Ch6_Medical_Terminology_PART2_Lymphatic_&_Immune_Systems_Lymphatic_Function_Pathology_&_Diagnostic_P

1. Absorbing fats & fat-soluble vitamins from small intestine

2. Removing waste from tissues

3. Providing aid to the immune system

• Small finger-like projections that line the small intestine and contain:
• 1. Blood vessels:
• .....a. Part of circulatory system
• .....b. Absorb most of the nutrients

• 2. Lacteals:
• .....a. Specialized structures of the lymphatic system
• .....b. Absorb & transport fats & fat-soluable vitamins that can't be directly absorbed thru bloodstream.

1. Specialized structures of the lymphatic system

2. Found within the villi of the small intesetine

3. Absorb & transport fat & fat-soluble vitamins that can't be absorbed directly into the bloodstream

1. Removes waste products & excess fluids created by the cells.

2. Destroys pathogens

3. Takes away foreign substances present in the tissues

Lymph nodes play active role working to immune system to protect body against invading microorganisms and diseases.

1. Transports lymph from tissue throughout body and eventually returns this fluid to the venous circulation.

2. Lymphatic vessels are closely aligned with cardiovascular system & sometimes referred to as the secondary circulatory system

• 1. Blood - circulates through entire body
• ....Lymph - flows in only one direction (from point of origin to return to venous circulation in region of the neck)

• 2. Blood circulation - flows in open system - leaves & re-enters blood vessels through the capillaries
• ....Lymphatic circulation is a closed system - from time lymph enters the lymphatic capillaries, it does not leave the lymphatic vessels until it returns to venous circulation

• 3. Blood - pumped through the body by the heart
• ....Lymph - does not have a pump-like organ - depends on help from the movement of nearby muscles & blood vessels to aid in its flow.

• 4. Blood - Color of blood makes arteries & veins readily visible.
• ....Lymph - Lymph is clear so lymphatic vessels are not readily visible

• 5. Blood - filtered by the kidneys - waste products excreted by the urinary system
• ....Lymph - filtered by lymph nodes loacted along the lymphatic vessels throughout body

1. Also called intercelluar or tissue fluid

2. Plasma from arterial blood that flows out of capillaries & into spaces between the cells

3. Transports food, oxygen, & hormones to cells

4. 90% reabsorbed by the capillaries & returned to venous circulation

5. 10% that isn't reabsorbed becomes lymph. It is transported by the lymphatic vessels and filtered by lymph nodes located along these vessels

1. Microscopic, blind-ended tubes located near body surface.

2. Capillary walls only one cell thick

3. Cells separate briefly to allow lymph to enter the capillary

4. Action of cells as they close forces lymph to flow forward.

1. Lymph flows from lymphatic capillaries on body surface to progressively large lymphatic vessels located deeper within tissues.

2. Vessels have valves like veins to prevent backward flow of lymph.

• 3. Larger lymphatic vessels eventually join together to form two ducts:
• .....a. Right lymphatic duct
• .....b. Thoracic duct (largest lymphatic vessel in body)

• 4. Each duct:
• .....a. Drains a specific part of the body
• .....b. Returns lymph to venous circulation

• 1. Collects lymph from:
• .....a. Right side of head & neck
• .....b. Right upper quadrnt of trunk
• .....c. Right arm

2. Empties into right subclavian vein.

1. Largest lymphatic vessel in the body.

• 2. Collects lymph from:
• .....a. Left side of head & neck
• .....b. Upper left quadrant of trunk
• .....c. Left arm
• .....d. Entire lower portion of trunk
• .....e. Both legs

3. Empties into the left subclavian vein

1. Small & bean-shaped - between 400 & 700 lymph nodes located along larger lymphatic vessels.

• 2. Approximately half of nodes are in the abdomen, most of other half on branches of larger lymphatic vessels throughout the body, with the exceptions of:
• .....a. Cervical lymph nodes
• .....b. Axillary lymph nodes
• .....c. Inguinal lymph nodes

• 3. Each lymph node contains:
• .....a. Specialized lymphocytes capable of destroying pathogens. Unfiltered lymph flows into nodes where lymphocytes destroy harmful substances such as:
• ...........(1.). Bacteria
• ...........(2.) Viruses
• ...........(3.) Malignant cells

.....b. Additional structures filter lymph to remove additional impurities

3. After these processes, lymph leaves the node & continues on way to return to venous circulation

Innate immune responses are those we are born with

• Components of the innate response:
• 1. There are a variety of phagocytes circulating in the blood as part of the innate response:
• ......a. Macrophage - large phagocytes that can surround & eat invading cells.
• ......b. Neutrophil - most common WBC, it is a phagocyte that can eat a variety of pathogens
• ......c. Dendritic cells - phagocyte that eats pathogens then displays leftover remmants on long tentacles for T cells. When the T cells sees it they realize that something new is invading the body.
• ......d. Basophils & Eosinophils -

• 2. Component - part of innate response, it is a protein that normally circulates in the blood until it comes in contact with an antigen. The complement will mark the antigen for desctruction by one of the phagocytes.
• Example: Inflammation is an innate response or reaction of the body to an injury or disease.

1. The adaptive response develops over time as the body encounters various pathogens. This is the type of response that most people think of when they think of an immune response.

