Chapter 6: Skeletal System Bones And Joints

Front 1

Collagen

Back 1

ropelike protein of the extracellular matrix

Front 2

Proteoglycans

Back 2

large molecules consisting of polysaccharides attached to core proteins. attract and retain large amounts of water.

Front 3

tendons

Back 3

tough connective tissue band connecting a muscle to a bone.

Front 4

ligaments

Back 4

tough connective tissue band usually connecting bone to bone

Front 5

cartilage

Back 5

firm, smooth, resilient, nonvascular connective tissue

Front 6

long bones

Back 6

longer than wide. upper and lower limbs

Front 7

short bones

Back 7

broad as they are long; in wrist and ankles

Front 8

Flat bones

Back 8

thin, flattened shape; skull, ribs, scapulae, sternum

Front 9

Irregular bones

Back 9

vertebrae and facial bones

Front 10

diaphysis

Back 10

shaft of a long bone

Front 11

epiphysis

Back 11

end of a bone; separated from the remainder of the bone by the epiphyseal plate or epiphyseal line.

Front 12

articular cartilage

Back 12

covers the ends of the epiphyses where the bone articulates with other bones. acts as a cushion.

Front 13

epiphyseal plate

Back 13

Site at which bone growth in length occurs; located between the epiphysis and diaphysis of a long bone; area of cartilage growth is followed by ossification; also called the growth plate

Front 14

epiphyseal line

Back 14

Dense plate of bone in a bone that is no longer growing, indicating the former site of the epiphyseal plate.

Front 15

medullary cavity

Back 15

large, marrow-filled cavity in the diaphysis of a long bone

Front 16

marrow

Back 16

soft tissue in center of bone

Front 17

Yellow marrow

Back 17

consists mostly of adipose tissue

Front 18

Red marrow

Back 18

blood-forming cells; children have more

Front 19

periosteum

Back 19

thick, double layered connective tissue sheath covering the entire surface of a bone, except the articular surface, which is covered by cartilage

Front 20

endosteum

Back 20

membranous lining of the medullary cavity and the cavities of spongy bone.

Front 21

osteoblasts

Back 21

cell that makes bone

Front 22

osteocytes

Back 22

mature bone cell surrounded by bone matrix

Front 23

lamellae

Back 23

thin sheet or layer of bone

Front 24

lacunae

Back 24

small space, cavity, or depression; a space in cartilage in which a chondrocyte is located; a space in bone matrix in which an osteocyte is located;

Front 25

canaliculi

Back 25

tiny canal in bone between osteocytes containing osteocyte cell processes; a cleftlike lumen between the cells of each hepatic cord, connects medial corner of the eye to the lacrimal sac.

Front 26

compact bone

Back 26

Bone that is denser and has fewer spaces than spongy bone

Front 27

spongy bone

Back 27

Bone with a latticelike appearance.

Front 28

central canal

Back 28

small canal containing blood vessels, nerves, and loose connective tissue and running parallel to the long axis of a bone; also called a haversian canal.

Front 29

osteon

Back 29

single central canal, with its contents, and the associated lamellae and osteocytes surrounding it. Also called a haversian system.

Front 30

trabeculae

Back 30

spongy bone consists of delicate interconnecting rods or plates of bone; resemble the beams or scaffolding of a building; add strength without adding weight

Front 31

ossification

Back 31

bone formation

Front 32

intramembranous ossification

Back 32

bone formation within connective tissue membranes.

Front 33

ossification centers

Back 33

osteoblasts line up on the surface of connective tissue fibers and begin depositing bone matrix to form trabeculae; process begins in these areas

Front 34

endochondral ossification

Back 34

bone formation within cartilage

Front 35

chondrocytes

Back 35

cartilage cells

Front 36

primary ossification center

Back 36

center part of the diaphysis, where bone first begins to appear

Front 37

osteoclasts

Back 37

cell that digests and removes bone

Front 38

secondary ossification centers

Back 38

form in the epiphyses

Front 39

bone remodeling

Back 39

involves the removal of existing bone by osteoclasts and the deposition of new bone by osteoblasts; responsible for changes in bone shape, the adjustment of bone to stress, bone repair, and calcium ion regulation in body fluids.

Front 40

parathyroid hormone

Back 40

hormone produced by the parathyroid gland; increases bone breakdown and blood calcium levels.

Front 41

calcitonin

Back 41

hormone released from cells of the thyroid gland, that acts on tissues, especially bone to cause a decrease in blood levels of calcium ions

Front 42

foramen

Back 42

hole; referring to a hole or opening in a bone.

Front 43

hydroxyapatite

Back 43

most of the mineral in bone; form of calcium phosphate crystals

Front 44

canal/meatus

Back 44

elongated hole, a tunnel-like passage through the bone

Front 45

fossa

Back 45

Depression below the level of the surface of a bone; usually longitudinal in shape.

Front 46

tubercle

Back 46

lump or knob on a bone

Front 47

tuberosity

Back 47

lump on a bone, usually larger than a tubercle

Front 48

process

Back 48

projection on a bone

Front 49

condyle

Back 49

rounded, articulating surface of a joint

Front 50

braincase

Back 50

encloses the cranial cavity; consists of 8 bones that immediately surround and protect the brain

Front 51

facial bones

Back 51

form the structure of the face

Front 52

parietal bones

Back 52

form the sides and roof of the cranium. Each bone is roughly quadrilateral in form, and has two surfaces, four borders, and four angles.

Front 53

temporal bones

Back 53

situated at the sides and base of the skull, and lateral to the temporal lobes of the cerebrum.

Front 54

squamous suture

Back 54

arches backward from the pterion and connects the temporal squama with the lower border of the parietal bone: this suture is continuous behind with the short, nearly horizontal parietomastoid suture, which unites the mastoid process of the temporal with the region of the mastoid angle of the parietal bone.

