Cardio-vascular System

 

Introduction

Learn all about the human cardio-vascular system. 

There are 3 learning objectives, each learning objective contains information and questions to help prepare you for the upcoming lesson.

 

 

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1. Define, Describe the structure, location and function of the Cardio-vascular system

The functions of blood are ?

Transport

Blood is the primary transport medium for a variety of substances that travel throughout the body.

  • Oxygen is carried from the lungs to the cells of the body in red blood cells.
  • Carbon dioxide is carried from the body’s cells to the lungs.
  • Nutrients such as glucose, amino acids, vitamins and minerals are carried from the small intestine to the cells of the body.
  • Cellular wastes such as water, carbon dioxide, lactic acid and urea are carried in the blood to be excreted.
  • Hormones, which are internal secretions that help to control important body processes, are transported by the blood to target organs.

 

Defence

White blood cells are collectively called leucocytes and they play a major role in combating disease and fighting infection.

 

Regulation

Blood helps to regulate heat in the body by absorbing large quantities of heat produced by the liver and the muscles. This is then transported around the body to help to maintain a constant internal temperature. Blood also helps to regulate the body’s pH balance.

 

Clotting

Clotting is an effective mechanism in controlling blood loss from blood vessels when they have become damaged as in a cut. Specialised blood cells called thrombocytes, or platelets, form a clot around the damaged area to prevent the body from losing too

  • Transport, heat regulation, secretion and clotting
  • Defence, transport, absorption and clotting
  • Transport, heat regulation, defence and clotting
  • Sensation, heat regulation, defence and clotting

What makes up 55% of the composition of blood?

The blood consists of a variety of blood cells and a watery substance called blood plasma.

Blood is composed of 55% of fluid or plasma which is a clear, pale yellow, slightly alkaline fluid consisting of the following substances:

  • 91 per cent of plasma is water
  • 9 per cent remaining consists of dissolved blood proteins, waste, digested food materials, mineral salts and hormones

• 45% of blood is made up of the blood cells erythrocytes, leucocytes and thrombocytes.

  • hormones
  • haemoglobin
  • blood cells
  • plasma

Blood Plasma

Plasma is a straw-coloured fluid consisting of about 91% water

7% of plasma is made up of proteins, most of which are synthesized by the liver. The plasma proteins include albumins, globulins and fibrinogen.

  • Albumins regulate osmotic pressure. This helps to maintain the water balance between the blood and the tissues, so regulating blood volume.
     
  • Globulins; This protein group includes antibodies (immunoglobulins) that play a vital role in immunity by attacking antigens. Alpha and beta globulins transport iron, fats and fat-soluble vitamins.
     
  • Fibrinogen plays a vital role in blood clotting (covered later in this section).

2% consist of other solutes.

Which blood cell designed to protect the body against infection?

  • Leucocyte
  • Erythrocyte
  • Platelet
  • Thrombocyte

Components of Blood

Which of the following is a unique part of the structure of a vein?

Arteries take blood away from the heart (memory hint: Arteries = Away). 

Arteries divide to form very small vessels called arterioles. Arterioles branch further to become capillaries.

Arteries expand as the blood is pumped from the heart, and then recoil to force the blood through the vessel. Arteries therefore have to be elastic and have the ability to contract.

Veins take blood back to the heart. Venous blood is under less pressure than arterial blood.

The lumen in a vein is larger than in an artery and the vein wall is weaker and thinner. This is particularly noticeable in the tunica media. Due to the reduced pressure under which the blood flows in the veins, most veins contain valves.

Valves prevent the back-flow of blood, so aiding its return to the heart.

  • thick muscular wall
  • valves
  • thick elastic wall
  • single cell layer thick

What is the function of the capillary?

Arteries divide to form arterioles, which continue to divide, getting smaller and smaller, until they become capillaries.

Capillaries are formed by the multiple division of the arteries. The capillaries allow the exchange of nutrients and waste and then, as the vessels leave the capillary network, they join to form venules.

Venules continue to merge until they become veins.

  • prevent back-flow of blood
  • supply cells and tissues with nutrients
  • carry only deoxygenated blood
  • carry only oxygenated blood

What is the function of an artery?

  • carry blood towards the heart
  • carry deoxygenated blood
  • carry oxygenated blood
  • carry blood under low pressure

Which is the correct sequence of structures through which the blood flows?

Arteries contain oxygenated blood. The exception to this is the pulmonary arteries. The pulmonary arteries take deoxygenated blood from the heart to the lungs.

