An Introduction to the Axial and Appendicular Skeleton

Flashcards covering the key vocabulary and concepts from the lecture notes on the axial and appendicular skeleton.

Articulations

Contacts with other bones.

Landmarks

Areas of muscle and ligament attachment.

Foramina

Openings for nerves and blood vessels.

Axial Skeleton

Forms the longitudinal axis of the body; consists of 80 bones including the skull, vertebral column, and thoracic cage.

Skull

8 cranial bones and 14 facial bones.

Vertebral Column

24 vertebrae, the sacrum, and the coccyx.

Thoracic Cage

24 ribs and the sternum.

Functions of the Axial Skeleton

Support and protect organs in body cavities, attach to muscles of the head, neck, and trunk, perform respiratory movements, and stabilize parts of the appendicular skeleton.

Skull Function

Protects the brain and entrances to respiratory and digestive systems.

Cranial Bones

Enclose the cranial cavity, which contains the brain.

Superficial Facial Bones

Muscle attachment.

Deep Facial Bones

Separate the oral and nasal cavities and form the nasal septum.

Lambdoid Suture

Separates occipital from parietal bones.

Sagittal Suture

Between the parietal bones from lambdoid suture to coronal suture.

Squamous Sutures

Form boundaries between temporal bones and parietal bones.

Coronal Suture

Attaches frontal bone to parietal bones.

Calvaria (Skullcap)

Consists of occipital, parietal, and frontal bones.

Foramen Magnum

Connects cranial and spinal cavities.

Functions of Temporal Bones

Part of lateral walls of cranium and zygomatic arches, articulate with mandible, surround and protect inner ear, and attach muscles of jaws and head.

Auditory Ossicles

Three tiny bones in tympanic cavity (middle ear) that transfer sound from tympanic membrane (eardrum) to inner ear.

Mandible

Forms the lower jaw.

Fontanelles

Areas of fibrous connective tissue (soft spots) that cover unfused sutures in the infant skull and allow the skull to flex during birth.

Craniostenosis

Premature closure of fontanelle, leading to unusual distortions.

Vertebral Column Functions

Protects the spinal cord and supports the head and body.

Vertebrae Regions

7 cervical vertebrae, 12 thoracic vertebrae, and 5 lumbar vertebrae.

Primary Curves

Present during fetal development; includes thoracic and sacral curves.

Secondary Curves

Appear after birth; includes lumbar and cervical curves.

Cervical Vertebrae

Small body; large vertebral foramen, transverse foramen; C7 (vertebra prominens) which acts as anatomical landmark.

Atlas

C1, has no spinous process.

Axis

C2, partially fuses to atlas.

Thoracic Vertebrae

Larger bodies; smaller vertebral foramen; long, slender spinous processes; dorsolateral surfaces of body have costal facets.

Lumbar Vertebrae

Largest vertebrae; triangular vertebral foramen; no costal facets; short, heavy spinous process.

Sacrum

Protects reproductive, urinary, and digestive organs; attaches the axial skeleton to the pelvic girdle.

Coccyx

Attaches ligaments and an anal sphincter.

Thoracic Cage

Supports the thoracic cavity and consists of thoracic vertebrae, ribs, and sternum

Functions of the Thoracic Cage

Protect organs of the thoracic cavity, attach muscles for respiration, of the vertebral column, and of the pectoral girdle and the upper limbs.

Appendicular Skeleton

Allows us to move and manipulate objects; includes all bones besides axial skeleton , the limbs, and the supportive girdles.

Pectoral Girdle

Provides a base for arm movement and consists of clavicles and scapulae.

Humerus

Articulates with the pectoral girdle.

Ulna

Medial forearm bone; the olecranon is the point of the elbow.

Radius

Lateral forearm bone.

Carpals

Wrist bones.

Pelvic Girdle

Part of the pelvis, is made up of 2 hip bones (coxal bones), and is strong to bear body weight and stress of movement.

Ilium

Articulates with sacrum.

Acetabulum

Hip socket.

Pelvic Modifications for Childbearing

Enlarged pelvic inlet and outlet, broad pubic angle.

Tibia

Supports body weight and is larger and medial to fibula.

Fibula

Attaches muscles of feet and toes.

Tarsals

Ankle bones.