Front 55

frontal bone

Back 55

a bone in the human skull. The name comes from the Latin word frons (meaning "forehead"). The bone resembles a cockleshell in form, and consists of three portions:[1]
a large vertical portion, the squama frontalis, corresponding with the region of the forehead.
an orbital or horizontal portion, the pars orbitalis, which enters into the formation of the roofs of the orbital and nasal cavities.
a nasal portion, it articulates with the nasal bones and the frontal process of the maxilla to form the root of the nose.

Front 56

coronal suture

Back 56

a dense, fibrous connective tissue joint that separates the frontal and parietal bones of the skull. At birth, the bones of the skull do not meet.

Front 57

occipital bone

Back 57

a saucer-shaped membrane bone situated at the back and lower part of the cranium, is trapezoidal in shape and curved on itself. It is pierced by a large oval aperture, the foramen magnum, through which the cranial cavity communicates with the vertebral canal.
The curved, expanded plate behind the foramen magnum is named the squama occipitalis.
The thick, somewhat quadrilateral piece in front of the foramen is called the basilar part of occipital bone.
On either side of the foramen are the lateral parts of occipital bone.

Front 58

lambdoid suture

Back 58

a dense, fibrous connective tissue joint on the posterior aspect of the skull that connects the parietal and temporal bones with the occipital bone.
Its name comes from its lambda-like shape.

Front 59

external auditory canal

Back 59

a tube running from the outer ear to the middle ear. The adult human ear canal extends from the pinna to the eardrum and is about 2.5 centimetres (1 in) in length and 0.7 centimetres (0.3 in) in diameter.

Front 60

mastoid process

Back 60

a conical prominence projecting from the undersurface of the mastoid portion of the temporal bone. It is located just behind the external acoustic meatus, and lateral to the styloid process. Its size and form vary somewhat; it is larger in the male than in the female. This part of the skull projects from the temporal bone and is roughly pyramidal or conical in shape. One important role for this bone is as a point of attachment for several muscles - the splenius capitis, longissimus capitis, digastric posterior belly, and sternocleidomastoid. These muscles are one reason the mastoid process tends to be larger in men, because men have bigger muscles as a general rule and thus require larger points of attachment.

Front 61

sphenoid bone

Back 61

an unpaired bone situated at the front middle of the skull in front of the temporal bone and basilar part of the occipital bone. The sphenoid bone is one of the seven bones that articulate to form the orbit. Its shape somewhat resembles that of a butterfly or bat with its wings extended. It is divided into the following parts:
a median portion, known as the body of sphenoid bone, containing the sella turcica which houses the pituitary gland
two greater wings and two lesser wings
Pterygoid processes of the sphenoides which project from it posteriorly (below)

Front 62

zygomatic bone

Back 62

a paired bone which articulates with the maxilla, the temporal bone, the sphenoid bone and the frontal bone. The zygomatic is homologous to the jugal bone of other tetrapods. It is situated at the upper and lateral part of the face and forms the prominence of the cheek, part of the lateral wall and floor of the orbit, and parts of the temporal and infratemporal fossa. It presents a malar and a temporal surface; four processes, the frontosphenoidal, orbital, maxillary, and temporal; and four borders.

Front 63

zygomatic arch

Back 63

formed by the zygomatic process of temporal bone (a bone extending forward from the side of the skull, over the opening of the ear) and the temporal process of the zygomatic bone (the side of the cheekbone), the two being united by an oblique suture;[1] the tendon of the Temporalis passes medial to the arch to gain insertion into the coronoid process of the mandible.

Front 64

maxilla

Back 64

a fusion of two bones along the palatal fissure that form the upper jaw. The maxilla assists in forming the boundaries of three cavities:
the roof of the mouth
the floor and lateral wall of the nasal antrum
the wall of the orbit

Front 65

mandible

Back 65

a bone forming the skull with the cranium. The mandible consists of:
a curved, horizontal portion, the body. (See body of mandible).
two perpendicular portions, the rami, which unite with the ends of the body nearly at right angles. (See ramus mandibulae). The angle formed at this junction is called gonial angle.
Alveolar process, the tooth bearing area of the mandible (upper part of the body of the mandible)
Condyle, superior (upper) and posterior projection from the ramus, which makes the temporomandibular joint with the temporal bone
Coronoid process, superior and anterior projection from the ramus. This provides attachment to the temporalis muscle.

Front 66

orbits

Back 66

he cavity or socket of the skull in which the eye and its appendages are situated. "Orbit" can refer to the bony socket, or it can also be used to imply the contents. In the adult human, the volume of the orbit is 30 ml, of which the eye occupies 6.5 ml. The base, which opens in the face, has four borders. The following bones take part in their formation:
Superior margin: frontal bone
Inferior margin: maxilla and zygomatic
Medial margin: frontal, lacrimal and maxilla
Lateral margin: zygomatic and frontal

Front 67

nasal cavity

Back 67

cavity divided by the nasal septum and extending from the external nares anteriorly to the nasopharynx posteriorly; bounded inferiorly by the hard palate.

Front 68

superior and inferior orbital fissures

Back 68

foramen in the skull, although strictly it is more of a cleft, lying between the lesser and greater wings of the sphenoid bone. transmits the maxillary nerve and its zygomatic branch, and the ascending branches from the pterygopalatine ganglion. The infraorbital vessels are found in the inferior orbital fissure, and travel down the infraorbital groove into the infraorbital canal and exit through the infraorbital foramen.
It is formed by the sphenoid bone and maxilla.

