Skeletal System (Definitions)

Support, Movement, Protection, Production of Blood Cells, and Maintenance of Electrolyte and Acid/Base Balance

functions of skeletal system

Bones

major organ of the skeletal system

Ligaments and Cartilages

Accessory Organs of the Skeletal System

80

The axial skeleton has ______ bones of the head, neck, and trunk

126

The appendicular skeleton has ______ bones of the arms and legs and the bones of the pectoral and pelvic girdle

Long Bones

classification of a bone that are longer than they are wide

Femur, Fibula, Tibia, Metatarsal, Phalanges, Humerus, Radius, Ulna, Metacarpal

example of long bones

Short Bones

classification of the bone that is cuboidal-like, length and width are equally proportional

Carpal and Tarsal

example of short bones

Flat Bones

classification of a bone that is almost sheet-like, not rounded and are thin

Skull, Sternum, and Ribs

examples of flat bones

Irregular Bones

classification of bones that are uniquely and irregularly shaped based on the function they serve

vertebrae column and pelvis

example of irregular bones

Sesamoid Bones

classification of bones that are embedded within a muscle formed in response to strain

Patella

example of sesamoid bone

FRONTAL BONE

anterior bone of the skull

PARIETAL BONE

makes up the sides and the roof of the skull

OCCIPITAL BONE

posterior portion of the skull; also the floor, with it at the base of the skull

TEMPORAL BONE

inferior to the parietal bones on the lateral side of the cranium; connected to the Temporomandibular Joint

Temporomandibular Joint

joint connecting the temporal bone and the mandible

Coronal Suture

suture that connects the frontal and parietal bones

Sagittal Suture

suture that connects the 2 parietal bones

Lambdoid Suture

suture that connects the occipital and parietal bones

Squamous Suture

suture that connects the temporal and parietal bones

Sphenoid Bone

forms part of the cranium floor, lateral posterior portions of the eye orbits, and lateral portions of the cranium anterior to the temporal bones

Sella turcica

Sphenoid bone contains ________________

Ethmoid Bone

anterior portion of the cranium, including the medial surface of the eye orbit and roof of the nasal cavity

Nasal Conchae

Ethmoid bone contains the ________________

External Auditory Meatus

ear canal; leads to the eardrum and middle ear; contains hammer, anvil, and stirrup

Malleus

hammer; transmits sound vibrations from the eardrum to the incus

Incus

anvil; passes sound vibrations from the malleus to the stapes

Stapes

stirrup; smallest bone in the body which transfers sound vibrations to the inner ear

Maxillae

forms the upper jaw, anterior portion of the hard palate, parts of the lateral walls of the nasal cavity and the floors of the eye orbits

Mandible

forms the lower jaw, the only movable skull bone

Lacrimal Bones

medial surfaces of the eye orbits

Zygomatic Bones

cheek bones; forms the floor and lateral walls of each eye orbit

Vomer

found at the midline of the nasal cavity; forms the septum with the ethmoid bone

Inferior Nasal Conchae

attached to the walls of the nasal cavity

Palatine Bones

forms the posterior portion of the hard palate and the lateral walls of the nasal cavity

The Spinal Cord

extends from skull to pelvis; flexible and sturdy longitudinal support for the trunk

24 movable vertebrae, Sacrum, Coccyx

what the spinal column contains

invertebral disks

shock absorbers

Scoliosis

abnormal lateral curvature

Kyphosis

hunchback; increase in the primary curvature

Lordosis

swayback; increase in the secondary curvature

Cervical Vertebra

has 7; supports the neck and possess a unique transverse foramen

Atlas

articulates occipital condyles of occipital bone and supports the head

Axis

possesses the odontoid process (dens) and serves as a pivot point for the atlas

Thoracic Vertebrae

larger vertebra with longer spinous process than the cervical vertebrae where ribs articulate on the facets of the transverse processes and bodies

Lumbar Vertebrae

have heavy and thick bodies to support greater stress and weight; has larger processes for attachment of back muscles

Sacrum

five fused sacral bones and forms the posterior wall of pelvic girdle

Coccyx

tailbone; 3-5 fused rudimentary vertebrae

Sternum

flat bone forming the anterior rib cage

Rib

12 pairs of bones attached to thoracic vertebrae

True Ribs

Ribs #1-#7 attached to sternum directly by coastal cartilages

False Ribs

ribs #8-#12 attach to coastal cartilage and small synovial joints of superior ribs

