Musculoskeletal and Endocrine Pathologies: Arthritis, Spondylitis, and Hormonal Disorders

Joint and Musculoskeletal Disorders

Osteoarthritis (OA)

Degeneration of weight-bearing and finger joints.

Types of Osteoarthritis

  • Primary: Associated with weight-bearing stress, obesity, and aging.
  • Secondary: Follows trauma or repetitive use.
  • Genetics play a role in susceptibility.

Pathological Changes in OA

  1. Articular cartilage is damaged, leading to the release of enzymes.
  2. This accelerates cartilage disintegration. Subchondral bone is exposed, leading to the development of cysts, osteophytes, or new bone
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Muscle Contraction, Joint Anatomy, and Skeletal Movement

Muscle Contraction and Anatomy Fundamentals

Steps in Skeletal Muscle Contraction

  1. Calcium ions are released from the sarcoplasmic reticulum.
  2. Calcium ions bind to troponin.
  3. Myosin cross-bridges bind to the actin filament.
  4. The myosin head pivots toward the center of the sarcomere (Power Stroke).
  5. The myosin head binds an ATP molecule and detaches from actin.
  6. The free myosin head splits ATP, resetting the head position.

Key Muscle Fiber Structures and Definitions

  • Triad (E): Terminal cisternae abutting a T-tubule.
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Understanding Muscle and Bone Structure for Movement

The Musculoskeletal System

Muscles are composed of elongated cells called muscle fibers. These organs have the ability to contract and relax. There are several types of muscles:

Smooth Muscle

Characterized by slow, involuntary contractions. Smooth muscle fibers form the walls of various internal organs.

Heart Muscle

This involuntary muscle contracts rapidly. Its fibers are found in the heart (myocardium).

Skeletal Muscle

These muscles enable fast, voluntary movements and are attached to the skeleton. Each

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Spinal and Thoracic Joint Anatomy: Ligaments & Movement

Spinal Column Joints and Ligaments

The vertebrae are linked together through their vertebral bodies by interposing between them a fibrocartilage disc (fibrous synchondrosis). This synchondrosis occurs in the center, a gelatinous core known as the nucleus pulposus. Around the nucleus pulposus, which is a remnant of the embryonic notochord, is the cartilaginous ring (annulus fibrosus). The fibers of the annulus fibrosus are oriented in layers, similar to an onion, with their direction changing: vertically

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Human Spine Anatomy: Vertebrae, Joints, and Curvatures

Spine Anatomy Fundamentals

The spine supports the head and provides mobility to the vertebral column. It combines flexibility (vertebrae) and firmness (intervertebral discs). The vertebrae are larger towards the base of the spine, narrowing superiorly.

Physiological Curvatures of the Spine

The adult spine exhibits four physiological lateral curvatures:

  • Cervical Lordosis: An anterior convexity in the neck region.
  • Thoracic Kyphosis: An anterior concavity in the upper back.
  • Lumbar Lordosis: An anterior convexity
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Essential Concepts in Chemistry and Biology

Thermodynamics Fundamentals

The first law of thermodynamics establishes the notion of internal energy for a thermodynamic system. All energy transfers must be accounted for to ensure strict conservation of the total energy of a thermodynamic system and its surroundings. This law states that energy can be neither created nor destroyed; however, energy can change forms and flow from one place to another. The total energy of an isolated system remains constant.

The second law of thermodynamics states

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