Front 69

optic foramen

Back 69

The superior surface of the sphenoid bone is bounded behind by a ridge, which forms the anterior border of a narrow, transverse groove, the chiasmatic groove (optic groove), above and behind which lies the optic chiasma; the groove ends on either side in the optic foramen, which transmits the optic nerve and ophthalmic artery (with accompanying sympathetic nerve fibres) into the orbital cavity.

Front 70

nasolacrimal canal

Back 70

The canal containing the nasolacrimal duct. It is formed by indentations in the inferior nasal conchae, maxilla and lacrimal bone. It drains to into the nasal cavity through the anterior portion of the inferior meatus which is between the inferior concha and the floor of the nasal cavity.

Front 71

lacrimal bone

Back 71

the smallest and most fragile bone of the face, is situated at the front part of the medial wall of the orbit. It has two surfaces and four borders.

Front 72

nasal septum

Back 72

separates the left and right airways in the nose, dividing the two nostrils. It is depressed by the Depressor septi nasi muscle. composed of five structures:
perpendicular plate of ethmoid bone
vomer bone
cartilage of the septum
crest of the maxillary bone
crest of the palatine bone

Front 73

vomer

Back 73

one of the unpaired facial bones of the skull. It is located in the midsagittal line, and articulates with the sphenoid, the ethmoid, the left and right palatine bones, and the left and right maxillary bones.

Front 74

perpendicular plate

Back 74

a thin, flattened lamina, polygonal in form, which descends from the under surface of the cribriform plate, and assists in forming the septum of the nose; it is generally deflected a little to one or other side. The anterior border articulates with the spine of the frontal bone and the crest of the nasal bones.

Front 75

ethmoid bone

Back 75

a bone in the skull that separates the nasal cavity from the brain. It is located at the roof of the nose, between the two orbits. The cubical bone is lightweight due to a spongy construction. The ethmoid bone is one of the bones that makes up the orbit of the eye. The ethmoid has three parts: the cribriform plate, the ethmoidal labyrinth, and the perpendicular plate.

Front 76

nasal bones

Back 76

two small oblong bones, varying in size and form in different individuals; they are placed side by side at the middle and upper part of the face, and form, by their junction, "the bridge" of the nose.
Each has two surfaces and four borders.

Front 77

nasal conchae

Back 77

a long, narrow and curled bone shelf (shaped like an elongated sea-shell) that protrudes into the breathing passage of the nose. the turbinates divide the nasal airway into four groove-like air passages, and are responsible for forcing inhaled air to flow in a steady, regular pattern around the largest possible surface of cilia and climate-controlling tissue. A rapidly dilating arteriolar circulation to these bones may lead to a sharp increase in the pressure within in response to acute cooling of the body core - the pain from this pressure is often referred to as "brain freeze", and is frequently associated with the rapid consumption of ice cream.

Front 78

Paranasal sinuses

Back 78

a group of four paired air-filled spaces that surround the nasal cavity (maxillary sinuses), above the eyes (frontal sinuses), between the eyes (ethmoid sinuses), and behind the ethmoids (sphenoid sinuses). The sinuses are named for the facial bones in which they are located.

Front 79

mastoid air cell

Back 79

A section of the mastoid process of the temporal bone of the cranium shows it to be hollowed out into a number of spaces. exhibit great variety in their size and number.

Front 80

foramen magnum

Back 80

a large opening in the occipital bone of the cranium. It is one of the several oval or circular apertures in the base of the skull (the foramina), through which the medulla oblongata (an extension of the spinal cord) enters and exits the skull vault.
Apart from the transmission of the medulla oblongata and its membranes, the foramen magnum transmits the spinal accessory nerve, vertebral arteries, the anterior and posterior spinal arteries, the membrana tectoria and alar ligaments.

Front 81

sella turcica

Back 81

a saddle-shaped depression in the sphenoid bone of the human skull and of the skulls of other Hominidae including chimpanzees, orangutans, and gorillas. The seat of the saddle is known as the hypophyseal fossa, which holds the pituitary gland. The hypophyseal fossa is located in a depression in the body of the sphenoid bone. Located anteriorly to the hypophyseal fossa is the tuberculum sellae.
Completing the formation of the saddle posteriorly is the dorsum sellae which is continuous with the clivus, inferoposteriorly. The dorsum sellae is terminated laterally by the posterior clinoid processes.

Front 82

occipital condyles

Back 82

undersurface facets of the occipital bone in vertebrates, which function in articulation with the superior facets of the atlas vertebra.

Front 83

styloid processes

Back 83

usually serving as points of attachment for muscles, refers to the slender, pointed process (protrusion) of :
temporal bone of the skull - Temporal styloid process
radius bone of the lower arm - Radial styloid process
ulna bone of the lower arm - Ulnar styloid process
Third metacarpal - Third metacarpal styloid process
Tibia and Fibula - Tibial process, fibular process.

Front 84

mandibular fossa

Back 84

the depression in the temporal bone that articulates with the mandibular condyle. In the temporal bone, the mandibular fossa is bounded, in front, by the articular tubercle; behind, by the tympanic part of the bone, which separates it from the external acoustic meatus; it is divided into two parts by a narrow slit, the petrotympanic fissure (Glaserian fissure). The mandibular fossa is also referred to as the glenoid fossa, especially in dental literature.

Front 85

hard palate

Back 85

a thin horizontal bony plate of the skull, located in the roof of the mouth. It spans the arch formed by the upper teeth.
It is formed by the palatine process of the maxilla and horizontal plate of palatine bone.
It forms a partition between the nasal passages and the mouth. Also on the anterior portion of the roof of the hard palate is the Rugae which are the irregular ridges in the mucous membrane that help facilitate the movement of food backwards towards the pharynx. This partition is continued deeper into the mouth by a fleshy extension called the soft palate.

