1. Blood cell formation is called ________.

a. ossification
b. hematopoiesis
c. homeostasis
d. metabolism

2. What bones protect the spinal cord?

a. ribs
b. sternum
c. vertebrae
d. coxal bones

3. Cube-shaped bones that contain mostly spongy bone are called ________ bones.

a. flat
b. long
c. short
d. irregular

4. Small canals that connect osteocytes in their lacunae to the central canal are known as ________.

a. canaliculi
b. perforating (Volkmann's) canals
c. central (Haversian) canals
d. perforating (Sharpey's) fibers

5. The process of bone formation is known as ________.

a. hematopoiesis
b. hemostasis
c. metabolism
d. ossification

6. Bone-destroying cells known as osteoclasts are activated by the hormone ________.

a. calcitonin
b. parathyroid hormone (PTH)
c. insulin
d. growth hormone

7. Striated involuntary muscle tissue is classified as ________ muscle.

a. skeletal
b. cardiac
c. smooth
d. either smooth or skeletal

8. The epimysium covering on the outside of the muscle can blend into cordlike ________ or sheetlike ________.

a. tendons; aponeuroses
b. ligaments; tendons
c. fascia; ligaments
d. aponeuroses; ligaments

9. The ________ is an organelle that wraps and surrounds the myofibril and stores calcium.

a. cross bridge
b. sarcomere
c. sarcolemma
d. sarcoplasmic reticulum

10. Muscle tissue has the ability to shorten when adequately stimulated, a characteristic known as ________.

a. elasticity
b. irritability
c. contractility
d. extensibility

11. One neuron and all the skeletal muscles it stimulates is known as a ________.

a. sarcoplasmic reticulum
b. motor unit
c. synaptic cleft
d. neuromuscular junction

12. The heads of the myosin myofilaments are called ________ when they link the thick and thin filaments together during skeletal muscle contraction.

a. neuromuscular junctions
b. synapses
c. cross bridges
d. motor units

13. The gap between the motor neuron and the muscle fiber it supplies at the neuromuscular junction is called the ________.

a. synaptic cleft
b. motor unit
c. cross bridge
d. H zone

14. The nervous system is structurally subdivided into two systems: ________ nervous system and ________ nervous system.

a. central; peripheral
b. somatic; autonomic
c. parasympathetic; sympathetic
d. autonomic; sympathetic

15. ________ cells form the myelin sheaths around nerve fibers in the PNS.

a. Satellite
b. Ependymal
c. Schwann
d. Nerve

16. Support cells in the central nervous system are collectively called ________.

a. myelin sheaths
b. neuroglia
c. oligodendrocytes
d. microglia

17. The part of the neuron that typically conducts nerve impulses away from the cell body is the ________.

a. dendrite
b. cell body
c. synaptic cleft
d. axon

18. The gaps between Schwann cells found at regular intervals in peripheral system neurons are called ________.

a. synaptic clefts
b. axon terminals
c. nodes of Ranvier
d. myelin sheathsUnit 2 Examination 86 GED 102 The Human Body

19. Sensory receptors located in muscles and tendons are termed ________.

a. Meissner's corpuscles
b. proprioceptors
c. lamellar corpuscles
d. association neurons

20. The membrane that covers the outer surface of the eye and lines the eyelids is the ________.

a. choroid
b. sclera
c. conjunctiva
d. retina

21. The ________ gland is located above the lateral end of each eye and releases tears.

a. tarsal
b. ceruminous
c. lacrimal
d. ciliary

22. The fibrous covering of the eye consists of the white outer layer, known as the ________, and a transparent portion known as the ________.

a. sclera; cornea
b. conjunctiva; sclera
c. iris; pupil
d. pupil; cornea

23. The innermost sensory layer of the eye that contains bipolar cells and ganglion cells is the ________.

a. choroid
b. retina
c. sclera
d. cornea

24. The region of the optic nerve lacking photoreceptor cells is known as the ________.

a. retina
b. optic disc (blind spot)
c. choroid
d. iris

25. The biconvex structure that focuses light on the retina is the ________.

a. cornea
b. pupil
c. lens
d. iris