Human Skeletal System and Muscles

Flashcards covering the taxonomy, structure, functions, and common disorders of the human skeletal and muscular systems based on the lecture transcript.

Number of bones in an adult

Adults have 206 bones in the human skeleton.

Functions of the skeletal system

Framework, movement, protection of internal organs, production of blood cells, immune system support, and storage of minerals ($Ca$) and fat.

Bone Composition

A living tissue richly supplied by blood vessels and nerves, strengthened by calcium phosphate and calcium carbonate.

Compact bone

The hard outer shell that forms the exterior of bones.

Spongy bone

A lighter bone tissue with spaces filled with fat or bone marrow.

Periosteum

A fibrous membrane that covers the bone structure.

Long bone

A classification of bone exemplified by the Femur.

Short bones

Bones such as the Lateral cuneiform, Intermediate cuneiform, and Medial cuneiform.

Flat bone

A classification of bone exemplified by the Sternum.

Irregular bone

A classification of bone exemplified by the Vertebra.

Sesamoid bone

A classification of bone exemplified by the Patella.

Cartilage

A resilient, smooth elastic tissue that covers and protects the ends of long bones at joints; it lacks blood vessels and nerves.

Axial skeleton

The central part of the skeletal system consisting of the skull, vertebral column, ribs, and sternum.

Appendicular skeleton

The portion of the skeleton that 'appends' to the axis, including the pectoral girdle with upper limbs and the pelvic girdle with lower limbs.

Cervical vertebrae

The first 7 vertebrae of the vertebral column.

Thoracic vertebrae

The 12 vertebrae located in the mid-section of the vertebral column.

Lumbar vertebrae

The 5 vertebrae located in the lower back region.

Sacrum

A section of the vertebral column consisting of 5 fused vertebrae.

Coccyx

The bottom-most part of the vertebral column consisting of 4 fused vertebrae.

Ribs

The 12 pairs of bones in the chest, including 10 attached pairs and 2 floating pairs.

Pectoral girdle

The shoulder girdle consisting of the Clavicle and Scapula.

Upper limb bones

Consists of the Humerus, Radius, Ulna, 8 Carpals, 5 Metacarpals, and 14 Phalanges.

Pelvic girdle

The coxal bones which include the ilium, ischium, and pubic bones.

Lower limb bones

Consists of the Femur, Tibia, Fibula, 7 Tarsals, and 5 Metatarsals.

Immovable or Fixed joints

Fibrous joints, such as the sutures found in the skull.

Slightly Movable joints

Cartilaginous joints, such as the intervertebral discs.

Freely Movable joints

Synovial joints characterized by articular cartilage, a joint capsule, and a synovial layer that produces lubricating fluid.

Hinge joint

A type of synovial joint allowing movement in one plane, with examples including the elbow, knee, fingers, and jaw.

Ball & Socket joint

A synovial joint providing the most range of movement, such as the hip and shoulder.

Gliding joint

A synovial joint found in the wrist and ankle.

Tendons

Cords of dense fibrous tissue that tie muscles to bones.

Ligaments

Bands of tough fibrous tissue that link bones together.

Skeletal muscles

Striped or striated muscles made of fibres that contract when stimulated by a nerve and are under conscious (voluntary) control.

Antagonistic pairs

Muscles that work in opposite directions; when one is contracted (the flexor), the other is relaxed (the extensor).

Biceps and Triceps

A pair of muscles where the biceps acts as the flexor (bending the arm) and the triceps acts as the extensor (straightening the arm).

Peak bone mass

Reached at age 30, after which a person loses slightly more bone mass than they make.