Human Anatomy & Physiology: General Orientation and the Respiratory System

Comprehensive vocabulary flashcards covering anatomical planes, directional terms, body regions, and the anatomy and physiology of the human respiratory system.

Anatomical Position

A standard body orientation used to describe body parts and locations, characterized by standing upright, facing forward, arms at the sides, palms forward, and feet forward (always viewed from the person's point of view).

Coronal/Frontal Plane

An anatomical plane that divides the body into front and back portions (e.g., chest at the front, spine at the back).

Transverse/Cross-sectional Plane

An anatomical plane that divides the body into top and bottom portions.

Sagittal Plane (Medial Plane)

An anatomical plane running from head to feet down the middle of the body that divides it into left and right sides.

Superior

An anatomical direction meaning up, above, or closer to the head.

Inferior

An anatomical direction meaning down, below, or closer to the feet.

Anterior

An anatomical direction meaning front or toward the front of the body.

Posterior

An anatomical direction meaning back or toward the back of the body.

Medial

An anatomical direction meaning middle or closer to the line going down the middle of the body.

Lateral

An anatomical direction meaning side or farther from the line going down the middle of the body.

Proximal

An anatomical direction used mainly for arms and legs meaning closer to the point of origin or trunk.

Distal

An anatomical direction used mainly for arms and legs meaning farther away from the point of origin or trunk.

Trunk (Trunck)

The main central anatomical region of the body, including the chest, stomach, and pelvic area.

Nasal Cavity

The entry pathway for air that helps warm, filter, and moisten incoming air.

Pharynx

The throat; serves as a passageway for air traveling to the lower respiratory tract.

Trachea

The windpipe that acts as the main trunk carrying air toward the lungs, reinforced with cartilage rings to keep it from collapsing.

Bronchi

The two main large branches extending from the trachea, carrying air into the right and left lungs.

Bronchioles

Smaller branches that divide from the bronchi and carry air toward the alveoli.

Alveoli

Tiny grape-like air sacs at the end of bronchioles that serve as the main site of gas exchange, where $O_2$ moves into the blood and $CO_2$ moves into the sacs.

Type 1 Alveolar Cells

Cells that form the thin alveolar wall (one cell thick) to allow gas exchange.

Type 2 Alveolar Cells

Alveolar cells that produce surfactant to prevent the alveoli from collapsing.

Surfactant

A substance produced by Type 2 alveolar cells that prevents alveoli from collapsing.

Right Lung

The lung consisting of 3 lobes: superior, middle, and inferior.

Left Lung

The lung consisting of 2 lobes (superior and inferior) because the heart takes up space.

Mediastinum

The anatomical space located between the lungs where the heart is positioned.

Pleura

A double protective membrane around each lung containing pleural fluid that helps reduce friction and protect the lungs during breathing.

Capillaries

Tiny blood vessels surrounding the alveoli that bring circulating blood close enough to the alveoli to permit gas exchange.

Diffusion

The movement of substances from an area of high concentration to low concentration, such as $O_2$ moving from alveoli to blood and $CO_2$ moving from blood to lungs.

Passive Transport

Movement of substances that does not require energy, such as diffusion moving molecules from high to low concentration.

Ventilation

The physical process of moving air in and out of the lungs, composed of inhalation and exhalation.

Diaphragm

The breathing muscle situated underneath the lungs that contracts during inhalation and relaxes during exhalation.

Intercostal Muscles

Muscles located between the ribs that contract and relax to help drive inhalation and exhalation.

Tidal Volume

The amount of air inhaled or exhaled during a typical normal breath.