Axial Skeleton - The Vertebrae, Ribs, Sternum, Hyoid Bone, and Auditory Ossicles Flashcards Preview

Anatomy & Physiology > Axial Skeleton - The Vertebrae, Ribs, Sternum, Hyoid Bone, and Auditory Ossicles > Flashcards

Flashcards in Axial Skeleton - The Vertebrae, Ribs, Sternum, Hyoid Bone, and Auditory Ossicles Deck (42):
1

What is the vertebral column?

The spine -- composed of a chain of 33 vertebrae with fibrocartilage intervertebral discs between them --which envelops and protects the spinal cord and provides vertical support for the body

2

What is the body of a typical vertebra?

A mass of spongy bone and red bone marrow covered with a thin shell of compact bone; the weight-bearing portion of the vertebra

3

What are intervertebral discs?

Fibrocartilage between bodies of adjacent vertebra

4

What is the vertebral foramen?

Large hole in a vertebra formed by body and vertebral arch; spinal cord passes through these holes in stacked vertebrae

5

What is the vertebral arch?

The lateral and posterior border of vertebral foramen comprised of two parts: pedicles (2) and laminae (2)

6

What are pedicles?

Two 'pillar-like' structures that originate from the body of the vertebra and form the lateral borders of the vertebral foramen

7

What are laminae?

Plural form of lamina, two 'plate-like' structures extending from pedicles that fuse posteriorly to form the posterior border of the vertebral foramen

8

What is a spinous process?

Posterior projection from junction of right and left laminae directed downward; can be easily palpated in the neck and back

9

What is the transverse process?

Lateral extension from point where pedicles and laminae meet that provide points of attachment for ligaments, ribs, and spinal muscles

10

What is the superior and inferior articular processes?

Articular facets projecting upwards and downwards from a vertebra, respectively, that prevent excessive twisting of the vertebral column which might injure the spinal cord

11

What are the intervertebral foramina?

Lateral openings between the pedicles of two adjacent vertebrae through which the spinal nerves pass from the spinal cord

12

How many regions (or divisions) is the vertebral column divided into?

Five: cervical, thoracic, lumbar, sacral, and coccygeal (from superior to inferior, in order)

13

How many cervical vertebrae are there?

Seven, located in the back of the neck, from C1 (Atlas) to C7 (vertebral promenens)

14

Describe C1 (Atlas)

Articulates with occipital condyles to support the head; doesn't resemble typical vertebra (lacks body and spinous process -- delicate ring of bone surrounding a very large vertebral foramen); allows for the nodding, "yes" motion of the head

15

Describe C2 (Axis)

Articulates with C1 and C3 and allows pivotal head rotation from side-to-side (lateral movement); features prominent anterior knob called the dens which projects into the vertebral foramen of C1 (Atlas)

16

Describe C7 (vertebral prominens)

The seventh and final cervical vertebra that has a very long, prominent spinous process that is easily palpated through the skin between the shoulder blades at the base of the neck; has no bifid (split) spinous process like C2-C6 and marks the transition from cervical to thoracic vertebrae

17

How many thoracic vertebrae are there?

Twelve: T1 thru T12

18

What are the characteristics of the thoracic vertebrae?

The bodies of these vertebrae have costal facets that articulate with the ribs; their spinous processes are pointed and angled sharply downward

NOTE: T1 thru T10 have transverse costal facets on ends of their transverse processes; T11 and T12 do not

19

What is the thoracic cage?

Twelve thoracic vertebrae, twelve pairs of ribs, and the sternum forms the thoracic cage that encloses and protects the heart and lungs

20

How many lumbar vertebrae are there?

Five: L1 thru L5

21

What are the characteristics of the lumbar vertebrae?

They are the largest vertebrae as they bear the most weight; have larger, thicker, oval bodies and blunt, square, thick spinous processes to provide area for attachment to inferior back muscles

22

How many sacral vertebrae are there?

Five: S1 thru S5; fused

23

What are the characteristics of the sacrum?

The sacrum is a curved, somewhat triangular bone that forms the posterior wall of the pelvic cavity; the five separate vertebrae begin to fuse around age 16 and complete their fusion by the mid-20's

24

What are sacral foramina?

Four pairs of openings lateral to the sacral canal that allows the passage of nerves and arteries to the pelvic organs

25

What are transverse lines?

Four lines of vertebral fusion along the anterior surface of the sacrum

26

What is are the lateral auricular surfaces of the sacrum?

"Ear-shaped" sockets lateral to the sacral canal that articulate with the iliac portions of the hip bones to form the sacroiliac (SI) joint

27

How many coccygeal vertebrae are there?

Four: Co1 thru Co4; fused

28

What are the characteristics of the coccyx?

Known as the "tail bone," it is the vestige of a tail that provides an area of attachment for muscles of the pelvic floor; can be fractured during difficult child birth or a hard fall

29

What is the sternum?

The flat breastbone of the thoracic cage which forms the anterior, midline portion and lies just anterior to the heart; divided into three portions: the manubrium, gladiolus (body -- middle and longest part), and xiphoid process

30

What is the manubrium?

The widest and most superior portion of the sternum, it has two clavicular notches that articulate with the right and left clavicle; a suprasternal (jugular) notch; and, a raised suture line called a sternal angle that separates the manubrium from the body of the sternum

31

What is the suprasternal (jugular) notch?

A depression on the middle of the superior aspect of the manubrium; easily palpated and is a CPR landmark

32

What is the xiphoid process?

The inferior, sharp portion of the sternum which is cartilaginous and does not become bone until the age of 40; also a CPR landmark

33

What is the hyoid bone?

A slender 'U' shaped bone between the chin and larynx, unique because it does not articulate with any other bone; it is suspended from the styloid process of the temporal bone by muscles and ligaments and forms the superior bony framework for the larynx

34

What are characteristics of the hyoid bone?

Has a medial body and two paired horn-like processes, the greater and lesser cornu; is fractured in most strangulation deaths

35

What are the auditory ossicles?

The smallest bones in the body (6 total -- 3 in each ear) housed in the middle ear cavity within the temporal bone of the skull, they at responsible for both amplifying sound waves and transmitting them to the inner ear

36

Name the three auditory ossicles.

From lateral to medial, they are the malleus (hammer), incus (anvil), and stapes (stirrup)

37

What are ribs?

Elongated, curved, flattened bones that originate posteriorly on or between the 12 thoracic vertebrae, most of which attach on the anterior end to the sternum by way of strips of hyaline cartilage called costal cartilages

38

What is the rib head?

The vertebral end of the rib that attaches posteriorly to a thoracic vertebra

39

What is the neck of a rib?

Narrower portion of the rib between the head and the tubercle

40

What is a tubercle?

Point of attachment of most ribs (pairs 1-10) to the transverse processes of the thoracic vertebrae

41

What are true ribs?

Pairs of ribs (1 thru 7) each with its own costal cartilage attaching directly to the sternum

42

What are false ribs?

Pairs of ribs (8 thru 12) with each pair lacking its own direct costal cartilage attachment to the sternum; pairs 8-10 have an indirect attachment via upwards fusion to costal cartilage of rib 7, while pairs 11-12 have no cartilage connection and are thus false AND floating ribs lacking tubercles