Floating Ribs

Ribs #11-#12 do not attach anteriorly, no coastal cartilages

Hyoid Bone

found in anterior portion of neck, inferior to mandible; does not articulate with any other bones; used as attachment site for tongue plans

2 clavicles and 2 scapulae

pectoral girdle is composed of:

Clavicle

articulate with sternum and scapula

Scapula

located on each side of vertebral column which is held in place by muscles to allow free shoulder movement

Humerus

arm bone that articulates with scapula (glenoid cavity) at shoulder joint and articulates with radius and ulna at elbow

Radius

lateral bone in the forearm which rotates when the hand is rotated; bony markings include the head and styloid process

Ulna

medial bone in forearm which does not move with hand rotation; bony markings include the olecranon, trochlear notch, and styloid process

Carpals

wrist bones

Metacarpals

bones of the palm of the hand

Phalanges

bones of the fingers

Pelvic Girdle

forms a rigid, bony pelvis, alongside the sacrum and coccyx (tailbone)

2 coxal (hip) bones

Pelvic Girdle is made up of:

Pubic Symphysis

where coxal bones are attached to one another

Ilium, Ischium, and Pubis

coxal (hip) bones that is made up of the fusion of 3 parts from the uppermost to the lowest

Female Pelvis

pelvis that is wider and more shallow, more rounded pelvic brim (oval), larger pelvic inlet/opening, and a curved pubic arch

Male Pelvis

pelvis that has a less rounded pelvic brim that has a smaller pelvic inlet/opening and has a sharp pubic arch

Femur

thigh bone that is the largest and strongest bone in the body — because it is responsible for handling all of the upper body weight

Patella

kneecap that is a sesamoid bone in the tendon that extends to the anterior knee

Tibia

shinbone; larger, medial bone of the lower leg and bears the body weight

Fibula

slender, lateral bone in the lower leg

Phalanges

J.

Tarsals

ankle bones

Metatarsals

bones of the instep

Phalanges

Toe bones

8

1

1

1

1

2

2

HOW MANY BONES?

Cranial Bones in total:

• Frontal

• Occipital

• Sphenoid

• Ethmoid

• Parietal

• Temporal

14

1

1

2

2

2

2

2

2

HOW MANY BONES?

Facial Bones in total:

• Vomer

• Mandible

• Maxilla

• Palatine

• Zygomatic

• Nasal

• Lacrimal

• Inferior Nasal Conchae

6

2

2

2

HOW MANY BONES?

Middle Bones in total:

• Malleus

• Incus

• Stapes

1

HOW MANY BONES?

Hyoid

24

7

12

5

HOW MANY BONES?

Vertebrae

• Cervical

• Thoracic

• Lumbar

4

1

1

2

HOW MANY BONES?

Pelvis

• Sacrum

• Coccyx

• Pelvic Girdle

8

2

2

2

2

HOW MANY BONES?

Lower Limb

• Femur

• Patella

• Tibia

• Fibula

6

2

2

2

HOW MANY BONES?

Upper Limbs

• Humerus

• Ulna

• Radius

4

2

2

HOW MANY BONES?

Shoulder Girdle

• Scapula

• Clavicle

25

1

24

HOW MANY BONES?

Thoracic

• Sternum

• Ribs

28

10

8

10

HOW MANY BONES?

Phalanges (Fingers)

• Proximal

• Intermediate

• Distal

10

HOW MANY BONES?

Metacarpals

16

2

2

2

2

2

2

2

2

HOW MANY BONES?

Carpals

• Scaphoid

• Lunate

• Triquetrum

• Pisiform

• Trapezium

• Trapezoid

• Capitate

• Hamate

28

10

8

10

HOW MANY BONES?

Phalanges (Toes)

• Proximal

• Intermediate

• Distal

10

HOW MANY BONES?

Metatarsals

14

2

2

2

2

2

2

2

HOW MANY BONES?

Tarsal

• Talus

• Calcaneus

• Navicular

• Medial Cuneiform

• Intermediate Cuneiform

• Lateral Cuneiform

• Cuboid

206 bones

total bones in an adult body