Veins contain deoxygenated blood. The exception is the pulmonary veins. The pulmonary veins take oxygenated blood from the lungs to the heart.  

  • arteries, arterioles, capillaries, venules, veins
  • arterioles, arteries, capillaries, veins, venules
  • veins, venules, capillaries, arterioles, arteries
  • venules, veins, capillaries, arteries, arterioles

What effect does the circulatory system have on the skin and muscles?

  • It reduces the blood supply to the skin and muscle, nourishing the cells causing less cell renewal.
  • The blood supply to the skin and muscle is reduced, nourishing the cells causing improved cell renewal.
  • An increase of the blood supply to the skin and muscle nourishes the cells and causes less cell renewal.
  • It would increase the blood supply to the skin and muscle, nourishing the cells and improving cell renewal.

2. Define, Describe the structure, location and function of the Coronary circulation

Which layer is the thickest layer of the heart wall?

The wall of the heart is composed of three layers:

  • The outer layer is the epicardium (visceral pericardium).
  • The inner layer is the endocardium.
  • The middle layer of the heart is called the myocardium, or heart muscle. By far the thickest layer is the middle layer. 

The specialized muscle fibres of the myocardium allow the heart to ‘beat’ in response to nerve impulses. As the nerve impulses travel through the heart, electrical impulses are generated which result in its rhythmical contraction and relaxation.

  • endocardium
  • epicardium
  • myocardium

What is the function of the pulmonary veins?

The heart pumps deoxygenated (without oxygen) blood to the lungs via the pulmonary arteries.

It receives oxygenated blood back from the lungs through the pulmonary veins.

This oxygenated blood is then pumped out of the heart from the aorta. The aorta branches to form a complex network of arteries that circulates the blood around the body

The deoxygenated blood is received back from the body tissues via major veins called the superior and inferior vena cava.

Internally, the heart is comprised of four chambers.

  • The upper chambers are called atriums.
  • The lower chambers are called ventricles

The septum divides the left and right sides of the heart, keeping the oxygenated and deoxygenated blood separate.

The heart receives deoxygenated blood from the body tissues via the superior and inferior vena cavae.

This deoxygenated blood enters the right atrium and passes through the tricuspid valve to the right ventricle.

The deoxygenated blood leaves the right ventricle via the pulmonary trunk that quickly divides into the left and right pulmonary arteries. The pulmonary arteries transport the blood to the lungs

There is a valve at the point that the pulmonary trunk leaves the right ventricle. It is called the pulmonary semilunar valve.

The pulmonary semilunar valve has 3 cusps. The valve opens to allow blood through when pressure in the right ventricle is greater than that in the pulmonary arteries, and closes when the pressure in the ventricle falls below that of the pulmonary arteries. The valve only allows blood to flow in one direction. It prevents the back-flow of blood.

  • Carry O2 blood from the lungs to the left atrium
  • Carry O2 blood from left ventricle to all parts of the body
  • Carry CO2 blood from the left ventricle to the lungs
  • Carry CO2 blood from the body to the left atrium

Fill in the blank

 carries de-oxygenated blood from the heart to the lungs.

What is the valve between the left atrium and left ventricle called?

The Heart

There is a valve at the point that the pulmonary trunk leaves the right ventricle. It is called the pulmonary semilunar valve.

The pulmonary semilunar valve has 3 cusps. The valve opens to allow blood through when pressure in the right ventricle is greater than that in the pulmonary arteries, and closes when the pressure in the ventricle falls below that of the pulmonary arteries. The valve only allows blood to flow in one direction. It prevents the back-flow of blood. 

genated blood is returned from the lungs in the pulmonary veins. The oxygenated blood from the pulmonary veins is received in the left atrium.

The flow of deoxygenated blood from the right ventricle to the lungs, and the return of oxygenated blood from the lungs to the left atrium, is called pulmonary circulation. 

From the left atrium, the oxygenated blood passes through the mitral (bicuspid) valve to the left ventricle.

The left ventricle is the largest, most muscular chamber as it is responsible for pumping the oxygenated blood around the whole body. The oxygenated blood leaves the heart via the aorta.

There is a 3-cusped valve called the aortic semilunar valve at the point that the aorta leaves the left ventricle. Like the pulmonary semilunar valve, this prevents the back-flow of blood.  

-MEMORY HINT-

  • TR: Tricuspid valve
  • PUL: Pulmonary valve
  • M: Mitral valve
  • AORTA: Aortic valve

TRPULling MAORTA

  • Tricuspid valve
  • Bicuspid valve
  • Aortic valve
  • Pulmonary valve

The bicuspid valve of the heart is found between?

