B9 - Transport in Humans

Explain how do blood clots form

- Blood vessel is damaged; a signal is sent to platelets which rush to the site of damage - fibrinogen is converted to insoluble fibrin to form a mesh that traps red blood cells

Compare the circulatory system of fish to animals

- Fish have a single circulatory system (blood flows through he heart once during a cycle), whereas animals have a double circulatory system (blood flows between the heart and lungs, and the heart and body). - In fish blood is oxygenated at the gills, whereas in animals this occurs at the lungs - Both fish and animals transport blood in arteries and veins

Describe how blood travels from the lungs to the right ventricle

- Oxygenated blood travels from the lungs along the pulmonary vein into the left atrium. - The left atrium contracts, causing the atrioventricular valves to open and blood to enter the left ventricle. - The atrioventricular valves close and the left ventricle contracts, causing the semi-lunar valves to open and blood to flow along the aorta towards to the rest of the body to deliver oxygen. - The semi-lunar valves close to prevent backflow of blood from the aorta into the left ventricle

Describe how blood travels from the body to the lungs

- The vena cava rings deoxygenated blood from the body into the heart - The deoxygenated blood enters the right atrium - The atria contract forcing blood into the ventricles - The atrioventricular valve close the stop blood flowing backwards out of the heart - The semi lunar valves close - The pulmonary artery now takes the deoxygenated blood away from the heart to the lungs

Where do arteries, capillaries and veins carry blood to?

A - carries blood away from the heart (except for coronary artery C - all directions V - to the heart

What type of blood do arteries, capillaries and vein carry?

A - oxygenated (except for pulmonary artery) C - both V - deoxygenated

Explain what is meant by a double circulatory system

A circulatory system that keeps oxygenated and deoxygenated blood separated. There is one system between the heart and lungs, and one between the heart and body

Name the blood vessel that carries oxygenated blood under high pressure

Aorta (artery, oxygenated = from the heart)

What is coronary heart disease?

Arteries became narrowed by a gradual build up of fatty martial within their walls - fat is deposited in walls of coronary arteries - arteries are blocked / blood flow is restricted in arteries - less / no, blood flow to, heart muscle - less / no, nutrients, glucose, oxygen reaches heart - the heart muscle cannot respire anaerobically

Name 5 blood vessels

Arteries, arterioles, capillaries, venules, veins

What is the function of atrioventricular valves?

Atrioventricular valves close when the ventricle contracts so prevent backflow of blood from the ventricle to the atrium

What is the function of artierioles?

Carry blood from arteries to capillaries. Receive nerve impulses and change diameter (links to temperature control in homeostasis topic 14)

What is the function of venules?

Carry blood from capillaries to veins

What does the pulmunory vein do?

Carry oxygenated blood from the lungs to the heart

What is angina?

Chest pain, discomfort, tightness occurs

What is the function of semi-lunar valves in the aorta?

Close when blood is in the aorta (=higher pressure), preventing backflow from the aorta into the left ventricle

How can someone reduce the risk of coronary heart disease

Don't smoke, low salt diet, regular exercise

How can coronary heart disease be treated?

Drug treatment: aspirin to thin the blood, reduces the risk blood clotting Surgery - stent: a small metal tube is inserted to help keep the artery open, restore blood supply - angioplasty: inflating a small balloon inside the artery to widen it - heart by-pass: a blood vessel is taken from another part of the body and is attached to carry blood around the blocked artery

How can you monitor the heart?

ECG, Measure pulse, listen to valves closing

What is the function of a capillary?

Exchange of substances between blood and cells

If you investigate the affect of different types of exercise on pulse rate what is the IV, DV, CV?

IV - Different types of exercise DV - Pulse rate before, during / after CV - length of time of exercise, age/gender of participants etc

What do the valves in lymph capillaries do?

It allows the tissue fluid to enter but will not let the lymph pass out

How is tissue fluid useful?

It helps substance diffuse into an out of the cells

What is thrombosis?

It is when blood vessel are blocked. - Healthy arteries have a smooth lining which allows blood to flow easily - Atherosclerosis occurs (build up of fatty materials) causing blood to be disrupted; slowed down or stopped

Name the 3 parts of the blood circulatory system

Lungs, heart, blood vessels

What does an ECG do?

Monitors the activity of the heart by looking at the electrical activity of the heart

Why is the left ventricle wall thicker than the right?

More muscular tissue in the left ventricle wall, in order to create a contraction to create more pressure to push blood around the body, whereas the right ventricle only needs to create enough pressure to push blood to the lungs

Explain how the structure of a capillary is suited to its function

Narrow lumen causes blood to flow slowly to maximise time for exchange of substances, walls made of one layer of cells creating a short exchange pathway

What is the function of the atrioventricular valves?

Prevent backflow of blood from the ventricles into the atria when the ventricles contract

Outline the function of the semi-lunar valves

Prevent backflow of the blood from the arteries into the ventricles when the ventricles contract

Why is it important that blood clots?

Prevents pathogens entering, prevents blood loss

What type of blood does the pulmonary vein and artery carry?

Pulmonary vein - deoxygenated blood Pulmonary artery - oxygenated blood

What affect does exercise have on pulse rate? Why?

