Module 7 - Skeletal System: Bones And Joints

Skeleton

Complete bony framework of the body divided into axial and appendicular portions

Diaphysis

Long narrow shaft region of a long bone

Medullary Cavity

Central hollow space within the diaphysis of a long bone containing yellow marrow

Epiphysis

Irregular enlarged end region of a long bone containing spongy bone and red marrow

Bone Functions

Essential bodily roles including structural support organ protection muscle movement levering calcium storage and blood cell production

Compact Bone

Dense hard bone tissue forming the outer main layer of long bone shafts

Spongy Bone

Porous lattice-like bone tissue containing red marrow located within the ends of long bones

Axial Skeleton

Bony framework of the head and trunk consisting of 80 bones

Appendicular Skeleton

Bony framework of the extremities shoulder girdle and pelvic girdle consisting of 126 bones

Cranium

Eight cranial bones enclosing and protecting the brain including frontal parietal temporal ethmoid sphenoid and occipital

Frontal Bone

Cranial bone forming the forehead anterior roof of the skull and upper eye orbits

Parietal Bones

Paired cranial bones forming the superior roof and lateral walls of the cranium

Temporal Bones

Paired cranial bones forming the lower sides and base of the skull enclosing middle and inner ear structures

Ethmoid Bone

Fragile cranial bone between the eyes forming parts of the orbit roof of nasal cavity and upper nasal septum

Sphenoid Bone

Bat-shaped cranial bone at the skull base housing the sphenoid sinuses and sella turcica

Sella Turcica

Saddle-like depression in the sphenoid bone that houses and protects the pituitary gland

Occipital Bone

Cranial bone forming the posterior skull and base containing the foramen magnum

Foramen Magnum

Large opening at the base of the occipital bone allowing the spinal cord to connect with the brain

Sutures

Immovable fibrous joints connecting individual bones of the skull such as coronal sagittal squamous and lambdoid

Mandible

Lower jawbone which is the only movable bone in the human skull

Maxillae

Paired bones fusing at the midline to form the upper jaw and anterior hard palate

Zygomatic Bones

Paired bones forming the prominences of the cheeks and cheek arches

Vomer

Plow-shaped bone forming the lower portion of the nasal septum

Fontanels

Soft membrane-covered spaces between infant cranial bones that permit compression during birth

Appendicular Skeleton

Skeletal division including upper and lower limbs plus shoulder and pelvic girdles