Front 86

palatine bones

Back 86

It is situated at the back part of the nasal cavity between the maxilla and the pterygoid process of the sphenoid. The human palatine articulates with six bones: the sphenoid, ethmoid, maxilla, inferior nasal concha, vomer and opposite palatine.

Front 87

soft palate

Back 87

the soft tissue constituting the back of the roof of the mouth. distinguished from the hard palate at the front of the mouth in that it does not contain bone.

Front 88

hyoid bone

Back 88

a horseshoe-shaped bone situated in the anterior midline of the neck between the chin and the thyroid cartilage. At rest, it lies at the level of the base of the mandible in the front and the third cervical vertebra (C3) behind.
Unlike other bones, the hyoid is only distantly articulated to other bones by muscles or ligaments. The hyoid is anchored by muscles from the anterior, posterior and inferior directions, and aids in tongue movement and swallowing.

Front 89

vertebral column

Back 89

the vertebral column usually consists of 24 articulating vertebrae,[1] and 9 fused vertebrae in the sacrum and the coccyx. It is situated in the dorsal aspect of the torso, separated by intervertebral discs. It houses and protects the spinal cord in its spinal canal, and hence is commonly called the spine, or simply backbone.
There are normally thirty-three (33) vertebrae in humans, including the five that are fused to form the sacrum (the others are separated by intervertebral discs) and the four coccygeal bones that form the tailbone.

Front 90

cervical vertebrae

Back 90

vertebrae immediately inferior to the skull. first seven.

Front 91

thoracic vertebrae

Back 91

the middle segment of the vertebral column, between the cervical vertebrae and the lumbar vertebrae.[1] In humans, they are intermediate in size between those of the cervical and lumbar regions; they increase in size as one proceeds down the spine, the upper vertebrae being much smaller than those in the lower part of the region. the first one (T1) located closest to the skull and higher numbered vertebrae (T2-T12) proceeding away from the skull and down the spine.

Front 92

lumbar vertebrae

Back 92

the five vertebrae between the rib cage and the pelvis. They are the largest segments of the vertebral column and are characterized by the absence of the foramen transversarium within the transverse process, and by the absence of facets on the sides of the body. They are designated L1 to L5, starting at the top. The lumbar vertebrae help support the weight of the body, and permit movement.

Front 93

sacral bone

Back 93

a large, triangular bone at the base of the spine and at the upper and back part of the pelvic cavity, where it is inserted like a wedge between the two hip bones. Its upper part connects with the last lumbar vertebra, and bottom part with the coccyx (tailbone). It consists of usually five initially unfused vertebrae which begin to fuse between ages 16–18 and are usually completely fused into a single bone by age 34.

Front 94

coccygeal bone

Back 94

the final segment of the vertebral column in tailless primates. Comprising three to five separate or fused vertebrae (the coccygeal vertebrae) below the sacrum, it is attached to the sacrum by a fibrocartilaginous joint, the sacrococcygeal symphysis, which permits limited movement between the sacrum and the coccyx.

Front 95

Kyphosis

Back 95

condition of over-curvature of the thoracic vertebrae (upper back). It can be either the result of degenerative diseases (such as arthritis), developmental problems (the most common example being Scheuermann's disease), osteoporosis with compression fractures of the vertebrae, or trauma.
In the sense of a deformity, it is the pathological curving of the spine, where parts of the spinal column lose some or all of their lordotic profile. This causes a bowing of the back, seen as a slouching posture.

Front 96

Lordosis

Back 96

the inward curvature of a portion of the lumbar and cervical vertebral column.[1] Two segments of the vertebral column, namely cervical and lumbar, are normally lordotic, that is, they are set in a curve that has its convexity anteriorly (the front) and concavity posteriorly (behind), in the context of human anatomy.

Front 97

Scoliosis

Back 97

a medical condition in which a person's spine is curved from side to side. Although it is a complex three-dimensional deformity, on an X-ray, viewed from the rear, the spine of an individual with scoliosis may look more like an "S" or a "C", rather than a straight line.

Front 98

intervertebral disks body

Back 98

lie between adjacent vertebrae in the spine. Each disc forms a cartilaginous joint to allow slight movement of the vertebrae, and acts as a ligament to hold the vertebrae together. Discs consist of an outer annulus fibrosus, which surrounds the inner nucleus pulposus. The annulus fibrosus consists of several layers of fibrocartilage. The strong annular fibers contain the nucleus pulposus and distribute pressure evenly across the disc. The nucleus pulposus contains loose fibers suspended in a mucoprotein gel with the consistency of jelly. The nucleus of the disc acts as a shock absorber, absorbing the impact of the body's daily activities and keeping the two vertebrae separated. The disc can be likened to a jelly doughnut

Front 99

vertebral arch

Back 99

the posterior part of a vertebra.
It consists of a pair of pedicles and a pair of laminae, and supports seven processes:
four articular processes
two transverse processes
one spinous process

Front 100

vertebral foramen

Back 100

the foramen (opening) formed by the anterior segment (the body), and the posterior part, the vertebral arch.
The vertebral foramen begins at cervical vertebra #1 (atlas) and continues inferior to lumbar vertebra #5. Within this foramen the spinal cord and associated meninges are housed.

Front 101

vertebral canal

Back 101

the space in vertebrae through which the spinal cord passes. It is a process of the dorsal human body cavity. This canal is enclosed within the vertebral foramen of the vertebrae. In the intervertebral spaces, the canal is protected by the ligamentum flavum posteriorly and the posterior longitudinal ligament anteriorly.

Front 102

pedicles

Back 102

two short, thick processes, which project dorsally, one on either side, from the superior part of the vertebral body at the junction of its posterior and lateral surfaces. They connect the body of the spinal vertebra to the arch. It is often used as a radiographic marker and entry point in vertebroplasty, kyphoplasty, and spinal fusion procedures.