  • left atrium and left ventricle
  • right atrium and right ventricle
  • pulmonary artery and right ventricle
  • left ventricle and aorta

Name the parts

  • Superior Vena Cava
  • Aorta
  • Pulmonary Vein
  • Mitral Valve
  • Left Ventricle
  • Right Ventricle

Which of the following is not part of the circulatory system to the leg and foot?

Head and Neck

Arteries
Blood is supplied to parts within the neck, head and brain through branches of the subclavian and common carotid arteries. The common cartoid artery extends from the brachiocephalic artery. It extends on each side of the neck and divides at the level of the larynx into two branches.

Veins
The external jugular veins are smaller than the internal jugular veins and lie superficial to them. They receive blood from superficial regions of the face, scalp and neck.

Arm and Hand

Arteries
The blood supply to the arm begins with the subclavian artery (a branch of the aorta). The subclavian artery becomes the axillary artery and then the brachial artery which runs down the inner aspect of the upper arm to about 1 cm below the elbow where it divides into the radial and ulnar arteries.

Veins
The venous return of blood from the hand begins with the palmar arch and plexus which is a network of capillaries in the palm. The veins that carry deoxygenated blood up the forearm are the radial vein, ulnar vein and median vein Just above the elbow, the radial and ulnar veins join to become the brachial vein and t h e median vein joins the basilic vein which originates just below the elbow along with the cephalic vein.

Leg

Arteries
The aorta travels down the length of the trunk to the lower abdomen where it divides into two arteries which supply either leg. The femoral artery is the artery in the thigh, named after the thigh bone. At the knee the femoral artery becomes the popliteal artery which divides into two below the knee. One of these arteries runs down the front of the lower leg and is called the anterior tibial artery, while the other runs down the back and is called the posterior tibial artery. This artery divides at the inside of the ankle becoming the medial plantar artery on the inside of the foot and the plantar arch on the sole of the foot. The anterior tibial artery becomes the doral metatarsal artery on top of the foot.

Veins
Two small veins called the anterior tibial veins travel up the front of the lower leg, while two veins, the posterior tibial veins, run up the back. These four veins converge just below the knee to become the popliteal vein at the back of the knee and then eventually the femoral vein in the thigh. The great saphenous vein and the femoral vein join at the groin and return to the heart via the inferior vena cava.

  • peroneal artery
  • basilic artery
  • femoral artery
  • great saphenous vein

The blood supply to the arm begins with which artery?

  • brachial artery
  • subclavian artery
  • ulnar artery
  • radial artery

Coronary Circulation Song

3. Describe disease and disorders of Cardio-vascular system

Anemia

Anaemia is a reduction in the blood’s ability to carry oxygen, caused either by a decrease in red blood cells, or the haemoglobin they carry, or both. It may be caused by extensive loss of blood, lack of iron in the diet, the failure of bone marrow to produce the normal level of cells or it may be inherited.

What is the circulatory disorder where hardening of the arteries is called?

Arteriosclerosis

A degenerative disease of the arteries, in which the walls of the vessels harden and lose elasticity.

The loss of elasticity causes an increase in blood pressure. This condition mainly affects the elderly.

  • arteriosclerosis
  • aneurysm
  • angina
  • thrombosis

Atherosclerosis / Atheroma

Atherosclerosis / Atheroma‚Äč

A build-up of fats, including cholesterol, inside the arteries which causes a narrowing of the artery passage, hardening of the vessel walls and a loss of elasticity.

Coronary Thrombosis

Coronary Thrombosis

Blood clot in the heart or blood vessels

Leukemia

Leukaemia is a cancer of the blood, caused by over-production of white blood cells.

Haemophilia

Haemophilia

The blood’s inability to clot. This is an inherited disease which affects mainly men but which can be carried by women.

Haemorrhoids

Haemorrhoids

Also known as piles, these are enlarged veins in the rectum or anus which may collapse or contain blood clots.

What cause Hepatitis B?

Hepatitis A / B / C

Inflammations of the liver, caused by viruses, toxic substances or immunological abnormalities.

Type A is spread by fecally contaminated food.

Types B and C are transmitted by infected body fluids including blood. Contagious!

  • Fungus
  • Bacteria
  • Parasite
  • Virus

High Cholesterol

High Cholesterol is an excessive build-up of a fatty substance called cholesterol, which can cause a reduction in arterial capacity (atherosclerosis) and thus high blood pressure.

