Skeletal System Axial Division
The Axial Skeleton You will see that each bone has special features (overviewed in section I below) that provide Sites of Attachment (for muscles, ligaments, tendons, etc.) and Sites of Passage (for blood vessels and nerves). Study the prefixes, suffixes, and roots from Lecture 1. These terms are used repeatedly during the remainder of the course to describe various parts of all of the major systems. STUDY and KNOW these word components. They will be an enormous aid in learning the terms of GROSS Anatomy.
From this point on, there is no substitute for STUDYING. Do not do it all in one sitting. Constant review and quizzing each other is the best way to learn it and know it. One super way to learn all of the terms you are about to be bombarded with is to make 3'X 5' FLASH CARDS. Write the term on one side and where it is located on the other. These are extremely useful when it comes to quizzing yourself in the lab and certainly in reviewing for quiz/midterm/final. The process of making the cards themselves is very didactic. I cannot overemphasize how useful flashcards can be in learning anatomical terminology.
I. Different Bone Markings - Essential Terminology Depressions and Openings A. fissure-cleft-like opening between adjacent parts of bones through which vessels & nerves pass B. foramen-hole through which blood vessels, nerves, ligaments can pass C. meatus-tunnel-like passageway through a bone D. sinus-cavity within a bone with narrow opening
E. sulcus-groove or depression that accommodates a soft structure such as vessels, nerve, or tendon F. fossa-depression in/on a bone; generally at a joint G. process-prominent projection or point of attachment
Articular Processes (of the joints) H. condyle-large, rounded articular (joint) prominence I. head-rounded articular projection supported by a more constricted portion of a bone (neck) J. facet-smooth, flat surface on a bone
Processes for Attachment (tendons, ligaments, etc.) K. tubercle-small, rounded process L. tuberosity-large, rounded, usually rough process M. trochanter-large, blunt projection; only on the femur N. line-less prominent ridge than a crest O. spine-sharp, slender process P. epicondyle-prominence found "above" a condyle
II. Curvature of the Vertebral Column A. Normal Curves in Vertebral Column 1. cervical curve - concave posteriorly 2. thoracic curve - convex posteriorly 3. lumbar curve - concave posteriorly 4. sacral-coccygeal curve - convex posteriorly
B. Abnormal Curves of the Vertebral Column 1. kyphosis-exaggerated thoracic curve (hunchback) 2. lordosis - exaggerated lumbar curve (slumping) 3. scoliosis-s-shaped deviation out of midsagittal plane
III. Identifying Characteristics of Different Vertebrae A. cervical * C1 (atlas) no body, no spine * C2 (axis) bifid spine, dens (head) * C3-6 bifid spine * C7 non-bifid spine, bulges from lower neck * transverse foramen vessel+nerve) *vertebral foramen (down->smaller)
B. thoracic * T1 sup. whole facet : inf. demifacet * T2-8 two demifacets; sup. large/inf. small * T9 single superior demifacet * T10-12 whole facet for individual rib * long, inferior-directed spinous processes * transverse processes are long and heavy
C. lumbar * all have largest, thickest bodies * spinous processes are oblong and heavy
D. sacral * 5 bones fused at middle age to form sacrum
E. Coccygeal * 3/5 bones fused to form coccyx
IV. Intervertebral Disc A. Functions 1. absorb stress/shock on the vertebral column 2. provide surface for vertebra to twist B. Structure 1. annulus fibrosus - outer ring of fibrocartilage 2. nucleus pulposus - inner structure, highly elastic
C. Herniated Disc 1. nucleus pulposus ruptures through the fibrocartilage 2. generally ruptures at L3-5 (lower back slipped disc) 3. most often occurs in posterior direction 4. can compress spinal nerves and spinal cord