Everything Life Sciences Grade 10

• Lymph plays an important role inreturning plasma proteins to the bloodstream.


• Digested fats are absorbedand then transported from the villi in the small intestine to
  the bloodstream via the lymph vessels.


• Lymphocytes are manufactured in the lymph nodes


• Antibodies manufactured in the lymph nodes assist the body to build up an effective
  immunityto infectious diseases.


• Lymph nodes play an important role in the defence mechanism of the body. They
  filter out micro-organisms (such as bacteria) and foreign substances such as toxins.


• Lymph transports large molecular compounds (such as enzymes and hormones) from
  their manufactured sites to the bloodstream.

See video: SHORTCODEat http://www.everythingscience.co.za

NOTE:

Elephantiasis is a disease characterised by thickening of the skin and underlying tissues,

especially in the legs and genitals. It occurs when the body becomes infected by parasitic

infections, which target the lymphatic system.

Figure 8.19: An Ethiopian farmer affected by elephantiasis after being infected by a worm that settled

in the lymphatic system thereby causing the disease.

Cardiovascular System Lymphatic System

Bloodis responsible for collecting and

distributing oxygen, nutrients and

hormones to the tissues of entire body.

Lymphis responsible for collecting

and removing waste products left

behind in the tissues.

Blood flowsin the arteries, capillaries,

and veins.

Lymph flowsin an open circuit from

the tissues into lymphatic vessels.

Bloodflows towards the heart and

away from the heart.

Lymphflows in one direction only

(towards the heart).

Bloodis pumped by the heart to all

parts of the body.

Lymph is not pumped. It passively

flows from the tissues into the lymph

capillaries.

Bloodconsists of the liquid plasma

that transports the red and white blood

cells and platelets.

Lymphthat has been filtered and is

ready to return to the cardiovascular

system is a clear or milky white fluid.

Blood is visibleand damage to blood

vessels causes obvious signs such as

bleeding or bruising.

Lymph is colourless or translucentand

damage to the lymphatic system is

difficult to detect until swelling occurs.

Blood is filteredby the kidneys. Lymph is filteredby lymph nodes

located throughout the body.

Table 8.2: Comparison between the cardiovascular system and the lymphatic system

242 8.3. Lymphatic circulatory system