Which of the following is considered a normal blood pressure reading in a healthy adult at rest?

Blood Pressure

Blood pressure is defined as the amount of pressure exterted by blood on a arterial wall due to the contraction of the left ventricle.

The maximum pressure is called the systolic pressure and represents the pressure exerted on the arterial walls during ventricular contraction The lowest pressure is called the diastolic pressure and is when the heart muscle relaxes (ventricular relaxation) and blood flows into the heart from the veins.

  • normal blood pressure reading is between 100 and 140 mmHg systolic and between 60 and 90 mmHg diastolic.
  • High blood pressure is when the resting blood pressure is above normal and when consistently exceeding 160 mmHg systolic and 95 mmHg diastolic.
  • Low blood pressure is defined as a systolic pressure of 99 mmHg or less and diastolic of 59 mmHg.

• The pulse is a pressure wave that can be felt in the arteries, such as the carotid or brachial, and corresponds to the beating of the heart and the contraction of the left ventricle.

• An average pulse is between 60 and 80 beats per minute.

  • 120/80
  • 160/90
  • 140/100
  • 180/90

What is the average pulse in beats per minute?

  • 40 and 50
  • 50 and 70
  • 60 and 80
  • 90 and 120

What is Phlebitis?

Phlebitis

Inflammation of a vein. Thrombo-phlebitis is the inflammation of a vein where a blood clot has formed.

  • Blood clot in the coronary artery
  • Inflammation of the liver
  • Inflammation of a vein
  • Cancer of the blood

Septicaemia

Septicaemia is also known as blood poisoning, this is a generalised disease associated with the circulation and multiplication of toxic bacteria in the blood.

Which of the following is not likely to raise blood pressure?

Stress

Stress can be defined as any factor which affects mental or physical health. When a person is stressed, the heart beats faster, thus pumping blood more quickly. Excessive and unresolved stress can lead to high blood pressure, coronary thrombosis and heart attacks.

  • stress
  • relaxation
  • pain
  • heat

Revision

Which blood cell designed to protect the body against infection?

  • Leucocyte
  • Erythrocyte
  • Platelet
  • Thrombocyte

What effect does the circulatory system have on the skin and muscles?

  • It reduces the blood supply to the skin and muscle, nourishing the cells causing less cell renewal
  • The blood supply to the skin and muscle is reduced, nourishing the cells causing improved cell renewal
  • An increase of the blood supply to the skin and muscle nourishes the cells and causes less cell renewal
  • It would increase the blood supply to the skin and muscle, nourishing the cells and improving cell renewal

Which is the correct sequence of structures through which the blood flows?

  • arteries, arterioles, capillaries, venules, veins
  • arterioles, arteries, capillaries, veins, venules
  • veins, venules, capillaries, arterioles, arteries
  • venules, veins, capillaries, arteries, arterioles

What is the valve between the left atrium and left ventricle?

  • Tricuspid valve
  • Bicuspid valve
  • Aortic valve
  • Pulmonary valve

Which layer is the thickest layer of the heart?

  • Epicardium
  • Endocardium
  • Myocardium

The blood supply to the arm begins with?

  • brachial artery
  • subclavian artery
  • ulnar artery
  • radial artery

Where is the bicuspid valve of the heart is found?

  • between left atrium and left ventricle
  • between right atrium and right ventricle
  • between pulmonary artery and right ventricle
  • between left ventricle and aorta

Which of the following is considered a normal blood pressure reading in a healthy adult at rest?

  • 120/80
  • 160/90
  • 140/100
  • 180/90

What cause Hepatitis B?

  • Fungus
  • Bacteria
  • Parasite
  • Virus

What is the function of the pulmonary veins?

  • Carry O2 blood from the lungs to the left atrium
  • Carry O2 blood from left ventricle to all parts of the body
  • Carry CO2 blood from the left ventricle to the lungs
  • Carry CO2 blood from the body to the left atrium

What is the average pulse in beats per minute?

  • 40 and 50
  • 50 and 70
  • 60 and 80
  • 90 and 120

The functions of blood are ?

  • Transport, heat regulation, secretion and clotting
  • Defence, transport, absorption and clotting
  • Transport, heat regulation, defence and clotting
  • Sensation, heat regulation, defence and clotting

Which of the following is the main vein of the leg?

  • Femoral vein
  • Brachial vein
  • Saphenous vein
  • Popliteal vein

Name the parts

  • Superior Vena Cava
  • Aorta
  • Pulmonary Vein
  • Mitral Valve
  • Left Ventricle
  • Right Ventricle