Circulatorysystem.

What’s in the

red blood cells

white blood cells

platelets

plasma

carbon dioxide

digested food

waste (urea)

hormones

oxygen

Functions of Blood

• Replenishing tissue fluid• Transport: to and from tissue cells

– • Nutrients from small intestine to cells: amino acids, glucose, vitamins, minerals, lipids (as lipoproteins).

– • Oxygen: by red blood corpuscles (oxyhaemoglobin - 4 x O2 molecules/haemoglobin)from lungs to tissues

– • Waste products from cells: urea, CO2 (from liver kidneys / from tissueslungs)

– Hormones to their target organs– Heat from muscles/brain/abdominal organs to head and limbs

• Defence against infection/Immunity: protection against pathogens blood clotting; phagocytes, lymphocytes and antibodies distributed in blood.

What is HOMEOSTASIS, Sheldon?

• Homeostatic functions Maintain constancy of internal environment(Temperature Regulation:by alter the blood flow through the skin.)

Blood The fluid that

circulates in the heart, arteries, capillaries, and veins of a vertebrate animal carrying nourishment and oxygen to and bringing away waste products from all parts of the body.

plasma

red blood cell

white blood cell

platelets

Red Blood Cells

Bilirubin excreted in

the BILE

a biconcave disc that is round and flat without a nucleus

contain haemoglobin, a molecule specially designed to hold oxygen and carry it to cells that need it. (oxyhaemoglobin)

can change shape to an amazing extent, without breaking, as it squeezes single file through the capillaries.

After 4 months breakdown in the LIVER

Iron (stored)

PlateletsPlatelets are bits of cell broken off larger cells.

Platelets produce tiny fibrinogen fibres to form a net. This net traps other blood cells to form a blood clot.

No nucleusMade in the red bone marrow

White Blood Cellsthere are many different types and all contain a big nucleus. the two main ones are the lymphocytes and the phagocytes.

some lymphocytes fight disease by making antibodies to destroy invaders by dissolving them. other lymphocytes make antitoxins to break down poisons.

‘eat’ and digest micro-organisms

Made in white bone marrow/lymph nodes.Mature in Thymus/ Spleen/Lymph Nodes

Antibodieslymphocytes T and

B

Lymphocytes *B (from Bone marrow) short- lived plasma cells May attack antigens stick to the surface membrane of the alien cell

Lymphocytes *T (from Thymus) KILLER T damaging cell membrane of

infected cell

HELPER T stimulate B cells to %

IMMUNITY * Natural Acquired * Innate * Artificially Acquire Vaccine

Plasma

A straw-coloured liquid that carries the cells and the platelets which help blood clot.

• carbon dioxide• glucose • lipids• amino acids• proteins• minerals

(sodium/potassium/calcium)

• vitamins• hormones• waste materials like urea.

It also contains useful things like;

BLOOD VESSELS

CIRCULATORY SYSTEM

HEART +

External view of the heart

pulmonary artery

pulmonary vein

coronaryartery

left ventricle

right ventricle

inferior vena cava

right atrium

pulmonary vein

aorta

superiorvena cava

left atrium

Explanation of HeartRightAtrium

Right Ventricle

Left Atrium

Left VentricleValves

The heart has 4 chambers:2 on the Right: received blood and 2 on the left: pumps the blood out

How does the heart pump?

What kind of blood

does each side

pump?

Which side of

the heart is thicker

The vena cava carries deoxygenated blood from the body to the right atriumsuperior vena cava(transports blood from the head)

inferior vena cava(transports blood from rest of body)

The right atrium collects deoxygenated blood and pumps it to the right ventricle

right atrium

The right ventricle pumps deoxygenated blood to the lungs

right ventricle

The pulmonary artery carries deoxygenated blood from the right ventricle to the lungs

aorta

The septum separates the left and right sides of the heart

septum

The pulmonary veins carry oxygenated blood from the lungs to the left atrium

Pulmonary veins

The left atrium collects the oxygenated blood and pumps it to the left ventricle

Left atrium

The left ventricle pumps oxygenated blood to the body via the aorta

Left ventricle

The aorta carries the oxygenated from the left ventricle to the rest of the body

Aorta

Aortic arch

Blood doesn’t flow Backwards because of 4 sets of valves

Bicuspid valve(mitral valve)

Tricuspid valves

Tendon

semi-lunar valve

semi-lunar valve

LEFTRIGHT

The Heart

Left Ventricle

Left AtriumRight Atrium

Right Ventricle

valve

Vein from Lungs

Artery to Head and BodyArtery to Lungs

Vein from Head and Body

valve

The beat is initiated by the PACEMAKER

The * receives FOOD and O2 from CORONARY ARTERIES

• NORMAL RATE 50-100 beats per minute

Depends on AGE SEX EXERCISE

ADRENALINE

RIGHT ATRIUM

Specialized muscle cells

Receives 2 sets of nerves from BRAIN

1set speeds up the rate

1set slows down the rate Has IMPUT from receptors in the circ. System for BLOOD PRESSURE and levels of O2 and CO2

How does the Heart work?

blood from the body

blood from the lungs

The heart beat begins when theheart muscles relax and bloodflows into the atria.

