Mastering A & P chapters 12-15
In the pathway leading to the lacrimal and nasal glands, the preganglionic neurons synapse with ganglionic neurons in the__________.
pterygopalatine ganglion
List the main functions of the nervous system.
sensory, integration, and motor.
Which of these organs/tissues are NOT innervated by parasympathetic fibers, or do not exhibit parasympathetic effects?
sweat glands, arrector pili muscles, and adipose tissue
Which type of sensory receptors are found in dermal papillae of hairless skin, particularly nipples and fingertips?
tactile corpuscles (Meissner's corpuscles)
The__________nerve transmits afferent impulses for the special senses of hearing and balance.
vestibulocochlear
List the major lobes, fissures, and functional areas of the cerebral cortex.
GYRI: elevated ridges of tissue. SULCI: shallow grooves FISSURES: deeper grooves LONGITUDINAL FISSURE: separates the cebral hemispheres TRANSVERSE CEREBRAL FISSURE: separates the cerebral hemispheres from the cerebellum bellow. CENTRAL SULCUS: lies in the frontal plane, separates the Frontal lobe from the Parietal lobe. PRECENTRAL GYRUS: bordering the central suclus anteriorly. POSTCENTRAL GYRUS: bordering the central sulcus posteriorly OCCIPITAL LOBE is separated from the PARIETAL LOBE by the PARIETO-OCCIPITAL SULCUS LATERAL SULCUS outlines the flaplike TEMPORAL LOBE and seperates it from the parietal and frontal lobes. INSULA: is buried deep within the lateral sulcus and forms part of its floor.
Grey matter
Grey matter (or gray matter) is a major component of the central nervous system, consisting of neuronal cell bodies, neuropil (dendrites and myelinated as well as unmyelinated axons), glial cells (astrocytes and oligodendrocytes), synapses, and capillaries.
Describe the roles of interneurons in the CNS.
Interneurons create neural circuits, enabling communication between sensory or motor neurons and the central nervous system (CNS). They have been found to function in reflexes, neuronal oscillations, and neurogenesis in the adult mammalian brain.
Which brain region coordinates all of these critical functions: adjusts the rate and force of heart contractions, adjusts blood vessel diameter to regulate blood pressure, and regulates respiration rates?
Medulla oblongata
describe how the general visceral motor system of the autonomic nervous system (ANS) differs from the general somatic motor system?
Motor units in the ANS include a chain of two motor neurons.
Explain the structural and functional divisions of the nervous system.
The CNS is the brain and spinal cord. The PNS is everything else. Functionally, the nervous system can be divided into those regions that are responsible for sensation, those that are responsible for integration, and those that are responsible for generating responses.
Describe the structure of myelin sheaths.
The Myelin Sheath of a neuron consists of fat-containing cells that insulate the axon from electrical activity.
Outline the organization of the peripheral nervous system.
The PNS consists of the nerves and ganglia outside the brain and spinal cord. The main function of the PNS is to connect the CNS to the limbs and organs, essentially serving as a relay between the brain and spinal cord and the rest of the body.
Describe the structural components of the peripheral nervous system
The PNS consists of the nerves and ganglia outside the brain and spinal cord. The peripheral nervous system is divided into the somatic nervous system and the autonomic nervous system.
Name three classes of fiber tracts in the white matter of the cerebrum.
projection, commissural, and association.
Describe the structure of a synapse.
1) the presynaptic membrane which is formed by the terminal button of an axon, 2) the postsynaptic membrane which is composed of a segment of dendrite or cell body, and 3) the space between these two structures which is called the synaptic cleft.
Define dermatomes
A dermatome is the area of sensory nerves near the skin that are supplied by a specific spinal nerve root.
Define nerve and describe the structural components of nerves.
A nerve is the primary structure of the peripheral nervous system (PNS) that encloses the axons of peripheral neurons. A nerve provides a structured pathway that supports neuron function.
