Human Anatomy and Physiology Lesson 1

Comprehensive practice flashcards covering introductory concepts of human anatomy, physiology, levels of organization, homeostatic mechanisms, and anatomical terminology.

Anatomy

The field that investigates body structure; derived from the word parts "Ana" meaning apart and "tomy" meaning cut.

Physiology

The study of the function within the human body to understand how the body works.

Surface Anatomy

The study of external features used to locate parts of the body, such as bone projections (trochanters), pulses (radial, carotid), and landmarks for placing a stethoscope.

Anatomical Imaging

The study of internal structures using technologies such as X-rays, ultrasound, MRI (Magnetic Resonant Imaging), and CT scans.

CT Scan

An imaging technique that provides cross-sections of the body; nurses must check if the patient is allergic to seafood (iodine) before using contrast dye.

Systemic Anatomy

A branch of anatomy that studies specific body organ systems.

Regional Anatomy

A branch of anatomy that studies specific body regions, typically used in medical school.

Cellular Physiology

The study of body cells and the functions that occur at the cellular level.

Chemical Level

The level of organization involving chemical bonds that make up the human being, including molecules like $O_2$, $CO_2$, $H_2O$, and DNA.

Cellular Level

The level where molecules come together to form the cell, which is the basic structural unit of life.

Tissue Level

The level where groups of cells come together to build tissue, categorized into connective, epithelial, muscular, and nervous types.

Organ Level

A level of organization where two or more tissue types perform a simple function.

Organ System Level

The level where two or more organs work together to perform complex functions; the human body contains 11 organ systems.

Organism

The highest level of organization, representing the living human body.

Metabolism

The sum of all chemical and physical changes sustaining an organism, including the ability to acquire and use energy.

Responsiveness

The ability of the body to sense and respond to environmental changes in both internal and external environments.

Development

Changes in form, size, cell structure, and function over time, moving from generalized to specialized states.

Germ Layers

The three layers where a fetus arises: ectoderm (outer), mesoderm (middle), and endoderm (inner).

Homeostasis

The body's ability to maintain stable internal conditions despite changing external environments.

Receptor

The component in a homeostatic loop that detects changes in variables, such as skin temperature receptors.

Control Center

The part of the homeostatic mechanism (often the brain) that receives signals, establishes a set point, and compares the stimulus to that set point.

Effector

A structure, such as a sweat gland, that produces a physiological response to signals from the control center to restore balance.

Normal Blood Pressure

According to the American Heart Association, a value $< 120\,mmHg$ systolic (top number) and $< 80\,mmHg$ diastolic (bottom number).

Set Point

The normal, average value of a physiological variable around which the body fluctuates to maintain balance.

Negative Feedback

The main mechanism for homeostatic regulation that stabilizes the system by returning a deviating variable back toward the normal range.

Positive Feedback

A mechanism where the response further stimulates the initial stimulus, causing progressive deviation from the set point; often associated with injury, disease, or childbirth.

Anatomical Position

A universal position where a person stands erect with palms and face forward, used as a reference regardless of actual body orientation.

Superior (Cephalic)

A directional term meaning above or toward the head.

Inferior (Caudal)

A directional term meaning below or toward the tail.

Anterior (Ventral)

A directional term meaning toward the front of the body.

Posterior (Dorsal)

A directional term meaning toward the back of the body.

Medial

A directional term meaning close to the midline of the body.

Lateral

A directional term meaning away from the midline of the body.

Proximal

A directional term meaning close to the point of attachment.

Distal

A directional term meaning far from the point of attachment.

Sagittal Plane

A plane that separates the body into left and right portions; known as midsagittal or median if it is exactly along the midline.

Transverse Plane

A horizontal plane that separates the body into superior (top) and inferior (bottom) portions.

Frontal Plane

A vertical plane that separates the body into anterior (front) and posterior (back) portions.

Supine

A position describing a person lying on their back with the anterior side exposed.

Prone

A position describing a person lying face downward with the dorsal side exposed.

Axial Region

The central vertical axis consisting of the head, neck, thorax, and abdomen.

Appendicular Region

The parts of the body consisting of the upper and lower limbs.

Visceral Layer

The portion of a serous membrane that covers the outside of an organ.

Parietal Layer

The portion of a serous membrane that touches the wall of the body cavity.

Pericardium

The serous membrane and cavity surrounding the heart; the visceral layer covers the heart and the parietal layer is thick fibrous tissue.

Pleura

The serous membrane and cavity surrounding the lungs.

Peritoneum

The serous membrane and cavity located in the abdominal cavity protecting abdominal organs.