BSC 2085 Exam Review: Integumentary, Skeletal, and Articular Systems (Ch. 5-8)

Ch. 5: The Integumentary System

Structure of the Skin

The skin is composed of two main layers: the epidermis (superficial) and the dermis (deep). Beneath the dermis lies the hypodermis (subcutaneous layer), which is not technically part of the skin but anchors it to underlying tissues.

• Epidermis: Stratified squamous epithelium; avascular; contains several cell types.

• Dermis: Dense irregular connective tissue; contains blood vessels, nerves, glands, and hair follicles.

• Hypodermis: Composed mainly of adipose tissue; provides insulation and cushioning.

Cells of the Epidermis

• Keratinoctyes: Produce keratin, a tough, protective protein.

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

• Langerhans (Dendritic) cells: Immune cells that help detect pathogens.

• Merkel (Tactile) cells: Sensory receptors for touch.

Skin Color Components

• Melanin: Brown-black pigment produced by melanocytes; main determinant of skin color.

• Carotene: Yellow-orange pigment from diet; accumulates in stratum corneum and fat.

• Hemoglobin: Red pigment in blood; gives pinkish hue to fair skin.

Burn Degrees

• First-degree: Only epidermis is damaged; redness, swelling, pain.

• Second-degree: Epidermis and upper dermis damaged; blisters form.

• Third-degree: Entire thickness of skin destroyed; area appears gray-white, cherry red, or blackened; not initially painful due to nerve destruction.

ABCDE Rule for Melanoma

• Asymmetry: Two sides of the pigmented area do not match.

• Border irregularity: Edges are notched, uneven, or blurred.

• Color: Pigmentation is not uniform; may include shades of brown, black, tan, red, or blue.

• Diameter: Larger than 6 mm (about the size of a pencil eraser).

• Evolving: Changing in size, shape, or color.

Types of Carcinomas

• Basal cell carcinoma: Most common, least malignant; arises from stratum basale.

• Squamous cell carcinoma: Arises from keratinocytes of stratum spinosum; can metastasize.

• Melanoma: Cancer of melanocytes; most dangerous due to rapid metastasis.

Ch. 6: Bones and Skeletal Tissues

Types of Cartilage: Locations and Functions

• Hyaline cartilage: Most abundant; found in articular surfaces, costal cartilages, nose, trachea, larynx; provides support and flexibility.

• Elastic cartilage: Contains more elastic fibers; found in external ear and epiglottis; maintains shape and flexibility.

• Fibrocartilage: Highly compressible; found in intervertebral discs, pubic symphysis, menisci; resists tension and pressure.

Functions of Bones

• Support for the body and soft organs

• Protection of brain, spinal cord, and vital organs

• Movement (levers for muscle action)

• Mineral storage (calcium and phosphate)

• Blood cell formation (hematopoiesis in red marrow)

• Triglyceride (fat) storage in yellow marrow

• Hormone production (osteocalcin)

Microscopic Bone Anatomy

• Osteon (Haversian system): Structural unit of compact bone; consists of concentric lamellae around a central canal.

• Lacunae: Small spaces housing osteocytes.

• Canaliculi: Tiny canals connecting lacunae for nutrient/waste exchange.

• Trabeculae: Lattice-like structures in spongy bone; align along lines of stress.

Cross-section of a Long Bone

• Diaphysis: Shaft; compact bone surrounding medullary cavity.

• Epiphyses: Ends; spongy bone interior, covered by articular cartilage.

• Metaphysis: Region between diaphysis and epiphysis; contains epiphyseal plate (growth plate) in children.

Compact vs. Spongy Bone Microstructure

• Compact bone: Dense, organized into osteons; provides strength.

• Spongy bone: Porous, composed of trabeculae; houses red marrow.

Types of Bones (Shapes) and Examples

• Long bones: Longer than wide (e.g., femur, humerus).

• Short bones: Cube-shaped (e.g., carpals, tarsals).

• Flat bones: Thin, flat, slightly curved (e.g., sternum, skull bones).

• Irregular bones: Complicated shapes (e.g., vertebrae, hip bones).

• Sesamoid bones: Form within tendons (e.g., patella).

Bone Marrow Types, Locations, and Functions

• Red marrow: Hematopoietic tissue; found in trabecular cavities of spongy bone (e.g., hip bones, sternum, proximal femur/humerus in adults).

• Yellow marrow: Fat storage; found in medullary cavities of long bones in adults.

Ossification Processes

• Intramembranous ossification: Bone develops from fibrous membrane; forms flat bones (e.g., skull, clavicle).

• Endochondral ossification: Bone forms by replacing hyaline cartilage; forms most bones below the skull.

Bone Cell Types

• Osteogenic cells: Stem cells that differentiate into osteoblasts.