Which statement is true concerning neuronal regeneration? A. Reinnervation of the target organ with partial recovery of function is sometimes possible in the PNS. B. In the CNS, if neuroglial cells form parallel bands to guide new axonal extensions, some return of function to the damaged region of the brain or spinal cord is possible. C. After injury, most neurons are prompted to undergo mitosis. D. According to recent studies, regions of the thalamus and medulla oblongata have been shown to form new neurons. E. None of the listed choices is correct.
A. Reinnervation of the target organ with partial recovery of function is sometimes possible in the PNS.
Define CNS
Central Nervous System, consisting of the brain and spinal cord which occupy the cranium and vertebral column, respectively. The CNS is the integrating and command center of the nervous system. It receives incoming sensory signals, interprets the signals and dictates motor responses based on past experiences, reflexes and current conditions.
Define nerve plexus. Name the four main plexuses formed by ventral rami, and the body region innervated by each. Describe the major nerves originating from each plexus.
Cervical plexus - serves the head, neck and shoulders. Brachial plexus - serves the chest, shoulders, arms and hands. Lumbar plexus - serves the back, abdomen, groin, thighs, knees, and calves. Sacral plexus - serves the pelvis, buttocks, genitals, thighs, calves, and feet.
List the six types of neuroglia in nervous tissue, and distinguish them by location and function.
Astrocyte.- star-shaped and are the most abundant glial cells of the CNS. They have many radiating processes with bulbous ends. Some of these bulbs cling to neurons whereas others cling to capillaries. Functions include (1) regulating neurotransmitter levels by high neuronal activity. (2) Signaling increased blood flow through the capillaries in active regions of the brain. (3) Controlling the ionic environment around neurons. Astrocytes also help synapses form in developing neural tissue, producing molecules necessary for neural growth and propagating calcium signals that maybe involved with memory. Oligodendrocyte.- : have fewer branches than astrocytes, line up in small groups and wrap their cell process around the thicker axons in the CNS producing insulating coverings called myelin sheaths. Microglia.- the smallest and least abundant neuroglia of the CNS. They have elongated cell bodies and cell processes with many pointed projections like a thorny bush. They are phagocytes; the macrophages of the CNS. They migrate to and then engulf invading microorganisms and dead or injured neurons. Ependymal cell.-these cells form a simple epithelium that lines the central cavity of the spinal cord and brain. These cells provide a fairly permeable layer between the cerebrospinal fluid that fills this cavity and the tissue fluid that bathes the cells of the CNS. They also bear cilia that help circulate the cerebrospinal fluid. Satellite cell.- surround neuron cell bodies within ganglia. Schwann cell.- surround all axons in the PNS and form myelin sheaths around many of these axons.
Define the autonomic nervous system (ANS), and explain its relationship to the peripheral nervous system as a whole.
Autonomic Nervous system (ANS)- (Motor) Efferent division of the PNS that innervates cardiac and smooth muscles and glands: also called the involuntary or visceral motor system.
Which of the following functions is NOT associated with the spinal cord? A. The spinal cord is a major integration center for reflexes. B. Through the cranial nerves that attach to it, the spinal cord is involved in sensory and motor innervation of the head and neck. C. It provides a two-way conduction pathway for signals between the body and the brain. D. Through the spinal nerves that attach to it, the spinal cord is involved in sensory and motor innervation of the entire body inferior to the head. E. All of the statements are functions attributed to the spinal cord. There are no exceptions.
B. Through the cranial nerves that attach to it, the spinal cord is involved in sensory and motor innervation of the head and neck.
The oculomotor nerve __________.
Directs somatic motor axons to four of the six extrinsic eye muscles and also transmits parasympathetic visceromotor impulses to pupillary constrictor muscle of the eye
Cranial nerves III, VII, IX, and X _________.
Each contain general visceral motor axons and are characterized as nerves of the parasympathetic division of the autonomic nervous system
Describe the sympathetic function of the adrenal medulla.
Epinephrine is the main catecholamine produced by the adrenal medulla, in contrast to sympathetic ganglia, which produce predominantly norepinephrine. Adrenal medulla is part of the sympathetic system and is important for the regulation of blood pressure.
