Skeletal and Muscular Systems Review (Chapter 08 & 09)

Flashcards covering vocabulary and key concepts from Chapter 08 (Skeletal System) and Chapter 09 (Muscular System) based on Herlihy's The Human Body in Health and Illness.

Humerus

A bone of the upper limbs located in the arm that articulates distally with the ulna and proximally with the scapula at the glenohumeral joint.

Maxilla

A facial bone that contains the upper teeth and forms the anterior part of the hard palate.

Mandible

The lower jaw bone that articulates with the temporal bone at the TMJ and is the only movable bone of the skull.

Zygomatic bone

A facial bone commonly referred to as the cheekbone.

Atlas and Axis

The first two cervical vertebrae ($C1$ and $C2$) of the vertebral column.

Foramen magnum

A large opening in the occipital bone through which the spinal cord passes.

Fontanels

Membranous "soft spots" in an infant's skull that allow for expansion during growth and eventually fuse.

Tibia

A bone of the lower leg, also known as the shin, which contains the medial malleolus.

Acetabulum

A depression formed by the ilium, ischium, and pubis that receives the head of the femur to form a ball-and-socket joint.

Coxal bone

The hip bone formed by the fusion of the ischium, ilium, and pubis.

Epiphysis

The structure located at the ends of a long bone.

Cancellous bone

Another name for spongy bone.

Periosteum

The tough, outer lining of connective tissue surrounding the diaphysis of a long bone that provides a site for tendon attachment.

Osteon

Also called the Haversian system, it is the cylindrical arrangement of dense bone tissue.

Diaphysis

The shaft of a long bone, composed primarily of compact bone.

Epiphyseal disc

The growth plate of a bone that allows for longitudinal growth; injury to it can stunt growth.

Ossification

The process of bone formation where cartilage is replaced by bone.

Kyphosis

An abnormal thoracic curvature of the spine, commonly known as hunchback.

Osteoclasts

Bone cells that break down bone tissue and raise blood calcium levels.

Synovial joint

A classification for joints that are freely movable, such as the hip, knee, and shoulder.

Actin

A contractile protein that makes up the thin filament within a sarcomere.

Myosin

A contractile protein called the thick filament that forms cross-bridges with actin.

Sarcomere

The functional contractile unit of a myofibril that extends from Z line to Z line.

T tubule

An extension of the sarcolemma that carries electrical signals into the deepest part of the muscle to trigger calcium release.

Sarcoplasmic reticulum

The site of calcium storage within a relaxed skeletal muscle fiber.

Acetylcholine (ACh)

The neurotransmitter released from a somatic motor neuron that activates NM receptors to initiate muscle contraction.

Acetylcholinesterase

An enzyme that degrades acetylcholine to terminate muscle stimulation.

Tetany

A sustained state of muscle contraction.

Atrophy

A decrease in muscle size often caused by disuse, denervation, or disease.

Frontalis

A flat muscle covering the forehead that raises the eyebrows for a "surprised" look.

Zygomaticus

Known as the smiling muscle, it pulls the corners of the mouth upward.

Diaphragm

The chief muscle of respiration that separates the thoracic and abdominal cavities.

Sternocleidomastoid

A muscle that rotates the head down and to the left or right.

Trapezius

A muscle in the upper back and neck that allows one to shrug the shoulders or look up at the sky.

Gastrocnemius

The calf muscle that attaches to the calcaneus via the Achilles tendon; known as a "toe dancer's" muscle.

Sartorius

A long muscle that lies obliquely across the anterior thigh, allowing for a crossed-leg position.

Recruitment

The process of stimulating additional motor units to increase the force of a whole muscle contraction.

Aponeurosis

A flat, sheetlike fascia composed of connective tissue that serves as a site of attachment for skeletal muscle.

Myoglobin

A protein found in muscle tissue that stores oxygen.

Fascicles

Bundles of muscle fibers bound together by connective tissue.