Monday 14th May 2018

The Body – Anatomy and Physiology

Lesson 10 – Cardio-Respiratory System

Homework –

1. What is the function of the cardiovascular system?

2. List the main components of blood and describe their respective functions

3. Describe the structure and role of –

a) Arteries

b) Veins

c) Capillaries

4. The circulatory system is described as a double pump system. Why is this?

The cardiovascular system is also known as the circulatory system.It consists of…

3. The Heart1. Blood 2. Blood Vessels

The Cardiovascular System

It has three main functions-

The Cardiovascular System

2 - Protection of the body by white blood cells, and antibodies that circulate in the blood and defend the body against disease/ infection. Clotting mechanisms are also present that protect the body from blood loss after injuries via platelets.

1 - Transport of nutrients, oxygen, and hormones to cells throughout the body and removal of metabolic wastes (carbon dioxide, nitrogenous wastes).

3 - Regulation of body temperature, fluid pH, and water content of cells.

Blood does the job of a non-stop courier service - it collects chemicals from one part of the body and delivers them to other parts, for use or disposal.

What is Blood made of?If blood is spun in a centrifuge it will separate into 4parts…

What does Blood do?

Plasma is a straw-coloured liquid. It is mostly water with dissolved nutrients,salts, hormones and proteins.

White blood cells help to fight infection. Platelets are cell

fragments.

Blood spinning in a centrifuge.

Red blood cells make up about 45% of the total volume of the

blood

Blood StructureA photomicrograph of a blood smear showing

the appearance of blood as seen with thelight microscope (1000 x Magnification).

White blood cells

Plasma

Platelets Red blood cells

White blood cells

Plasma

Platelets Red blood cells

PLASMA This is the liquid part of blood - it is straw coloured.

Transports waste products away from

cells for removal from the body, e.g. urea

and heat when the body is hot.

These are tiny pieces of cell which have no

nucleus.

Platelets

Clump together when blood vessels are damaged

and help to clog a ‘meshwork’ of fibres which

create a clot, to help stop bleeding: form a scab

Their main role is to:

Arteries VeinsThe Major Blood Vessels

Arteries

Veins

Capillaries

Blood Vessels

Non-elastic fibres

Muscle + elastic fibres

Non-elastic fibres

Muscle + elastic fibres

Arteries carry blood away from the heart and have a thick, elastic, muscular wall as they pump blood at high pressure – this creates a pulse. Arteries carry oxygenated blood (except the pulmonary artery)

Veins have a relatively thinner and less a muscular wall than arteries. They also have valves to stop the blood flowing in the wrong direction. Veins carry oxygenated blood (except the pulmonary vein)

Capillaries are found where gaseous exchange takes place - Lungs, organs and muscles. Capillary walls are one cell thick. Exchange of gases occurs across their surface.

The Heart - Structure

Right ventricle

Vena cavae

Aorta

Right atrium

Pulmonary arteryPulmonary veins

Left atrium

Left ventricle

Cardiac muscle

Semi lunar valves

Bicuspid valvesTricuspid

valves

(A)

(V)

Lungs

Heart

Body

How Blood is Pumped around the Body

Blood flows around the body in a ‘figure of eight’ circuit, passing through the heart twice on each circuit.

Blood travels away from the heart through arteries (A).

Blood returns to the heart through veins (V).

There are 2 separate ‘loops’ to the circuit:

The top loop – carries blood from the heart to the lungs and back.

The bottom loop – carries blood from the heart to all over the body and back.

(A)

(V)

The heart is divided into 2 parts. Each part is a pump, so the heart is a double pump.

The right side

pumps

deoxygenated blood

to the lungs to pick

up oxygen.

The left side

pumps oxygenated

blood to the rest of

the body for use.

Fromthe lungs

Fromthe body

Tothe lungs

Tothe body

How the Heart Pumps Blood

The Cardiac Cycle - How the Heart Beats

1. Blood leaves the right side of the heart via the pulmonary

artery and goes to the lungs where it is oxygenated.

2. It then travels

back to the left

side of the heart

via the pulmonary

vein.

Pulmonaryartery Pulmonary

vein

Body

Heart

Lungs

Blood Flow around the Body – Top Loop

3. The left side of the

heart then pumps the

oxygenated blood

around the rest of the

body for use, via the

aorta.

4. Once the

oxygen has

been used, the

blood becomes

deoxygenated

and returns to

the right side

of the heart via

the vena cava.

Vena Cava

Aorta

Blood Flow around the Body - Bottom Loop

Body

Heart

Lungs

Y10 Exam: Monday 18 June – 1.30pmAll content from paper 1 and paper 2 since September

Paper 1 – AG

• Health and Fitness

• Components of Fitness

• Fitness Testing

• Training Types (inc injury prevention, seasons, safety, training zones, warming up/ cooling down etc)

• Effects of exercise

• Skeletal/ Muscular Systems

• Movement analysis

• Circulatory/ Respiratory Systems