Week 2 Axial Skeleton

Question 1

What is the axial skeleton?

Answer 1

Question 2

What are the functions of the vertebral column?

Answer 2

1. Support
   - head, arms & trunk
   - weight bearing
   - posture
   - scaffolding for breathing mechanisms
2. Protection
   - spinal cord
   - central body cavities
3. Attachment site
   - ribs
   - many muscles

Question 3

What are the regions of the vertebral column?

Answer 3

33 segments:

•7 Cervical vertebrae

12 Thoracic vertebrae

• 5 Lumbar vertebrae
• 5 Sacral vertebrae
• 4 Coccygeal vertebrae

Question 4

Describe the Curvatures of the Vertebral Column

Answer 4

1.Primary Curvatures:

• Develop in utero
• Thoracic and Sacral
• are convex posteriorly

2.Secondary Curvatures:

• Develop after birth
• Cervical and Lumbar
• are concave posteriorly •

Question 5

What is the function of the Curvatures of the Vertebral Column?

Answer 5

Aid in absorption of weight bearing forces during locomotion (walking) Curvatures help balance weight over lower limbs

Question 6

What are the typical components of vertebrae, their location and function?

Answer 6

Question 7

What is the vertebral canal?

Answer 7

when multiple vertebrae are joined together the foramen makes a long tube or canal.

Question 8

How do spinal nerves go to different parts of the body?

Answer 8

Inbetween the vertabrae

Intervertebral foramen Are smaller spaces that allow spinal nerves to pass between the spinal cord and body regions. Formed by superior and inferior vertebral notches

Question 9

What are Intervertebral discs?

Answer 9

a disc-like structure in between vertebrae - a squishy structure absorbs shock and influences how weight is distributed along the vertebral body

Question 10

What is the typical structure of Intervertebral discs?

Answer 10

Annulus fibrosis-

– outer laminae of fibrocartilage

AND

Nucleus pulposis-

– gelatinous hydrophilic substance

– give shock absorbing properties

Question 11

What are the abdominal wall muscles?

Answer 11

– Rectus abdominus

– External and internal obliques

– Transverse abdominus

Question 12

Where is the rectus abdominus and what does it do?

Answer 12

Think ‘six pack’ muscles

Depresses lower ribs and sternum

Originates from front edge of coxal bone and inserts into the outer surfaces of the fifth through seventh costal cartilages and lower sternum

Question 13

Where is the external oblique and what does it do?

Answer 13

Think ‘hands in pockets’

Depresses lower eight ribs and forces front and sides of abdominal wall inward

Originates from the upper surface of the coxal bone and abdominal aponeurosis near the midline and inserts on the lower eight ribs

Question 14

Where is the internal oblique and what does it do?

Answer 14

Think ‘opposite to hands in pockets’

Depresses lower ribs and forces front and sides of abdominal wall inward

Originates from the upper surface of the coxal bone and lumbodorsal fascia and inserts into the abdominal aponeurosis and lower borders of the costal cartilages of the lower three to four ribs

Question 15

Where is the Transversus abdominis and what does it do?

Answer 15

Think ‘sucking your tummy in’

Forces front and sides of abdominal wall inward

Originates from the upper surface of the coxal bone, lumbodorsal fascia, and inner surfaces of the costal cartilages of ribs seven through twelve and insert into the abdominal aponeurosis

Question 16

What are the 3 scalene muscles? Where are they and what is their function?

Answer 16

– three paired muscles in the lateral neck

• anterior scalene
• middle scalene
• posterior scalene

– The scalenes perform flexion at the neck, and act as accessory muscles of respiration.