STEP ONE

The atria then contract andthe valves open to allow bloodinto the ventricles.

How does the Heart work?

STEP TWO

How does the Heart work?

The valves close to stop bloodflowing backwards.

The ventricles contract forcing the blood to leave the heart.

At the same time, the atria arerelaxing and once again filling

withblood.

The cycle then repeats itself.

STEP THREE

1 2 Systoles

What is DIASTOLE?

What is SYSTOLE?

• The time period when the heart is in a state of relaxation

• It is a phase of the cardiac cycle where the myocardium is contracting

SummarySYSTOLE Atria contract

Blood enters ventricles

Blood pressure closes tricuspid and bicuspid valves

SYSTOLE Ventricles contract

Blood enters arteries

DIASTOLE Ventricles relax

Blood pressure in arteries close the semi-lunar valves

Valve opens

Semi-lunar valve opens

lungs

head & arms

liver

digestive system

kidneys

legs

pulmonary artery

aorta

pulmonary vein

main vein

Left Right

How does this system work?

Circulatory System

Lungs

Body cells

Our circulatory system is a double circulatory system.

This means it has two parts.

the right side of the system

deals with deoxygenated

blood.

the left side of the system deals with

oxygenated blood.

Is the muscle that pumps blood through yourblood vessels to allparts of your body.

Blood travels through the heart twice before returning to the body

The double circulatory system

blood from the heart gets around

the body through blood vessels

There are 3 types of blood vessels

a. ARTERY

c. VEIN

b. CAPILLARY

The ARTERY

thick muscle and elastic fibres

Arteries carry blood away from the heart.

the elastic/muscle fibres allow the

artery to stretch under pressure

the thick muscle can contract to push the blood

along.Semi- lunar valves

The Aorta

The largest artery in the body, originating from the left ventricle of the heart and extending down to the abdomen, where it branches off into two smaller arteries and arterioles. The aorta distributes oxygenated blood to all parts of the body.

The VEINVeins return blood to the heart.

thin muscle and elastic fibres

veins have valves which act to stop the blood from going in the wrong direction.

body muscles surround the veins so that when they contract to move the body, they also squeeze the veins and push the blood along the vessel --

The CAPILLARYCapillaries link Arteries with Veins

the wall of a capillary is *only one cell thick*permeable

they exchange materials between the blood and other body cells.

The exchange of materials between the blood and the body can only occur through capillaries.

A collection of capillaries is known as a capillary bed.

Type of blood

Direction Structure Valves Reason for structure

ARTERIES Oxygenated(in most arteries)

From heart to body

Elastic tissues+muscle fibresTHICK WALLS (To resist the pressure of blood)

Semi-lunar Thick walls as arteries carry blood with high pressure, this prevents walls from collapsing

VEINS deoxygenated(less food more CO2)(in most veins)

From body to heart

Less elastic, less muscularTHINNER WALLS/ WIDER LUMEN

Valves for blood not to go backwards

Less thick walls as they carry blood with low pressure

CAPILLARIES

oxygenated or deoxygenated

Supply all the cells with their requirements/ take away waste

1 cell-thick thin wallsPERMEABLENarrow lumen

-------------It allows tissue fluid to squeeze out and give the cells what they need and take away waste

BLOOD CLOTTING• 2 functions prevents loss of

blood prevents entrance of

bacteriaStimulus damage in blood vessels

Activates platelets (they aggregate)Produce chemicals to activate

Prothrombin Fibrinogen (always in the blood)Thrombin (enzyme) acts on Fibrinogen

(soluble)CLOT red cells + Fibrin(insoluble)

• When the pumps it produces pressure

• Arteries HIGH pressure • Capillaries offer resistance to blood

flow blood pressure in VEINS is LOW

• Blood pressure varies with sex/age/activity

• Fairly consistent for the FILTRATION process in the KIDNEYS

• Blood pressure heart disease/ stroke• Blood pressure kidney fail