Chapter 17 - Skeletal System Flashcards
Accessory ribs are most commonly found
attached to the
(A) cervical vertebrae (B) thoracic vertebrae (C) lumbar vertebrae (D) manubrium (E) sternebrae
C. Lumbar Vertebrae
Accessory ribs are most commonly attached to lumbar vertebrae. When present
(incidence 0.5%–1%), a cervical rib is usually attached to the seventh cervical vertebra.
Cervical ribs may compress the brachial plexus and subclavian vessels and cause superior
thoracic outlet syndrome.
The anterior fontanelle is usually closed
by
(A) birth (B) age 6 months (C) age 18 months (D) age 2 years (E) age 5 years
D. Age 2 years
The anterior fontanelle is usually closed by 2 years of age; the posterior and sphenoid
fontanelles are usually closed by the end of 6 months of age.
The condition where the pedicles of the
vertebral arches fail to fuse with the
vertebral body is called
(A) block vertebrae (B) cleft vertebrae (C) hemivertebrae (D) spondylolisthesis (E) spina bifida occulta
D. Spondylolisthesis
When the pedicles fail to fuse with the vertebral body, a condition called spondylolisthesis
results. This allows the vertebral body to move anterior with respect to the vertebrae
below, it causing lordosis.
During an ultrasound examination,
numerous fractures of the long bones of the
fetus are observed. This condition is called
(A) achondroplasia (B) osteogenesis imperfecta (C) Marfan syndrome (D) cretinism (E) acromegaly
B. Osteogenesis Imperfecta
Osteogenesis imperfecta is a deficiency of type I collagen and results in spontaneous
fractures of fetal bones and blue sclera of the eye.
A female newborn presents with a squareshaped
skull with a short occipital–frontal
diameter. Premature closure of which of the
following sutures is the most likely cause of
this finding?
(A) Sphenofrontal (B) Sphenoparietal (C) Lambdoidal (D) Sagittal (E) Coronal
E. Coronal
Brachycephaly is the premature closure of the coronal sutures, which leads to a squareshaped
skull with a short occipital–frontal diameter.