Explain the concept of referred pain.
Pain felt at a site other than where the cause is situated. An example is the pain from the pancreas, which is felt in the back. Pain in internal organs is often referred to sites distant from them.
Define PNS
Peripheral Nervous System, the part of the nervous system outside of the CNS. It consists of the nerves that extend from the brain and spinal cord. Cranial nerves carry signals to and from the brain. Spinal nerves carry signals to and from the spinal cord. Also included in the PNS are ganglia (areas where the cell bodies of neurons are clustered.)
Explain how the reflex arc relates to the basic organization of the nervous system
Reflex arcs are simple axons of neurons that cause our simplest, reflexive behavior and reflect the basic structural plan of the nervous system. Reflex arcs account for reflexes (which are defined as rapid, automatic motor responses to stimuli. Reflexes are unlearned, unpremeditated and involuntary.)
Explain the following types of sensory and motor information carried by the nervous system: Somatic sensory Visceral sensory Somatic motor Visceral motor Branchial motor
SS-sensory innervation of the outer tube (skin, body wall and limbs) VS- sensory innervation of the viscera SM- voluntary motor) motor innervation of the outer tube (specifically skeletal muscles) VM- part of the PNS that regulates the contraction of smooth and cardiac muscle as well as secretion by the body's many glands. BM- Typical skeletal muscle derived from somitomeres
why are cell bodies of sensory neurons are located in the PNS (outside the CNS) in ganglia?
Sensory neurons arise from neural crest cells.
Differentiate serial processing and parallel processing.
Serial processing allows only one object at a time to be processed, whereas parallel processing assumes that various objects are processed simultaneously. ... The same model can explain both serial and parallel processing by adopting different parameter regimes
Explain how various regions of the CNS help to regulate the autonomic nervous system.
The autonomic nervous system is a control system that acts largely unconsciously and regulates bodily functions such as the heart rate, digestion, respiratory rate, pupillary response, urination, and sexual arousal. Within the brain, the autonomic nervous system is regulated by the hypothalamus.
Name and describe the locations of the ventricles of the brain.
The brain ventricles are four cavities located within the brain that contain cerebral spinal fluid (CSF). There are two lateral ventricles—one on each side of the cerebral cortex.
Describe the structural link between the peripheral nervous system and the central nervous system.
The central nervous system includes the brain and spinal cord, while the peripheral nervous system includes all of the nerves that branch out from the brain and spinal cord and extend to other parts of the body including muscles and organs
Describe the structure and function of the cerebellum.
The cerebellum receives information from the sensory systems, the spinal cord, and other parts of the brain and then regulates motor movements. The cerebellum coordinates voluntary movements such as posture, balance, coordination, and speech, resulting in smooth and balanced muscular activity.
Compare autonomic neurons to somatic motor neurons.
The main difference between the somatic and autonomic systems is in what target tissues are effectors. Somatic responses are solely based on skeletal muscle contraction. The autonomic system, however, targets cardiac and smooth muscle, as well as glandular tissue.
Name the 12 pairs of cranial nerves, and describe the structures innervated by each.
The olfactory nerve (I): This is instrumental for the sense of smell, it is one of the few nerves that are capable of regeneration. The optic nerve (II): This nerve carries visual information from the retina of the eye to the brain. The oculomotor nerve (III): This controls most of the eye's movements, the constriction of the pupil, and maintains an open eyelid. The trochlear nerve (IV): A motor nerve that innervates the superior oblique muscle of the eye, which controls rotational movement. The trigeminal nerve (V): This is responsible for sensation and motor function in the face and mouth. The abducens nerve (VI): A motor nerve that innervates the lateral rectus muscle of the eye, which controls lateral movement. The facial nerve (VII): This controls the muscles of facial expression, and functions in the conveyance of taste sensations from the anterior two-thirds of the tongue and oral cavity. The vestibulocochlear nerve (VIII): This is responsible for transmitting sound and equilibrium (balance) information from the inner ear to the brain. The glossopharyngeal nerve (IX): This nerve receives sensory information from the tonsils, the pharynx, the middle ear, and the rest of the tongue. The vagus nerve (X): This is responsible for many tasks, including heart rate, gastrointestinal peristalsis, sweating, and muscle movements in the mouth, including speech and keeping the larynx open for breathing. The spinal accessory (XI): This nerve controls specific muscles of the shoulder and neck. The hypoglossal nerve (XII): This nerve controls the tongue movements of speech, food manipulation, and swallowing.
