ch. 7

Question 1

Vertebral Column

Answer 1

Transmits weight of trunk to lower limbs
Surrounds and protects spinal cord
Flexible curved structure containing 26 irregular bones (vertebrae)
Cervical vertebrae (7)—vertebrae of the neck
Thoracic vertebrae (12)—vertebrae of the thoracic cage
Lumbar vertebrae (5)—vertebra of the lower back
Sacrum—bone inferior to the lumbar vertebrae
Coccyx—terminus of vertebral column

Question 2

Vertebral Column: Curvatures

Answer 2

Increase the resilience and flexibility of the spine
Two posteriorly concave curvatures
Cervical and lumbar
Two posteriorly convex curvatures
Thoracic and sacral

Question 3

Abnormal spine curvatures

Answer 3

Scoliosis (abnormal lateral curve)
Kyphosis (hunchback)
Lordosis (swayback)

Question 4

Developmental Aspects: Spinal Curvature

Answer 4

Thoracic and sacral curvatures are obvious at birth
These primary curvatures give the spine a C shape
Convex posteriorly

Question 5

Developmental Aspects: Spinal Curvature

Answer 5

Secondary curvatures
Cervical and lumbar—convex anteriorly
Appear as child develops (e.g., lifts head, learns to walk)

Question 6

Ligaments

Answer 6

Anterior and posterior longitudinal ligaments
From neck to sacrum
Ligamentum flavum
Connects adjacent vertebrae
Short ligaments
Connect each vertebra to those above and below

Question 7

Intervertebral Discs

Answer 7

Cushionlike pad composed of two parts
Nucleus pulposus
Inner gelatinous nucleus that gives the disc its elasticity and compressibility
Anulus fibrosus
Outer collar composed of collagen and fibrocartilage

Question 8

The Lower Limb

Answer 8

Carries the weight of the body
Subjected to exceptional forces 
Three segments of the lower limb
Thigh: femur
Leg: tibia and fibula
Foot: 7 tarsal bones in the ankle, 5 metatarsal bones in the metatarsus, and 14 phalanges in the toes

Question 9

Foot: Tarsals

Answer 9

Seven tarsal bones form the posterior half of the foot
Talus transfers most of the weight from the tibia to the calcaneus
Other tarsal bones: cuboid, navicular, and the medial, intermediate, and lateral cuneiforms

Question 10

Metatarsals:

Answer 10

Five metatarsal bones (#1 to #5)

Enlarged head of metatarsal 1 forms the “ball of the foot”

Question 11

Phalanges

Answer 11

The 14 bones of the toes
Each digit (except the hallux) has three phalanges
Hallux has no middle phalanx

Question 12

Arches of the Foot

Answer 12

Arches are maintained by interlocking foot bones, ligaments, and tendons
Arches allow the foot to bear weight
Three arches
Lateral longitudinal 
Medial longitudinal 
Transverse

Question 13

Arch and keystone (boss)
Developmental Aspects: Old Age
Arch

Answer 13

Intervertebral discs become thin, less hydrated, and less elastic
Risk of disc herniation increases
Loss of stature by several centimeters is common by age 55
Costal cartilages ossify, causing the thorax to become rigid
All bones lose mass

Question 14

Pelvic (Hip) Girdle

Answer 14

Two hip bones (each also called coxal bone or os coxae)
Attach the lower limbs to the axial skeleton with strong ligaments
Transmit weight of upper body to lower limbs
Support pelvic organs
Each hip bone consists of three fused bones: ilium, ischium, and pubis
Together with the sacrum and the coccyx, these bones form the bony pelvis

Question 15

Female pelvis

Answer 15

dapted for childbearing
True pelvis (inferior to pelvic brim) defines birth canal
Cavity of the true pelvis is broad, shallow, and has greater capacity
Comparison of Male and Female Pelves

Question 16

Male pelvis

Answer 16

Tilted less forward
Adapted for support of male’s heavier build and stronger muscles
Cavity of true pelvis is narrow and deep