Anatomy & Physiology: Study Guide for Test 2 (Chapters 4–6)

Chapter 4: The Integumentary System

Overview of Epithelial Membranes

• Cutaneous membrane: The skin; a dry membrane exposed to air, composed of epidermis (keratinized stratified squamous epithelium) and dermis (dense connective tissue).

• Mucous membranes: Line body cavities open to the exterior (e.g., digestive, respiratory tracts); composed of epithelium and loose connective tissue (lamina propria).

• Serous membranes: Line closed ventral body cavities; consist of simple squamous epithelium on areolar connective tissue. Examples: pleura, pericardium, peritoneum.

• Key differences: Location, structure, and function.

Functions and Structure of the Skin

Organ system: The skin and its appendages (hair, nails, glands) form the integumentary system.

• Functions: Protection, temperature regulation, sensation, excretion, vitamin D synthesis.

• Layers: Epidermis (outer), dermis (middle), hypodermis/subcutaneous tissue (deepest, not technically part of skin).

Cell Types in the Epidermis

• Keratinocytes: Produce keratin, a protective protein.

• Melanocytes: Produce melanin, pigment that protects against UV radiation.

• Dendritic cells: Immune cells that help protect against pathogens.

Organization of the Epidermis

• Layers (from deep to superficial):

  1. Stratum basale (germinativum): actively dividing cells.

  2. Stratum spinosum: several layers of keratinocytes.

  3. Stratum granulosum: cells begin to die, keratinization starts.

  4. Stratum lucidum: only in thick skin (palms, soles).

  5. Stratum corneum: dead, keratinized cells.

• Dermis: Two layers—papillary (areolar connective tissue, forms fingerprints) and reticular (dense irregular connective tissue).

• Hypodermis: Subcutaneous tissue, mostly adipose, anchors skin to underlying structures.

Glands of the Skin

• Sebaceous glands: Produce sebum (oil), lubricates skin and hair.

• Sudoriferous (sweat) glands: Eccrine (most numerous, thermoregulation) and apocrine (axillary/genital areas, active at puberty).

Homeostatic Imbalances of the Skin

• Acne: Inflammation of sebaceous glands.

• Burns: Classified as first, second, or third degree based on depth and tissue damage.

• Skin cancer: Basal cell carcinoma (least malignant), squamous cell carcinoma, malignant melanoma (most dangerous). ABCDE rule for melanoma: Asymmetry, Border irregularity, Color, Diameter, Evolving.

Chapter 5: The Skeletal System

Classification and Structure of Bones

• Axial skeleton: Skull, vertebral column, thoracic cage.

• Appendicular skeleton: Limbs and girdles.

• Bone types: Long, short, flat, irregular.

• Compact bone: Dense, smooth, forms outer layer.

• Spongy bone: Porous, contains trabeculae, found at ends of long bones.

Microscopic Anatomy of Bone

• Osteon (Haversian system): Structural unit of compact bone.

• Cells: Osteocytes (mature bone cells), osteoblasts (bone-forming), osteoclasts (bone-resorbing).

• Canaliculi: Tiny canals connecting osteocytes.

Bone Marrow

• Red marrow: Hematopoiesis (blood cell formation).

• Yellow marrow: Fat storage.

Bone Growth and Remodeling

• Ossification: Process of bone formation.

• Epiphyseal plate: Growth plate; site of lengthwise bone growth in children.

• Remodeling: Continuous process; responds to stress and calcium levels.

Fractures and Repair

• Types of fractures: Comminuted, impacted, spiral, greenstick, etc.

• Repair stages: Hematoma formation, fibrocartilaginous callus, bony callus, bone remodeling.

Major Bones of the Skeleton

• Axial skeleton: Skull (cranium, facial bones), hyoid, vertebral column (cervical, thoracic, lumbar, sacrum, coccyx), thoracic cage (sternum, ribs).

