Untitled Quiz

Introduction

• The skeletal system is composed of various tissues, including bone, cartilage, dense connective tissue, epithelium, blood-forming tissues, adipose tissue, and nervous tissue.
• Each bone is an organ, and together they form the skeletal system.

Functions of the Skeletal System

• Support: Provides a framework and attachment sites for muscles.
• Protection: Shields internal organs with bony coverings.
• Movement: Assists muscles in producing body movements.
• Mineral Storage: Stores and releases minerals (calcium and phosphorus).
• Hemopoiesis: Blood cell formation occurs in red marrow.
• Energy Storage: Yellow marrow stores triglycerides.

Structure of Bone

• Long Bone Anatomy:
  • Diaphysis: The shaft of the bone.
  • Epiphyses: The ends of the bone, articulating with other bones.
  • Metaphyses: Areas between the diaphysis and epiphyses.
  • Periosteum: Connective tissue covering for growth and repair.
  • Articular Cartilage: Reduces friction at joints.
  • Marrow Cavity: Contains yellow marrow.
  • Endosteum: Lining of the medullary cavity.

Histology of Bone Tissue

• Bone Cells:
  • Osteogenic Cells: Develop into osteoblasts.
  • Osteoblasts: Bone-building cells.
  • Osteocytes: Mature bone cells maintaining bone tissue.
  • Osteoclasts: Cells that break down bone.
• Matrix Composition: Inorganic salts (hydroxyapatite) and collagen fibers provide hardness and tensile strength.
• Types: Compact or spongy, based on matrix arrangement.

Blood and Nerve Supply of Bone

• Richly supplied with blood through periosteal and nutrient arteries.
• Veins accompany arteries to drain blood from bones.
• Nerves follow blood vessels into bone tissue.

Bone Formation

• Osteogenesis/Ossification: Two types:
  • Intramembranous: Bone forms from fibrous connective tissue (e.g., skull bones).
  • Endochondral: Bone replaces hyaline cartilage (most bones of the body).
  • Growth:
    • Length: Through the epiphyseal plate.
    • Thickness: Through appositional growth at the periosteum.
• Remodeling: Continuous replacement of old bone with new bone.

Bone's Role in Calcium Homeostasis

• Bone acts as a calcium reservoir.
• Hormonal Regulation:
  • Parathyroid Hormone (PTH): Increases blood calcium levels.
  • Calcitonin: Decreases blood calcium levels.

Exercise and Bone Tissue

• Mechanical stress increases bone strength through mineral deposition and collagen production.
• Weight-bearing activities help maintain bone mass.

Aging and Bone Tissue

• Aging results in demineralization and decreased collagen production, increasing fracture risk and conditions like osteoporosis.

Medical Terminology

• Familiarize yourself with terminology related to skeletal tissue for better understanding.

Introduction to the Skeletal System

• The skeletal system is comprised of bones, muscles, and joints, forming the musculoskeletal system.
• Understanding bone structure aids in locating organs and understanding muscle movements.

Divisions of the Skeletal System

• Axial Skeleton:
  • Skull
  • Hyoid bone
  • Vertebral column
  • Sternum
  • Ribs
• Appendicular Skeleton:
  • Upper and lower extremities (limbs)
  • Pectoral girdle
  • Pelvic girdle

Types of Bones

• Based on their shape. Include: long, short, flat, irregular, sesamoid, and sutural.

Bone Surface Markings

• Depressions and openings allow passage of soft tissue or form joints.
• Processes help form joints or are attachment points for connective tissues.

The Skull

• Composed of 22 bones, divided into cranial and facial bones.
• Key features include sutures, immovable joints connecting skull bones, and paranasal sinuses.

Vertebral Column

• Composed of 26 vertebrae, divided into five regions (cervical, thoracic, lumbar, sacral, and coccygeal).
• Functions: Support and protection of the spinal cord.

Thorax

• Forms the skeletal part with sternum, ribs, and thoracic vertebrae.
• Protects thoracic and abdominal organs and supports upper limbs

Disorders and Homeostatic Imbalances

• Herniated Disc: Protrusion of disc material causing nerve pressure.
• Spina Bifida: Congenital defect due to incomplete closure of the vertebral column.
• Osteoporosis: Decreased bone density leading to fractures.
• Rickets/Osteomalacia: Disorders characterized by improper calcification of bones.

Introduction to the Appendicular Skeleton

• Definition: The appendicular skeleton includes bones of upper and lower limbs, shoulder (pectoral) and hip (pelvic) girdles.
• Function: Primarily facilitates movement.

