body systems

Integumentary System

Protects the body from external damage, regulates temperature, prevents dehydration, and serves as a sensory interface.

Skin

The largest organ of the body, consisting of the epidermis, dermis, and hypodermis.

Appendages of the Integumentary System

Hair, nails, sweat glands, and sebaceous glands that serve various protective and regulatory functions.

Barrier Function

The role of the integumentary system in preventing pathogen entry and water loss.

Thermoregulation

Process by which the integumentary system regulates body temperature via sweat glands and blood vessels.

Vitamin D Synthesis

The conversion of 7-dehydrocholesterol to vitamin D by the skin under UV exposure.

Skeletal System

Provides structural support, protects organs, enables movement, stores minerals, and produces blood cells.

Bones

206 individual structures in adults, classified into long, short, flat, and irregular types.

Cartilage

Flexible connective tissue found in joints, nose, and ears, serving to reduce friction.

Hematopoiesis

The process of blood cell production occurring in red bone marrow.

Muscular System

Enables movement, maintains posture, generates heat, and supports bodily functions.

Skeletal Muscle

Voluntary, striated muscle attached to bones, responsible for movement.

Smooth Muscle

Involuntary, non-striated muscle found in the walls of internal organs.

Cardiac Muscle

Involuntary, striated muscle found only in the heart.

Contraction

The process by which muscle fibers shorten to produce movement.

Heat Production

Generated by muscle contractions to help maintain body temperature.

Nervous System

Controls body activities through rapid communication and coordination of responses.

Central Nervous System (CNS)

Consists of the brain and spinal cord, responsible for processing information.

Peripheral Nervous System (PNS)

Includes all nerves outside the CNS, facilitating sensory and motor functions.

Neurons

The functional units of the nervous system that transmit signals via neurotransmitters.

Hormones

Chemical messengers released by glands in the endocrine system to regulate bodily functions.

Endocrine System

Regulates body functions via hormones, including growth, metabolism, and reproduction.

Glands

Organs that secrete hormones; includes pituitary, thyroid, and adrenal glands.

Negative Feedback

Mechanism that maintains homeostasis by inhibiting secretion of hormones.

Cardiovascular System

Transports oxygen, nutrients, hormones, and waste products throughout the body.

Heart

The four-chambered pump responsible for circulating blood in the body.

Blood Vessels

Includes arteries, veins, and capillaries; essential for blood circulation.

Lymphatic System

Maintains fluid balance, supports immunity, and absorbs fats from the digestive system.

Lymph

Fluid containing white blood cells that helps fight infection.

Lymph Nodes

Filter lymph and house lymphocytes, crucial for immune responses.

Respiratory System

Facilitates gas exchange, regulates blood pH, and supports vocalization.

Alveoli

Tiny air sacs in the lungs where gas exchange occurs.

Gas Exchange

Process of oxygen entering the blood and carbon dioxide being expelled.

Digestive System

Breaks down food, absorbs nutrients, and eliminates waste.

Enzymes

Biological catalysts that facilitate the breakdown of food components.

Urinary System

Filters blood, excretes waste, regulates water and electrolyte balance.

Nephrons

Functional units of the kidneys that filter blood and form urine.

Reproductive System

Produces gametes, facilitates reproduction, and supports fetal development.

Gametogenesis

The process of forming gametes—spermatogenesis in males and oogenesis in females.

Homeostasis

The stable balance of bodily functions maintained by all body systems.

Interplay of Systems

The way in which different body systems work together to maintain health.

Hematopoiesis

The process of creating new blood cells in the bone marrow.

Lacteals

Lymphatic vessels in the small intestine that absorb dietary fats.

Diaphragm

The primary muscle involved in breathing, aiding in ventilation.

Thyroid Hormone

A hormone responsible for regulating metabolism.

Erythropoietin

A hormone produced by the kidneys that stimulates red blood cell production.

FSH

Follicle-stimulating hormone involved in reproductive processes.

Autonomic Nervous System

Regulates involuntary functions such as heart rate and digestion.

Oocytes

Immature eggs present in females that decrease in number with age.

Adrenaline

A hormone released during stress that prepares the body for 'fight or flight' responses.

Intercalated Discs

Unique connections between cardiac muscle cells that ensure synchronized contractions.

Microvilli

Small projections in the small intestine that increase surface area for absorption.

Melanocytes

Cells in the skin that produce melanin for UV protection.

Platelets

Small cell fragments in blood involved in clotting processes.

Alveolar Surfactant

Substance that reduces surface tension in the alveoli, preventing collapse.