Front 103

laminae

Back 103

two broad plates, extending dorsally and medially from the pedicles, fusing to complete the roof of the vertebral arch.

Front 104

transverse process

Back 104

project one at either side from the point where the lamina joins the pedicle, between the superior and inferior articular processes. They serve for the attachment of muscles and ligaments.

Front 105

spinous process

Back 105

directed backward and downward from the junction of the laminae (in humans), and serves for the attachment of muscles and ligaments

Front 106

intervertebral foramina

Back 106

articulated with each other the bodies form a strong pillar for the support of the head and trunk, and the vertebral foramina constitute a canal for the protection of the medulla spinalis (spinal cord). Between every pair of vertebrae are two apertures (openings),

Front 107

articular process

Back 107

projections of the vertebra that serve the purpose of fitting with an adjacent vertebra. The actual region of contact is called the articular facet.[1]
Articular processes spring from the junctions of the pedicles and laminæ, and there are two right and left, and two superior and inferior. These stick out of an end of a vertebra to lock with a zygapophysis on the next vertebra, to make the backbone more stable.
The superior processes or prezygapophysis project upward from a lower vertebra, and their articular surfaces are directed more or less backward.
The inferior processes or postzygapophysis project downward from a higher vertebra, and their articular surfaces are directed more or less forward and outward.
The articular surfaces are coated with hyaline cartilage.

Front 108

articular facet

Back 108

a surface where two anatomical structures (usually bones) meet.

Front 109

atlas

Back 109

the most superior (first) cervical vertebra of the spine.

Front 110

axis

Back 110

It forms the pivot upon which the first cervical vertebra (the atlas), which carries the head, rotates. the second cervical vertebra.

Front 111

dens

Back 111

a protuberance (process or projection) of the axis (second cervical vertebra). It exhibits a slight constriction or neck, where it joins the main body of the vertebra. The condition, where the dens is separated from the body of the axis, is called os odontoideum, and may cause nerve and circulation compression syndrome.

Front 112

median sacral crest

Back 112

surmounted by three or four tubercles, the rudimentary spinous processes of the upper three or four sacral vertebrae.

Front 113

sacral hiatus

Back 113

The laminae of the fifth sacral vertebra, and sometimes those of the fourth, fail to meet behind, and thus a sacral hiatus occurs in the posterior wall of the sacral canal.

Front 114

sacral promontory

Back 114

the anatomical term for the superiormost portion of the sacrum. It marks part of the border of the pelvic inlet. The rectosigmoid junction is at the level of the sacral promontory.

Front 115

thoracic cage

Back 115

a bony and cartilaginous structure which surrounds the thoracic cavity and supports the pectoral girdle, forming a core portion of the human skeleton. A typical human rib cage consists of 24 ribs, the sternum (with Xiphoid process), costal cartilages, and the 12 thoracic vertebrae. It, along with the skin and associated fascia and muscles, makes up the thoracic wall and provides attachments for the muscles of the neck, thorax, upper abdomen, and back.

Front 116

true ribs

Back 116

The first seven ribs are connected posteriorly with the vertebral column, and anteriorly, through the intervention of the costal cartilages, with the sternum

Front 117

false ribs

Back 117

interconnected membranous structures that are connected with the sternum process.

Front 118

floating ribs

Back 118

four atypical ribs (two lowermost pairs, XI-XII) in the human ribcage. They are called so because they are attached to the vertebrae only, and not to the sternum or cartilage coming off the sternum.

Front 119

sternum

Back 119

breastbone

Front 120

manubrium

Back 120

the broad, upper part of the sternum. Located ventrally with a quadrangular shape, wider superiorly and narrower inferiorly, it articulates with the clavicles and the cartilages of the first pair of ribs.

Front 121

xiphoid process

Back 121

a small cartilaginous process (extension) of the lower part of the sternum which is usually ossified in the adult human. By age 15 to 29, the xiphoid usually fuses to the body of the sternum with a fibrous joint.

Front 122

jugular notch

Back 122

found at the superior border of the manubrium of the sternum, between the clavicular notches

Front 123

sternal angle

Back 123

the anterior angle formed by the junction of the manubrium and the body of the sternum[1] (the manubriosternal junction) in the form of a secondary cartilaginous joint (symphysis). This is also called the manubriosternal joint or Angle of Louis. The sternal angle is a palpable clinical landmark.

Front 124

appendicular

Back 124

relating to an appendage, such as the limbs and their associated girdles

Front 125

pectoral girdle

Back 125

the set of bones which connects the upper limb to the axial skeleton on each side. It consists of the clavicle and scapula in humans and, in those species with three bones in the pectoral girdle, the coracoid

Front 126

scapula

Back 126

shoulder blade

Front 127

glenoid cavity

Back 127

part of the shoulder. It is a shallow pyriform, articular surface, which is located on the lateral angle of the scapula. It is directed laterally and forward and articulates with the head of the humerus; it is broader below than above and its vertical diameter is the longest.

Front 128

spine

Back 128

a ridge that runs across the posterior surface of the scapula.

Front 129

acromion process

Back 129

extends from the scapular spine to form the point of the shoulder

Front 130

clavicle

Back 130

articulates with the scapula at the acromion process. the proximal end is attached to the sternum providing the only bony attachment of the scapula to the reminder of the skeleton.

