1.10 Propulsion and transportation

Natural sciences

Grade 9

Life processes: healthy life

Module 11

Propulsion and transportation

Propulsion: muscles and skeleton

People have to be able to move around for the sake of better opportunities.

The propulsion system of humans involves the SKELETON, the JOINTS, and the MUSCLES, LIGAMENTS and TENDONS is a system of lever.

THE SKELETON

Questions: MUSCLES AND SKELETON

1. What happens when you sprain an ankle?

2. Why should ice be applied to a sprained ankle without delay?

3. How would you determine whether someone has broken a leg? What would you do?

4. Explain the difference between a ligament and a tendon.

Transportation: the system of blood vessels

All body cells require oxygen and nutrients. We have already studied the role of the respiratory system, so we will be focusing on the BLOOD , BLOOD VESSELS and the HEART .

Blood vessels comprise:

• Capillaries - the delicate, thin-walled blood vessels that surround cells.
• Arteries - transport blood from the heart to the organs and tissues.
• Veins - transport blood from the tissues and organs to the heart.

The heart:

• A muscular pump that comprises four heart chambers.
• Valves control the flow of blood between the heart chambers.
• The right side of the heart receives the blood from the largest veins, the venae cavae, and directs it to the lungs so that carbon dioxide can be removed and the blood can be charged with oxygen.
• From the lungs, the blood returns to the left side of the heart.
• From here, the blood is pumped through the AORTA to the rest of the body.

The heart

Blood:

• Consists of BLOOD PLASMA and CORPUSCLES (red blood corpuscles, white blood corpuscles and platelets)
• Blood plasma is the medium of transportation – it is a straw-coloured fluid in which everything is in suspension, e.g. gases, waste products, nutrients and hormones.
• Red blood corpuscles are produced in the bone marrow and contain HAEMOGLOBIN, the red pigment that transports oxygen in the blood.
• White blood corpuscles attack germs and are also produced in the bone marrow.
• Blood platelets assist blood coagulation and forming scabs.

Red blood corpuscles white blood corpuscles

Questions: THE BLOOD SYSTEM

1. What is leukaemia?

2. Why would a patient who has leukaemia be given bone marrow transplantation?

3. What is anaemia and why do people suffering from this condition receive iron supplements?

4. The walls of arteries have muscles. Why is this so?

5. What is coronary heart disease? Explain the role of cholesterol in this condition.

6. What is the difference between coronary heart disease and a heart attack?

7. Explain the following:

a) Stroke

b) Thrombosis

Assessment: interpretation

Could you apply your existing knowledge to understand other problems?

LO2.3

Assessment

Learning Outcomes 2 : Constructing Science knowledge

The learner will know and be able to interpret and apply scientific, technological and environmental knowledge.

We know this when the learner:

2.3 interprets information

Memorandum

QUESTIONS: MUSCLES AND SKELETON

1. tendon and ligaments strained – tissue damage

2. limited tissue damage

3. pain; unnatural shape; loss of movement – immobilise; doctor

4. Ligaments attach one bone to another; tendons attach muscles to bones

QUESTIONS: BLOOD SYSTEM / CIRCULATORY SYSTEM

1. leukaemia – white blood corpuscles normally destroy red blood corpuscles

2. This is where blood corpuscles are manufactured

3. anaemia – iron is part of haemoglobin pigment

4. propulsion and pulsation of blood

5. Coronary arteries are blocked because of a coating of cholesterol

6. Coronary heart disease is a result of a condition of the coronary artery and is usually leads to a heart attack which results from an oxygen deficit in the tissues of the cardiac muscle.

7. a) blood vessels on the brain that rupture – brain tissue is damaged as a result of increased pressure

b) Thrombosis: formation of a blood clot – blocking of the arteries.