Chapter 11: Nervous System 2 (PPT & Textbook Review)

47. Distinguish between alpha-adrenergic and beta-adrenergic receptors.

α- adrenoceptors mediate smooth muscle contraction and vasoconstriction β-adrenoceptors mediate vasodilation, smooth muscle relaxation, bronchodilation, and excitatory cardiac function

50. Describe sleep problems that may accompany aging.

• Changes in sleep patterns that result in fewer sleeping hours

19. Describe the location and function of the reticular formation.

• Complex network of nerve fibers scattered throughout brainstem • Extends into the diencephalon • Connects to centers of hypothalamus, basal nuclei, cerebellum, and cerebrum with ascending and descending tracts • Filters incoming sensory information, passing some to cerebral cortex, and discarding unimportant information • Arouses cerebral cortex into state of wakefulness • Decreased activity causes sleep

26. Describe a withdrawal reflex.

• Occurs when person touches or steps on something painful (stove, tack) • Prevents or limits tissue damage, by removing limb from painful stimulus • Polysynaptic: contains sensory neuron, interneuron, motor neuron • Reciprocal innervation: flexors contract, extensors are inhibited

49. List ways that the nervous system changes as we age.

• Over average lifetime, brain shrinks 10% • More gray matter than white matter is lost with aging • Many cells die in temporal lobes, but few in brainstem • By age 90, frontal cortex has lost half its neurons • Number of dendritic branches in cerebral cortex decreases • Decreased levels of neurotransmitters • Action potentials propagation rate declines by 5 to 10% • Fading memory • Slowed responses and reflexes • Increased risk of fainting, falling

33. Match the cranial nerve with its function(s). Functions may be used more than once. (I) olfactory nerve (II) optic nerve (III) oculomotor nerve (IV) trochlear nerve (V) trigeminal nerve (VI) abducens nerve (VII) facial nerve (VIII) vestibulocochlear (IX) glossopharyngeal (X) vagus nerve (XI) accessory nerve (XII) hypoglossal nerve A. conducts impulses to muscles used in swallowing B. conducts impulses to muscles that move the tongue C. conducts impulses to muscles that move the eyes D. conducts impulses to viscera E. conducts impulses to nerve muscles of facial expression F. conducts impulses to nerve muscles of the neck G. conducts impulses associated with hearing H. conducts impulses to muscles that raise eyelids I. conducts impulses associated with the sense of smell J. conducts impulses from upper and lower teeth K. conducts impulses associated with vision

(I) olfactory nerve - I. conducts impulses associated with the sense of smell (II) optic nerve - K. conducts impulses associated with vision (III) oculomotor nerve - H. conducts impulses to muscles that raise eyelids (IV) trochlear nerve (V) trigeminal nerve (VI) abducens nerve (VII) facial nerve (VIII) vestibulocochlear (IX) glossopharyngeal (X) vagus nerve (XI) accessory nerve (XII) hypoglossal nerve

30. Describe the connective tissue and nervous tissue making up a peripheral nerve.

- Endoneurium: Loose connective tissue that surrounds individual axons - Perineurium: Loose connective tissue that surrounds fascicles - Epineurium: Dense connective tissue that surrounds a group of fascicles

29. Distinguish between the somatic and autonomic nervous systems.

- Motor nerves of the PNS contain either somatic or autonomic fibers. - The somatic nervous system includes somatic motor fibers that innervate the skeletal muscles and the skin, which gives the CNS ability to voluntarily move the muscles.

4. List the functions of cerebrospinal fluid.

- Secreted by the choroid plexuses, special capillaries of pia mater covered by ependymal cells - Selective transfer of substances from the blood to form CSF - Nutritive and protective of CNS neurons - Helps maintain stable ionic concentrations in the CNS - Circulates in ventricles, central canal of spinal cord, and subarachnoid space - After exchanging substances, CSF is absorbed by the arachnoid granulations - Volume is about 140 mL at any time

1. Explain the general functions of the brain and spinal cord and their interrelationship

- The brain oversees many aspects of physiology, including sensation and perception, movement, and thinking. - The brainstem connects the brain and spinal cord and allows two-way communication between them. - The spinal cord provides two-way communication between the CNS and the PNS.

3. Describe the relationship among the cerebrospinal fluid, the ventricles, the choroid plexuses, and arachnoid granulations.

