Unit 316- Structure, organisation and function of the human body

Question 1

blood- What does the blood transport?

Answer 1

• Oxygen
• Nutrients
• Hormones
• Heat
• Substances essential to protect against infection
• Substances essential to healing – clotting factors

Question 2

What is blood composed of?

Answer 2

Blood makes up 7% of the body’s weight. This is around 5.6 litres in a
man weighing 70 kg.

Blood is composed of :
- Plasma 55%
- Cells 45%
- Of these cells:
- 41% are red blood cells
- 4% are white blood cells and
platelets

Question 3

What is the function of the blood?

Answer 3

• Blood is in perpetual motion due to the action of the heart
• The movement maintains a fairly constant internal environment
• The volume of blood and the concentration of its constituents are
  kept within narrow limits by homeostatic actions of the body
• The blood is also used to maintain consistent body temperature

Question 4

Plasma content of blood are 2 components

Answer 4

• Plasma proteins

* waste products

Question 5

Cellular content of the blood - Erythrocytes (red blood cells)

Answer 5

• Main function is to carry oxygen
• Flexible, in order to squeeze through narrow vessels
• contain the haemoglobin protein, responsible for gas transport and which gives blood its colour

Question 6

Cellular content of the blood - Leukocytes (white blood cells)

Answer 6

_ main function is to locate and destroy foreign or abnormal material

• largest blood cell
• number of white blood cells increase in the presence of disease. infection or trauma

Question 7

Cellular content of the blood - Thrombocytes (platelets)

Answer 7

• contain factors that promote blood clotting

- essential in the cessation of bleeding

Question 8

What does plasma proteins contain?

Answer 8

• albumins
• clotting factors (most commonly fibrinogen)
• globulins
• Electrolytes
• Nutrients

Question 9

What does plasma waste products contain?

Answer 9

• Hormones
• gases:
• oxygen
• carbon dioxide
• nitrogen

Question 11

What is anemia?

Answer 11

anaemia is caused by lack of iron , often because of blood loss or pregnancy

Question 12

What is the structure of the Cardiovascular system

Answer 12

The cardio (heart) vascular (blood vessels) system is made up of two sections:
- the heart
- the blood vessels

The blood vessels are separated into the pulmonary circulation and the systemic circulation.

the cardiovascular system has significant links with the lymphatic system and the respiratory system

Question 14

Function of the Cardiovascular system

Answer 14

• The function of the cardiovascular system is to move the blood around the body
• Cardiovascular malfunction and disease of the cardiovascular system will have significant consequences on the other body systems
• The cardiovascular system ensures a continues flow of blood to all the body cells as required (circulation)
• The cardiovascular system also ensures the flow of blood at the right pressure (blood pressure)
• Failure of the cardiovascular system will cause death

Question 15

Cardiovascular: structure and function of systemic circulation (Heart)

Answer 15

Right-hand side of the heart:
- pumps blood to the lungs
- gas exchange occurs in the lungs
- blood collects oxygen, and carbon dioxide is removed via diffusion

Left-hand side of the heat
- pumps blood into the systemic circulation
- nutrients and oxygen are supplied to the tissue
- waste products are removed from the tissues and passed into the blood for excretion

Question 16

Cardiovascular: structure and function of blood vessels- arteries and arterioles

Answer 16

• transport blood away from the heart
• With the exception of the pulmonary artery, arteries contain oxygenated blood.
• arteries and arterioles have three layers of tissue:

1- Tunica adventitia: outer layer
2- Tunica media: middle layer
3- Tunica intima: inner lining

Question 17

Cardiovascular: function of blood vessels- arteries and arterioles

Answer 17

• The amount of each layer varies depending on the function. For
  example, the tunica media contains a large amount of elastic tissue.
  This enables the vessel to absorb the large amount of pressure on
  the walls of the vessel as the heart beats
• As the arteries become smaller, becoming arterioles, the amount of
  elastic tissue decreases until there is hardly any elastic tissue.
• The diameter of the smallest vessels is controlled, regulating the
  pressure within. This pressure largely controls the systemic blood
  pressure.