Choose Options from Following Acc to Number of Neurons in Animals Flashcards

1) Although an exact count is not available, it is likely that the human brain has as many as A) 10,000 neurons. B) 500,000 neurons. C) 1 million neurons. D) 10 million neurons. E) 100 billion neurons.

2) The central nervous system is lacking in animals that have A) a complete gut. B) bilateral symmetry. C) radial symmetry. D) a closed circulatory system. E) excitable membranes.

3) Cephalization, the clustering of neurons and interneurons in the anterior part of the animal, is apparent in A) Hydra. B) cnidarians. C) Planaria. D) sea stars. E) invertebrate animals with radial symmetry.

4) An organism that lacks integration centers A) cannot receive stimuli. B) will not have a nervous system. C) will not be able to interpret stimuli. D) can be expected to lack myelinated neurons.

5) In the human knee-jerk reflex, as the calf is raised from the vertical toward the horizontal, the muscles of the quadriceps (flexors on the ventral side of the thighs) and the muscles of the hamstring (extensors on the dorsal side of the thighs) are A) both excited and contracting. B) both inhibited and relaxed. C) excited and inhibited, respectively. D) inhibited and excited, respectively.

6) The stretch receptors of the sensory neurons in the human knee-jerk reflex are located in the A) gastrocnemius muscle, in the calf. B) cartilage of the knee. C) quadriceps, the flexor muscles on the ventral side of the thighs. D) hamstring, the extensor muscles on the dorsal side of the thighs. E) brain, the sensorimotor relay.

7) Choose the correct match of glial cell type and function. A) astrocytesmetabolize neurotransmitters and modulate synaptic effectiveness B) oligodendrocytesproduce the myelin sheaths of myelinated neurons in the peripheral nervous system C) microgliaproduce the myelin sheaths of myelinated neurons in the central nervous system D) radial gliathe source of immunoprotection against pathogens. E) Schwann cellsprovide nutritional support to non-myelinated neurons

8) The cerebrospinal fluid is A) a filtrate of the blood. B) a secretion of glial cells. C) a secretion of interneurons. D) cytosol secreted from ependymal cells. E) secreted by the hypothalamus.

9) The human knee-jerk reflex requires an intact A) spinal cord. B) hypothalamus. C) corpus callosum. D) cerebellum. E) medulla.

10) The blood-brain barrier A) is formed by tight junctions. B) is formed by oligodendrocytes. C) tightly regulates the intracellular environment of the CNS. D) uses chemical signals to communicate with the spinal cord. E) provides support to the brain tissue.

11) Myelinated neurons are especially abundant in the A) gray matter of the brain and the white matter of the spinal cord. B) white matter of the brain and the gray matter of the spinal cord. C) gray matter of the brain and the gray matter of the spinal cord. D) white matter in the brain and the white matter in the spinal cord. E) all areas of the brain and spinal cord.

12) An amino acid neurotransmitter that operates at inhibitory synapses in the brain is A) acetylcholine. B) epinephrine. C) endorphin. D) serotonin. E) gamma-aminobutyric acid, GABA.

13) Cerebrospinal fluid can be described as all of the following except A) functioning in transport of nutrients and hormones through the brain. B) a product of the filtration of blood in the brain. C) formed from layers of connective tissue. D) functioning to cushion the brain. E) filling cavities in the brain called ventricles.

14) The divisions of the nervous system that have antagonistic, or opposing, actions are A) motor and sensory systems. B) sympathetic and parasympathetic systems. C) presynaptic and postsynaptic membranes. D) forebrain and hindbrain. E) central nervous system and peripheral nervous system.

15) Preparation for the fight-or-flight response includes activation of the ________ nervous system. A) sympathetic B) somatic C) central D) visceral E) parasympathetic