Shoulder Girdle

Structure consisting of the clavicle and scapula

Clavicle

Slender collarbone joining sternum anteriorly and scapula laterally

Scapula

Flat shoulder blade bone located on posterior upper back

Spine of Scapula

Posterior raised ridge felt behind shoulder on upper back

Acromion

Highest point process on scapula joining clavicle

Glenoid Cavity

Shallow scapular socket forming ball and socket joint with humerus

Coracoid Process

Scapular projection medial to glenoid cavity for muscle attachment

Humerus

Proximal bone of upper extremity or arm bone

Epicondyles

Distal projections on humerus serving as attachment points for tendons

Trochlea

Pulley shaped distal midportion of humerus articulating with ulna

Ulna

Medial forearm bone located on little finger side

Radius

Lateral forearm bone located on thumb side

Olecranon

Proximal process of ulna forming point of elbow

Olecranon Fossa

Distal humerus depression that receives olecranon during extension

Trochlear Notch

Deep ulnar depression forming hinge joint with humerus trochlea

Carpal Bones

Eight small wrist bones arranged in two rows of four

Metacarpal Bones

Five bones forming palm framework with distal ends as knuckles

Phalanges

Fourteen finger or toe bones in each hand or foot

Os Coxae

Hip bone formed by fusion of ilium ischium and pubis

Ilium

Upper flared portion of hip bone

Iliac Crest

Curved superior border rim of ilium felt below waist

Anterior Superior Iliac Spine

Prominent bony projection at anterior end of iliac crest

Ischium

Lowest and strongest portion of pelvic hip bone

Ischial Spine

Posterior pelvic projection used as reference point in childbirth

Ischial Tuberosity

Large projection supporting body weight while sitting

Pubis

Anterior part of os coxae hip bone

Pubic Symphysis

Anterior joint uniting two hip bones that relaxes in pregnancy

Acetabulum

Deep socket formed by three pelvic bones holding femur head

Obturator Foramen

Large opening in hip bone partially covered by membrane

Female Pelvis

Pelvic shape lighter in weight with wider ilia and broader pubic arch

Femur

Thigh bone that is longest and strongest bone in body

Greater Trochanter

Large lateral femur projection used as anatomical landmark

Linea Aspera

Long central posterior ridge on femur for muscle attachment

Patella

Kneecap embedded in quadriceps tendon as sesamoid bone

Tibia

Medial weight bearing shin bone of leg

Fibula

Slender lateral non weight bearing leg bone

Medial Malleolus

Distal tibia projection forming inner ankle bump

Lateral Malleolus

Distal fibula projection forming outer ankle bump

Calcaneus

Heel bone which is largest of seven tarsals

Talus

Tarsal bone articulating with tibia to form ankle joint

Metatarsal Bones

Five bones forming instep framework and ball of foot

Osteopenia

Condition of reduced bone mass that is less severe than osteoporosis

Osteoporosis

Metabolic disorder characterized by severe loss of bone tissue and increased fracture risk

Postmenopausal Osteoporosis

Common bone loss condition caused by decreased estrogen levels after menopause

Bisphosphonates

Class of bone strengthening drugs used to treat osteoporosis in postmenopausal females

Selective Estrogen Receptor Modulators

Drugs known as SERMs that activate estrogen receptors in bones to strengthen them

Paget Disease

Metabolic disorder resulting from excessive abnormal osteoclast and osteoblast activity

Osteitis Deformans

Another name for Paget disease of bone

Rickets

Condition in children caused by vitamin D or calcium deficiency leading to soft weak bones

Osteomalacia

Adult equivalent of rickets caused by vitamin D or calcium deficiency

Osteogenesis Imperfecta

Genetic disorder resulting in defective collagen production and brittle bones

Osteosarcoma

Malignant bone tumor occurring most commonly in young people around the knee

Chondrosarcoma

Malignant tumor arising in cartilage tissue usually appearing in midlife

Osteomyelitis

Inflammation of bone and bone marrow caused by pyogenic bacteria

Pott Disease

Tuberculosis infection of the spine causing weakened and collapsed vertebrae

Kyphosis

Exaggeration of the thoracic spinal curve commonly called hunchback

Lordosis

Excessive lumbar spinal curve commonly called swayback

Scoliosis

Abnormal lateral curvature of the vertebral column

Cleft Palate

Congenital failure of maxillary bones to fuse resulting in an open roof of mouth

Closed Fracture

Simple bone break with no open wound in skin

Open Fracture

Broken bone that protrudes through skin or involves an external wound

Greenstick Fracture

Bone break where one side is broken and other side is bent

Impacted Fracture

Bone fracture where broken ends are jammed tightly into each other

Comminuted Fracture

Bone fracture where bone is splintered crushed or broken in multiple places

Spiral Fracture

Bone fracture resulting from a twisting force often seen in skiing accidents

Transverse Fracture

Bone fracture that extends straight across the axis of bone

Oblique Fracture

Bone fracture occurring at an angle across the bone shaft

Articulation

Area of junction or union between two or more bones

Joint

An articulation or junction between two or more bones

Synarthrosis

Immovable joint tightly held together usually by fibrous tissue

Fibrous Joint

Joint connected by fibrous tissue such as skull sutures

Amphiarthrosis

Slightly movable joint typically joined by cartilage or fibrous tissue

Cartilaginous Joint

Joint joined by cartilage such as intervertebral discs

Diarthrosis

Freely movable joint containing a joint cavity filled with synovial fluid

Synovial Joint

Another term for diarthrosis characterized by a joint cavity and lubricating fluid