Front 131

coracoid process

Back 131

curves below the clavicle and provides for the attachment of arm and chest muscles

Front 132

arm

Back 132

the region between the shoulder and the elbow

Front 133

humerus

Back 133

a long bone in the arm or forelimb that runs from the shoulder to the elbow.
onnects the scapula and the lower arm (consisting of the radius and ulna), and consists of three sections. The upper extremity consists of a rounded head, a narrow neck, and two short processes (tubercles, sometimes called tuberosities.) Its body is cylindrical in its upper portion, and more prismatic below. The lower extremity consists of 2 epicondyles, 2 processes (trochlea & capitulum), and 3 fossae (radial fossa, coronoid fossa, and olecranon fossa). As well as its true anatomical neck, the constriction below the greater and lesser tubercles of the humerus is referred to as its surgical neck due to its tendency to commonly get fractured, thus often becoming the focus of surgeons.

Front 134

head

Back 134

proximal end of the humerus. smooth, rounded. attaches the humerus to the scapula at the glenoid cavity

Front 135

greater tubercle

Back 135

situated lateral to the head of the humerus and posterolateral to the lesser tubercle.

Front 136

lesser tubercle

Back 136

more prominent than the greater tubercle: it is situated in front, and is directed medially and anteriorly.

Front 137

deltoid tuberosity

Back 137

a rough, triangular area on the anterolateral (exterior-front) surface of the middle of the humerus to which the deltoid muscle attaches.

Front 138

epicondyles

Back 138

on the distal end of the humerus, just lateral to the condyles, provide attachment sites for forearm muscles

Front 139

forearm

Back 139

has two bones; ulna (medial) and radius (lateral)

Front 140

ulna

Back 140

one of the two long bones in the forearm, the other being the radius. It is prismatic in form and runs parallel to the radius, which is shorter and smaller. In anatomical position (i.e. when the arms are down at the sides of the body and the palms of the hands face forward) the ulna is located at the side of the forearm closest to the body (the medial side), the side of the little finger.

Front 141

radius

Back 141

one of the two large bones of the forearm, the other being the ulna. It extends from the lateral side of the elbow to the thumb side of the wrist and runs parallel to the ulna, which exceeds it in length and size. It is a long bone, prism-shaped and slightly curved longitudinally. The radius articulates with the capitulum of the humerus, the radial notch and the head of the ulna. The corresponding bone in the lower leg is the tibia.

Front 142

trochlear notch

Back 142

proximal end of the ulna. fits tightly over the end of the humerus, forming most of the elbow joint.

Front 143

olecranon process

Back 143

proximal to the trochlear notch, an extension of the ulna. felt as the point of the elbow.

Front 144

coronoid process

Back 144

distal to the trochlear notch. completes the grip of the ulna on the distal end of the humerus..

Front 145

styloid process

Back 145

the distal end of the ulna. located on medial side

Front 146

radial tuberosity

Back 146

distal to the radial head. biceps brachii attaches. articulates with the wrist bones.

Front 147

wrist

Back 147

eight carpal bones. two rows of four bones each.

Front 148

carpal bones

Back 148

eight bones of the wrist

Front 149

metacarpal bones

Back 149

attached to the carpal bones and form the bony framework of the hand. Align with five digits.

Front 150

digits

Back 150

thumb and fingers

Front 151

phalanges

Back 151

three small bones in each digit

Front 152

pelvic girdle

Back 152

place where lower limbs attach to the body.

Front 153

coxal bones

Back 153

a large, flattened, irregularly shaped bone, constricted in the center and expanded above and below. In some vertebrates (including humans) it is composed of three bones; ilium, ischium, and pubis.

Front 154

ilium

Back 154

the uppermost and largest bone of the pelvis,

Front 155

ischium

Back 155

the lower and back part of the hip bone

Front 156

pubis

Back 156

the ventral and anterior of the three principal bones composing either half of the pelvis.

Front 157

iliac crest

Back 157

the superior border of the wing of ilium and the superolateral margin of the greater pelvis

Front 158

anterior superior iliac spine

Back 158

refers to the anterior extremity of the iliac crest of the pelvis, which provides attachment for the inguinal ligament, and the sartorius muscle. The Tensor Fasciae Latae muscle attaches about 5cm away at the iliac tubercle.

Front 159

pubic symphysis

Back 159

he midline cartilaginous joint (secondary cartilaginous) uniting the superior rami of the left and right pubic bones. It is located anterior to the urinary bladder and superior to the external genitalia; for females it is above the vulva and for males it is above the penis.

Front 160

sacroiliac joints

Back 160

in the bony pelvis between the sacrum and the ilium of the pelvis, which are joined by strong ligaments. In humans, the sacrum supports the spine and is supported in turn by an ilium on each side. The joint is a strong, weight bearing synovial joint with irregular elevations and depressions that produce interlocking of the two bones. The human body has two sacroiliac joints, one on the left and one on the right, that often match each other but are highly variable from person to person.

Front 161

acetabulum

Back 161

a concave surface of the pelvis. The head of the femur meets with the pelvis at the acetabulum, forming the hip joint.

Front 162

obturator foramen

Back 162

he hole created by the ischium and pubis bones of the pelvis through which nerves and blood vessels pass.

Front 163

pelvic inlet

Back 163

a planar surface which defines the boundary between the pelvic cavity and the abdominal cavity (or, according to some authors, between two parts of the pelvic cavity, called lesser pelvis and greater pelvis).
Its position and orientation relative to the skeleton of the pelvis is anatomically defined by its edge, the pelvic brim. The pelvic brim is an approximately apple-shaped line passing through the prominence of the sacrum, the arcuate and pectineal lines, and the upper margin of the pubic symphysis.

Front 164

pelvic outlet

Back 164

The lower circumference of the lesser pelvis is very irregular; the space enclosed by it is named the inferior aperture or pelvic outlet.

Front 165

thigh

Back 165

the area between the pelvis and the knee.

