Musculoskeletal System Quiz

Muscular System

• Muscles facilitate all body movements through contraction.
• Three types of muscle: skeletal, cardiac, and smooth.

Function of Muscles

• Maintains heartbeat and body posture.
• Facilitates body movement and generates heat.
• Provides shape and protects organs and bones.
• Stabilizes joints.

Skeletal Muscles

• Voluntary muscles, comprising about 40% of body weight.
• Attach to bones via tendons and are striated.
• Cells are multinucleate and enveloped by connective tissue.

Connective Tissue Surrounding Skeletal Muscle

• Endomysium: encases individual muscle fibers.
• Perimysium: surrounds muscle fiber bundles.
• Epimysium: covers entire skeletal muscle.

Skeletal Muscle Attachments

• Attachment through tendons (cord-like) and aponeuroses (sheet-like).
• Muscle sites of attachment include bones, cartilages, and connective tissues.

Muscles for Intermuscular Injection

• Common injection sites include the deltoid and gluteus maximus muscles.

Cardiac Muscles

• Involuntary muscles located in the heart, responsible for blood movement.
• Striated with single nucleus and connected by intercalated discs.
• Nerve supply originates from the autonomic nervous system.

Smooth Muscles

• Found in the gastrointestinal tract, blood vessels, and hollow organs.
• Involuntary muscles characterized by spindle-shaped cells and single nucleus.
• Lack striations and function without conscious control.

Comparison between Muscle Types

• Skeletal: voluntary, striated, multinucleate.
• Cardiac: involuntary, striated, single nucleus.
• Smooth: involuntary, non-striated, single nucleus.

Joints

• Joints are where two or more bones meet.
• Types include synovial (moveable), cartilaginous (limited movement), and fibrous (immovable).

Fibrous Joints

• Composed of fibrous connective tissue, allowing no movement.
• Example: sutures in the skull.

Cartilaginous Joints

• Bones joined by cartilage, allowing limited movement.
• Example: intervertebral discs separating vertebrae.

Synovial Joints

• Most joints in the skeletal system are synovial.
• Bones covered with articular cartilage and supported by ligaments.

Examples of Synovial Joints

• Upper limb: shoulder joint, elbow joint, wrist joint.
• Lower limb: hip joint, knee joint, ankle joint.

Bone Functions

• Support body weight and protect internal organs.
• Store inorganic salts such as calcium, phosphate, magnesium, sodium, and potassium.
• Facilitate blood cell formation (hematopoiesis) in red marrow.

Skeletal System

• Divided into two parts: axial and appendicular skeletons.

Axial Skeleton

• Comprises the skull (8 cranial and 14 facial bones), vertebral column (33 vertebrae), and thoracic cage (sternum, ribs, costal cartilages).

Vertebral Column

• Contains cervical (7), thoracic (12), lumbar (5), sacrum (5 fused), and coccyx (4 fused vertebrae).
• Vertebrae are separated by intervertebral discs made of fibrocartilage.

Bony Thorax

• Protects thoracic organs and composed of the sternum, ribs, costal cartilages, and thoracic vertebrae.
• Sternum has three parts: manubrium, body, and xiphoid process.

Appendicular Skeleton

• Includes the pectoral girdle, pelvic girdle, and bones of the upper and lower limbs.