Human Anatomy & Physiology: Defence Against Infection, Immunity, and Homeostasis

These flashcards cover key vocabulary and concepts related to human anatomy, physiology, the immune system, homeostasis, and digestion.

Pathogen

An organism that causes disease, such as bacteria, viruses, fungi, or parasites.

Bacteria

Single-celled microorganisms that are prokaryotic and can be pathogenic or beneficial.

Virus

A microscopic infectious agent that can only replicate inside the living cells of an organism.

Immune System

A network of cells and tissues that work together to defend the body against pathogens.

Antigen

A molecule or part of a pathogen that is recognized by the immune system and triggers an immune response.

Phagocytosis

A process by which certain cells engulf and digest pathogens and debris.

Inflammation

A biological response to harmful stimuli, characterized by redness, heat, swelling, and pain.

Lymphocyte

A type of white blood cell that is involved in the immune response.

Vaccination

The administration of a vaccine to stimulate an immune response without causing disease.

Antibody

A protein produced by plasma cells that can specifically bind to an antigen to neutralize or eliminate it.

Homeostasis

The process by which organisms regulate their internal environment to maintain stable conditions.

Feedback Mechanism

A process that uses the conditions of one component to regulate the function of another; can be negative or positive.

Glomerulus

A cluster of capillaries in the kidney where ultrafiltration of blood occurs.

Ultrafiltration

The process of filtering blood in the kidneys, allowing water and small solutes to pass while retaining larger molecules.

Endocrine System

The system of glands that produce hormones to regulate various body functions.

Hormone

Chemical messengers secreted into the bloodstream that regulate physiological processes.

Nephron

The functional unit of the kidney responsible for filtering and reabsorbing substances from blood.

Countercurrent Multiplication

A mechanism in the Loop of Henle that enhances the concentration of urine by creating a gradient.

Osmoregulation

The process of maintaining the proper balance of salts and water in the body.

Receptor

A protein molecule in a cell's membrane that responds to specific signals such as hormones.

Cytotoxic T cells

A type of lymphocyte that kills infected or cancerous cells.

Memory cells

Long-lived immune cells that remember specific pathogens for faster response upon re-exposure.

Passive Immunity

Immunity acquired through the transfer of antibodies from another source.

Active Immunity

Immunity that develops after exposure to a pathogen or after vaccination.

Homeostasis

The ability to maintain a stable internal environment despite external changes.

Peristalsis

Involuntary muscle contractions that move food through the digestive tract.