CHAPTER 12

LYMPHATIC SYSTEM

CONSISTS OF 2 PARTS

1. LYMPHATIC VESSELS- transport fluids that have escaped the cardiovascular system called LYMPH

2. LYMPHATIC ORGANS- (lymph nodes)- filter the fluid and kill off invaders with lymphocytes

LYMPHATIC SYSTEM

Very similar to veins with lymph capillaries becoming successively larger and eventually called LYMPHATIC COLLECTING DUCTS. Have valves very similar to veins that help to move lymph

RIGHT LYMPHATIC DUCT – collects lymph from the right arm and right thorax and right head- drains into the subclavian vein

THORACIC DUCT- collects lymph from the rest of body – drains into the sub clavian vein

Lymphatic Vessels

-KIDNEY SHAPED-ABOUT 1 INCH LONG-about 1000 found in the body-contains large amounts of lymphocytes –B

cells and T cells-FOUND IN CLUSTERS IN 3 MAJOR REGIONS

1. AXILLARY– (armpit)2. CERVICAL- (side of neck)3. INGUINAL- (groin)

LYMPH NODES

SPLEENTHYMUSTONSILSPEYER’S PATCHES

LYMPH ORGANS

Located on the left side and curls around the stomach

Filters the blood of bacteria, viruses and other debris

Breaks down worn out RED BLOOD CELLS so hemoglobin can be reused.

Storage site of blood.Produce Lymphocytes

SPLEEN

Produces hormones- thymosin that programs lymphocytes

Located low in the throat

More active in youth

THYMUS

Lymphatic tissue located in the pharynx-

Trap bacteria entering the pharynx

May become sore and swollen called --- TONSILITIS

TONSILS

“tonsils” of the small intestine

Capture bacteria that are found in the digestive system.

MUCOSA-ASSOCIATED LYMPHATIC TISSUE(MALT) consists of tonsils and Peyer’s patches which protect the respiratory and digestive tracts from never-ending invasion

PEYER’S PATCHES

SKIN-SWEAT contains a low pH level preventing bacterial growthSEBUM- contains chemicals toxic to bacteriaVAGINAL SECRETIONS- highly acidic

NON SPECIFIC DEFENSE SYSTEMS

STOMACH- hydrochloric acid is highly acidic

SALIVA- contains lysozomes- enzyme that kills bacteria

MUCUS- traps organisms from entering the digestive and respiratory systems

NON SPECIFIC DEFENSE SYSTEM

Immunity

- New particles take longer to identify, and a person remains ill until a new antibody can be crafted

- Old particles are quickly recognized, and a person may never become ill from that invader again. This person is now immune.

STEM CELL– undifferentiated cells made in the red bone marrow (can become Lymphocytes or Granulocytes)

LYMPHOCYTES- NATURAL KILLER CELLS- protect us from tumored cells and virus

infected cells

B CELLS- (bone cells) lymphocytes that mature in the bone marrow-produce antibodies, help present antigens., and form Memory B cells

T CELLS- (Thymus cells) lymphocytes that mature in the thymus- do not produce antibodies– but do release chemicals to spend up phagocytosis by MACROPHAGES- become T HELPER cells that help in the maturity of B cells and Cytotoxic T cells that aid tumored cells and in organ rejection

CELLS OF THE IMMUNE SYSTEM

GRANULOCYTESNEUTROPHILS- 1st responder to infection site- “phagocytize”

EOSINOPHILS- phagocytize parasites and help with allergic reactions and asthma

BASOPHILS– contains vasodilator HISTAMINE and anticoagulant HEPARIN with aide in the INFLAMMATION RESPONSE

MONOCYTES- stored in the spleen can become MACROPHAGES or DENDRITIC CELLS

CELLS OF THE IMMUNE SYSTEM

DENDROCYTE

1. INFLAMMATORY RESPONSE- general

2. ANTIGEN SPECIFIC RESPONSE-

2 types of responses

INFLAMMATION RESPONSE---

(Histamines)

Any substance capable of setting off an immune response.

Almost all things are ANTIGENIC (including our own cells) but our body had learn to identify our cells and these SELF-ANTIGENS (Human leukocyte antigen- HLA) do not trigger an immune response in us.

ANTIGEN

Antibody Production

1. MACROPHAGES-gobble up invading particles and break them up

2. They show the ANTIGEN pieces to T-cells, who identify the pieces

3. T CELLS help to find specific B-cells to help

4. B-cells produce antibodies that are equipped to find that specific antigen on a new cell.

5. Memory B cells are also made- for future attacks

ANTIBODIESalso known as an

immunoglobulin, is a large Y-shaped protein used by the immune system to identify and neutralize foreign objects like bacteria and viruses

May be free flowing or attached to B cells

Active Immunity- You produce the antibodies

- Your body has been exposed to the antigen in the past either through:- Exposure to the actual disease causing antigen –

You fought it, you won, you remember it- Planned exposure to a form of the antigen that has

been killed or weakened – You detected it, eliminated it, and remember it

What is this second type of exposure called?

Vaccine----Passive ImmunityAntigens are deliberately introduced

into the immune system to produce immunity

Because the bacteria has been killed or weakened, minimal symptoms occur

Have eradicated or severely limited several diseases from the face of the Earth, such as polio and smallpox

Immune Disorders~Allergies~

- Immune system mistakenly recognizes harmless foreign particles as serious threats

- Launches immune response, which causes sneezing, runny nose, and watery eyes

- Anti-histamines block effect of histamines and bring relief to allergy sufferers

Aquired Immune Deficiency Syndrome

Caused by the Human Immunodeficiency Virus

Discovered in 1983Specifically targets and

kills T-cellsBecause normal body

cells are unaffected, immune response is not launched

MULTIPLE SCLEROSIS- immune system attacks the myelin sheath of the nervous system

MYASTHENIA GRAVIS

GRAVES DISEASE

AUTOIMMUNE DISEASES