The Transport SystemThe Heart and Circulatory System

Ribs

Diaphragm

Thorax

The Heart

The Pump

Jobs of the Heart

#1 – Systemic flow

#2 – Pulmonary flow

vein

artery

vein

6.2.2 State that the coronary arteries supply heart muscle with oxygen & nutrients

6.2.1 Draw and label a diagram of the heart showing the four chambers, associated blood vessels, valves and the route of blood through the heart.

Internal Anatomy of the heart

Vein – blood goes to the heart

Artery = away

Internal Anatomy of the heart

Rt atrioventricular valve

6.2.3 Explain the action of the heart in terms of collecting blood, pumping blood, and opening and closing of valves.

6.2.3 left ventricle fills with blood

Left ventricle contracts

Closure of the atrioventricular valve to prevent backflow into the left atrium

Dramatic increase in blood pressure inside the left ventricle which opens the left semilunar valve and allows blood to enter the aorta

Due to the increase in pressure, blood leaves the heart through the aorta

6.2.5 Explain the relationship between the structure & function of arteries, capillaries and veins.

Comparison of arteries, capillaries, and veins

Artery Capillary Vein

Thick walled Wall is 1 cell thick

Thin walled

No exchanges All exchanges No exchanges

No internal valves

No internal valves

Have internal valves

Internal pressure high

Internal pressure low

Internal pressure low

Path of a Red Blood CellArteries

Arterioles

Capillary bed – one cell thick

Venules

Veins

6.2.4 Outline the control of the heartbeat in terms of myogenic muscle contraction, the role fo the pacemaker, nerves, the medulla of the brain & adrenaline.

Control of heart rate The majority of heart tissue

is muscle

Contracts & relaxes without nervous system control

Right atrium – sinoatrial node

Electrical signal – both atria

Atrioventricular node

2nd electrical signal – to ventricles

What happens when you exercise? Increase demand for oxygen (cell respiration)

Need to get rid of excess carbon dioxide

Brainstem area (medulla) chemically sense the increase in CO2

Medulla signals cranial nerve (cardiac nerve) to increase heart rate

SA node receives signal

Changes timing

Done exercising?Signal from medulla to different cranial nerve

SA node receives signal

Goes back to resting heart rate

Other factors?Chemicals:

Adrenaline

Lub Dub

6.2.6 State that blood is composed of plasma, erythrocytes, leucocytes, (phagocytes and lymphocytes) and platelets.

Components of blood

Component Description

Plasma Liquid portion of blood

Erythrocytes Red blood cells (carry oxygen & carbon dioxide

Leucocytes White blood cells (phagocytes and lymphocytes

Platelets Cell fragments (assist in blood clotting)

6.2.7 State that the following are transported by the blood: nutrients, oxygen, carbon dioxide, hormones, antibodies, urea, and heat.

Transport by bloodWhat is transported What it is or does

Nutrients Glucose, amino acids, etc

Oxygen Reactant needed for aerobis cell respiration

Carbon dioxide Waste product of aerobic cell respiration

Hormones Transported from gland to target cells

Antibodies Protein molecules involved in immunity

Urea Nitrogenous waste (filtered out of the blood by kidneys)

Heat Skin arterioles (can change diameter in order to gain or lose heat