Endocrine Hormones and Musculoskeletal System Function
The Endocrine System: Chemical Messengers
Endocrine glands respond to stimuli by producing hormones transported in the blood throughout the body. Each hormone affects its target cell, which contains specific receptors. Hormones are chemical messengers that activate or stop, accelerate or delay processes within organs. Hormone receptors cause chemical reactions inside the cell, producing a response.
Hypothalamus Function
The Hypothalamus produces nerve signals and hormones, specifically releasing factors
Read MoreMusculoskeletal 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
- Articular cartilage is damaged, leading to the release of enzymes.
- This accelerates cartilage disintegration. Subchondral bone is exposed, leading to the development of cysts, osteophytes, or new bone
Muscle Contraction, Joint Anatomy, and Skeletal Movement
Muscle Contraction and Anatomy Fundamentals
Steps in Skeletal Muscle Contraction
- Calcium ions are released from the sarcoplasmic reticulum.
- Calcium ions bind to troponin.
- Myosin cross-bridges bind to the actin filament.
- The myosin head pivots toward the center of the sarcomere (Power Stroke).
- The myosin head binds an ATP molecule and detaches from actin.
- The free myosin head splits ATP, resetting the head position.
Key Muscle Fiber Structures and Definitions
- Triad (E): Terminal cisternae abutting a T-tubule.
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
Read MoreSpinal 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
Read MoreHuman 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