- Tiny masses of specialized capillaries, called choroid plexuses, secrete CSF. - These structures project into the cavities of the ventricles. - CSF is continuously reabsorbed into the blood through tiny, fingerlike structures called arachnoid granulations that project from the subarachnoid space into the blood-filled dural sinuses

17. List the parts of the limbic system, and explain its functions.

- hypothalamus, thalamus, basal nuclei, & other deep nuclei - controls emotional experience & expression - can modify the way a person acts, producing feelings such as, anger, fear, pleasure, and sorrow. - reacts to potentially life-threatening upsets in persons physical or psychological condition. - by causing pleasant or unpleasant feelings about experiences the limbic system guides behavior that may increase the chance of survival - parts of the limbic system interpret sensory impulses from receptors associated with sense of smell (olfactory receptors)

9. Describe the location and function of the sensory areas of the cortex.

1. Cutaneous sensory area: • Parietal lobe • Interprets sensations on skin 2. Sensory speech area (Wernicke's area): • Temporal/parietal lobe, usually left hemisphere • Understanding and formulating language 3. Visual area: • Occipital lobe • Interprets vision 4. Auditory area: • Temporal lobe • Interprets hearing 5. Sensory area for taste: • Near base of the central sulcus •Includes part of insula 6. Sensory area for smell: • Arises from centers deep within temporal lobes

10. Explain the function of the association areas of the lobes of the cerebrum.

1. Frontal lobe association areas: • Concentrating, planning, complex problem solving • Emotional behavior, judging consequences of behavior 2. Parietal lobe association areas: • Understanding speech • Choosing words to express thoughts and feelings 3. Temporal lobe association areas: • Interpret complex sensory experiences (understanding speech, reading) • Store memories of visual scenes, music, and complex patterns 4. Occipital lobe association areas: • Analyze and combine visual images with other sensory experiences 5. Insula: • Translating sensory information into proper emotional responses

11. Describe the location and function of the motor areas of the cortex.

1. Primary motor areas (motor cortex): • Frontal lobes • Control voluntary muscles • Most nerve fibers cross over in brainstem 2. Broca's area: • Anterior to primary motor cortex • Usually in left hemisphere • Controls muscles needed for speech 3. Frontal eye field: • Above Broca's area • Controls voluntary movements of eyes and eyelids

23. List the two main functions of the spinal cord.

2 main functions of the spinal cord: • Center for spinal reflexes • Conduit (pathway) for impulses to and from the brain

34. Explain how the spinal nerves are grouped and numbered.

31 pairs of spinal nerves: • 8 cervical nerves, (C1 to C8) • 12 thoracic nerves (T1 to T12) • 5 lumbar nerves (L1 to L5) • 5 sacral nerves (S1 to S5) • 1 coccygeal nerve (Co)

27. Indicate whether each nerve tract is ascending or descending: a. rubrospinal d. fasciculus gracilis b. corticospinal e. reticulospinal c. spinothalamic f. spinocerebellar

Ascending (Sensory) Spinal Cord Tracts: d. Fasciculus gracilis c. Spinothalamic tracts f. Spinocerebellar tracts Descending (Motor) Spinal Cord Tracts: b. Corticospinal tracts e. Reticulospinal tracts a. Rubrospinal tract

48. Explain the effects of apoptosis on the developing brain.

Brain cells begin to die before birth, due to apoptosis, a form of normal programmed cell death

7. Describe the structure of the cerebrum.

Cerebrum is largest part of brain: - Cerebral hemispheres: 2 halves, separated by falx cerebri - Corpus callosum: Connects cerebral hemispheres - Gyri: Ridges or convolutions - Sulci: Shallow grooves in surface; Ex.) Central sulcus - Fissures: Deep grooves in surface - Longitudinal: separates the cerebral hemispheres - Transverse: separates cerebrum from cerebellum 5 lobes of cerebral hemisphere: - Frontal lobe - Parietal lobe - Temporal lobe - Occipital lobe - Insula (Island of Reil): Deep within lateral sulcus

44. Distinguish between cholinergic and adrenergic nerve fibers.

Cholinergic neurons: • Release acetylcholine • All preganglionic sympathetic and parasympathetic fibers • Postganglionic parasympathetic fibers Adrenergic neurons: • Release norepinephrine (noradrenaline) • Most postganglionic sympathetic fibers

