BIOL-231: Unit 2 Study Guide

Functions of the Skeletal System

Support, movement, protection, mineral storage, blood cell production, and energy storage.

Types of Skeletal Tissue

Cartilage, compact bone, and spongy bone, each with specific functions such as support, shock absorption, and production of blood cells.

Relationship between cartilage and bone

Cartilage provides flexibility and support to joints, while bone offers rigidity and strength; cartilage can develop into bone through ossification.

Three Types of Cartilage

Hyaline (found in joints), elastic (found in ear), and fibrocartilage (found in intervertebral discs); each serves different support and cushioning functions.

Compact Bone vs Spongy Bone

Compact bone is dense and forms the outer layer of bones, while spongy bone is lighter and houses bone marrow.

Four Bone Classifications

Long (femur), short (carpals), flat (skull), irregular (vertebrae); differ in shape and function.

Anatomical Regions of Long Bones

Diaphysis (shaft) and epiphyses (ends), with distinct periosteum and endosteum cellular layers.

Osteoprogenitor Cells vs Osteoblasts vs Osteocytes vs Osteoclasts

Osteoprogenitor cells are stem cells, osteoblasts build bone, osteocytes maintain bone, osteoclasts break down bone.

Components of an Osteon

Includes concentric lamellae, central canal, lacunae, and canaliculi; functional unit of compact bone.

Bone Remodeling Process

Involves the resorption of old bone and formation of new bone; can be disrupted by pathological conditions.

Osteoporosis

A metabolic bone disorder characterized by low bone density; major at-risk population includes postmenopausal women.

Intramembranous vs Endochondral Ossification

Intramembranous ossification forms bone directly from mesenchyme, while endochondral ossification forms bone from a cartilage model.

Epiphyseal Plates Growth

Growth occurs in zones: zone of resting cartilage, proliferating cartilage, hypertrophic cartilage, and ossification.

Bone Remodeling Cycle Steps

Includes bone resorption, reversal, formation, and quiescence.

Matrix Mineralization Process

Involves deposition of minerals in bone matrix; crucial for maintaining Calciums (Ca2+) levels.

Parathyroid Hormone

Regulates calcium levels in blood and stimulates osteoclast activity to increase bone resorption.

Calcitonin Role

Lowers blood calcium levels by inhibiting osteoclasts and promoting calcium deposition in bones.

Calcium Disorders

Hypocalcemia causes muscle spasms; hypercalcemia can lead to kidney stones; both have major health consequences.

Estrogen and Bone Health

Estrogen inhibits osteoclast activity; its reduction in menopause is linked to osteoporosis.

Growth Hormone in Bone Regulation

Stimulates growth at epiphyseal plates and influences bone density.

Bone Marrow Locations and Functions

Red marrow produces blood cells; yellow marrow stores fat; gelatinous marrow arises with age.

Fracture Types

Include simple, compound, comminuted; repair involves hematoma formation, callus formation, and bone remodeling.

Complications of Fracture Repair

Can include osteomyelitis, fat embolism, nerve damage, and compartment syndrome.

Fibrous Joint Types

Sutures, syndesmoses, and gomphoses; examples include cranial sutures and the tibiofibular joint.

Cartilaginous Joint Types

Synchondroses (hyaline cartilage) and symphyses (fibrocartilage); examples include pubic symphysis and ribs.

Synarthroses vs Amphiarthroses vs Diarthroses

Synarthroses are immovable joints, amphiarthroses are slightly movable, diarthroses are freely movable.

Synostoses Definition

Bony joints formed when two bones fuse; example includes the frontal bone fusion.

Synovial Joints Characteristics

Characterized by a joint cavity, articular capsule, and synovial fluid; allows for free movement.

Synovial Membrane Composition

Composed of intima and subintima layers; intima contains synoviocytes and subintima contains loose connective tissue.

Fatty Pads and Joint Structures

Fatty pads provide cushioning; articular discs (menisci) and bursae reduce friction.

Range of Motion Factors

Determined by joint structure, ligament tension, and muscle tone.

Types of Synovial Joints

Nonaxial (gliding), uniaxial (hinge), biaxial (saddle), multiaxial (ball-and-socket); each allows specific movements.

Hypermobility Causes

Can be caused by joint structure anomalies or connective tissue disorders; leads to increased range of motion.

Common Body Movements

Includes flexion, extension, abduction, and rotations; distinct structures produce each movement.

Six Types of Synovial Joints

Hinge (elbow), pivot (atlantoaxial), ball-and-socket (hip), saddle (thumb), condylar (wrist), plane (carpals).

Joint Mobility vs Strength Tradeoff

Increased mobility can compromise stability, making joints susceptible to injury.

Synovial Joint Stabilization

Stabilized by ligaments and cartilage; shoulder is less stable than knee due to anatomical differences.

Knee ACL Injury

Injury involves tearing the anterior cruciate ligament; repair may require surgical reconstruction.

Osteoarthritis vs Rheumatoid Arthritis

Osteoarthritis is degenerative, while rheumatoid arthritis is autoimmune; both affect joint function.

Arthroplasty Definition

Surgical procedure for joint replacement to restore function and relieve pain.

Joint Types Based on Mobility

Classified into fibrous, cartilaginous, and synovial joints based on movement capabilities.

Synovial Fluid Function

Acts as a lubricant and shock absorber in synovial joints, reducing friction between cartilage surfaces.

Joint Disorders Examples

Common joint disorders include bursitis, tendinitis, and arthritis.

Bone Density and Osteoporosis

Bone density measures the amount of bone mineral in a specific area; low density increases osteoporosis risk.

Role of Bisphosphonates

Medications used to treat osteoporosis by inhibiting osteoclast activity and preventing bone resorption.

Role of Vitamin D in Bone Health

Essential for calcium absorption in the gut, promoting bone mineralization and overall bone health.

Ligament vs Tendon

Ligaments connect bone to bone, while tendons connect muscle to bone.

Articular Cartilage Composition

Comprised predominantly of collagen and proteoglycans, providing smooth articulation surface in joints.

Osteopenia Definition

A condition where bone mineral density is lower than normal but not severe enough to be classified as osteoporosis.

Common Causes of Joint Pain

Include overuse, injury, inflammation, and degenerative diseases like arthritis.

Articular Capsule Structure

Surrounds synovial joints, composed of an outer fibrous layer and an inner synovial membrane.

Primary Functions of Synovial Fluid

Provide lubrication, reduce friction, and nourish articular cartilage.