The Brain

The human brain is the most complex organ in the body. It is made up almost entirely of nerve cells.At any given moment there are millions of electrical impulses running through the brain. The brain is constantly receiving and responding to hundreds of messages from the environment and the internal organs of our body.

Sample Qs Transport

The Question with student's answer

Marking Scheme

Another Sample Answer

Mind Map Nervous System

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The use of Mind Map has proven to enhance students understanding on certain concepts in Bio..

Mind Map Global Warming

Take note that Global Warming is related to Greenhouse effect..

THE SKELETAL SYSTEM | human anatomy

Root Hair

THE STRUCTURE OF THE ROOT HAIR

Root hairs are adapted to perform their function by:

• Increasing the surface area for absorption because they extend beyond the cell;
• Having cell walls that are thin and permeable for quick diffusion;
• Containing a very large vacuole to maintain the concentration gradient; and
• The absence of a cuticle on any root cells.

Transpirational Pull

Transpiration pull

Stomata are found on the leaf surface.
The suction force of transpiration is caused by the loss of water vapour through the stomata.
Transpiration pull is the force responsible for moving water all the way up the stem, to the leaves and is the most powerful of the three forces.
Water moves from the xylem in the main vein of the leaf, through the spongy parenchyma, into the intercellular air spaces and out through the stoma as water vapour.
The water moves from the leaf surface by evaporation.
This creates a water potential around the leaf, resulting in a negative pressure developing in the xylem.
This suction force is transferred along the leaves and stem, resulting in a decrease in the water potential of the roots.
Transpiration may cause excess water loss resulting in the plant wilting.
Excess wilting will cause death.

Gutattion

Guttation through Hydathodes !

Guttation Vs Transpiration

Guttation

(i) It 'occurs through hydathodes in the leaves.
(ii) It is exuded in the form of liquid.
(iii) It takes place either in the morning or during the night.
(iv) The hydathode remains open whole day and night.
(v) Oozed out water is not pure and contains inorganic and organic substances.
(vi) It occurs through hydathodes.
(vii) It takes place mostly in herbaceous plants.
(viii) It has no relation with the temperature.
(ix) It takes place due to development of root pressure.

Transpiration

(i) It occurs through stomata, cuticle and lenticels.
(ii) Water is lost in the form of water vapour.
(iii) It occurs only in day time.
(iv) The stomata of leaves usually remain open during day and get closed at night.
(v) Water is pure and contains no salt.
(vi) Major loss of water takes place through stomata.
(vii) It takes place in all higher terrestrial plants.
(viii) Transpiration maintains the temperature of the plant,
(ix) Root pressure is not involved.

Immune system

Immune system plays a vital role in defending our body against infections and diseases.
A strong immune system ensures that you stay healthy. Sometimes it fails to do its job, which leads to microorganism invasion and you get sick. Immune system starts to weaken due to several reasons and there are ways in which you can improve it. Seven ways that will help in improving your immune system are as follows:

1. A balanced diet is the primary requirement for better functioning of immune system.
2. Green vegetables are high in nutrition. Include fresh juices or smoothies.
3. Liver plays an important role in body detoxification. Limit consumption of alcohol, corn syrup and avoid pain killers.
4. Consume probiotic foods like yogurt.
5. Garlic is a powerful immunity booster.
6. Take magnesium, enzyme supplements and Vitamins C, D3.
7. Regular exercising helps to drain toxins from the lymph nodes. 

Lymphatic System

Conceptualise the relationship between the lymphatic system and circulatory system.

Interstitial Fluid

CHECK LIST

A student is able to:

·         describe the formation of interstitial fluid,

·         state the composition of interstitial fluid, state the importance of interstitial fluid, describe the fate of interstitial fluid,

·         describe the structure of the lymphatic system,

·         explain how the lymphatic system complements the circulatory system,

·         compare the content of blood interstitial fluid and lymph,

·         predict what will happen if interstitial fluid fails to return to the circulatory system,

·         conceptualise the relationship between the lymphatic system and circulatory system.

Lymphatic System

~May use the following Learning Outcomes as your check list :

A student is able to:
• state another function of the circulatory system besides transport,
• identify the three lines of defence mechanism of the body,
• describe the process of phagocytosis,
• state the meaning of antigen and antibody,
• state the meaning of immunity and immunization,
• relate antigen and antibody to immunity,
• name and give examples of various types of immunity,
• state the effects of human immunodeficiency virus (HIV) on the body’s defence mechanism,
• describe the transmission of HIV,
• suggest ways to prevent the spread of acquired immune deficiency syndrome (AIDS)

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Lymphatic System.mov

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