Lab 1: Anatomical Terminology and Organization of the Human Body

A comprehensive vocabulary review of anatomical terminology, covering the six levels of structural organization, the eleven human organ systems, and the anatomy and accessory structures of the skin and duodenum.

Intracellular

A directional and structural term meaning occurring or located within cells, such as cellular organelles.

Chemical Level

The simplest level of biological organization where atoms bond together to form molecules (such as oxygen atoms, carbon atoms, or glucose molecules) to create the smallest structures in the body.

Cellular Level

The level of structural organization where combinations of molecules form organelles, which make up body cells such as muscle cells, neurons, and stem cells.

Tissue Level

The level of organization in which groups of specialized cells and fluids join together to carry out specialized functions (e.g., muscle tissue, nervous tissue, epithelial tissue).

Organ Level

A level of organization consisting of two or more kinds of tissues joined together to carry out a specific common function for the body (e.g., uterus, pancreas, colon).

Organ System Level

A level of organization composed of two or more organs working collaboratively to carry out a shared physiological function (e.g., digestive system, endocrine system, reproductive system).

Organismal Level

The highest level of biological organization, composed of all organ systems working together to sustain life and maintain homeostasis in an individual living being (e.g., humans, animals, seals).

Integumentary System

The organ system whose primary functions are to protect the body from outside threats, microbes, and excessive water loss, as well as to insulate against cold.

Skeletal System

The organ system that provides structural support, enables movement, protects internal organs (e.g., the ribcage), produces blood cells, and stores and releases minerals such as calcium.

Muscular System

The organ system that facilitates movement, maintains body posture, aids blood circulation, generates body heat, and assists with respiration (via the diaphragm and chest muscles) and digestion (via peristalsis).

Lymphatic System

The organ system that transports excess fluids back to the bloodstream, filters pathogens from the blood, and contributes to immunity by producing lymphocytes (white blood cells).

Respiratory System

The organ system that delivers oxygen to the blood and body, expels waste gas ($CO_2$), and traps and eliminates foreign particles via mucosa and sneezing.

Digestive System

The organ system that mechanically and chemically breaks down food (using peristalsis and acid), breaks down molecules to be absorbed, absorbs nutrients, and expels waste.

Nervous System

The bodily communication and integration system that senses sensations and transmits rapid response signals through autonomic or somatic pathways.

Endocrine System

The communication system that secretes hormones into the body for responses that do not require immediate action and need to last longer than electrical signaling (e.g., a drop in estrogen/progesterone triggering the shedding of the uterine lining).

Cardiovascular System

The transport system that circulates oxygen, nutrients, and hormones to body tissues, delivers $CO_2$ to the lungs, and carries platelets to stop bleeding and lymphocytes to combat infection.

Urinary System

The organ system that regulates fluid volume and filters waste products from blood, stimulates red blood cell (RBC) production in bone marrow, and synthesizes Vitamin D to enable calcium absorption for bone health and muscle contraction.

Reproductive System

The organ system responsible for forming and releasing gametes that can fertilize to yield offspring for species survival, and for secreting sex hormones that regulate sexual development.

Epidermis

The outer, thin, keratinized layer of the skin composed of 4 to 5 layers of stratified squamous epithelium; it acts as a tough barrier against bacteria, water, UV light, and chemicals.

Dermis

The inner layer of the skin composed of two layers of connective tissue; it provides structural support and houses glands and sensory receptors.

Hypodermis

The layer of tissue beneath the dermis (containing adipose tissue) that connects the skin to underlying structures.

Sweat Glands

Exocrine glands located in the skin that release warm water in sweat, which cools the body as it evaporates.

Sebaceous Glands

Exocrine oil glands in the skin that secrete oils to lubricate and protect the skin.

Hair

An accessory structure of the skin made of dead keratinized cells growing out of a hair follicle; it insulates the body and shields openings such as the eyes, nose, and ears.

Mucosa (Duodenum)

The mucous membrane layer of the duodenum composed of epithelium and connective tissue; it lubricates the lumen and contains blood and lymph vessels that transport absorbed nutrients.

Submucosa (Duodenum)

The layer of loose connective tissue in the duodenum that joins the mucosa to the muscularis layer.

Muscularis (Duodenum)

The double-layered involuntary smooth muscle of the duodenum that promotes mechanical digestion and propels food along the alimentary canal.

Serosa (Duodenum)

The outer sheath of collagen fibers that secures and holds the duodenum in place.

Microvilli

Specialized surface features found on epithelial cells lining the duodenal lumen that expand surface area to enhance nutrient absorption.

Cilia

Hair-like surface projections found on epithelial cells whose primary function is to push mucus and dust.