A&P Lymphatic System Chapter 16

NK cells

defend the body against various viruses and cancer cells by secreting cytolytic ("cell- cutting") substances called perforins that lyse the cell membrane, destroying the infected cell. these cells also secrete chemicals that enhance inflammation.

Where do B lymphocytes proliferate?

germinal centers

What creates mechanical barriers?

he skin and mucous membranes lining the passageways of the respiratory, digestive, urinary, and reproductive systems

Where does the right Lymphatic duct originate and where does it empty into?

in the right thorax at the union of the right jugular, right subclavian, and right bronchomediastinal trunks. It empties into the right subclavian vein near the junction of the right jugular vein.

Direct Attacks Include:

(a) Agglutination Antibody causes Antigens to Clump (b) Precipitation Causes Antigens to form into Insoluble Substances (c) Neutralization Some microorganisms produce Toxins or specific sites on Viruses End Result: The virus or toxin can no longer bind to receptor sites on our tissue cells to cause cell injury

What are the major functions of lymph?

1. Takes fluid away that has escaped out into the tissue and did not return to the capillary vessel. (contaminated) 2. Low 3. Ideal for drainage and delicate thin walls

First line of defense (two types)

1. physical barrier 2. chemical barrier

How much bacteria can macrophages engulf?

100

How much can a neutrophil engulf

20 Bacteria

How many layers are there in lymphatic vessels and what are they?

3, an endothelial lining, a middle layer of smooth muscle and elastic fibers, and an outer layer of connective tissue.

L-Chains

: Two of the chains are identical light chains

Tissue fluids containing clotting factors seep into the area.

A clot containing threads of fibrin may form.

Fibroblasts arrive.

A connective tissue sac may form around the injured tissues.

How does a fever start

A fever begins as a viral or bacterial infection that stimulates lymphocytes to proliferate, producing cells that secrete a substance called interleukin-1 (IL-1), IL-1 raises the thermoregulatory set point in the brain's hypothalamus to maintain a higher body temperature.

Immunoglobulin G

Acts against bacteria, viruses, and toxins Activates the Complement Proteins

Hapten

Allergic Reactions

Antibody Actions:

Antibodies attack Antigens directly, activate the Complement Proteins, or stimulate local tissue changes that are unfavorable to the antigen-bearing agents

Phagocytes are active.

Bacteria, dead cells, and other debris are removed.

Suppressor (TS) Cells (Also referred to as Regulator T Cells (T-regs) Primary Receptor:

Both CD4 and CD25

Normally the Complement Proteins are Inactive

But an Antigen-Antibody Complex stimulates a series of reactions that activates the Complement System Cascading effect - C1 -> C1A -> C2 ...

T Helper (TH) Cells Primary Receptor:

CD4

T Cytotoxic (TC) Cells (Also referred to as Killer T Cells) Primary Receptor:

CD8

In which body regions are lymph nodes most abundant?

Cervical, axillary, supratrochlear, inguinal, pelvic, abdominal, thoracic

What is the consequence of lymphatic obstruction?

Continuous movement of fluid from interstitial spaces into blood capillaries and lymphatic capillaries stabilizes the volume of fluid in the spaces. An obstruction would cause tissue fluid to accumulate in interstitial spaces , producing edema. Surgey such as the removal of axillary lymph nodes due to a breast tumor, can obstruct drainage from the upper limb.

When does lymph flow peak?

During physical exercise

How do plasma proteins in blood capillaries affect lymph formation?

Filtration from the plasma normally exceeds reabsorption, leading to the net formation of tissue fluid. This increases the tissue fluid hydrostatic pressure moving tissue fluid into lymphatic capillaries, forming lymph.

What is Lymph?

Fluid, derived from interstitial fluid, that the lymphatic vessels carry.

Immunoglobulin A

Found in the secretions of Exocrine Glands: tears, saliva, breast milk, nasal fluid, gastric juice, bile ... Defends against bacteria and viruses

Immunoglobulin D

Found on the surface of most B Cells, especially those of infants Functions as the Antigen receptor of B Cells

What is the thymus Function?

Houses lymphocytes; differentiates thymocytes into T lymphocytes

What is the function of the spleen?

Houses macrophages that remove foreign particles, damaged red blood cells, and cellular debris from the blood; contains lymphocytes

Types of Immunoglobulins

Immunoglobulin G, Immunoglobulin A, Immunoglobulin M, Immunoglobulin D, Immunoglobulin E

Lines of defence include

Line 1 - Barriers Line 2 - Innate (non-specific) defence Line 3 - Adaptive (specific) defence

Make "Lousy Antigens"

Lipids

Cardinal Signs & Symptoms of Inflammation:

Local redness, Swelling/Edma, Heat, Pain and loss of function

Types of chemical barriers

Low pH and Lysozyme

Through which lymphatic structures would lymph pass in traveling from a lower limb back to the bloodstream?

Lymph fromt he lower body regions, the left upper limb and the left side of the head and neck enters the thoracic duct; lymph from the right side of the head and neck, the right upper limb, and the right thorax enters the right lymphatic duct

What is the relationship between tissue fluid and lymph?

Lymph is essentially tissue fluid that has entered a lymphatic capillary. Lymph formation depends upon tissue fluid formation.

What is Lymph Formation?

Lymph is formed from the absorbed fluids from cells in the capillary beds. The lymph vessels return this fluid, after undergoing filtration in lymph glands, into the subclavian veins.