Pectoral (Shoulder) Girdle

• Components: Clavicle and scapula.
• Function: Provides attachment for muscles, allowing wide range of motion for the arm

Upper Limb (Extremity)

• Composition: Includes humerus, ulna, radius, carpals, metacarpals, and phalanges.

Pelvic (Hip) Girdle

• Composition: Coxal bones (ilium, pubis, and ischium) fused.
• Function: Supports lower extremities and bears body weight.

True and False Pelves

• Pelvic Structure: Formed by the hip bones, sacrum, and coccyx
• Subdivisions: Greater and lesser pelvis.

Comparison of Female and Male Pelves

• Differences in size and shape, related to childbirth.

Lower Limb (Extremity)

• Composition: Includes femur, patella, tibia, fibula, tarsals, metatarsals, and phalanges
• Function: Supports weight and provides leverage for movement

Arches of the foot

• Function: Support weight and provide leverage during walking.
• Clinical Conditions: Flatfoot and clawfoot.

Development of the Skeletal System

• Ossification Processes: Intramembranous and endochondral
• Limb Development: Limb buds

Introduction to Joints

• Definition: A point of contact between two or more bones, cartilage, or teeth.
• Study of Joints: Arthrology

Joint Classification

• Structural: Fibrous (sutures, syndesmoses, gomphosis), cartilaginous (synchondroses, symphyses), and synovial.
• Functional: Synarthroses (immovable), amphiarthroses (partially movable), diarthroses (freely movable).

Movements at Synovial Joints

• Gliding, angular (flexion, extension, hyperextension, abduction, adduction, circumduction, rotation), and special movements (elevation, depression, protraction, retraction, inversion, eversion, dorsiflexion/plantar flexion, opposition).

Clinical Connections

• Torn cartilage, sprains, strains, bursitis, and arthritis.

Aging and Joints

• Effects of decreased production of synovial fluid, thinning of articular cartilage and loss of ligament flexibility.

Muscle Contractions

• Involuntary contractions (cramps).
  • Causes include inadequate blood flow, overuse, or abnormal electrolyte levels.
• Types of muscle tissue ( skeletal, cardiac, smooth)

Disorders of Muscle Tissue

• Myasthenia Gravis: Autoimmune disorder causing muscle weakness.
• Muscular Dystrophy: Group of inherited muscle-destroying diseases.
• Myopathy: Disease or disorder of skeletal muscle tissue.

Regeneration of Muscle Tissue

• Skeletal muscle fiber regeneration is limited.

Aging and Muscle Tissue

• Effects of aging on muscle strength, fiber type, and endurance.

Summary of Key Points

• Muscle cramps, myasthenia gravis, muscular dystrophy, regenerations, aging effects on muscles.

Introduction to the Muscular System

• Definition: The muscular system is comprised of skeletal muscles and associated connective tissues for movement.

How Skeletal Muscles Produce Movement

• Muscle attachment sites (origin, insertion).
• Lever systems (first, second, third class levers) and types.
• Fascicle arrangements (parallel, fusiform, pennate, circular).
• Coordination within muscle groups (prime mover, antagonist, synergist, and fixator).

How Skeletal Muscles Are Named

• Criteria used for naming muscles (location, size, number of origins, shape, direction of fibers, origin and insertion, muscle action).

Principal Skeletal Muscles

• Specific muscles with their functions include facial, neck, upper limb, lower limb, and trunk muscles.

Disorders: Homeostatic Imbalances

• Common running injuries, compartment syndrome, and tenosynovitis.

Introduction to the Integumentary System

• Definition: The integumentary system is comprised of skin and accessory structures (hair, nails, glands).
• Functions include protection, thermoregulation, sensation, excretion, and Vitamin D synthesis

Structure of the Skin

• Layers (epidermis and dermis).
• Cells and structures in each layer (keratinocytes, melanocytes, Langerhans cells, Merkel cells, stratum corneum, stratum lucidum, stratum granulosum, stratum spinosum, and stratum basale).
• Dermis composition: Connective tissue, collagen, elastic fibers.

Skin Color and Pigmentation

• Pigments: Melanins, Hemoglobin, Carotene.
• Conditions: Freckles, albinism, and vitiligo.
• Accessory structures, glands, hair, and nails.

Functions of the Skin

• Thermoregulation
• Protection
• Sensation
• Excretion and absorption
• Vitamin D synthesis

Disorders of the Integumentary System

• Skin cancer (types), burns (degrees), pressure sores (decubitus ulcers), and psoriasis

Aging and the Integumentary System

• Effects: Thinning skin, decreased elasticity, slower healing, loss of subcutaneous fat.