Front 166

femur

Back 166

the most proximal (closest to the center of the body) bone of the leg. articulates with the acetabulum in the pelvic bone forming the hip joint, while the distal part of the femur articulates with the tibia and patella forming the knee joint.

Front 167

head

Back 167

the highest part of the thigh bone (femur). It is supported by the neck of the femur.

Front 168

condyles

Back 168

the round prominence at the end of a bone, most often part of a joint - an articulation with another bone

Front 169

epicondyles

Back 169

Front 170

trochanters

Back 170

large, irregular, quadrilateral eminence and a part of the skeletal system.
It is directed a little lateralward and backward, and, in the adult, is about 1 cm lower than the head. Because the pelvic outlet in the female is larger than in the male, there is a greater distance between the greater trochanters in the female.

Front 171

patella

Back 171

a thick, circular-triangular bone which articulates with the femur and covers and protects the anterior articular surface of the knee joint. It is the largest sesamoid bone in the human body.

Front 172

leg

Back 172

knee to ankle

Front 173

tibia

Back 173

the larger and stronger of the two bones in the leg below the knee in vertebrates (the other being the fibula), and connects the knee with the ankle bones. The tibia is named for the Greek aulos flute, also known as a tibia. Medial of the two leg bones

Front 174

fibula

Back 174

a leg bone located on the lateral side of the tibia, with which it is connected above and below. It is the smaller of the two bones, and, in proportion to its length, the most slender of all the long bones. Its upper extremity is small, placed toward the back of the head of the tibia, below the level of the knee joint, and excluded from the formation of this joint. Its lower extremity inclines a little forward, so as to be on a plane anterior to that of the upper end; it projects below the tibia, and forms the lateral part of the ankle joint.

Front 175

tibial tuberosity

Back 175

a large oblong elevation on the proximal, anterior aspect of the tibia, just below where the anterior surfaces of the lateral and medial tibial condyles end.

Front 176

medial malleolus

Back 176

the bony prominence on each side of the ankle. Formed by the tibia.

Front 177

lateral malleolus

Back 177

the prominence on the outer side of the ankle, formed by the lower end of the fibula.

Front 178

ankles

Back 178

consists of seven tarsal bones

Front 179

tarsal bones

Back 179

a cluster of seven articulating bones in each foot situated between the lower end of tibia and fibula of the lower leg and the metatarsus. In the foot the tarsus articulates with the bones of the metatarsus, which in turn articulate with the bones of the individual toes. The joint between the tibia and fibula above and the tarsus below is referred to as the ankle joint.
In humans the largest bone in the tarsus is the calcaneus, which is the weight-bearing bone within the heel of the foot.

Front 180

talus

Back 180

a bone in the collection of bones in the foot called the tarsus. The tarsus forms the lower part of the ankle joint through its articulations with the lateral and medial malleoli of the two bones of the lower leg, the tibia and fibula. Within the tarsus, it articulates with the calcaneus below and navicular in front within the talocalcaneonavicular joint. Through these articulations, it transmits the entire weight of the body to the foot.[2]
The second largest of the tarsal bones, it is also one of the bones in the human body with the highest percentage of its surface area covered by articular cartilage. Additionally, it is also unusual in that it has a retrograde blood supply, i.e. arterial blood enters the bone at the distal end.[citation needed]

Front 181

calcaneus

Back 181

a bone of the tarsus of the foot which constitute the heel.

Front 182

cuboid

Back 182

The dorsal surface, directed upward and lateralward, is rough, for the attachment of ligaments.
The plantar surface presents in front a deep groove, the peroneal sulcus, which runs obliquely forward and medialward; it lodges the tendon of the peroneus longus, and is bounded behind by a prominent ridge, to which the long plantar ligament is attached.
The ridge ends laterally in an eminence, the tuberosity, the surface of which presents an oval facet; on this facet glides the sesamoid bone or cartilage frequently found in the tendon of the peroneus longus. The surface of bone behind the groove is rough, for the attachment of the plantar calcaneocuboid ligament, a few fibers of the flexor hallucis brevis, and a fasciculus from the tendon of the tibialis posterior.
The lateral surface presents a deep notch formed by the commencement of the peroneal sulcus.
The posterior surface is smooth, triangular, and concavo-convex, for articulation with the anterior surface of the calcaneus (the calcaneocuboid joint); its infero-medial angle projects backward as a process which underlies and supports the anterior end of the calcaneus.
The anterior surface, of smaller size, but also irregularly triangular, is divided by a vertical ridge into two facets, forming the fourth and fifth tarsometatarsal joints: the medial facet, quadrilateral in form, articulates with the fourth metatarsal; the lateral, larger and more triangular, articulates with the fifth.
The medial surface is broad, irregularly quadrilateral, and presents at its middle and upper part a smooth oval facet, for articulation with the third cuneiform; and behind this (occasionally) a smaller facet, for articulation with the navicular bone; it is rough in the rest of its extent, for the attachment of strong interosseous ligaments.

Front 183

navicular

Back 183

located on the medial side of the foot, and articulates proximally with the talus, distally with the three cuneiform bones, and laterally with the cuboid.

Front 184

cuneiforms

Back 184

located between the navicular bone and the first, second and third metatarsal bones and are medial to the cuboid bone.

Front 185

metatarsal bones

Back 185

a group of five long bones in the foot located between the tarsal bones of the hind- and mid-foot and the phalanges of the toes. Lacking individual names, the metatarsal bones are numbered from the medial side (side of great toe): the first, second, third, fourth, and fifth metatarsal. The metatarsals are analogous to the metacarpal bones of the hand.

Front 186

arches

Back 186

formed by the positions of the tarsal bones and metatarsal bones and held in place by ligaments. two longitudinal arches extend from the heel to the ball of the foot and a transverse arch extends across the fott.

