Introduction to Human Anatomy and Physiology

Vocabulary terms and definitions covering the introduction to human anatomy and physiology, including levels of organization, homeostatic mechanisms, organ systems, and anatomical terminology.

Anatomy

The study of the structure/morphology of the human body and its parts; derived from Greek for "a cutting up".

Physiology

The study of the functions of the human body and its parts; derived from Greek for "relationship to nature".

Subatomic Particles

Protons, neutrons, and electrons that make up cells.

Atom

Tiny particles that make up chemicals, such as hydrogen and carbon.

Molecule

Particles consisting of atoms joined together, such as water or glucose.

Macromolecule

Large particles consisting of molecules, such as D N A or protein.

Organelle

A functional part of a cell, such as a mitochondrion or lysosome.

Cell

The basic unit of structure and functions, such as a muscle, nerve, or blood cell.

Tissue

A layer or mass of cells with a specific function, such as adipose tissue.

Organ

A group of different tissues with a function, such as the heart, kidney, or stomach.

Organ System

A group of organs with a common function, such as the digestive system.

Organism

Composed of organ systems interacting, such as a human.

Homeostasis

The maintenance of a stable internal environment.

Metabolism

The sum of all chemical reactions in a living system, involving energy production and nutrient cycling.

Respiration

The process of making energy; most organisms do it by taking in $O_2$ and giving off $CO_2$.

Receptor

A part of a homeostatic mechanism that detects and provides information about the stimuli.

Control Center

The decision-maker in homeostatic mechanisms that maintains the set point.

Effector

A muscle or gland that responds to the control center and causes the necessary change in the internal environment.

Negative Feedback

The most common homeostatic mechanism where the response to the change moves the variable in the opposite direction of the deviation from the set point.

Positive Feedback

An uncommon mechanism where the change or deviation is intensified instead of reversed, such as blood clotting or uterine contractions during childbirth.

Axial portion

The part of the human body consisting of the head, neck, and trunk.

Appendicular portion

The part of the human body consisting of the upper and lower limbs.

Diaphragm

The muscle that separates the thoracic and abdominopelvic cavities.

Serous membranes

Double-layered membranes lining the thoracic and abdominopelvic cavities that secrete a slippery fluid to prevent friction.

Visceral layer

The inner layer of a serous membrane which covers an organ.

Parietal layer

The outer layer of a serous membrane which lines the wall of a cavity.

Integumentary System

System providing body covering, protection, temperature regulation, sensory reception, and production of Vitamin D.

Skeletal System

System providing support, movement, framework, protection, and the production of blood cells.

Muscular System

System providing support, movement, and serving as the main source of body heat and posture.

Nervous System

Integration and coordination of organ function through nerve impulses and neurotransmitters for rapid short-term effects.

Endocrine system

Integration and coordination of organ function through hormones for slower, longer-lasting effects.

Cardiovascular System

System负责 transportation of gases, nutrients, blood cells, hormones, and wastes.

Lymphatic System

System that transports fluids from tissue spaces to blood, carries fats, and defends the body against infection.

Microbiota

The total population of microbial cells on the human body.

Microbiome

The combination of microbial cells and their genes.

Anatomical Position

Standing erect, facing forward, upper limbs at the sides, and palms facing forward.

Sagittal section

A longitudinal cut that divides the body into left and right portions.

Transverse section

A cut that divides the body into superior and inferior portions; also called a horizontal section.

Coronal section

A longitudinal cut that divides the body into anterior and posterior portions; also called a frontal section.

Proximal

A term of relative position meaning closer to the point of attachment to the trunk.

Distal

A term of relative position meaning farther from the point of attachment to the trunk.