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