The functional units of the lymph node are

Lymph nodules

What are lymphatic trunks?

Lymph trunk is a collection of lymph vessels that carries lymph, and is formed by confluence of many efferent lymph vessels. It in turn drains into one of the two lymph ducts

What can lymphatic capillaries do what blood capillaries con not?

Lymphatic capillaries are adapted to receive proteins and foreign particles in a way that blood capillaries are not.

mononuclear phagocytic system (reticuloendothelial system).includes...

Monocytes and macrophages

What factors promote lymph flow?

Muscular activity influences the movement of lymph through the lymphatic vessels.

Cells divide.

Newly formed cells replace injured ones.

Is a fever a specific response

No

What may cause an infection?

Pathogens

Physical barriers

Physical structures that prevent the pathogen from entering (into your body cells)

Immunoglobulin M

Produced First during an Infection; IgG will Follow Activates the Complement Proteins Anti-A and Anti-B antibodies (Chapter 14) are examples of IgM

White blood cells invade the region. so.....

Pus may form as white blood cells, bacterial cells, and cellular debris accumulate.

When a Splenectomy is performed some of its functions are taken over by the:

Red Bone Marrow and the Liver

What are the two collecting ducts?

Right lymphatic duct and thoracic duct

Distinguish between the thoracic duct and the right lymphatic duct.

Right lymphatic duct: drains lymph from the right upper limb, right side of thorax and right halves of head and neck. Thoracic duct: drains lymph into the circulatory system at the left brachiocephalic vein between the left subclavian and left internal jugular veins.

Immunoglobulin E

Secreted by Plasma Cells in the Skin, Mucosa of the GI & Respiratory Tracts and the Tonsils Associated with allergic reactions and promotes Inflammation

Types of physical barriers

Skin and Mucosa

what are the types of Nonspecific Defenses?

Species resistance, Mechanical barriers, Chemical barriers, Natural killer cells, Inflammation, Phagocytosis, Fever

Activate the Complement System

The Complement refers to a group of at least 20 plasma proteins that circulate in the plasma of the blood in an: Inactive State

In what organ does the lymphatic capillaries play a major role in the absorption of dietary fats

The Small intestine

Lymphatic Pathway

The lymphatic pathways begin as lymphatic capillaries that merge to form lymphatic vessels. These, in turn, lead to larger vessels, trunks, and ducts that unite with the veins in the thorax.

Distinguish between a lymph node and a lymph nodule

The nodule differs from a lymph node in that it is much smaller and does not have a well-defined connective-tissue capsule as a boundary. It also does not function as a filter, because it is not located along a lymphatic vessel

Why are the thymus and spleen considered organs of the lymphatic system?

Their functions are similar to those of the lymph nodes

What are lymph nodules?

They are patches of lymphatic tissues embedded in muscous membranes

Epithelial Cells within the Thymus Produce Several Hormones Called:

Thymosins

What are the major functions of the thymus and the spleen?

Thymus- Houses lymphocytes; differentiates thymocytes into T lymphocytes Spleen- Houses macrophages that remove foreign particles, damaged red blood cells, and cellular debris from the blood; contains lymphocytes

Blood vessels dilate. Capillary permeability increases and fluid leaks into tissue spaces. Then what happens?

Tissues become red, swollen, warm, and painful.

H- Chains

Two of the chains are identical heavy chains

Orange- Right Lymphatic Duct Green- Thoracic Duct (Left Lymphatic Duct)

Which Ducts are in orange and which is in green?

Does Lymph vessels Have valves if so, Why?

Yes, to prevent back flow

What is endothelium composed of?

a single layer of squamous epithelial cells

defensin

antimicrobial peptide

Natural killer (NK) cells

are a small population of lymphocytes that are distinctly different from the lymphocytes that provide adaptive defense mechanisms.

What are lymphatic capillaries?

are microscopic, closed-ended tubes.

Chemical barriers are

consist of some type of secreted chemical that helps prevent the entry of a pathogen

What does Lymphatic vessels transport and where?

excess fluid away from the interstitial spaces in most tissues and return it to the bloodstream

What are the major functions of lymph nodes?

filtering potentially harmful particles from lymph before returning it to the bloodstream and monitoring body fluids (immune surveillance) through the actions of lymphocytes and macrophages.

What is the cisterna chlyi and where is it located?

is a dilated sac at the lower end of the thoracic duct

What happens to iron in blood when the body temperature is up?

it is reduced so bacteria cant feed off of it

Name the lymphatic organs that are encapsulated

lymph nodes, thymus, and spleen

What does M.A.L.T Stand for?

mucosa-associated lymphoid tissue

collectin

protein that protects against bacteria, yeasts, and some viruses

What does interleukin-1 do

raises the thermoregulatory set point in the brain's hypothalamus to maintain a higher body temperature.

What is the function of the lymphatic vessels?

to pick up and return excess tissue fluid to the blood vascular system

complement

​Group of proteins activated when an antibody binds an antigen; enhances reaction against nonself substances.

What is Species Resistance?

​Natural ability of one type of organism to resist infection by pathogens that cause disease in another type of organism.

perforin

​Protein that natural killer cells release that forms pores in the cell membrane of infected cell.

What are interferons?

​Subgroup of cytokines (immune system chemicals) that inhibit viral multiplication and tumor growth.