36. Describe the parts of a spinal nerve and their functions.

Each spinal nerve splits into an anterior and posterior root inside the vertebral column: • Anterior (ventral or motor) root: Contains axons of motor neurons whose cell bodies are in the spinal cord • Posterior (dorsal or sensory) root: Contains axons of sensory neurons • Posterior root ganglion: Contains cell bodies of sensory neurons that conduct impulses from periphery into the spinal cord Spinal nerves: • Formed by union of anterior root and posterior roots • Mixed nerves • Branches of spinal nerves outside the spinal cord: • Meningeal branch • Posterior branch/ramus • Anterior branch/ramus • Visceral branch (only in thoracic and lumbar)

35. Define cauda equina.

Formed by descending roots of lumbar, sacral, and coccygeal nerves

18. Name the functions of the midbrain, pons, and medulla oblongata.

Midbrain: • Short section of brainstem • Lies between diencephalon and pons • Contains bundles of fibers that join lower parts of brainstem and spinal cord with higher part of brain • Cerebral aqueduct: Connects 3rd to 4th ventricle • Cerebral peduncles: Main motor pathways that connect cerebrum to lower portions of nervous system • Corpora quadrigemina: Centers for visual and auditory reflexes • Red nucleus: Role in postural reflexes Pons: • Rounded bulge on underside of brainstem • Between midbrain and medulla oblongata • Relays nerve impulses between medulla oblongata and cerebrum • Relays impulses from cerebrum to cerebellum • Helps regulate rhythm of breathing Medulla Oblongata: • Enlarged continuation of spinal cord • Conducts ascending and descending impulses between brain and spinal cord • Contains cardiac, vasomotor, and respiratory control centers • Contains various nonvital reflex control centers (coughing, sneezing, swallowing, and vomiting) • Injuries are often fatal

5. Describe the events of brain development.

Neural tube gives rise to CNS Brain forms from 3 vesicles (cavities): 1. Forebrain (prosencephalon) 2. Midbrain (mesencephalon) 3. Hindbrain (rhombencephalon) - Forebrain divides into the telencephalon and diencephalon - Mesencephalon persists - Hindbrain divides into metencephalon and myelencephalon These 5 cavities persist in mature brain as ventricles and tubes that connect them: 1. Forebrain becomes cerebrum, basal nuclei, and diencephalon 2. Mesencephalon remains as midbrain 3. Hindbrain becomes cerebellum, pons, and medulla oblongata

20. Distinguish between normal and paradoxical sleep.

Non-rapid Eye Movement (Non-REM) Sleep: • Slow wave sleep • Person is tired • Decreasing activity of reticular formation • Restful and dreamless • Reduced blood pressure and respiratory rate • 3 stages, ranging from light to heavy • Alternates with REM sleep Rapid Eye Movement (REM) Sleep: • Called paradoxical sleep, because some areas of brain are active • Heart and respiratory rates irregular • Dreaming occurs

37. Define plexus, and locate the major plexuses of the spinal nerves.

Plexus is a dense branch of nerves (or blood vessels) which form a network which, in case of nerves, innervates The 4 major plexuses are: - Cervical plexus (head and neck) - Brachial plexus (upper limbs and chest) - Lumbar plexus (pelvic girdle, lower limbs) - Sacral plexus (like lumbar plexus)

40. Distinguish between a preganglionic fiber and a postganglionic fiber.

Preganglionic fibers: • Axons of preganglionic neurons • Neuron cell bodies are in CNS • Axons leave CNS and synapse in autonomic ganglion Postganglionic fibers: • Axons of postganglionic neurons • Neuron cell bodies are in ganglia • Axons extend to visceral effector

24. Distinguish between a reflex arc and a reflex.

Reflex: • Automatic, subconscious response to a stimulus within or outside the body • Maintain homeostasis by controlling involuntary processes, such as heart rate, blood pressure, swallowing, coughing Reflex arc: • Neural pathway, consisting of a sensory receptor, 2 or more neurons, and an effector • Simple reflex arc contains only sensory and motor neurons • Most common reflex arc contains sensory neuron, interneurons, motor neurons

14. Distinguish between short-term and long-term memory.

Short-term (working) memory: • Neurons connected in a circuit • Circuit is stimulated over and over Long-term memory: • Holds more memory than short-term, lasts a lifetime • Changes structure or function of neurons, makes new synaptic connections by increases branching of processes