Front 187

joint

Back 187

a place where two bones come together. usually moveable.

Front 188

synarthrosis

Back 188

non moveable joint

Front 189

amphiarthrosis

Back 189

slightly moveable joint

Front 190

diathrosis

Back 190

freely moveable joint

Front 191

fibrous joints

Back 191

consist of two bones that are united by fibrous tissue and that exhibit little or no movement. 3 divisions: sutures, syndesmoses or gomphoses

Front 192

sutures

Back 192

fibrous joints between the bones of the skull

Front 193

fontanels

Back 193

one of several membranes gaps between bones of the skull

Front 194

syndesmoses

Back 194

fibrous joints in which the bones are separated by some distance and held together by ligaments.

Front 195

gomphoses

Back 195

consist of pegs fitted into sockets and held in place by ligaments. Ex tooth and socket.

Front 196

cartilaginous joints

Back 196

unite two bones by means of cartilage. only slight movement can occur at these joints. Ex. epiphyseal plates

Front 197

synovial joints

Back 197

freely movable joint

Front 198

articular cartilage

Back 198

efers to the hyaline cartilage on the articular surfaces of bones.
Though it is often found in close contact with menisci and articular disks, articular cartilage is not considered a part of either of these structures, which are made entirely of fibrocartilage.

Front 199

joint cavity

Back 199

filled with fluid. space between articular cartilage in joints.

Front 200

joint capsule

Back 200

an envelope surrounding a synovial joint. Each capsule consists of two layers:
an outer layer (stratum fibrosum) composed of avascular white fibrous tissue
an inner layer (stratum synoviale) which is a secreting layer, and is usually described separately as the synovial membrane.

On the inside of the capsule, articular cartilage covers the end surfaces of the bones that articulate within that joint.
The outer layer is highly innervated by the same nerves which perforate through the adjacent muscles associated with the joint.

Front 201

synovial membrane

Back 201

membrane that lines the inside of a joint cavity; produces synovial fluid.

Front 202

synovial fluid

Back 202

somewhat viscous substance serving as a lubricant in movable joints, tendon sheaths and bursae.

Front 203

bursa

Back 203

closed sac or pocket containing synovial fluid; usually found in areas where friction occurs.

Front 204

bursitis

Back 204

inflammation of a bursa

Front 205

tendon sheath

Back 205

Synovial membrane that is extended along some tendons associated with joints.

Front 206

plane joints

Back 206

consist of two opposed flat surfaces that glide over each other. Ex. vertebrae

Front 207

saddle joints

Back 207

consist of two saddle-shaped articulating surfaces oriented at right angles to each other. Ex. thumb

Front 208

hinge joints

Back 208

movement in one plane only. Convex cylinder of one bone applied to a corresponding concavity of the other bone. Ex. knee and elbow

Front 209

menisci

Back 209

shock absorbing fibrocartilage pads

Front 210

pivot joints

Back 210

restrict movement to rotation around a single axis. Ex. shaking head no.

Front 211

ball and socket joints

Back 211

consist of a ball at the end of oen bone and a socket in an adjacent bone into which a portion of the ball fits. Ex. shoulder and hip joints

Front 212

ellipsoid joints

Back 212

elongated ball and socket joints. Ex atlas and occipital bone

Front 213

flexion

Back 213

moves a part of the body in the anterior direction from the frontal plane.

Front 214

extension

Back 214

moves a part in the posterior direction from the frontal plane.

Front 215

plantar flexion

Back 215

movement of the foot toward the plantar surface

Front 216

dorsiflexion

Back 216

movement of the foot toward the shin

Front 217

abduction

Back 217

movement away from the median or midsagittal plane.

Front 218

adduction

Back 218

movement toward the median plane

Front 219

pronation

Back 219

a rotational movement of the forearm at the radioulnar joint, or of the foot at the subtalar and talocalcaneonavicular joints.[1][2] For the forearm, when standing in the anatomical position, pronation will move the palm of the hand from an anterior-facing position to a posterior-facing position without an associated movement at the shoulder (glenohumeral joint). This corresponds to a counterclockwise twist for the right forearm and a clockwise twist for the left (when viewed superiorly). For the foot, pronation will cause the sole of the foot to face more laterally than when standing in the anatomical position. Pronation is the opposite of supination.

Front 220

supination

Back 220

a position of either the forearm or foot. When the arms are unbent and at the sides, the forearm is in supination when the palm faces to the front (anteriorly), or faces up. Supination in the foot occurs when a person appears "bow-legged" with their weight supported primarily on the lateral side of their feet (5th Metatarsal)

Front 221

eversion

Back 221

turning the foot so that the plantar surface

Front 222

inversion

Back 222

turning the foot so that the plantar surface faces medially.

Front 223

rotation

Back 223

the turning of a structure around its long axis, as shaking the head no.

Front 224

circumduction

Back 224

occurs at freely movable joints, such as the shoulder. ex the arm moves so that it describes a cone with the shoulder joint at the apex.

Front 225

protraction

Back 225

a movement in which a structure, such as the mandible, glides anteriorly.

Front 226

retraction

Back 226

the structure glides posteriorly

Front 227

elevation

Back 227

movement of a structure in a superior direction.

Front 228

depression

Back 228

movement of a structure in an inferior direction. Opening the mouth involves depression of the mandible.

Front 229

excursion

Back 229

movement of a structure to one side, as in moving the mandible from side to side

Front 230

opposition

Back 230

a movement unique to the thumb and little finger. It occurs when the tips of the thumb and little finger are brought toward each other across the palm of the hand.

Front 231

reposition

Back 231

return digits to anatomical position.

Front 232

hyperextension

Back 232

If a part of the body such as a joint is overstretched or "bent backwards" because of exaggerated extension motion