• Osteoblasts: Bone-forming cells; secrete bone matrix.

• Osteocytes: Mature bone cells; maintain bone matrix.

• Osteoclasts: Bone-resorbing cells; break down bone matrix.

Bone Fracture Types

• Simple (closed): Bone breaks cleanly but does not penetrate skin.

• Compound (open): Broken bone ends penetrate the skin.

• Comminuted: Bone fragments into three or more pieces.

• Greenstick: Bone breaks incompletely (common in children).

• Spiral: Ragged break due to twisting forces.

• Compression: Bone is crushed (common in vertebrae).

Ch. 7: The Skeleton

Axial vs. Appendicular Skeleton

• Axial skeleton: Forms the long axis of the body; includes skull, vertebral column, and thoracic cage.

• Appendicular skeleton: Bones of the limbs and girdles (pectoral and pelvic) that attach them to the axial skeleton.

Bone Identification and Articulations

• Each bone has a unique shape and location; identification is aided by anatomical landmarks.

• Bones articulate (form joints) with specific neighboring bones; e.g., humerus articulates with scapula and radius/ulna.

• Understanding articulations is key for studying movement and injury.

Vertebrae Differentiation

• Cervical vertebrae (C1–C7): Smallest; have transverse foramina; C1 (atlas) and C2 (axis) are specialized.

• Thoracic vertebrae (T1–T12): Articulate with ribs; have long, downward-pointing spinous processes.

• Lumbar vertebrae (L1–L5): Largest; bear most weight; short, thick spinous processes.

Bone Identification on Skeletons

• Diagrams and models are used to practice identifying bones and their features.

• Key features include processes, foramina, condyles, and fossae.

Ch. 8: Joints

Classifications of Joints

• Structural classification: Based on material binding bones and presence of joint cavity.

  • Fibrous: Bones joined by dense connective tissue; no cavity (e.g., sutures).

  • Cartilaginous: Bones joined by cartilage; no cavity (e.g., symphysis).

  • Synovial: Bones separated by fluid-filled cavity; most movable (e.g., knee, shoulder).

• Functional classification: Based on movement allowed.

  • Synarthroses: Immovable joints.

  • Amphiarthroses: Slightly movable joints.

  • Diarthroses: Freely movable joints.

Material Classifications of Joints

• See structural classification above; material is either fibrous tissue, cartilage, or synovial fluid and capsule.

Synovial Joint Types

• Plane (gliding): Flat surfaces; allow short gliding movements (e.g., intercarpal joints).

• Hinge: Cylindrical projection fits into trough; flexion/extension (e.g., elbow).

• Pivot: Rounded end fits into ring; rotation (e.g., proximal radioulnar joint).

• Oval articular surface fits into depression; all angular motions (e.g., wrist).

• Saddle: Both surfaces concave and convex; greater movement (e.g., thumb carpometacarpal joint).

• Ball-and-socket: Spherical head fits into socket; multiaxial (e.g., shoulder, hip).

Knee Joint Diagrams

• The knee is a complex synovial joint; includes femur, tibia, patella, menisci, ligaments (ACL, PCL, MCL, LCL), and bursae.

• Diagrams typically label these structures for identification.

Bursae and Tendon Sheaths

• Bursae: Flattened sacs filled with synovial fluid; reduce friction between tissues.

• Tendon sheaths: Elongated bursae that wrap around tendons; common in hands and feet.

Synovial Joint Movements

• Gliding: Flat surfaces slide past each other.

• Angular movements: Flexion, extension, abduction, adduction, circumduction.

• Rotation: Bone turns around its own long axis.

• Special movements: Supination, pronation, inversion, eversion, protraction, retraction, elevation, depression, opposition.

Axes of Movement

• Nonaxial: Slipping movements only (e.g., plane joints).

• Uniaxial: Movement in one plane (e.g., hinge, pivot joints).

• Biaxial: Movement in two planes (e.g., condyloid, saddle joints).

• Multiaxial: Movement in or around all three planes (e.g., ball-and-socket joints).

Joint Type	Structural Classification	Functional Classification	Example	Axes of Movement
Plane	Synovial	Diarthrosis	Intercarpal joints	Nonaxial
Hinge	Synovial	Diarthrosis	Elbow	Uniaxial
Pivot	Synovial	Diarthrosis	Proximal radioulnar joint	Uniaxial
Condyloid	Synovial	Diarthrosis	Wrist	Biaxial
Saddle	Synovial	Diarthrosis	Thumb carpometacarpal	Biaxial
Ball-and-socket	Synovial	Diarthrosis	Shoulder, hip	Multiaxial

Additional info: Academic context and definitions have been added to expand on the brief review points and ensure the notes are self-contained for exam preparation.