Blood, Lymphatic, and Immune Systems

Vocabulary terms covering the gross and cellular anatomy, physiological processes, and common pathologies of the blood, lymphatic, and immune systems.

Bone marrow

Found inside the bone; it produces red blood cells, white blood cells, and platelets.

Thymus Gland

Located in the upper chest behind the sternum; the site where $T$ - cells mature and a critical component for immune system development.

Lymph notes

Small bean shaped glands found throughout the body that filter lymph fluid and help detect infections to start immune responses.

Lymphatic Vessels

A network of vessels that carry lymph fluid, return extra tissue fluid to the bloodstream, and transport fat and fat soluble vitamins from the gut.

Spleen

Found in the upper left abdomen; it filters the blood, removes damaged red blood cells, and stores blood for emergencies.

Tonsils

Found in the throat; they help trap pathogens which enter through the mouth or nose.

Red blood cells

Cells that carry $O_2$ around the body and transfer $CO_2$ away from the tissues.

White blood cells

Cells that protect the body from pathogens by engulfing them and producing anti bodies to neutralise them.

Platelets

Blood components that help with blood clots to prevent excessive bleeding.

Granulocytes

Types include neutrophils, eosinophils, and basophils; they destroy germs using phagocytosis and release chemicals to fight infection.

Phagocytosis

A biological process where certain cells engulf and digest particles such as germs.

Monocytes

Cells that travel in the blood and move into tissues to become macrophages and dendritic cells to destroy pathogens.

Lymphocytes ($B$ - Cells)

Immune cells that mature in bone marrow and produce antibodies that mark pathogens for destruction.

Lymphocytes ($T$ - Cells)

Immune cells that mature in the thymus gland; they include cytotoxic types that kill infected cells and helper types that activate other immune cells.

Macrophages

Large cells that destroy bacteria, viruses, and damaged cells, and carry the waste of the lymph nodes.

Dendritic cells

Cells that capture pieces of germs and show them to other immune cells to start adaptive immune responses.

First line of defence

Includes physical barriers like skin and mucous membranes, chemical barriers like low pH (stomach acid), and the inflammatory response.

Vaccines

Exposure to a harmless form of a pathogen to trigger an immune response and produce memory cells for future protection.

Cytokines and chemokines

Signaling molecules that regulate cell growth, trigger inflammation, and direct the movement of immune cells (chemotaxis).

Chemotaxis

The directed movement of immune cells to the correct location.

Lymphoedema

A condition where lymph fluid builds up in soft tissues causing swelling because lymph drainage is blocked or damaged.

Rheumatoid arthritis

An autoimmune condition where the immune system attacks the joint lining (synovium), causing inflammation, pain, and joint damage.

Synovium

The joint lining that secretes fluid to help with lubrication and prevent friction.