Intro to the Human Body: Levels of Structural Organization and Major Body Systems

Practice flashcards covering levels of structural organization, the major body systems, and the defining characteristics of living organisms from the lecture notes.

What is the first level of structural organization in the human body?

Chemical level.

What are atoms?

The smallest units of matter that retain their unique chemical properties; examples include carbon, hydrogen, oxygen, and nitrogen.

What do atoms form when they join together?

Molecules such as water (H2O), oxygen (O2), and carbon dioxide (CO2).

What are macromolecules?

Large, complex biological molecules like proteins, lipids, carbohydrates, and nucleic acids (DNA).

What is the smallest unit of life?

The cell.

Give three examples of specialized cell types and their functions.

Muscle cells contract to produce movement; nerve cells transmit electrical signals; skin cells form protective barriers.

What are tissues?

Groups of similar cells that perform specific coordinated functions.

What are the four main tissue types?

Epithelial, connective, muscle, and nervous tissue.

What does epithelial tissue do?

Covers body surfaces, lines hollow organs and cavities, and forms glands.

What does connective tissue do?

Supports, binds, protects body structures; stores energy and transports substances; it is rich in blood vessels.

What does muscular tissue do?

Responsible for movement; contracts to move structures and generate heat (includes skeletal, smooth, and cardiac muscle).

What does nervous tissue do?

Carries information through nerve impulses; the body’s communication system.

What is required for an organ to form?

At least two tissue types; most organs contain all four tissue types.

Give an example of an organ and its tissue composition.

The heart—muscle, epithelial, connective, and nervous tissues.

What is an organ system?

A team of specialized organs working together to perform a major function.

Name a key feature of the digestive system as described in the notes.

Mouth, stomach, intestines, and related structures; breaks down food, absorbs nutrients, eliminates waste.

Which organs form the respiratory system?

Lungs, trachea, and diaphragm (and related structures) for gas exchange.

What is the hypothalamus' dual role?

Part of both the nervous system and the endocrine system; regulates hormone release via its control of the pituitary gland.

What is the organismal level?

The entire human body functioning as an integrated living being.

Name the 11 major body systems.

Integumentary, Skeletal, Muscular, Nervous, Endocrine, Cardiovascular, Lymphatic/Immune, Respiratory, Digestive, Urinary, Reproductive.

What are the six defining characteristics of living organisms listed in the notes?

Metabolism, responsiveness, movement, growth, differentiation, reproduction.

What are the two parts of metabolism and what do they mean?

Catabolism (breaking down complex substances to release energy) and Anabolism (building up complex substances to create new structures and store energy).

What is differentiation?

The process by which unspecialized cells become specialized (e.g., stem cells becoming neurons or muscle cells).

What is reproduction?

Formation of new cells for growth/repair via cell division or creation of a whole new organism through fertilization.