Anatomy & Physiology Study Guide: Integumentary, Skeletal, and Muscular Systems

Guida di studio - Note intelligenti

Appunti personalizzati basati sui tuoi materiali, ampliati con definizioni chiave, esempi e contesto.

The epidermis is the outermost layer of the skin, composed of several distinct cell types and layers, each with specialized functions.

Cell Types: Includes keratinocytes (produce keratin), melanocytes (produce melanin), Langerhans cells (immune defense), and Merkel cells (sensory function).
Layers of the Epidermis: From deep to superficial: stratum basale, stratum spinosum, stratum granulosum, stratum lucidum (only in thick skin), and stratum corneum.
Functions: Protection, sensation, thermoregulation, and synthesis of vitamin D.

The dermis lies beneath the epidermis and provides structural support and nourishment to the skin.

Layers: Papillary layer (loose connective tissue, contains capillaries and sensory neurons) and reticular layer (dense irregular connective tissue, provides strength and elasticity).
Structures: Contains blood vessels, nerves, hair follicles, sebaceous (oil) glands, and sweat glands.

Hair Growth: Hair grows from follicles in cycles: anagen (growth), catagen (regression), and telogen (resting).
Factors Affecting Skin Color: Melanin (produced by melanocytes), carotene, and hemoglobin contribute to skin color. Genetic and environmental factors (e.g., sun exposure) also play roles.

Types of Sweat Glands: Eccrine (thermoregulation, found all over body) and apocrine (found in axillary and genital areas, active after puberty).
Sebaceous Glands: Secrete sebum (oil) to lubricate skin and hair.
Functions of Skin: Protection, sensation, temperature regulation, excretion, and vitamin D synthesis.

Types of Skin Cancer: Basal cell carcinoma, squamous cell carcinoma, and melanoma. Each affects different cell types and varies in severity.
Classification: Based on cell of origin and malignancy.
Skin Changes with Age: Thinning, decreased elasticity, slower healing, and reduced gland activity.

Types of Cartilage: Hyaline (most common, found in joints), elastic (ear, epiglottis), and fibrocartilage (intervertebral discs).
Functions of Bone: Support, protection, movement, mineral storage, blood cell formation (hematopoiesis), and triglyceride storage.
Long Bone Anatomy: Diaphysis (shaft), epiphyses (ends), metaphysis, medullary cavity, periosteum, and endosteum.

Organic Components: Collagen fibers and ground substance (provide flexibility).
Inorganic Components: Hydroxyapatite (calcium phosphate crystals, provide hardness).
Bone Classification: Long, short, flat, irregular, and sesamoid bones.

Intramembranous Ossification: Bone develops from fibrous membranes (e.g., flat bones of skull).
Endochondral Ossification: Bone forms by replacing hyaline cartilage (most bones of the body).
Growth in Childhood/Adolescence: Occurs at epiphyseal plates via interstitial growth.
Hormonal Regulation: Growth hormone, thyroid hormone, and sex hormones regulate bone growth.

Bone Remodeling: Continuous process involving osteoblasts (build bone) and osteoclasts (break down bone).
Fracture Healing: Hematoma formation, fibrocartilaginous callus formation, bony callus formation, and bone remodeling.

Osteomalacia/Rickets: Softening of bones due to vitamin D deficiency (rickets in children).
Osteoporosis: Decreased bone mass and increased fracture risk, common in elderly.

Joint Classification: Structural (fibrous, cartilaginous, synovial) and functional (synarthroses, amphiarthroses, diarthroses).
Fibrous Joints: Bones joined by dense connective tissue (e.g., sutures of skull).
Cartilaginous Joints: Bones joined by cartilage (e.g., intervertebral discs).
Synovial Joints: Freely movable, contain synovial fluid (e.g., knee, shoulder).

Movements: Flexion, extension, abduction, adduction, rotation, circumduction.
Common Injuries: Sprains (ligament injury), dislocations, cartilage tears.
Joint Stability: Influenced by shape of articular surfaces, ligaments, and muscle tone.
Specific Joints: Shoulder (high mobility, less stability), elbow (hinge joint), knee (largest, complex joint).
Joint Disorders: Bursitis (inflammation of bursae), tendinitis (inflammation of tendons), arthritis (joint inflammation).

Types: Skeletal (voluntary, striated), cardiac (involuntary, striated, heart), smooth (involuntary, non-striated, walls of organs).
Functions: Movement, posture, joint stabilization, heat generation.
Connective Tissues: Epimysium (surrounds whole muscle), perimysium (surrounds fascicles), endomysium (surrounds muscle fibers).

Gross Anatomy: Muscle fibers (cells) grouped into fascicles, which form muscles.
Microscopic Anatomy: Myofibrils (contain myofilaments: actin and myosin), sarcomeres (contractile units), sarcoplasmic reticulum (stores Ca2+), T-tubules (conduct impulses).
Sliding Filament Model: Muscle contraction occurs as myosin heads bind to actin, pulling filaments past each other.
Neuromuscular Junction: Site where motor neuron stimulates muscle fiber; involves release of acetylcholine.
Excitation-Contraction Coupling: Sequence linking action potential to muscle contraction (involves depolarization, Ca2+ release).
Muscle Twitch and Summation: A single stimulus produces a twitch; increased frequency leads to summation and tetanus.
ATP Sources: Creatine phosphate, anaerobic glycolysis, aerobic respiration.
Muscle Fiber Types: Slow oxidative (endurance), fast oxidative (intermediate), fast glycolytic (power, fatigue quickly).
Response to Exercise: Endurance training increases oxidative capacity; resistance training increases muscle size (hypertrophy).

Fiber Type	Contraction Speed	Fatigue Resistance	Primary ATP Source	Example
Slow Oxidative	Slow	High	Aerobic respiration	Postural muscles
Fast Oxidative	Fast	Intermediate	Aerobic (some anaerobic)	Leg muscles
Fast Glycolytic	Fast	Low	Anaerobic glycolysis	Arm muscles

Additional info: Some explanations and examples were expanded for clarity and completeness based on standard Anatomy & Physiology curricula.