Lecture Notes: Unit II: Principles of Support and Movement
Chapter Seven The Skeletal System: The Axial Skeleton
-
There are NO FORMAL LECTURE NOTES for Chapter 7.
Since most of the material in this Chapter has to do with boney landmarks (ie, the surface markings or structural
features of each bone of the Axial Skeleton), this information becomes the domain of Biology 241- Lab.
You WILL BE RESPONSIBLE for learning / knowing the surface landmarks of the 80 bones of the Axial
Skeleton, so you will be using the Ch. 7 information; but more in connection with Lab sessions than Lecture.
There are 212 bones total in the human skeleton. Six of them, the ossicles (three per inner ear), however,
have to do only with the special sense of Hearing, and therefore will not be counted at this time. Thus,
we will consider a total of 206 bones in the human skeleton. Anatomists recognize TWO DIVISIONS
to the Human Skeleton, and four sub-divisions (or compartments) within each of these two Divisions.
Chapter 7 presents the first of these two Divisions: The Axial Skeleton consisting of bones arranged
along the longitudinal (or vertical) axis of the body. The bones of this Division may best be studied using
the following organizational arrangement:
I. The Axial Skeleton (which is made up of 80 bones)
A. Skull 22 bones (again, a reminder that we will not study the ossic/es at this time)
1. Neurocranium (Those bones which house the Brain) 8 bones
a. Unpaired: Frontal
Ethmoid
Occipital
Sphenoid
b. Paired:
Parietal
Temporal
2. Faciocranium (Those bones which support the Face) 14 bones
a. Unpaired: Vomer
Mandible
b. Paired:
Nasal
Maxilla
Palatine
Lacrimal
Zygoma Inferior nasal concha
-
B. Hyoid Bone - 1 bone (unpaired) (This bone articulates with NO OTHER bone in the body)
C. Vertebral Column - 32 bones
1. Cervical vertebrae: 7 (Cl = "Atlas"; C2 ="Axis"; C3, C4, C5, C6, C7)
2. Thoracic vertebrae: 12 (Tl, T2, T3, T4, T5, T6, T7, T8, T9, T10, T11, Tl2)
3. Lumbar vertebrae:
5 (Ll, L2, L3, L4, L5)
4. Sacral vertebrae:
5 (fused together into "the Sacrum") (S1, S2, S3, S4, S5)
5. Coccygeal vertebrae: 3 (these vary in number from 1 - 4; usual is 3) (Col, Co2, Co3)
-
D. Thoracic Cage (aka: "Rib Cage") 25 bones
1. Sternum: 1 bone (three parts: Manubrium, Gladiolus; Xiphoid Process)
2. Ribs: 24 bones (two of these articulate with each of the 12 Thoracic vertebrae)
Chapter 8 presents the second of these two Divisions: The Appendicular Skeleton which consists of
bones of the upper and lower limbs and the girdles by which they connect to the Axial Skeleton.
Now, see Lecture Notes for Chapter 8 regarding . . .
II. The Appendicular Skeleton (which is made up of 126 bones)