the water in the buyrrow is low so their haemoglobin has a high affinity for oxygen and have low metabolic needs

How is carbon dioxide transported

-5% in solution in plasma

-10% combines with haemoglobin to make Carbaminohaemoglobin

-85% as hydrogen carbonate

Bohr effect and chloride shift in blood

Bohr effect in lungs

How is tissue fluid formed

ultrafiltration, formed by two pressures:

Osmotic pressure- pulling materials into capilleries

Blood pressure- forcing materials out of capilleries

has water, gluose, amino acids, fatty acids,glycerol, mineral salts, vitamins

tissue fluid journey

At the begining of the capillary beds water and small solutes pass out throuhg the endothelium. The presence of proteins means hydrostatic pressure is greater then water potential and osmotic pressure.

At the end of the tissue bed the hydrostatic opressure had dropped due to loss of fluid and resistance of blood flow through capilleries. Osmotic pressure causes water and solutes to flow back in

T.S of an artery

T.S of vein