Fundamentals of Anatomy & Physiology: Study Guide

Introduction to Anatomy & Physiology

Definition and Scope

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 work together to sustain life.

• Histology: The study of tissues at the microscopic level.

• Gross Anatomy: The study of structures visible to the naked eye.

• Microscopic Anatomy: The study of structures requiring magnification, such as cells and tissues.

Levels of Organization

The human body is organized into hierarchical levels:

• Cell: The basic unit of life.

• Tissue: Groups of similar cells performing a common function.

• Organ: Structures composed of two or more tissue types working together.

• Organ System: Groups of organs that perform related functions.

Anatomical Position and Planes

Standard anatomical position is used as a reference in describing locations and directions on the body.

• Anatomical Position: Standing upright, facing forward, arms at sides, palms facing forward.

• Planes:

  • Sagittal: Divides the body into left and right parts.

  • Parasagittal: Parallel to the sagittal plane, but off-center.

  • Transverse: Divides the body into superior (upper) and inferior (lower) parts.

  • Frontal (Coronal): Divides the body into anterior (front) and posterior (back) parts.

Body Cavities and Organs

Body cavities house and protect vital organs.

• Thoracic Cavity: Contains the lungs and heart.

• Cranial Cavity: Contains the brain.

• Abdominopelvic Cavity: Contains digestive, urinary, and reproductive organs.

• Vertebral Cavity: Contains the spinal cord.

Feedback Mechanisms

Homeostasis is maintained by feedback mechanisms.

• Negative Feedback: Reduces the effect of a stimulus to maintain balance (e.g., body temperature regulation).

• Positive Feedback: Enhances the effect of a stimulus (e.g., blood clotting, childbirth).

Cellular Structures and Functions

Cells contain specialized structures for various functions.

• Plasma Membrane: Regulates entry and exit of substances.

• Golgi Apparatus: Modifies, sorts, and packages proteins.

• Ribosomes: Site of protein synthesis.

• RNA: tRNA brings amino acids to ribosomes for protein synthesis.

Cell Division

Cells reproduce by dividing.

• Mitosis: Process by which a cell divides to produce two identical daughter cells.

Membrane Transport

Movement of substances across cell membranes is essential for cell function.

• Osmosis: Movement of water across a semipermeable membrane.

• Effect of Solutions:

  • Pure water: Red blood cells swell and may burst (lysis).

  • Very salty water: Red blood cells shrink (crenation).

  • 0.9% saline: Isotonic, no net movement of water.

Microscopic Anatomy: Tissues

Tissues are groups of cells with similar structure and function.

• Connective Tissue: Supports, protects, and binds other tissues. Contains cells, fibers, and ground substance.

• Epithelial Tissue: Covers body surfaces and lines cavities.

• Muscle Tissue: Responsible for movement.

• Nervous Tissue: Transmits electrical impulses.

Types of Cells in Connective Tissue

• Osteoblast: Bone-forming cell.

• Hemocytoblast: Blood cell precursor.

• Chondroblast: Cartilage-forming cell.

• Fibroblast: Produces fibers and ground substance.

Types of Epithelia

• Stratified Columnar: Multiple layers, column-shaped cells.

• Pseudostratified Columnar: Appears layered but all cells touch the basement membrane; often contains goblet cells.

• Transitional: Specialized for stretching, found in urinary bladder.

Glandular Tissue

• Exocrine Glands: Secrete products into ducts (e.g., sweat, salivary glands).

• Endocrine Glands: Secrete hormones directly into the bloodstream.

• Merocrine Glands: Release products by exocytosis.

• Apocrine Glands: Release products along with part of the cell.

• Sebaceous Glands: Secrete sebum (oil) into hair follicles.

Skin Structure and Function

The skin is the largest organ, providing protection and regulating body temperature.

• Epidermis: Outermost layer, contains keratinocytes and melanocytes.

• Dermis: Two layers:

  • Papillary Layer: Superficial, contains capillaries and sensory neurons.

  • Reticular Layer: Deep, contains collagen and elastin fibers.

• Melanocytes: Produce melanin, protecting against UV damage.

• Keratinocytes: Produce keratin, providing strength and waterproofing.

• Arrector Pili Muscle: Causes hair to stand up (goosebumps), helps with thermoregulation.

Hair and Nails

• Hair Shaft Regions: Medulla (central core), cortex (middle layer), cuticle (outer layer).

• Nails: Protect fingertips and aid in picking up objects.

Types of Sweat (Sudoriferous) Glands

• Merocrine (Eccrine) Glands: Widely distributed, regulate temperature.

• Apocrine Glands: Found in axillary and genital areas, begin functioning at puberty.

Connective Tissue Properties

• Hyaline Cartilage: Provides support with flexibility; found in nose, trachea, and ends of long bones.

• Elastic Cartilage: More flexible; found in ear and epiglottis.

• Fibrocartilage: Strongest; found in intervertebral discs.

• Bone Tissue: Contains lacunae, calcium salts, and blood vessels.

Repair and Regeneration

• Stages of Tissue Repair: Inflammation, organization, regeneration.

Identification of Tissues (Microscopy)

Recognizing tissue types under the microscope is essential for histology.

Label	Tissue Type	Main Features
A	Simple Squamous Epithelium	Single layer, flat cells
B	Simple Cuboidal Epithelium	Single layer, cube-shaped cells
C	Stratified Squamous Epithelium	Multiple layers, flat cells at surface
D	Areolar Connective Tissue	Loose arrangement of fibers and cells
E	Dense Regular Connective Tissue	Parallel collagen fibers

Additional info:

• Parietal pleura is a membrane lining the thoracic cavity, providing protection and reducing friction for the lungs.

• Cleavage lines (tension lines) in the dermis are regions where collagen fibers are oriented, important for surgical incisions.

• Melanocytes and keratinocytes work together to protect the skin from UV damage by producing and distributing melanin.

• Flagella are whip-like structures that enable cell movement; cilia are hair-like structures that move substances across cell surfaces; microvilli increase surface area for absorption.