2. It has the ability to remember previous attacks and quickly generate defenses against them.

• 3. Components:
• ......a. An antigen is any substance the body regards as foreign
• ......b. Lymphocytes are a specical type of WBC, that are a major part of the adaptive response. Lymphocytes are originally formed in the red bone marrow as stem cells.

These immature immature lymphocytes start circulating through the body where they undergo differentiation (meaning the stem cells will mature into different types of cells with different characteristics.)

• They differentiate into 2 different types of cells:
• ............(1.) The first type is a B cell which is a type of lymphocyte that has the abiity to recognize a specific antigen. When it is activated by the presence of this antigen it becomes a plasma B cell which will secrete an antibody against the antigen.

An antibody (also known as immunoglobulin) is a disease-fighting protein that is coded to destroy a particular antigen.

In addition to the plasma B cells that activate, make the antibodies and kill off off all these invaders, B cells can also become memory B cells that have the ability to remember an antigen that has been fought before and 'notify' the body that a former invader is back. This allows the plasma B cells to respond very quickly.

......2. The second type of lymphocyte is the T cell. The T cell is another type of lymphocyte that has been exposed to thyosin, which is secreted in the thymus.

T cells can coordinate immune defenses and kill infected cells ON CONTACT.

T cells do a variety of things, particularly as far as creating chemical proteins that will help fight off an infection.

Example: T cells secrete interferon, a protein produced by T cells to fight viruser.

T cells also produce lymphokines - cells that direct other cells in the imune ystem and tell them wht to do.

Located along sides of neck

Located under the arms in the area known as the armpits (axilla.)

Located in the inguinal (groin) area of the lower abdomen.

Located around back of knee.

• Means:
• .....1. Pertaining to the lymphatic system
• .....2. Resembling lymph or lymphatic tissue

1. Consist of lymphoid tissue, but primary roles are in conjunction with the immune system

• 2. Include:
• .....a. Tonsils (Adenoids, palantine tonsils, & lingual tonsils)
• .....b. Thymus (composed of lymphoid tissue but is an endocrine gland)
• .....c. Peyer's patches (on walls of ileum- small intestine)
• .....d. Veriform appendix (hangs from loer portion of cecum - the first section of the large intestine)
• .....e. Spleen (saclike mass of lymphoid tissue in left upper quadrant of abdomen)
• .....

• 1. Three masses of lymphoid tissue:
• .....a. Adenoids - Nasopharyngeal tonsils - located in nasopharynx
• .....b. Palatine tonsils - located on left and right sides of 'top' (visible part) of throat.
• .....c. Lingual tonsils - located at the base of the tongue.

2. Form a protective ring around the back of the nose and upper throat - protect upper respiratory tract

3. Prevent pathogens from entering body through the nose and mouth.

1. Located superior to the heart.

2. Composed mostly of lymphoid tissue, but is endocrine gland that assists the immune system.

3. Secretes hormone thymosin.

4. T cells mature in thymus as a result of exposure to thymosin.

1. Consist of lymphoid tissue & work with immune system to prevent entry of pathogens through the digestive system.

2. Peyer's patches are located on the walls of the ileum the last section of the small intestine.

3. Veriform appendix hangs down from the cecum, the first section of the large intestine. NOTE: Recent research indicataes the appendix plays an important part in the immune system.

1. Saclike mass of lymphoid tissue located in left upper quadrant of the abdomen, just inferior to the diaphragm & posterior to the stomach.

2. Filters microorganisms and other foreign material from the blood.

3. Forms lymphocytes and monocytes, which are specialized white blood cells with roles in the immune system.

NOTE: Jeff says "contains or houses lymphocytes and involved in B-cell activation..." and that lymphocytes are first created in the red bone marrow.

• 4. Has hemolytic function of:
• .....a. Destroying worn-out red blood cells
• .....b. Releasing their hemoglobin for reuse

5. Stores extra erythrocytes & maintains the appropriate balance between these cells & the plasma of the blood.

1. Called swollen glands - terms lymph nodes and lymph glands are sometimes used interchangeably.

2. Inflammation of the lymph nodes - frequently an indication of an infection.

Any disease process affecting a lymph node or nodes.

Benign tumor formed by an abnormal collection of lymphatic vessels due to a congenital malformation of the lymphatic system.

1. Abnormal enlargement of the spleen.

• 2. Condition can be due to:
• .....a. Bleeding caused by an injury
• .....b. Infectious disease such as mononucleosis
• .....c. Abnormal functioning of the immune system.

Bleeding from the spleen

Inflammation of the tonsils

Surgical removal of the tonsils

Diagnostic test performed to detect damage or malformations of the lymphatic vessels.

• Note: Scintigraphy is diagnostic technique where a 2-dimensional picture of internal body tissue is produced through the detection of radiation emitted by a radioactive substace administered into the body.

• 1. Swelling due to an abnormal accumulation of lymph fluid within the tissues.
• 2. There are two types:
• .....a. Primary
• .....b. Secondary

1. Hereditary disorder due to malformation of the lymphatic system.

2. Can appear at amy time in life, most commonly produces swelling in legs and feet.

1. Caused by damage to the lymphatic system.

2. Most commonly produces swelling in the limb nearest to the damaged lymphatic vessels.

• 3. Most frequent causes of this condition are:
• .....a. Cancer treatment (surgery, chemotherapy, and/or radiation)
• .....b. Trauma (burns, injuries, and scarring)