Describe the basic differences between the parasympathetic and sympathetic divisions of the ANS.
The parasympathetic nervous system (PNS) controls homeostasis and the body at rest and is responsible for the body's "rest and digest" function. The sympathetic nervous system (SNS) controls the body's responses to a perceived threat and is responsible for the "fight or flight" response.
Describe the gross structure of the spinal cord.
The spinal cord is part of the central nervous system (CNS), which extends caudally and is protected by the bony structures of the vertebral column. It is covered by the three membranes of the CNS, i.e., the dura mater, arachnoid and the innermost pia mater.
Why are sensory neurons that monitor touch, pressure, vibration, pain, and temperature considered "general sensory receptors"?
Their receptors are widely distributed over the body.
describe the location of a spinal nerve, and distinguish spinal roots from rami.
These nerves are mixed, having both a sensory and a motor aspect. Their motor fibers begin on the ventral part of the spinal cord at the anterior horns of the gray matter. The roots of their sensory fibers are located on the dorsal side of the spinal cord in the posterior root ganglia.
Part complete Lamellar corpuscles (Pacinian corpuscles) and bulbous corpuscles (Ruffini endings) are similar in many aspects,EXCEPT for?
They are both slowly adapting receptors
Which of these statements regarding the collateral ganglia of the sympathetic division is FALSE?
They are the same as the sympathetic trunk ganglia.
white matter
White matter refers to areas of the central nervous system (CNS) that are mainly made up of myelinated axons, also called tracts.
Why are white rami communicantes found only in the region of T1â€"L2?
White rami carry the preganglionic sympathetic outflow from the spinal cord.
neurons are rare neurons, but are located in the retina and in the olfactory mucosa.
bipolar
The medial and anterior regions of the hypothalamus direct__________functions.
parasympathetic
Nerve fascicles are bound into bundles by a wrapping of connective tissue called __________.
perineurium
The processes that branch from the cell body of a neuron and receive signals from other neurons are__________.
dendrites
Microglia are unlike other neuroglial cells in that they __________.
derive from pre-natal monocyte
Activation of the sympathetic division of the ANS causes__________of bronchioles.
dilation
__________is seen in a stretch reflex when the stretch of a muscle stimulates numerous sensory neurons that then synapse with 100 or more neurons in the grey matter of the spinal cord. divergence
divergence
If you were very nervous about speaking in front of a group of people, which of the following would be likely to develop?
dry mouth, due to sympathetic inhibition of secretions from the salivary glands
Classify neurons both structurally and functionally.
functional classification of neurons is based on the direction the action potential travel relative to the central nervous system. Structural classification of neurons is based upon the number of processes that extend out from the cell body.
The CNS structure that is the main integration center of the ANS is the__________
hypothalamus
The gray matter of the spinal cord __________.
is a mixture of neuronal cell bodies, unmyelinated axons, dendrites, and neuroglia
Multiple sclerosis (MS) __________.
is not always easy to diagnose because of its range of symptoms and presentation is a demyelinating disease that affects more women than men, and affects men later in life is five times more common in temperate Europe or the United States than in tropical countries is an autoimmune disease that is characterized by numbness or pain on the skin, muscle weakness, slurred speech, and difficulty in maintaining balance
Which factors contribute to increasing the speed of nerve impulse transmission?
larger diameter of axon and the presence of myelin sheath
The simplest type of reflex, in which there is no interneuron between the sensory and motor neuron, is called a __________reflex.
monosynaptic
