BIOL 40A Unit 1: Introduction to the Human Body

Comprehensive vocabulary flashcards covering Unit 1: Introduction to the Human Body, key body systems, life processes, homeostasis mechanisms, directional terminology, anatomical planes, and body cavities.

Anatomy

The study of body structures.

Physiology

The study of body functions.

Chemical Level

The structural organization level where atoms combine to form molecules.

Cellular Level

The structural organization level that includes organelles and structural components that make up a cell, along with cellular processes.

Tissue Level

A group of similar cells performing a common specific function.

Organ Level

A discrete body structure composed of more than one type of tissue.

Organ System Level

A group of organs working together to perform a common purpose.

Organismal Level

The highest level of biological organization, resulting from all simpler structural levels working in unison.

Integumentary System

Forms external body covering, protects from injury and infection, contains oil/sweat glands, helps regulate body temperature, provides sensory information, synthesizes vitamin D, and prevents water loss.

Skeletal System

Protects and supports body organs, provides a framework for muscles, forms blood cells within bones, and stores minerals.

Muscular System

Allows environmental manipulation, locomotion, and facial expression; maintains posture; and produces heat.

Nervous System

A fast-acting control system that responds to internal and external changes.

Cardiovascular System

System in which the heart pumps blood through blood vessels to transport oxygen, carbon dioxide, nutrients, and wastes.

Respiratory System

Keeps blood supplied with oxygen and removes carbon dioxide via gas exchange across the air sacs in the lungs.

Lymphatic System

Picks up leaked fluid from blood vessels, disposes of debris, houses white blood cells (lymphocytes), and mounts attacks against foreign substances.

Lymphedema

A condition where lymph fluid accumulates in tissues because the lymphatic system cannot drain properly, causing persistent swelling in the arms or legs.

Endocrine System

System of glands that secrete hormones regulating body activities such as growth, reproduction, and nutrient utilization.

Digestive System

Breaks down food into absorbable units and eliminates indigestible solids as feces.

Urinary System

Eliminates nitrogenous wastes and regulates water, electrolyte, and acid-base balance.

Reproductive System

Produces offspring and sexual pleasure, with male testes producing sperm and female ovaries producing eggs.

Metabolism

All the chemical reactions occurring inside the body that maintain life.

Exergonic Reaction

A chemical reaction that releases energy.

Endergonic Reaction

An energy-costing chemical reaction that requires net energy input.

Catabolism

Metabolic breakdown of large molecules into smaller ones, releasing energy.

Anabolism

Metabolic synthesis of small molecules into larger ones, requiring energy.

Responsiveness

The body's ability to detect and respond to internal or external changes.

Growth

An increase in body size resulting from an increase in cell size, cell numbers (via mitosis), or intercellular substance.

Differentiation

The development of an unspecialized stem cell into a specialized cell type with distinct structures and functions.

Homeostasis

The tendency of living organisms to regulate and maintain a relatively stable internal environment despite external fluctuations.

Feedback System

A cyclic pathway that monitors, evaluates, and regulates controlled conditions using a stimulus, receptor, control center, effector, and response.

Controlled Variable

The specific condition being regulated in a feedback loop, such as body temperature (~$37^{\text{o}}\text{C}$) or blood glucose (~$99\text{ mg/dL}$).

Receptor

A body structure that monitors changes in a controlled variable and sends input signals along an afferent pathway to the control center.

Control Center

The component of a feedback loop that evaluates incoming signals, establishes the set point, and sends output commands along an efferent pathway.

Effector

An organ or tissue that receives output signals from the control center and produces a response that alters the controlled variable.

Negative Feedback System

A control mechanism that reverses a change in a controlled variable to restore the body to its set point.

Positive Feedback System

A self-amplifying, time-limited mechanism where the response reinforces or amplifies the initial stimulus until a specific outcome halts the loop.

Telomeres

Specific terminal DNA sequences on chromosomes that protect against chromosomal erosion and shorten with each cycle of cell division.

Intracellular Fluid (ICF)

Fluid located inside body cells.

Extracellular Fluid (ECF)

Fluid located outside body cells, including interstitial fluid and blood plasma.

Anatomical Position

Standard body reference position where a person stands erect facing forward, arms at sides, palms facing forward, and feet flat on the floor.

Axial Region

The central body axis comprising the head, neck, and trunk.

Appendicular Region

The limbs (upper and lower appendages) and the supporting bony girdles.

Superior

Directional term meaning toward the head or upper part of a structure.

Inferior

Directional term meaning away from the head or toward the lower part of a structure.

Anterior

Directional term meaning nearer to or at the front of the body.

Posterior

Directional term meaning nearer to or at the back of the body.

Medial

Directional term meaning nearer to the imaginary vertical midline of the body.

Lateral

Directional term meaning farther away from the body's vertical midline.

Ipsilateral

Directional term meaning located on the same side of the body as another structure.

Contralateral

Directional term meaning located on the opposite side of the body relative to another structure.

Proximal

Directional term meaning nearer to the attachment point of a limb to the trunk or origin of a structure.

Distal

Directional term meaning farther from the attachment point of a limb to the trunk or origin of a structure.

Superficial

Directional term meaning located toward or on the outer surface of the body.

Deep

Directional term meaning located away from the body surface.

Frontal Plane

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

Transverse Plane

A horizontal anatomical plane that divides the body into superior (upper) and inferior (lower) portions.

Sagittal Plane

A vertical anatomical plane that divides the body into right and left portions.

Median Plane

A specific sagittal plane running directly along the midline, dividing the body into equal right and left halves.

Paramedian Plane

A sagittal plane parallel to but offset from the body's central midline.

Oblique Plane

An anatomical plane passing through the body at an angle other than a $90^{\text{o}}$ angle.

Cranial Cavity

The dorsal body cavity enclosing and protecting the brain.

Vertebral Cavity

The dorsal body cavity formed by the vertebral column that contains the spinal cord.

Thoracic Cavity

Superior chest cavity surrounded by ribs and muscles, housing the pleural cavities, pericardial cavity, and mediastinum.

Abdominal Cavity

Superior section of the abdominopelvic cavity containing organs such as the stomach, liver, gallbladder, spleen, kidneys, and most intestines.

Pelvic Cavity

Inferior section of the abdominopelvic cavity containing the urinary bladder, internal reproductive organs, and rectum.

Abdominopelvic Quadrants

Four anatomical divisions (RUQ, LUQ, RLQ, LLQ) formed by vertical and horizontal lines intersecting at the umbilicus.

Abdominopelvic Regions

Nine anatomical subdivisions created by two vertical and two horizontal lines: right hypochondriac, epigastric, left hypochondriac, right lateral, umbilical, left lateral, right inguinal, hypogastric, and left inguinal.

Serous Membrane

A thin, double-layered tissue that lines internal body cavities and covers enclosed viscera, consisting of parietal and visceral layers.

Parietal Layer

The outer epithelial layer of a serous membrane lining the internal cavity wall.

Visceral Layer

The inner epithelial layer of a serous membrane directly covering internal organs.

Pericardium

The double-layered serous membrane enclosing the heart.

Pleura

The double-layered serous membrane lining the thoracic cavity and covering the lungs.

Peritoneum

The double-layered serous membrane lining the abdominal cavity and covering most abdominal viscera.