15. Explain the conversion of short-term to long-term memory.

Short-term memory: - When impulse flow ceases, memory does also, unless it enters long-term memory via memory consolidation Long-term memory: - Long-term potentiation: Increase in neurotransmitter release and effectiveness of synaptic transmission upon repeated stimulation

22. Describe the structure of the spinal cord.

Structures of the spinal cord (cross section): • Anterior median fissure and posterior median sulcus: Grooves that extend whole length of spinal cord • White matter surrounds core of gray matter • Gray matter arranged in horns • White matter arranged in funiculi • Posterior roots contain sensory neurons; cell bodies are outside spinal cord, in posterior root ganglia • Anterior roots contain motor neurons • Gray commissure surrounds central canal

39. Contrast the sympathetic and parasympathetic divisions of the autonomic nervous system.

Sympathetic division: • Prepares body for "fight or flight" situations • Most active under energy-requiring, stressful, emergency situations Parasympathetic division: • Prepares body for "rest and digest" activities • Most active under resting, non-stressful conditions

46. Explain how autonomic neurotransmitters influence the actions of effector cells.

The autonomic neurotransmitters influence actions of effector cells by regulating the function of hormones, digestion or excretion of the effector organs.

45. Define sympathetic tone.

The condition of a muscle when the tone is maintained predominantly by impulses from the sympathetic nervous system.

2. Name the layers of the meninges, and explain their functions.

The layers of the meninges surround the brain and spinal cord. They are, from the outermost to the innermost layers: - Dura mater—the dura mater is a tough, fibrous connective tissue layer containing many blood vessels and nerves. It functions as a protective layer, surrounding the brain and spinal cord. ("tough mother") - Arachnoid mater—the arachnoid mater is a thin web-like membrane that lacks blood vessels and nerves. It is attached to the pia mater by thin strands. ("spider mother") - Pia mater—the pia mater is a thin membrane containing many nerves and blood vessels that provide nourishment to the underlying brain cells and spinal cord. It is attached directly to the surface of the brain and spinal cord. ("soft mother")

13. Explain hemisphere dominance.

The left hemisphere is dominant in most people Dominant hemisphere controls: • Language skills of speech, writing, reading • Verbal, analytical, and computational skills Nondominant hemisphere controls: • Nonverbal tasks • Motor tasks involving orientation in space • Understanding and interpreting musical and visual patterns • Provides emotional and intuitive thought processes

41. Define paravertebral ganglion.

The paravertebral ganglia, also termed the sympathetic chain or trunk, are a series of ganglia which lie in a line lateral and parallel to the vertebral bodies of the spinal column.

8. Define cerebral cortex.

Thin layer of gray matter, which makes up outermost layer of all outer lobes of the cerebrum

31. Which of the following conducts sensory impulses to the CNS from receptors in muscle or skin? a. general somatic efferent fibers b. general somatic afferent fibers c. general visceral afferent fibers d. general visceral efferent fibers

a. general somatic efferent fibers

6. Which choice lists the parts of the brainstem? a. midbrain, pons, and medulla oblongata b. forebrain, midbrain, and hindbrain c. sulci and fissures d. frontal, parietal, and temporal lobes

a. midbrain, pons, and medulla oblongata

25. Which of the choices is the correct sequence of events in a reflex arc? a. effectors to motor neurons to interneurons to CNS to sensory receptor b. sensory receptor to CNS to interneurons to motor neurons to effectors c. effectors to CNS to interneurons to motor neurons to sensory receptor d. sensory receptor to motor neurons to CNS to interneurons to effectors

b. sensory receptor to CNS to interneurons to motor neurons to effectors

16. The ________ conducts sensory information from other parts of the nervous system to the cerebral cortex. a. pineal gland c. thalamus b. hypothalamus d. basal nuclei

c. thalamus

38. The autonomic portion of the PS functions. a. consciously b. voluntarily c. without conscious effort d. dependently

c. without conscious effort

21. The cerebellum a. communicates with the rest of the CNS b. creates awareness of the body's location in space c. coordinates skeletal muscle activity d. all of the above

d. all of the above

12. Broca's area controls a. memory b. defecation c. understanding grammar d. movements used in speaking

d. movements used in speaking

28. Explain the consequences of nerve fibers crossing over.

our body is controlled oppositely, meaning the opposite hemisphere controls the movement and sensory stimuli of the opposite side of the body.