Anatomy & Physiology I: Exam 1 Study Guide

Introduction to Anatomy

Levels of Anatomical Organization

Anatomy is the study of body structure, while physiology is the study of body function. The human body is organized into hierarchical levels, each with increasing complexity.

• Chemical Level: Atoms and molecules essential for life.

• Cellular Level: Basic structural and functional units of life.

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

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

• Organ System Level: Groups of organs working together for a common purpose.

• Organismal Level: The complete living being.

Anatomical Position: Standard reference position for the body (standing, facing forward, arms at sides, palms forward).

• Directional Terms: Used to describe locations (anterior/posterior, superior/inferior, medial/lateral, proximal/distal, superficial/deep).

• Planes: Sagittal, frontal (coronal), and transverse planes divide the body for study.

Cell Structure and Function

Cell Theory and Organelles

Cells are the basic units of structure and function in living organisms. Each organelle within a cell has a specific role.

• Nucleus: Contains genetic material (DNA).

• Ribosomes: Sites of protein synthesis.

• Endoplasmic Reticulum (ER): Rough ER synthesizes proteins; smooth ER synthesizes lipids.

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

• Mitochondria: Powerhouse of the cell, site of ATP production.

• Lysosomes: Contain digestive enzymes.

• Cytoskeleton: Provides structural support and facilitates movement.

Cell Membrane: Phospholipid bilayer with embedded proteins; regulates entry and exit of substances.

Histology: The Study of Tissues

Major Tissue Types

Tissues are groups of similar cells that perform specific functions. There are four primary tissue types:

• Epithelial Tissue: Covers surfaces, lines cavities, forms glands.

• Connective Tissue: Supports, protects, and binds other tissues.

• Muscle Tissue: Produces movement.

• Nervous Tissue: Transmits electrical impulses.

Epithelial Tissue

• Cellularity: Composed almost entirely of cells.

• Polarity: Has apical (free) and basal (attached) surfaces.

• Attachment: Basal surface attached to basement membrane.

• Avascularity: Lacks blood vessels.

• Regeneration: High capacity for renewal.

Classification: Based on cell layers (simple, stratified) and cell shape (squamous, cuboidal, columnar).

Connective Tissue

• Components: Cells, fibers (collagen, elastic, reticular), and ground substance (matrix).

• Types: Loose (areolar, adipose, reticular), dense (regular, irregular, elastic), cartilage, bone, blood.

• Functions: Support, protection, transport, storage, immune defense.

The Integumentary System

Structure and Function

The integumentary system includes the skin and its derivatives (hair, nails, glands). It protects the body, regulates temperature, and provides sensory information.

• Epidermis: Stratified squamous epithelium; layers include stratum basale, spinosum, granulosum, lucidum (in thick skin), and corneum.

• Dermis: Connective tissue; contains blood vessels, nerves, hair follicles, and glands.

• Hypodermis: Subcutaneous layer; stores fat and anchors skin.

Glands: Sebaceous (oil), sweat (eccrine and apocrine), and mammary glands.

Skeletal Tissue and the Skeletal System

Bone and Cartilage

The skeletal system provides support, protection, movement, mineral storage, and blood cell formation.

• Cartilage Types: Hyaline (most common), elastic, fibrocartilage.

• Bone Types: Compact and spongy bone.

• Cells: Osteoblasts (build bone), osteocytes (maintain bone), osteoclasts (break down bone).

Bone Growth: Occurs via intramembranous and endochondral ossification.

Bone Remodeling: Continuous process involving resorption and deposition; influenced by mechanical stress and hormones.

Joints

Classification and Function

Joints (articulations) connect bones and allow movement. They are classified by structure and function.

• Structural: Fibrous, cartilaginous, synovial.

• Functional: Synarthroses (immovable), amphiarthroses (slightly movable), diarthroses (freely movable).

Synovial Joints: Most common; characterized by a joint cavity, articular cartilage, synovial fluid, and supporting ligaments.

Muscular Tissue

Types and Structure

Muscle tissue is specialized for contraction and movement. There are three types:

• Skeletal Muscle: Voluntary, striated, attached to bones.

• Cardiac Muscle: Involuntary, striated, found in the heart.

• Smooth Muscle: Involuntary, non-striated, found in walls of hollow organs.

Muscle Contraction: Involves the sliding filament theory, where actin and myosin filaments slide past each other to shorten the muscle.

• Key Proteins: Actin, myosin, troponin, tropomyosin.

• Neuromuscular Junction: Site where a motor neuron stimulates a muscle fiber.

Muscle Fiber Types: Slow-twitch (endurance), fast-twitch (power/speed).

Additional info:

• This study guide covers content from chapters 1, 2, 4, 5, 6, 9, and 10 of a typical Anatomy & Physiology course, including introductory concepts, cell biology, histology, integumentary system, skeletal tissue, joints, and muscular tissue.