Midterm Review Guide: Human Anatomy & Physiology Study Notes

Chapter 1: Introduction to Physiology

Terminology and Anatomical Directions

Understanding anatomical terminology is essential for describing locations and relationships within the human body.

• Anterior: Refers to the front of the body.

• Posterior: Refers to the back of the body.

• Superficial: Located closer to the surface of the body.

• Deep: Located further from the surface, toward the interior.

Organization Chart of the Human Body

The structural organization of the human body follows a hierarchical sequence:

• Cells: Basic unit of life.

• Tissues: Groups of similar cells performing a specific function.

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

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

• Organism: The complete living being.

Abdominal Quadrants and Regions

The abdomen is divided for clinical and anatomical reference:

• Quadrants: Right Upper, Left Upper, Right Lower, Left Lower.

• Regions: Includes epigastric, umbilical, hypogastric, and others.

Body Cavities

Body cavities house and protect internal organs.

• Peritoneal cavity: Contains abdominal organs.

• Pleural cavity: Contains the lungs.

• Pelvic cavity: Contains reproductive organs, bladder, and rectum.

Key Definitions

• Anatomy: Study of structure.

• Physiology: Study of function.

Parietal vs. Visceral

• Parietal: Refers to the lining attached to the body wall.

• Visceral: Refers to the lining covering the organs.

Chapter 2: Molecular Interactions

Cell Organelles and Their Functions

Each organelle within a cell has a specific function essential for cellular activity.

• Nucleus: Contains genetic material; controls cell activities.

• Mitochondria: Site of ATP production; "powerhouse" of the cell.

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

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

• Lysosomes: Digest cellular waste and foreign material.

• Ribosomes: Site of protein synthesis.

Forms of Cellular Transport

Cells transport materials across membranes using various mechanisms:

• Endocytosis: Uptake of materials into the cell by engulfing them.

• Exocytosis: Release of substances from the cell via vesicles.

• Diffusion: Movement of molecules from high to low concentration.

• Osmosis: Diffusion of water across a membrane.

Chapter 4: Energy and Cellular Metabolism (Integumentary System)

Functions of the Integumentary System

The integumentary system protects the body and regulates internal conditions.

• Protection: Against pathogens, physical injury, and dehydration.

• Temperature regulation: Through sweat and blood flow.

• Sensation: Contains sensory receptors for touch, pain, and temperature.

• Vitamin D synthesis: Initiated by exposure to sunlight.

Cells of the Skin

• Keratinocytes: Produce keratin, a protective protein.

• Melanocytes: Produce melanin, which protects against UV radiation.

• Langerhans cells: Immune cells that detect pathogens.

• Merkel cells: Sensory cells for touch.

Layers of the Strata

The epidermis consists of several layers, from superficial to deep:

1. Stratum corneum

2. Stratum lucidum (only in thick skin)

3. Stratum granulosum

4. Stratum spinosum

5. Stratum basale

Functions of Skin Appendages

• Hair: Protection and sensation.

• Glands: Sebaceous (oil) and sweat glands regulate moisture and temperature.

• Nails: Protect fingertips and aid in manipulation.

Thick Skin vs. Thin Skin

• Thick skin: Found on palms and soles; contains stratum lucidum; lacks hair and sebaceous glands.

• Thin skin: Covers most of the body; lacks stratum lucidum; contains hair and sebaceous glands.

Chapter 5: Membrane Dynamics (Skeletal System)

Cells of Bone Tissue

• Osteocytes: Mature bone cells maintaining bone matrix.

• Osteoprogenitor cells: Stem cells that differentiate into osteoblasts.

• Osteoblasts: Build new bone matrix.

• Osteoclasts: Break down bone matrix.

Anatomy of the Osteon

The osteon is the functional unit of compact bone, consisting of concentric lamellae surrounding a central canal.

• Central (Haversian) canal: Contains blood vessels and nerves.

• Lamellae: Rings of bone matrix.

• Lacunae: Spaces housing osteocytes.

• Canaliculi: Tiny channels connecting lacunae.

Functions of the Skeletal System

• Support: Framework for the body.

• Protection: Shields vital organs.

• Movement: Provides attachment for muscles.

• Mineral storage: Stores calcium and phosphorus.

• Blood cell production: Occurs in bone marrow.

Compact vs. Spongy Bone

• Compact bone: Dense, forms outer layer; provides strength.

• Spongy bone: Porous, found at ends of bones; contains red marrow.

Intramembranous vs. Endochondral Ossification

• Intramembranous ossification: Bone develops directly from mesenchyme; forms flat bones.

• Endochondral ossification: Bone develops from cartilage model; forms most bones.

Types of Fractures

• Simple (closed) fracture: Bone breaks but does not pierce skin.

• Compound (open) fracture: Bone breaks and pierces skin.

• Comminuted fracture: Bone shatters into multiple pieces.

• Greenstick fracture: Partial fracture, common in children.

• Additional info: Other types include spiral, transverse, and oblique fractures.

Periosteum and Endosteum

• Periosteum: Outer fibrous covering of bone; important for growth and repair.

• Endosteum: Lines internal bone surfaces; involved in bone remodeling.

Chapter 9: The Central Nervous System (Muscular System)

Functions of the Muscular System

• Movement: Facilitates locomotion and manipulation.

• Posture: Maintains body position.

• Heat production: Generates heat through contraction.

• Stabilization: Supports joints.

Types of Muscle Tissue

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

• Cardiac muscle: Involuntary, striated, found in heart.

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

Four Qualities of Muscle Tissue

• Excitability: Ability to respond to stimuli.

• Contractility: Ability to shorten and generate force.

• Extensibility: Ability to stretch.

• Elasticity: Ability to return to original shape.

Steps to Skeletal Muscle Contraction

1. Action potential arrives at neuromuscular junction.

2. Acetylcholine released, triggering muscle cell depolarization.

3. Calcium ions released from sarcoplasmic reticulum.

4. Actin and myosin interact, causing contraction.

5. ATP required for both contraction and relaxation.

Motor Unit

• Definition: A motor neuron and all the muscle fibers it innervates.

• Importance: Controls the strength and precision of muscle contraction.

Recruitment

• Definition: Activation of additional motor units to increase contraction strength.

Muscle Hypertrophy vs. Atrophy

• Hypertrophy: Increase in muscle size due to exercise or increased workload.

• Atrophy: Decrease in muscle size due to inactivity or disease.