AP Chp 16 Lymphatic system

Question 1

Main functions of Lymphatic system

Answer 1

Fluid balance (lymph)- excess interstitial fluid and proteins from blood left behind drain out thru the lymphatic vessels.
Protection from infection- Lymphocytes (WBC's) live and multiply in system to attack and destroy foreign organisms. Lymphoid tissue thru-out the body filters out pathogens and other foreign matter, tumor cells, etc.
Absorption of fats- Large digested fats absorbed into Lymphatic system thru lacteals then taken to the blood in lymph.

Question 2

Lymphatic circulation

Answer 2

One way system
Begins in tissue
Ends in blood stream

Question 3

Lymphatic capillaries

Answer 3

Walls (endothelium) are flattened epithelial cells.
More permeable than blood capillaries.
Overlapping cells form one way valves.
Arise blindly in the tissue (closed at one end).
Lacteals absorb digested fats.

Question 4

Lymphatic vessels

Answer 4

Superficial and deep sets
Names according to location e.g. in the breast called mammary lymphatic vessels.
Lymph nodes are at certain points in the vessels to filter the lymph.
Right lymphatic duct- receives only lymph that comes from the superior right quadrant, right side of head, neck, thorax and upper extremity into the right subclavian vein.
Thoracic duct- receives lymph from the body. First part forms the cisterna chyli (temp storage pouch). Chyle is the milky fluid that drains from the intestinal lacteals.

Question 5

Movement of lymph

Answer 5

Caused by:
Valves in lymphatic vessels that prevent back flow.
Contraction of lymphatic vessels from skeletal movement drive lymph forward, breathing pushes and pulls on vessels.
Improper flow causes lymphedema.

Question 6

Lymphoid tissue

Answer 6

Distributed throughout the entire body and makes up the specialized organs of the lymphatic system.

Question 7

Lymph nodes

Answer 7

Named based on location in the body:
Cervical nodes (neck) become enlarged during upper respiratory infections.
Axillary nodes (axillae, armpits) enlarged after infections of the upper extremities and breasts.
Tracheobronchial nodes (trachea and large bronchial tubes) fill with airborne contaminants in people who smoke, are exposed to smoke or live in highly polluted areas.
Mesenteric nodes (between peritoneum that form the mesentery) there are 100 to 150 of these nodes.
Inguinal nodes (groin region) when enlarged are referred to as buboes from which bubonic plague got its name.

Question 8

Spleen

Answer 8

Organ containing lymphoid tissue that filters the blood. Unusually rich supply of blood, harbors lymphocytes and phagocytes that are active in immunity.
Destroys old RBC’s.
Produces RBC’s before birth.
Serves as blood reservoir that can be returned to the bloodstream in case of hemorrhage or other emergency.

Question 9

Thymus

Answer 9

Plays key role in early immune system development during fetal life and infancy.
Lymphocytes T-cells must mature in the thymus before they can perform their functions in the immune system.
Shrinks after puberty and is replaced by connective tissue and fat.

Question 10

The tonsils

Answer 10

Remove contaminants and trap pathogens.
Palatine tonsils- each side of the soft palate.
Pharyngeal tonsils- (adenoid) behind the nose on the posterior wall of the upper pharynx.
Lingual tonsils- posterior of the tongue.
Surgery to remove if recurrent infection makes swallowing or breathing difficult.

Question 11

Lymphedema

Answer 11

Obstruction of lymph flow, possible causes: infection of the lymphatic vessels, a malignant growth that obstructs lymph flow, or loss of lymphatic vessels and nodes as a result of surgery or injury.
Areas more prone to infection because lymphatic systems filtration activity is diminished.