Lymphatic System

Question 1

Composition of the Lymphatic System:

Answer 1

1. Lymph Fluid
2. Lymphatic Vessels
3. Lymphoid organs: lymph nodes, thymus, spleen,
   tonsils

Question 2

Lymph

Answer 2

is formed as plasma filters out of the capillaries (interstitial fluid) due to pressure generated by the pumping action of the heart.
. Most of this fluid is reabsorbed by blood capillaries. About ninety percent (90%) of this fluid re-enters the capillaries and venules to join again the cardiovascular system.

Question 3

What happens to interstitial fluid that is not reabsorbed?

Answer 3

the blood capillaries drains into the lymphatic capillaries

Question 4

What does Lymph contain?

Answer 4

proteins, white blood cells, and waste products.

Question 5

What does the Lymphatic system prevents accumulation of?

Answer 5

excess tissue fluid.

Approximately ten percent (10%) of fluid will remain as lymph which contains proteins, white blood cells, waste products, impurities and foreign particles. Lymph will eventually be reabsorbed by the lymph capillaries.

Question 6

Lymphatic capillaries

Answer 6

Microscopic vessels formed by a single sheet of simple squamous epithelium (endothelium) similar to blood capillaries.
. With valves to prevent backflow of fluid
. More porous than blood capillaries therefore can allow bigger molecules to be absorbed (including microbes and cancer cells)
 One-way movement of lymph fluid
 Blind-ended capillaries

Question 7

Lacteals

Answer 7

• lymphatic capillaries in the walls of the small intestine
• Absorb and transport fat from the small intestines

Question 8

Lymphatic capillaries join to form what?

Answer 8

the lymphatic venules and veins that eventually enter the two big lymphatic ducts.

Question 9

Right Lymphatic Duct

Answer 9

– drains lymph from the right upper extremity, right side of the head, neck and upper torso

Question 10

Thoracic Duct

Answer 10

– largest lymphatic vessel in the body
 drains lymph from ¾ of the body
 has an enlarged pouch in abdomen, the cisterna chyli, a holding area for lymph

Question 11

What 2 big ducts eventually
join the subclavian veins
in the neck region.

Answer 11

Right Lymphatic Duct & Thoracic Duct

Question 12

LYMPH NODES

Answer 12

Biological “filters” of lymph, occurring in clusters all over the body
. Contains lymphoid tissue (mass of developing lymphocytes and related cells), therefore, involved in hematopoeisis

Two important functions:
1. Immune defense
2. White blood cell development

Question 13

What are the Two important functions of lymph nodes:

Answer 13

1. Immune defense
2. White blood cell development

Question 14

Flow of lymph through a lymph node:

Answer 14

1. enters through four afferent vessels
2. filtered in the sinuses (bacteria, cancer cells, damaged tissue cells are removed)
3. exits through one efferent vessel

This structure helps the lymph node perform its filtering function while bacteria and other harmful cells are acted upon by phagocytic cells as lymph fluid passes through it.

Question 15

Lymphatic Drainage

Answer 15

Knowledge of lymphatic drainage is vital in cancer surgery
 Lymph nodes with cancer cells must be surgically removed together with the cancer mass

Question 16

THYMUS

Answer 16

. Lymphoid organ in the mediastinum
. Source of lymphocytes before birth
. Produces thymosin, a hormone that influences development and maturation of T lymphocytes
. Undergoes involution later in life

Question 17

TONSILS

Answer 17

. Form a protective ring around the openings of the mouth and throat:
*palatine tonsils
*pharyngeal tonsils (adenoids - at the posterior nasal cavity)
*lingual tonsils
. one of the body’s first line of defense
. subject to chronic infection

Question 18

SPLEEN

Answer 18

Largest lymphoid organ of the body
. Located at left upper quadrant of the abdomen

Functions:
1. phagocytosis of bacteria and old RBCs
2. salvages iron from hemoglobin
3. acts as a blood reservoir

Question 19

Disorders of Blood and Lymphatic
Vessels

Answer 19

1. Aortic Aneurysm
2. Arteriosclerosis
3. Atherosclerosis
4. Varicose Veins
5. Phlebitis
6. Lymphangitis

Question 20

Aortic Aneurysm

Answer 20

• a weakened and ballooning area of the aorta, the large artery that carries blood from the heart through the chest and abdomen
  . Ruptured aortic aneurysm can cause life-threatening bleeding

Question 21

Arteriosclerosis

Answer 21

– hardening of arteries – the arterial walls become thick and stiff

Question 22

Atherosclerosis

Answer 22

– a specific type of arteriosclerosis due to buildup of fats and cholesterol in artery walls (plaques), which can restrict blood flow

Question 23

Varicose Veins

Answer 23

• swollen, twisted, and sometimes painful veins that have filled with an abnormal collection of blood

Risk factors include:
. congenitally defective valves
. pregnancy
. thrombophlebitis

Question 24

Phlebitis

Answer 24

• inflammation of one or more veins
  . May involve superficial veins or deeper veins with clot formation (thrombophlebitis)

Question 25

Lymphangitis

Answer 25

– infection of the lymph vessels that is often caused by bacterial infection
- If infection is uncontrolled, may lead to cellulitis, abscess, sepsis

Question 26

Hemorrhage and First Aid – Pressure Points

Answer 26

• Elevate the extremity and apply direct pressure on bleeding wound
• Apply pressure on superficial arteries if bleeding does not stop with applying direct pressure on wound

Question 27

What are pharyngeal tonsils and where are they located

Answer 27

(adenoids - at the posterior nasal cavity)