Year 11 Human Biology
Unit 2 - Internal Transport
Chapter 7 Solutions
FOCUS QUESTIONS
1. The function of blood & it's importance.
The Functions of Blood
Importance of each Function
Transport of oxygen & nutrients to all cells Need these raw materials for respiration
Transport od Carbon Dioxide and other
waste products away from the cells
Need to remove these wastes before
they become toxic to the body
Transport of chemical messangers
Called hormones, to the cells
Important for functions such as growth,
secondary sexual characteristics etc
Regulation of pH of body fluids
Regulation of body temperature
To maintain a constant body temperature
Regulation of the water content & ion
concentrations of the body fluids
Protection against disease causing
micro-organisms
2.
To fight diseases
(a) What is Plasma?
Plasma is the watery fluid of the blood.
(b) What is plasma made of, and what substances are
dissolved
in plasma.
Plasma is made up of:
• Water (91%)
• Plasma Proteins (7%)
• Other substances (2%)
Substances dissolved in plasma are:
• Cell wastes
• Respiratory gases
• hormones
• ions
• food materials
3.
(a) What are the formed elements of the blood?
They are:
• Erythrocytes – RED BLOOD CELLS
• Leucocytes – WHITE BLOOD CELLS
• Thrombocytes - platelets
(b) Describe the structure, origin and function.
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4.
Describe the three different types of Leucocytes
• Granulocytes - Have granules & a lobed nucleus
• Monocytes - Have no granules
• Lymphocytes - Have no granules and are generally found in
the lymph.
5.
(a) Importance of phagocytosis by leucocytes
They use phagocytosis to engulf the bacteria and dead cells
(b) Why do leucocytes live for shorter periods in times of
Infection.
The substances they take in interfere with cell functioning.
6. Diagram of & explanation of extracellular, intracellular
fluid & plasma.
• Extracellular: Fluid outside the cells – made of intercellular
(or interstitial) fluid (fluid between the cells) and blood
plasma.
• Intracellular: Fluid inside the cells
• Plasma: Fluid part of the blood
7. 2 Ways substances get from the blood plasma to the
tissue
fluid & hence cells.
• Diffusion
• General movement of fluids, eg osmosis & osmotic pressure.
8. (a) How blood is forced out of blood capillaries at the
arterial
end.
Plasma is pushed out by blood pressure
(b) Why is some fluid returned at the venous end of the
capillary?
Due to high osmotic pressure & low blood pressure
(c) What happens to the fluid that does not re-enter the
bloodstream.
The lymphatic system drains the fluid away.
9.
(a) Difference between lymph and blood.
Blood comprises of formed elements & Plasma , where lymph is
the fluid that enters the lymphatic system.
(b) Difference between lymph capillaries and blood
capillaries.
Lymph capillaries:
• Are blind ended tubes
• Occur everywhere except brain & Nervous system
• Are slightly larger than blood capillaries
• Are more permeable than blood capillaries
• Has slow moving fluid due to no pump.
(c) Difference between the lymph system & the
circulatory
system.
The Lymph System:
• Carries no nutrients to cells
•
10. What are the functions of the Lymphatic System?
The Functions are:
• To return excess fluid from the tissues to the
blood.
• Removes bacteria and foreign particles as they
pass through.
• Immune response.
APPLY YOUR KNOWLEDGE:
1.
A stationery person and swollen feet and ankles. Why?
The blood is staying in the legs not returning to the heart due to
no movement.
2.
(a) Why is haemoglobin red?
Due to the iron content of the haemoglobin.
(b) Royalty and Blue blood. Why?
Could be due to them being special people and not ordinary like
us????
3.
Differences in blood before the intestines and after.
These may include:
• More waste products
• Less oxygen and glucose
•
4.
How is the structure of the red blood cell suited to the
function it performs.
These are:
• No nucleus
• Biconcave in shape
5. Describe the effects of removing large quantities of
blood.
These would include:
• Fatigue
• Blue look to skin
6.
Difference in red blood count at high altitudes.
ey need to make up for the smaller amount of oxygen at a high altitude by
having more red blood cells.
Phagocytosis: An explanation.
The cell membrane surrounds the material and the membrane
moves to enclose the material within the cell. The membrane
then seal and the material is now inside the cell.