A&P Exam

Long Bones

Cylindrical in shape; longer than wide; function as levers; found in arms, legs, fingers, and toes.

Short Bones

Cube-like, approximately equal in length, width, and thickness; provide stability, support, and limited motion; found in carpals and tarsals.

Flat Bones

Typically thin but curved; serve as muscle attachment points and protect internal organs; examples include cranial bones and ribs.

Irregular Bones

Do not have easily characterized shapes; examples include vertebrae and many facial bones.

Sesamoid Bones

Small, round bones shaped like sesame seeds; form in tendons where high pressure is generated; protect tendons against compressive forces.

Osteogenic Cells

Develop into osteoblasts; are undifferentiated bone cells with high mitotic activity.

Osteocytes

Maintain mineral concentration of the matrix; primary cell of mature bone.

Spongy Bone

Cancellous bone; trabecular structure formed along stress lines; contains red marrow.

Endochondral Ossification

Bone develops by replacing hyaline cartilage; forms base of the skull and long bones.

Intramembranous Ossification

Bone forms directly from mesenchymal tissue, creating flat bones of the face and cranial bones.

Zygomatic Arch

Bony arch on the side of the skull formed by two bony processes; allows muscle attachment for jaw movement.

Nasal Complex

Comprises nasal bones, maxilla, ethmoid, and vomer; functions for air conditioning, filtration, and olfaction.

Orbital Complex

Formed by seven bones including frontal, sphenoid, and zygomatic bones; houses the eyeball.

Fontanelles

Soft gaps between cranial bones in infants; allow for skull flexibility and brain growth.

Spinal Curves

Enhance strength and flexibility; include primary (thoracic, sacrococcygeal) and secondary (cervical, lumbar) curves.

Pectoral Girdle

Attaches upper limbs to axial skeleton; includes clavicle and scapula.

Scapula

Anchors the upper limb; features include glenoid cavity, acromion, and various fossae for muscle attachment.

Humerus

Single bone of the upper arm; articulates with scapula and forearm bones; features include greater tubercle and epicondyles.

Radius

Lateral bone of the forearm; features include head, tuberosity, and styloid process.

Wrist

Composed of eight carpal bones arranged in two rows; support the hand's movements.

Ilium

Superior portion of the hip; features include iliac crest and various spines for muscle attachment.

Femur

Longest and strongest bone; connects with the hip and knee, featuring trochanters for muscle attachment.

Tibia

Main weight-bearing bone of the lower leg; features condyles and medial malleolus.

Synarthrosis

Immovable joint type providing strong union between bones.

Synovial Joints

Most common joint type; allows free movement and contains synovial fluid for lubrication.

Types of Synovial Joints

Include pivot, hinge, condyloid, saddle, plane, and ball-and-socket joints.

Abduction

Movement of a limb away from the midline of the body.

Adduction

Movement of a limb toward the body or across the midline.

Flexion

Decreases the angle between bones.

Extension

Increases the angle between bones.

Elevation

Upward movement of structures like the scapula.

Depression

Downward movement of structures like the scapula.

Ligaments

Support synovial joints and restrict motion.

Elbow Joint

Hinge joint formed by the humeroulnar and humeroradial joints.

Knee Joint

Largest joint in the body; involves femoropatellar and tibiofemoral joints.

Muscle Contraction

Occurs when actin is pulled by myosin, requiring ATP.

Sarcomere

Basic functional unit of muscle contraction consisting of myosin and actin filaments.

Isometric Contraction

Muscle produces tension without changing joint angle.

Isotonic Contraction

Muscle tension remains constant while muscle length changes.

Aerobic Respiration

More efficient process producing ATP in the presence of oxygen.

Facial Muscles

Muscles of facial expression that originate on the skull and insert into the skin.

Eye Muscles

Muscles that control eye movements including superior and inferior rectus.

Intrinsic Foot Muscles

Muscles that originate and insert within the foot, supporting its arch.