Axial skeleton
Axial skeleton
diagram of the axial skeleton
Latin
skeleton axiale
The axial skeleton consists of the 80 bones in the head and trunk of the human body. It is
composed of five parts; the human skull, the ossicles of the middle ear, the hyoid bone of the
throat, the rib cage, and the vertebral column. The axial skeleton and the appendicular skeleton
together form the complete skeleton and the sternum.
Overview
Flat bones house the brain, spinal cord, and other vital organs. This article mainly deals with the
axial skeletons of humans; however, it is important to understand the evolutionary lineage of the
axial skeleton. The human axial skeleton consists of 80 different bones. It is the central core of
the body and where the appendicular skeleton attaches. As the skeleton grows older the bones get
weaker with the exception of the skull. The skull remains strong so as to protect the brain from
injury.
Skull
Main article: Human skull
Skull (22)

Cranial Bones (8)
o Parietal (2)
o Temporal (2)
o Frontal (1)
o Occipital (1)
o Ethmoid (1)
o Sphenoid (1)

Facial Bones (14)
o Maxilla (2)
o Zygomatic (2)
o Mandible (1)
o Nasal (2)
o Palatine (2)
o Inferior nasal concha (2)
o Lacrimal (2)
o Vomer (1)
Auditory Ossicles
Ossicles (6 )


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Malleus (2)
Incus (2)
Stapes (2)
Hyoid bone
Hyoid bone (1) U-shape bone located in the neck. It anchors the tongue and is associated with
swallowing.
Vertebral column
Main article: Vertebral column
Vertebral Column (26)
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Cervical vertebrae (7)
Thoracic vertebrae (12)
Lumbar vertebrae (5)
Sacrum (1) (they are 5 but fused in adult stage)
Coccyx (1) (they are 4 but fused to form one single bone, varies between 3-5)
Chest
Main article: Chest
Thoracic cage (25)


Sternum (1)
Ribs (24)
Bones
Vertebral
vertebrae (cervical, thoracic, lumbar) · sacrum · coccyx
column
Thoracic
sternum · rib
skeleton
Neurocranium
Axial
Skull
nasal · maxilla · lacrimal · zygomatic · palatine · inferior
Facial bones nasal conchae · vomer · mandible · THROAT: hyoid
(greater cornu, lesser cornu, body)
Ossicles
Appendicular
occipital · parietal · frontal · temporal · sphenoid ·
ethmoid
malleus · incus · stapes
SHOULDER GIRDLE:clavicle · scapula · ARM: humerus · ulna · radiusUpper HAND:carpals (scaphoid · lunate bone · triquetral · pisiform · trapezium ·
trapezoid · capitate · hamate) · metacarpals · phalanges (prox, int, dist)
PELVIS:pelvis (ilium, ischium, pubis) · LEG: femur · patella · fibula ·
Lower tibia · FOOT: tarsals (calcaneus, talus, navicular, cuneiform, cuboid ) ·
metatarsals · phalanges (prox, int, dist)
Appendicular skeleton
Appendicular skeleton
Appendicular skeleton diagram
Latin
skeleton appendiculare
The appendicular skeleton is composed of 126 bones in the human body. The word
appendicular is the adjective of the noun appendage, which itself means a part that is joined to
something larger. Functionally it is involved in locomotion (Lower limbs) of the axial skeleton
and manipulation of objects in the environment (Upper limbs).
The appendicular skeleton is divided into six major regions:
1) Pectoral Girdles (4 bones) - Left and right Clavicle (2) and Scapula (2).
2) Arm and Forearm (6 bones) - Left and right Humerus (2) (Arm), Ulna (2) and Radius (2)
(Fore Arm).
3) Hands (58 bones) - Left and right Carpal (16) (wrist), Metacarpal (10), Proximal phalanges
(10), Middle phalanges (8), distal phalanges (10), and sesamoid (4).
4) Pelvis (2 bones) - Left and right os coxae (2) (ilium).
5) Thigh and leg (8 bones) - Femur (2) (thigh), Tibia (2), Patella (2) (knee), and Fibula (2) (leg).
6) Feet (56 bones) - Tarsals (14) (ankle), Metatarsals (10), Proximal phalanges (10), middle
phalanges (8), distal phalanges (10), and sesamoid (4).
It is important to realize that through anatomical variation it is common for the skeleton to have
many extra bones (sutural bones in the skull, cervical ribs, lumbar ribs and even extra lumbar
vertebrae)
The appendicular skeleton of 126 bones and the axial skeleton of 80 bones together form the
complete skeleton of 206 bones in the human body. Unlike the axial skeleton, the appendicular
skeleton is unfused. This allows for a much greater range of motion