Body Organization and Homeostasis Flashcards

Vocabulary flashcards focusing on tissue classification, cellular junctions, major organ systems, body cavities, skin layers, and homeostatic feedback mechanisms.

Simple Epithelial Tissue

A single layer of epithelial cells adapted for rapid diffusion, absorption, and secretion.

Tight Junction

A cell junction where no movement occurs between cells, controlling entry of substances, such as in the blood-brain barrier.

Gap Junction

A cell junction containing membrane channels that allows direct communication and ion flow between adjacent cells.

Adhesion Junction

A cell junction connected to cytoskeletal filaments that permits flexibility and stretching within tissues.

Fibroblasts

Cells present in almost all connective tissues that produce protein fibers for support and elasticity.

Macrophages

Immune cells located in connective tissue that protect organs by destroying outside pathogens like viruses and bacteria.

Adipocytes

Specialized connective tissue cells that store fat for energy storage and thermal insulation.

Collagen Fibers

Large protein fibers within connective tissue that provide structural support.

Elastic Fibers

Medium-width protein fibers in connective tissue that provide elasticity.

Reticular Fibers

Narrow protein fibers in connective tissue that offer additional structural support.

Integumentary System

The organ system consisting of the skin that protects the body, regulates temperature, synthesizes vitamin D, and provides sensory input.

Cardiovascular System

The organ system consisting of the heart and blood vessels that transports nutrients and maintains temperature, pH, and fluid homeostasis.

Respiratory System

The organ system comprising the lungs that carries out gas exchange ($CO_2$ and oxygen) and helps regulate pH homeostasis.

Urinary System

The system comprising the kidneys and urinary bladder that eliminates metabolic waste and maintains pH and salt-water balance.

Muscular System

The organ system responsible for movement, posture, supporting internal organs, and heat production through shivering.

Nervous System

The organ system made up of the brain and spinal cord that uses rapid electrochemical signals for fast, short-lived coordination.

Endocrine System

The organ system made up of hormone-secreting glands that provides long-term coordination, stress responses, and metabolic regulation.

Heart Rate Variability

A metric used as an indirect proxy for physiological stress, where high variability indicates low stress and low variability indicates high stress.

Ventral Cavity

The anterior body cavity separated by the diaphragm into the thoracic cavity above and the abdominal cavity below.

Dorsal Cavity

The posterior body cavity housing the cranial cavity for the brain and the spinal cavity for the spinal cord.

Epidermis

The outermost layer of the skin composed primarily of dead cells containing keratin to prevent water loss.

Dermis

The inner layer of skin beneath the epidermis containing blood vessels, nerves, hair follicles, and sweat and oil glands.

Subcutaneous Layer

The tissue layer beneath the dermis containing adipose tissue for insulation and cushioning.

Melanocytes

Cells located near the surface of the skin that produce melanin to protect against UV damage.

Mucous Membrane

A tissue membrane lining body openings that secretes mucus for lubrication and protection against pathogens.

Serous Membrane

A double-layered membrane lining organs within the ventral cavity that secretes fluid to reduce friction.

Synovial Membrane

A membrane lining movable joints that secretes fluid to minimize friction during movement.

Negative Feedback Loop

The primary homeostatic mechanism where a physiological response counteracts a stimulus to bring body conditions back to a set point.

Positive Feedback Loop

A feedback mechanism in which a response amplifies or continues in the same direction as the original stimulus, such as during childbirth or blood clotting.