Histology and Physiology NBDE 1987

In the sulcular epithelium, small spaces between cells in the stratum spinosum (prickle cell layer) are normally filled by
A) none of the above.
B) capillaries that course between cells to approach the free surface.
C) keratin.
D) a small amount of tissue fluid.

Excluding the effect of drugs, apnea occurring after hyperventilation of an anesthetized patient results from
A) increased hydrogen ion concentration.
B) decreased demand for oxygen.
C) increased cerebral blood flow.
D) decreased oxygenation of carotid bodies.
E) decreased carbon dioxide tension.

Which of the following increase with age in dental pulp?
(a) Vascularity; (b) Size of the pulp chamber; (c) Number of collagen fibers; (d) Calcification within the pulp

Sounds heard during systole in the antecubital space are produced by
A) turbulent blood flow through the artery.B) laminar blood flow through the occluded artery C) closure of the aortic valve.D) closure of AV valves.

Normal hemoglobin concentration is about 15 gm./dl. blood and normal arterial oxygen content is about 20 ml. 02/dl. blood. An anemic individual breathing room air with a hemoglobin concentration of 10 gm./dl. blood is expected to have
A) normal arterial oxygen tension and reduced arterial oxygen content.
B) normal arterial oxygen tension and normal arterial oxygen content.
C) reduced arterial oxygen tension and normal arterial oxygen content.
D) reduced arterial oxygen tension and reduced arterial oxygen content.

It is possible to distinguish histologically between the stomach and the duodenum because of the presence of
A) smooth muscle in the external musculature of the duodenum only.
B) simple columnar epithelium lining the stomach only.
C) submucosal glands in the duodenum only.
D) mucosal glands in the stomach only.
E) muscularis mucosa in the stomach only.

Tropocollagen is a protein molecule found in
A) collagen and elastic fibers only
B) collagen, elastic and reticular fibers.
C) collagen and reticular fibers only.
D) elastic and reticular fibers only.

Cells of the stratum granulosum of thick stratified squamous epithelium characteristically contain
A) granules that are organelles. B) keratohyalin granules.C) melanin granules.D) keratin granules.

At a muscle-tendon junction, the union is made by
A) an abundance of reticular fibers in the area of the junction.
B) myofibrils connecting with collagenous fibrils of the tendon.
C) a special thickening of sarcoplasm that unites with collagenous fibrils of the tendon.
D) a continuity of connective tissue sheaths of the muscle with those of the tendon.

The number of roots that are formed is determined by the
A) number of medial ingrowths of the cervical loop.
B) number of discontinuities developed in the root sheath.
C) thickness of the cervical loop.
D) number of root sheaths developed by the enamel organ.

Which of the following are mobilized when a cell produces an excessive amount of protein?
A) All of the above B) Lipofuscin granulesC) LysosomesD) MitochondriaE) Rough endoplasmic reticula

The alveolar bone proper (cribriform plate) usually consists of
A) lamellar bone only.B) bundle bone and lamellar bone. C) bundle bone only.D) woven bone.

Enamel spindles are formed by
A) odontoblasts.B) cracks.C) hypoplastic rods.D) hypocalcified rods. E) ameloblasts.