CH 13

Functions of the Lymphatic System

Draining excess interstitial fluid, transporting lipids and lipid-soluble vitamins, and immune responses.

Lymphatic Vessels

Transport fluids back to the blood.

Lymphatic Organs

Are scattered throughout the body and play a role in immune responses.

Lymph

The fluid contained in lymphatic vessels.

Lymphocytes

Primary cells of the immune system; two types are T Cells and B Cells.

T Cells

Manage immune responses and attack viruses and tumor cells.

B Cells

Protect the body by producing plasma cells that secrete antibodies.

Lymphatic Macrophages

Remove foreign substances and activate T Cells.

Lymphatic Capillaries

Small vessels that begin the lymphatic vessels and are closed at one end.

Lymphatic Collecting Vessels

Larger vessels that collect lymph from lymphatic capillaries.

Lymphatic Trunks

Formed by the union of the largest lymphatic collecting vessels.

Right Lymphatic Duct

Drains lymph from the right upper arm and right side of the body.

Thoracic Duct

Larger duct that receives lymph from the rest of the body.

Lymph Nodes

Filter lymph and activate the immune system.

Functions of the Spleen

Stores erythrocytes, removes old erythrocytes, and stores blood platelets.

White Pulp

Part of the spleen that stores lymphocytes.

Red Pulp

Part of the spleen involved in storing and removing old red blood cells.

Palatine Tonsils

Paired tonsils located at the posterior end of the oral cavity.

Lingual Tonsils

Paired tonsils located at the base of the tongue.

Pharyngeal Tonsil

Tonsil located at the posterior wall of the nasopharynx.

Innate (Nonspecific) System

System that responds quickly to protect the body from pathogens.

Surface Barriers

Include skin and mucosae that protect the body from infection.

Mucous Membranes

Line body cavities and serve as sticky surfaces to trap microorganisms.

Phagocytes

Cells that feed on and destroy invading microorganisms.

Macrophages

Primary phagocytes derived from monocytes.

Natural Killer Cells

Cells in the blood and lymph that kill cancer cells and virus-infected cells.

Inflammation

The body's response to injury aiming to clear pathogens and debris.

Antimicrobial Proteins

Attack microbes directly or limit their reproduction.

Interferons

Proteins that protect healthy cells from viral attacks.

Complement System

A group of proteins that circulate in blood and destroy cells via lysis.

Fever

A defensive response with an abnormally high body temperature.

Passive Humoral Immunity

Antibodies made from the serum of an immune human or animal donor.

Active Humoral Immunity

Occurs when B Cells produce antibodies against pathogens.

B Lymphocytes

Involved in producing antibodies for humoral immunity.

T Lymphocytes

Defend the body from microbial invasion and can initiate inflammation.

Acquired Immunodeficiency Syndrome (AIDS)

Caused by the HIV virus, attacking lymphocytes.

Elephantiasis

Condition caused by blocked lymphatic vessels, leading to swollen body parts.

Autoimmune Diseases

Occur when the body produces an immune response against its own tissues.

Rheumatoid arthritis

An autoimmune disease that damages joints.

Multiple Sclerosis

An autoimmune disease causing destruction of myelin sheaths in the CNS.

Grave's Disease

An autoimmune disease characterized by hyperthyroidism.

Humoral Immunity

Type of immunity produced by antibodies present in body fluids.

Cell-Mediated Immunity

Occurs when T Lymphocytes defend the body from infection.

Interferons

Proteins secreted by virus-infected cells to protect healthy cells.

Mild Fever

Can have a positive effect on body defenses during infection.

Adaptive (Specific) Defense System

Protects the body from a wide range of microorganisms and abnormal cells.

Antigens

Substances that can mobilize the immune system and provoke a response.

Lymphocytes

Key cells involved in adaptive immunity; includes B and T lymphocytes.

Booster shots

Given to provide extensive immunity against a particular microbe.

Antibody-Mediated Immunity

Another term for humoral immunity, involving antibodies.

Efferent Lymphatic Vessels

Vessels through which lymph exits a lymph node.

Afferent Lymphatic Vessel

Vessels through which lymph enters a lymph node.

Lymphatic Ducts

Receive lymph from lymphatic trunks.

Lymphatic organs

Organs associated with the lymphatic system and immune response.

Primary functions of lymph nodes

Filtering lymph and activating the immune system.

Pathogen

A microorganism that can cause disease.

Inflammatory Response

Initiated when body tissues are injured, aims to clear pathogens.

Macrophages

Derived from monocytes; major phagocytes in the body.

Phagocytosis

The process of engulfing and destroying pathogens by phagocytes.

B cells

Produce antibodies and are key in humoral immunity.

T cell activation

Initiated by the interaction of T cells with antigens.

Specificity in immune response

Recognition of particular pathogens by the adaptive immune system.

Systemic immunity

Immune response not restricted to the initial infection site.

Memory in immunity

Ability to recognize and respond strongly to previously encountered pathogens.

Complement proteins

Plasma proteins that enhance the immune response by destroying pathogens.

Adaptive immunity

Immunity developed through exposure to specific pathogens.

Natural immunity

Immunity acquired through natural exposure to pathogens.

Artificial immunity

Immunity gained through vaccines or medical interventions.

Inguinal lymph nodes

Located in the groin area; part of the lymphatic system.

Axillary lymph nodes

Located in the armpit area; part of the lymphatic system.

Cervical lymph nodes

Located in the neck area; part of the lymphatic system.

Chemical barriers

Substances that can neutralize pathogens, like acids secreted by mucous membranes.

Innate defenses

Non-specific defenses that provide immediate protection against pathogens.