Pulse rate increases because muscles require more oxygen for energy. So that the heart pumps more blood to the respiring cells, supplying more oxygen for aerobic respiration, to release energy for muscles to contract. Glucose is also need which is also supplied by the blood, that the heart pumps. As a result more carbon dioxide is produced which needs to be excreted so the pulse rate also increase to remove waster products from respiring cells.

What is the function of the septum?

Separates the two sides of the heart and therefore prevents deoxygenated blood on the right side of the heart mixing with oxygenated blood on the left side of the heart

Why do the atria have less muscular walls than the ventricles?

The atria only need to contract to force the blood into the ventricles a short distance away, whereas the ventricles need to contract and force blood out of the heart

why does the heart needs its own blood supply?

To supply oxygen, for the cardiac muscles to carry out aerobic respiration, to release energy for muscles to contract.

How does the lymoh enter the heart?

Two lymph vessels join up to form two large lymph vessels which empty into subclavian veins, under the collar bones before joining the vena cava

Name the blood vessel that carries deoxygenated blood under low pressure

Vena cava (low pressure = vein, deoxygenated = from the body)

Describe the structure of a capillary

Very narrow lumen, wall made of a single layer of cells

What is lymph?

When tissue fluid enters lymph capillaries

Whats is atherosclerosis?

When your arteries narrow and causes the blood flow to slow sown because cholesterol sticks to the walls

What is cardiac arrest?

When your heart suddenly stops

What is the circulatory system?

a system of blood vessels with a pump and valves to ensure one-way flow of blood

Name the blood vessel that carries oxygenated blood away from the heart

aorta (artery=away. Oxygenated=to the body)

Which arteries break the rule, and do have valves in?

aorta and pulmunary artery

Which blood vessel carries blood away from the heart?

arteries

Which blood vessel carries blood under high pressure?

arteries

Name the type of blood vessel that carries blood away from the heart

artery (Away)

Name the valves that separate the atrium from the ventricle

atrioventricular valves

What is the function of platelets?

blood clotting

If the ventricle contracts, are the atrioventricular valves open or closed?

closed (high pressure in the ventricles) - this stops blood flowing backwards into the atrum

If the atria contract, are the semi-lunar valves open or closed?

closed (low pressure in the ventricle as there is no/little blood in there!)

What creates the heart sounds?

closing of the valves

What is the function of red blood cells?

contains haemoglobin which combines reversibly with oxygen to form oxyhaemoglobin to transport oxygen around the body

Name the blood vessel that supplies blood to the heart

coronary artery

Name the blood vessel that carries blood to the liver

hepatic artery; hepatic portal vein

Name the blood vessel that carries blood from the liver

hepatic vien

Where in the heart is the thickest wall?

left ventricle

What is the function of shunt vessels?

links an artery directly to a vein, bypassing capillaries

What are the advantages of double circulation?

lower pressure blood reaches the lungs to become oxygenated. The left ventricle contracts with more force to create greater pressure for oxygenated blood to be delivered to the rest of the body. Oxygenated and deoxygenated blood do not mix

How is lymph moved around the body?

muscles surrounding the lymphatic vessels contract and move lymph

If the atria contract, are the atrioventricular valves open or closed?

open (higher pressure in the atrium than the ventricle will push the valves open)

What is the function of the two types of white blood cells?

phagocytes carry out phagocytosis, and lymphocytes produce antibodies

Name the blood vessel that carries blood to the lungs

pulmonary artery

Name the blood vessel that carries blood from the lungs

pulmonary vein

Name the blood vessel that carries deoxygenated blood from the right ventricle

pulmunory artery (pulmunory=lungs, artery=away from the heart)

Name 4 componants of blood

red blood cells, white blood cells, platelets and plasma

Name the blood vessel that carries oxygenated blood to the kidneys

renal artery

Name the blood vessel that carries blood from the kidney

renal vein

List the order of the structures blood passes through the heart if starting in the right atrium

right atrium (atrioventricular valves), right ventricle, (semi-lunar valves) pulmunory artery, lungs, pulmunory vein, left atrium, (atrioventricular valves) left ventricle, aorta, (semi-lunar valves), body, vena cava

What is the name of the valve in the pulmunory artery?

semi-lunar valve

Name the valves in the aorta and pulmunary artery

semi-lunar valves

Describe the structure of a vein

semi-lunar valves present, wider lumen, less muscular and elastic walls than arteries

Explain how the structure of a vein is suited to its function

semi-lunar valves to prevent back flow, wider lumen to reduce friction maintaining blood flow, less muscular and elastic walls as blood under low pressure

What is the part of the heart that separates left from the right?

septum

List risk factors associated with coronary heart disease

smoking, stress, high salt diet, high fat diet, age, gender

What is tissue fluid?

some parts of blood plasma that leave the blood and bathe cells (parts include plasma and white blood cells)

Explain how the sturcture of an artery is related to its function

thick muscular and elastic walls to withstand high blood pressure, and to stretch and recoil to maintain blood pressure, no valves as blood is under high pressure

Describe the structure of an artery

thick muscular and elastic walls, no valves (except aorta and pulmunary artery), narrow space

What is the function of plasma?

transport of bood cells, ions, nutrients, hormones and carbon dioxide

Name the type of blood vessel that carries blood to the heart

vein (INto)

What is lymph made up of?

white blood cells, but no red blood cells or proteins