Human Anatomy and Physiology: Chapter 7 - The Skeletal System

Comprehensive vocabulary flashcards covering anatomical markings, skull cavities, vertebrae, thoracic cage, and appendicular bones from Chapter 7: The Skeletal System.

Axial skeleton

The division of the skeletal system aligned along the body's longitudinal axis; includes the skull (22 bones), vertebral column (33 bones), and thoracic cage (12 pairs of ribs, sternum, and part of the vertebral column) to protect underlying organs and encase body cavities.

Appendicular skeleton

The division of the skeletal system consisting of the pectoral girdle, upper limb, pelvic girdle, and lower limb; primarily adapted for movement, support, and muscle attachment.

Facet

A shallow convex or concave bone marking surface where two bones articulate, such as the articular facet of a rib that articulates with a transverse process.

Fossa

A bone depression characterized as an indentation into which another structure fits, such as the olecranon fossa on the distal portion of the humerus.

Fovea

A shallow pit on a bone, such as the fovea capitis located on the head of the femur.

Sulcus (Groove)

A long bone indentation along which a narrow structure travels, such as the costal groove of a rib.

Meatus (Canal)

A tunnel-like opening passing through a bone, such as the external acoustic meatus of the temporal bone.

Fissure

A narrow slit in a bone or between adjacent parts of bones, such as the superior orbital fissure of the sphenoid bone.

Foramen

A hole in a bone that permits the passage of blood vessels and nerves, such as the supraorbital foramen in the frontal bone.

Condyle

A rounded projection at the end of a bone that articulates with another bone, such as the mandibular condyle of the mandible.

Crest

A prominent ridge or elongated projection on a bone, such as the iliac crest of the ilium.

Tubercle and tuberosity

A small, rounded bony projection; a tuberosity refers specifically to a large tubercle, such as the deltoid tuberosity of the humerus.

Trochanter

A very large bony projection found exclusively on the femur, such as the greater trochanter.

Cranial vault (calvarium)

The superior portion of the cranial cavity formed by the cranial bones.

Cranial base

The inferior portion of the cranial cavity, divided into three indentations (anterior, middle, and posterior cranial fossae) where the brain rests.

Paranasal sinuses

Air-filled, mucous membrane-lined cavities located within the frontal, sphenoid, ethmoid, and maxillary bones that warm and humidify air, decrease skull weight, and provide voice resonance.

Orbit

A complex cavity formed by seven fused bones (frontal, maxilla, zygomatic, sphenoid, ethmoid, lacrimal, and palatine) that encloses the eyeball, lacrimal gland, nerves, and blood vessels.

Nasal septum

A structure dividing the nasal cavity into two fossae; formed posteriorly by the perpendicular plate of the ethmoid bone and the vomer, and anteriorly by hyaline cartilage.

Fontanels

Membranous, unossified areas ("soft spots") between fetal cranial bones that facilitate passage through the birth canal and allow for rapid brain expansion, remaining until 18–24 months of age.

Hyoid bone

A C-shaped bone located in the superior neck suspended by ligaments to the styloid processes of the temporal bones and larynx; does not articulate directly with any other bone.

Primary curvatures

The thoracic and sacral spinal curvatures present during fetal development that retain the original C-shape of the newborn spine.

Secondary curvatures

The cervical and lumbar spinal curvatures that develop after the fetal period to allow upright walking; the cervical curve supports head elevation and the lumbar curve centers torso weight over the sacrum.

Scoliosis

An abnormal lateral curvature of the vertebral column.

Lordosis

An exaggerated lumbar and cervical curvature of the spine, commonly called swayback.

Kyphosis

An exaggerated thoracic curvature of the spine resulting in a hunchback appearance.

Vertebral arch

The posterior bony structure of a vertebra composed of two pedicles projecting from the vertebral body that merge posteriorly with two laminae, enclosing the vertebral foramen.

Atlas ($C_1$)

The first cervical vertebra, which lacks a vertebral body and spinous process, consisting instead of anterior and posterior arches and lateral masses that articulate with the occipital condyles to enable the "yes" head motion.

