Skeletal System

axial
appendicular

types of bone based on location

Support Protection Movement Storage (for minerals) Blood production (Hematopoiesis) Fat storage

functions of skeletal system

flat
long
irregular
short

types of bone based on shape

long bones

Longer than they are wide 

Ex. Upper and lower limbs, humerus, femur

upper limbs and lower limb
humerus
femur

example of long bones

short bones

Approximately as broad as they are long

Ex. wrist and ankle, metatarsals, metacarpals

wrist and ankle
metatarsals
metacarpals

example of short bones

flat bones

Relatively thin, flattened shape

Ex. Ribs, scapulae

Ribs, scapulae

example of flat bones

irregular bones

With shapes that do not fit into the other three

Ex. Vertebrae and facial bones, skull

vertebrae
facial bones
skull

example of irregular bones

270-305

how many bones in newborn

206 (80 axial, 126 appendicular)

how many bones in adults (axial, appendicular)

22
facial bones 14
cranial bones 8

how many bones are there in skull

tubercle / tuberosity
fossa
process
foramen
canal / meatus

common terms in bone anatomy

foramen

hole in a bone

canal / meatus

Elongated hole which is a tunnel-like passage through the bone

fossa

Depression on a bone

tubercle / tuberosity

Lump on a bone

process

projection from a bone

skull

refers to the entire skeleton of the head and the face, including the mandible. 

cranium

refers to the skull minus the mandible. 

Calvarium

refers to the skull after the bones of the face have been removed

sutures

 are immobile joints that unite the series of flattened and irregular bones of the skull, except the mandible.

cranial
orbital
nasal

bones of the skull encolse the cavities

cranial

where the brain is lodged

orbital

where the eyeballs and accessory organs are lodged

nasal

divided into 2 spaces by the bony nasal septum

bony nasal septum

the nasal is divided into 2 spaces by the?

cerebral/ cranial bones
visceral cranium / facial bones

divisions of the bones of the skull

unpaired 4
paired 4

how many unpaired and paired bones in cerebral/ cranial bones?

frontal
occipital
sphenoid
ethmoid

unpaired bones in cerebral / cranial bones

parietal
temporal

paired bones in cerebral / cranial bones

occipital

forms back of the head and posterior floor of the cranial cavity

frontal

forms the forehead, the roof of the orbit, and anterior floor of the cranial cavity

sphenoid

bat-shaped bone forming the middle floor of the cranial cavity and the back of the orbit

ethmoid

found between the cranial, nasal, and orbital cavities

parietal

forms the root of the cranial cavity 

temporal

forms the side and floor of the cranial cavity and houses the ear cavity and ossicles

paired 12
unpaired 2

how many paired and unpaired bones in visceral column/ facial bones?

Lacrimal
Maxilla
Zygomatic
nasal
Palatine
inferior nasal conchae

paired bones in visceral cranium / facial bones

Vomer
mandible

Unpaired bones in visceral cranium / facial bones

vertebral column

• Irregular bones , no definite short

• The central axis of the skeleton that has a normal curvature

Cervical 7
Thoracic 12
Lumbar 5
Sacrum 1
Coccyx 1

types of vertebrae

Cervical 7

The only vertebrae that has a transverse foramina 

C1/Atlas

• (Holds up the head) 

  • No body and no spinous process 

  • Has large superior facets, where it articulates with the occipital 

  • condyles on the base of the skull 

  • Rounded bone with no projection

C2/axis

• Has DENS 

• The dens fits into the enlarged vertebral foramen of the atlas, and the atlas rotates around this process. 

• Short process projecting upward (may odontoid process)

C7

• has most prominent spinous process

Thoracic 12

• Heart-shape

• Letter t-shape

Lumbar 5

• Kidney or bean shape

• Largest and strongest UNFUSED vertebra

Sacrum 1 (5)

• At the end of cervical coccyx or tail bone

Coccyx 1 (4)

• Tailbone

• Most inferior portion of the vertebral column

Ribs or thoracic cage 12 pairs

• Classified as either: TRUE RIBS (7) or FALSE RIBS (5)

true ribs 7 pairs

attached to sternum

false ribs 5 pairs

floating bones

sternum

Breastbone; Sword-shaped 

• Manubrium 

• Gladiolus/Body 

• Xiphoid Process

three parts of sternum

scapula or shoulder blade

Coracoid process provides attachments for some shoulder and arm muscles.

glenoid cavity

• located in the superior lateral portion of the bone, articulate with the head of the humerus

clavicle

• Collar bone 

• S-shaped bone 

acromial end
shaft
sternal end

parts of clavicle

diaphysis
epiphysis
metaphysis
articular cartilage

parts of long bones

diaphysis

shaft

epiphysis

endcontains bone marrow;

metaphysis

 between diaphysis and epiphysis

articular cartilage

 articulating surface

humerus
radius
ulna

long bones of upper appendicular

carpals

• Wrist bones 

• Composed of eight bones arranged into two rows of four each 

metacarpals

• five are attached to the carpal bones and constitute the bony 

• framework of the hand. 

• Five digits of each hand include one thumb and four fingers. 

• Each digit consists of small long bones called Phalanges

phalanges

• Each digit consists of small long bones called

thumb

• has two phalanges (proximal and distal) 

four fingers

have three phalanges (Proximal, Middle and Distal)