• Appendicular skeleton: Pectoral girdle (clavicle, scapula), upper limbs (humerus, radius, ulna, carpals, metacarpals, phalanges), pelvic girdle (ilium, ischium, pubis), lower limbs (femur, tibia, fibula, tarsals, metatarsals, phalanges).

Joints

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

• Structural classifications: Fibrous, cartilaginous, synovial.

• Synovial joints: Plane, hinge, condylar, ball-and-socket, etc.

• Dislocation: Displacement of a bone from its joint.

Homeostatic Imbalances of the Skeletal System

• Scoliosis: Lateral curvature of the spine.

• Kyphosis: Exaggerated thoracic curvature.

• Lordosis: Exaggerated lumbar curvature.

Chapter 6: The Muscular System

Types and Functions of Muscle Tissue

• Skeletal muscle: Voluntary, striated, attached to bones, responsible for movement.

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

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

• Muscle fiber: Muscle cell; called 'fiber' due to elongated shape.

Microscopic Anatomy of Muscle

• Myofibril: Rod-like unit within muscle fiber, contains sarcomeres.

• Sarcomere: Contractile unit; defined by Z lines, contains actin (thin) and myosin (thick) filaments.

• Key bands: A band (dark), I band (light), H zone, M line.

Muscle Contraction

• Sliding filament theory: Actin and myosin filaments slide past each other, shortening the sarcomere.

• Role of calcium: Binds to troponin, exposes binding sites on actin.

• Role of ATP: Provides energy for contraction and relaxation.

• Neuromuscular junction: Site where motor neuron stimulates muscle fiber; acetylcholine (ACh) is the neurotransmitter.

Muscle Metabolism

• ATP regeneration: Creatine phosphate, anaerobic glycolysis, aerobic respiration.

• Aerobic vs. anaerobic: Aerobic uses oxygen, produces more ATP; anaerobic is faster but less efficient, produces lactic acid.

Muscle Movements and Naming

• Origin: Attachment to immovable bone.

• Insertion: Attachment to movable bone.

• Prime mover (agonist): Main muscle responsible for movement.

• Antagonist: Opposes the prime mover.

• Synergist: Assists the prime mover.

• Muscle actions: Flexion, extension, rotation, abduction, adduction, etc.

• Muscle naming: Based on location, shape, size, direction of fibers, number of origins, location of attachments, action.

Major Muscles and Movements

• Head and neck: Frontalis, orbicularis oculi, orbicularis oris, buccinator, masseter, temporalis, platysma, sternocleidomastoid.

• Trunk: Pectoralis major, intercostals, rectus abdominis, external oblique, latissimus dorsi, deltoid.

• Upper limb: Biceps brachii, triceps brachii, brachialis, brachioradialis.

• Lower limb: Gluteus maximus, hamstrings, quadriceps femoris, gastrocnemius.

Homeostatic Imbalances of Muscle

• Muscular dystrophy: Group of genetic diseases causing progressive weakness and loss of muscle mass.

Key Tables

Membrane Type	Location	Structure	Function
Cutaneous	Skin	Epidermis + dermis	Protection, sensation
Mucous	Body cavities open to exterior	Epithelium + lamina propria	Secretion, absorption
Serous	Closed body cavities	Simple squamous + areolar	Lubrication

Muscle Type	Location	Control	Striations
Skeletal	Attached to bones	Voluntary	Yes
Cardiac	Heart	Involuntary	Yes
Smooth	Walls of hollow organs	Involuntary	No

Key Equations

• ATP hydrolysis: $\text{ATP} + \text{H}_2\text{O} \rightarrow \text{ADP} + \text{P}_i + \text{energy}$

• Sliding filament theory (force generation): $\text{Force} = \text{Number of cross-bridges formed}$

Additional info:

• Some content was inferred and expanded for clarity and completeness, such as the detailed structure of membranes, bone, and muscle tissue, and the inclusion of key tables and equations.