Exam Topics Overview

This study guide summarizes key terms, structures, and essay topics for an Anatomy & Physiology exam covering chapters 5-8. The material focuses on the integumentary and skeletal systems, as well as related physiological processes.

Integumentary System

Skin Structure and Function

The skin is the body's largest organ and serves as a protective barrier. It consists of multiple layers and specialized cells.

• Meissner's corpuscles: Sensory receptors for light touch, located in the dermal papillae.

• Dermis: The thick layer beneath the epidermis containing connective tissue, blood vessels, and nerves.

• Hypodermis: Also known as the subcutaneous layer; contains fat and connective tissue for insulation and cushioning.

• Dermal papillae: Projections of the dermis that interlock with the epidermis, increasing surface area for exchange.

• Keratinoctyes: The primary cell type in the epidermis, responsible for producing keratin.

• Melanocytes: Cells that produce melanin, the pigment responsible for skin color.

• Rule of Nines: A method for estimating the percentage of body surface area affected by burns.

Example: The Rule of Nines divides the body into sections, each representing 9% (or multiples thereof) of the total body surface area.

Skin Glands and Hair

• Sebaceous glands: Produce sebum, an oily substance that lubricates skin and hair.

• Sudoriferous glands: Sweat glands involved in thermoregulation.

• Ceruminous glands: Specialized sweat glands in the ear canal that produce earwax.

• Arrector pili: Small muscles attached to hair follicles that cause 'goosebumps' when contracted.

Example: Sudoriferous glands help regulate body temperature by releasing sweat, which cools the skin as it evaporates.

Skin Cancer

• ABCDE rule: A guideline for identifying melanoma based on Asymmetry, Border, Color, Diameter, and Evolving characteristics.

• Basal cell carcinoma vs. squamous cell carcinoma: Both are common skin cancers, but basal cell carcinoma arises from the basal cells of the epidermis, while squamous cell carcinoma originates from squamous cells.

Skeletal System

Bone Structure and Cells

Bones provide support, protection, and facilitate movement. They are composed of various cell types and structures.

• Osteon: The structural unit of compact bone, also known as the Haversian system.

• Osteocyte: Mature bone cell that maintains bone tissue.

• Osteoblast: Cell responsible for bone formation.

• Osteoclast: Cell responsible for bone resorption (breakdown).

• Epiphyseal plate vs. epiphyseal line: The plate is a region of growing tissue in children; the line is the remnant in adults after growth stops.

• Hyaline cartilage: Smooth, glassy cartilage found on joint surfaces and in the growth plate.

Example: Osteoblasts deposit new bone matrix, while osteoclasts remove old bone, maintaining bone health.

Bone Development and Growth

• Osteogenesis: The process of bone formation.

• Fontanelles: Soft spots on a baby's skull where bone formation is incomplete.

• Factors influencing hair growth: Genetics, hormones, nutrition, and health status.

Example: Fontanelles allow for flexibility of the skull during birth and rapid brain growth in infancy.

Skeleton Organization

• Axial skeleton: Consists of the skull, vertebral column, and rib cage.

• Appendicular skeleton: Includes the limbs and girdles (pelvic and pectoral).

• Atlas and axis: The first two cervical vertebrae; atlas supports the skull, axis allows rotation.

• Hyoid: A U-shaped bone in the neck that supports the tongue.

• Intervertebral discs: Pads of cartilage between vertebrae that absorb shock.

• Pelvic girdle: The hip bones connecting the lower limbs to the spine.

Example: The axial skeleton provides central support, while the appendicular skeleton enables movement.

Spinal Curvatures and Disorders

• Scoliosis: Abnormal lateral curvature of the spine.

• Kyphosis: Excessive outward curvature of the thoracic spine (hunchback).

• Lordosis: Excessive inward curvature of the lumbar spine.

Example: Scoliosis can be detected by uneven shoulders or hips and may require bracing or surgery.

Bone Hormones and Homeostasis

• Parathyroid hormone (PTH): Increases blood calcium by stimulating osteoclasts.

• Calcitonin: Lowers blood calcium by inhibiting osteoclast activity.

Example: PTH and calcitonin work together to maintain calcium balance in the body.

Osteoporosis

Osteoporosis is a condition characterized by decreased bone density and increased fracture risk.

• Causes: Aging, hormonal changes, lack of calcium or vitamin D, sedentary lifestyle.

• Prevention: Adequate calcium and vitamin D intake, regular weight-bearing exercise, medications.

Example: Postmenopausal women are at higher risk due to decreased estrogen levels.

Joints and Movement

Types of Joints

• Synarthroses: Immovable joints (e.g., sutures in the skull).

• Amphiarthroses: Slightly movable joints (e.g., intervertebral discs).

• Diarthroses: Freely movable joints (e.g., shoulder, knee).

• Synovial joints: Joints with a fluid-filled cavity allowing free movement.

• Menisci: Cartilaginous pads in the knee that absorb shock.

• Tendon sheaths: Tubular structures that surround tendons, reducing friction.

Example: The knee is a synovial joint containing menisci and ligaments for stability.

Joint Movements

• Abduction: Movement away from the midline.

• Adduction: Movement toward the midline.

• Dorsiflexion: Bending the foot upward at the ankle.

• Plantar flexion: Pointing the foot downward.

Example: Raising your arm to the side is abduction; bringing it back is adduction.

Ligaments and Arthritis

• Ligaments: Connect bone to bone, providing joint stability.

• Rheumatoid arthritis: An autoimmune disease causing joint inflammation and damage.

Example: Rheumatoid arthritis can lead to joint deformity and loss of function.

Essay Topics Guidance

• ABCDE rule for skin cancer: Describe each criterion and its importance in early detection.

• Skeleton analysis: Explain how to determine gender, age, and relative size from skeletal features (e.g., pelvis shape, skull characteristics, bone length).

• Rheumatoid arthritis: Discuss the pathophysiology, including immune system involvement and joint changes.

• Bone hormones: Explain the roles of calcitonin and parathyroid hormone in bone resorption and formation.

• Osteoporosis: Describe the condition and strategies to slow its progression (diet, exercise, medication).

Additional info:

• Some terms (e.g., "regions of vertebral column") refer to cervical, thoracic, lumbar, sacral, and coccygeal regions.

• "Layers of the epidermis" include (from superficial to deep): stratum corneum, stratum lucidum (in thick skin), stratum granulosum, stratum spinosum, stratum basale.

• "Types of sweat glands" are eccrine (widely distributed, for thermoregulation) and apocrine (in axillary/genital areas, active after puberty).