Introduction to Anatomy & Physiology: Study Guide

Introduction to Anatomy & Physiology

Overview

Anatomy and Physiology are foundational sciences in understanding the structure and function of the human body. Anatomy focuses on the physical structures, while physiology explores how these structures function and interact.

Ways to Study Anatomy

Gross Anatomy

Gross anatomy, or macroscopic anatomy, examines large, visible structures of the body.

• Surface anatomy: Study of exterior features.

• Regional anatomy: Focuses on specific body areas.

• Sectional anatomy: Examines cross-sections of the body.

• Systemic anatomy: Studies organ systems.

• Clinical anatomy: Includes medical specialties.

• Developmental anatomy: Examines changes from conception to adulthood, including embryology.

Microscopic Anatomy

Microscopic anatomy examines cells and molecules, requiring magnification.

• Cytology: Study of cells.

• Histology: Study of tissues.

Human Physiology

Physiology studies the functions of anatomical structures.

• Cell physiology: Functions of cells.

• Organ physiology: Functions of specific organs.

• Systemic physiology: Functions of organ systems.

• Pathological physiology: Effects of diseases on organs or systems.

Surface Anatomy

Surface anatomy involves locating structures on or near the body surface, often using anatomical landmarks.

• Anatomical position: Hands at sides, palms forward.

• Supine: Lying down, face up.

• Prone: Lying down, face down.

Regional Anatomy

Regional anatomy divides the body into specific regions for study.

• Abdominopelvic quadrants and regions: Used to describe locations of organs and pain.

Sectional Anatomy

Sectional anatomy uses slices through a three-dimensional object to visualize internal organization. This is important in radiological techniques such as MRI and CT scans.

• Planes of section:

  • Frontal (coronal) plane: Divides body into anterior and posterior portions.

  • Sagittal plane: Divides body into left and right portions.

    • Midsagittal: Plane is in the middle.

    • Parasagittal: Plane is offset from the middle.

  • Transverse (horizontal) plane: Divides body into superior and inferior portions.

Levels of Organization

The human body is organized into hierarchical levels, each building upon the previous.

• Chemical level: Atoms and molecules.

• Cellular level: Cells, the smallest living units.

• Tissue level: Groups of similar cells working together.

• Organ level: Two or more tissues working together.

• Organ system level: Groups of interacting organs. Humans have 11 organ systems.

• Organism level: The individual life form.

Major Organ Systems

The body consists of 11 major organ systems, each with specific organs and functions.

System	Major Organs	Functions
Integumentary	Skin, hair, sweat glands, nails	Protects against environmental hazards Helps regulate body temperature Provides sensory information
Skeletal	Bones, cartilages, ligaments, bone marrow	Provides support and protection Stores calcium and other minerals Forms blood cells
Muscular	Skeletal muscles, tendons	Provides movement Generates heat Supports skeletal position
Nervous	Brain, spinal cord, peripheral nerves, sense organs	Directs immediate responses to stimuli Coordinates/moderates other organ systems Provides/interprets sensory information
Endocrine	Pituitary, thyroid, adrenal glands, pancreas, gonads	Directs long-term changes in other organ systems Adjusts metabolic activity and energy use Controls many structural and functional changes during development
Cardiovascular	Heart, blood, blood vessels	Distributes blood cells, water, nutrients, waste products, oxygen, and carbon dioxide Distributes heat to control body temperature
Lymphatic	Spleen, thymus, lymphatic vessels, lymph nodes, tonsils	Defends against infection and disease Returns tissue fluids to the bloodstream
Respiratory	Nasal cavities, sinuses, larynx, trachea, bronchi, lungs, alveoli	Delivers air to alveoli Provides oxygen to bloodstream Removes carbon dioxide from bloodstream Produces sounds for communication
Digestive	Teeth, tongue, pharynx, esophagus, stomach, intestines, liver, gallbladder, pancreas	Processes and digests food Absorbs and conserves water Absorbs nutrients Stores energy reserves
Urinary	Kidneys, ureters, urinary bladder, urethra	Excretes waste products from blood Controls water balance Stores urine Regulates blood ion concentrations and pH
Male Reproductive	Testes, epididymis, ductus deferens, seminal vesicles, prostate gland, penis, scrotum	Produces male sex cells (sperm), seminal fluids, and hormones Sexual intercourse
Female Reproductive	Ovaries, uterine tubes, uterus, vagina, labia, clitoris, mammary glands	Produces female sex cells (oocytes) and hormones Supports developing embryo from conception to delivery Provides milk to nourish newborn infant Sexual intercourse

Body Cavities

Body cavities protect organs and permit significant changes in organ size and shape.

• Ventral body cavity (coelom): Divided by the diaphragm into the thoracic and abdominopelvic cavities.

• Thoracic cavity: Contains pleural cavities (lungs) and pericardial cavity (heart).

• Abdominopelvic cavity: Contains abdominal cavity (digestive organs) and pelvic cavity (reproductive organs, rectum, bladder).

Serous Membranes

Serous membranes line body cavities and cover organs, consisting of parietal and visceral layers.

• Parietal serosa: Lines the cavity wall.

• Visceral serosa: Covers the organ.

Homeostasis

Homeostasis is the maintenance of a stable internal environment. All body systems work together to keep variables within normal ranges (body temperature, fluid balance).

Homeostatic Regulation

• Autoregulation: Automatic response in a cell, tissue, or organ to an environmental change.

• Extrinsic regulation: Responses controlled by nervous and endocrine systems.

Homeostatic Regulatory Mechanism

• Receptor: Receives the stimulus.

• Control center: Processes the signal and sends instructions.

• Effector: Carries out instructions.

This mechanism limits fluctuations of internal conditions to keep them close to a set point.

Feedback Mechanisms

• Negative feedback: The response of the effector negates the stimulus, bringing the body back to homeostasis. Example: Regulation of body temperature.

• Positive feedback: The response of the effector increases the change of the stimulus, moving the body away from homeostasis. A positive feedback loop completes a dangerous process quickly to reestablish homeostasis. Example: Blood clotting.

Equilibrium

Homeostasis is a state of equilibrium, where opposing forces are in balance.

Additional info: The study of anatomy and physiology is essential for understanding health, disease, and the basis for medical practice. Mastery of these foundational concepts is critical for further study in health sciences.