Axis ($C_2$)

The second cervical vertebra, characterized by a superior tooth-like projection called the dens (odontoid process) that articulates with the atlas to allow rotational "no" head motion.

Dens (Odontoid process)

A prominent superior tooth-shaped projection protruding from the body of the axis ($C_2$) held against the atlas by the transverse ligament.

Intervertebral disc

A fibrocartilaginous pad (23 in total) positioned between adjacent vertebral bodies to absorb mechanical shock and join the vertebral column together.

Nucleus pulposus

The soft, inner, resilient jelly-like substance of an intervertebral disc that functions as a shock absorber.

Anulus fibrosus

The outer ring of fibrocartilage in an intervertebral disc that encases the nucleus pulposus and binds adjacent vertebrae together.

True ribs (Vertebrosternal ribs)

Rib pairs 1 through 7, which attach directly to the sternum via their own individual costal cartilages.

False ribs

Rib pairs 8 through 12, which do not attach directly to the sternum; includes vertebrochondral ribs (8–10) and floating ribs (11–12).

Floating ribs (Vertebral ribs)

Rib pairs 11 and 12, which lack any anterior attachment to the sternum or to other costal cartilages.

Pectoral girdle

The skeletal complex comprising the clavicle and scapula that supports the upper limb and anchors it to the axial skeleton.

Glenoid cavity

A shallow indentation located on the lateral aspect of the scapula that articulates with the head of the humerus to form the shoulder joint.

Acromion

The flattened lateral terminal end of the scapular spine that articulates with the acromial end of the clavicle at the acromioclavicular joint.

Capitulum

A spherical, lateral knob on the distal epiphysis of the humerus that articulates with the head of the radius.

Trochlea

A medial, spool-shaped knob on the distal epiphysis of the humerus that articulates with the trochlear notch of the ulna.

Olecranon

The prominent bony protrusion located on the posterior aspect of the proximal ulna that forms the tip of the elbow and sits in the olecranon fossa of the humerus during extension.

Carpals

The eight short bones forming the wrist (carpus), arranged in a proximal row (scaphoid, lunate, triquetrum, pisiform) and a distal row (trapezium, trapezoid, capitate, hamate).

Pollex

The thumb, which consists of only two phalanges (a proximal and a distal phalanx), unlike fingers II through V which contain three phalanges.

Colles fracture

A common fracture of the distal radius that frequently occurs from direct impact or landing on an outstretched hand.

Pelvic inlet

The oval superior aperture formed by the sacrum and the pelvic girdle that demarcates entry into the true pelvis.

Pelvic brim

The continuous bony ridge encircling the pelvic inlet that separates the greater (false) pelvis from the lesser (true) pelvis.

Acetabulum

The deep hemispherical socket situated on the lateral surface of the hip bone formed by the fusion of the ilium, ischium, and pubis; articulates with the head of the femur.

Obturator foramen

A large opening in the pelvic bone bounded primarily by the rami of the pubis and ischium, through which blood vessels and nerves travel.

Ischial tuberosity

A prominent, roughened projection on the posteroinferior aspect of the ischium that bears the full weight of the upper body when seated.

Pubic symphysis

The fibrocartilaginous joint where the two pubic bodies join along the anterior midline of the pelvis.

Fovea capitis

A small central pit on the head of the femur that serves as an attachment site for a stabilizing ligament of the hip joint.

Patella

A triangular sesamoid bone located within the tendon of the anterior thigh muscle (quadriceps) that protects the knee joint and continues distally as the patellar ligament.

Medial malleolus

The palpable medial projection of the distal tibia that articulates with the talus and stabilizes the medial side of the ankle joint.

Lateral malleolus

The expanded distal projection of the fibula that forms the lateral prominence of the ankle and articulates with the talus.

Talus

The dome-shaped tarsal bone that is the only foot bone to articulate directly with the tibia and fibula of the leg.

Calcaneus

The large heel bone that articulates with the talus on its dorsal surface and provides the insertion site for the calcaneal (Achilles) tendon on its posterior surface.

Hallux

The great toe (digit I), which possesses only two phalanges (proximal and distal).