Nervous System Flashcards
The Central Nervous System is composed of ___ & ____ ___
Brain & spinal cord
The _______ area that allows us to consciously move our skeletal muscles is anterior to the central sulcus in the _______ lobe.
somatic sensory; frontal primary motor; temporal primary motor; frontal lobe somatic sensory; parietal primary motor; parietal
primary motor; frontal lobe
Besides the accessory nerve (XI), which pair of cranial nerves extends beyond the head and neck?
Trigeminal (V) Hypoglossal (XII) Facial (VII) Oculomotor (III) Vagus (X)
Vagus (X)
The cell bodies of sensory neurons whose fibers enter the cord are found in the _______.
basal nuclei ventral root autonomic ganglia ventral root ganglion dorsal root ganglion
Dorsal root, ganglion
The cells that produce myelin in the peripheral nervous system (PNS) are called _______, and in the central nervous system (CNS) the cells are called _______.
satellite cells; astrocytes astrocytes; Schwann cells Schwann cells; oligodendrocytes oligodendrocytes; Schwann cells Schwann cells; microglia
Schwann cells; oligodendrocytes
The three connective tissue membranes covering and protecting CNS structures are collectively known as the _______. The _______ is the outermost, leathery layer.
meninges; dura mater periosteum; dura mater meninges; arachnoid endosteum; pia mater meninges; pia mater
meninges; dura mater
What is the minimum number of neurons that can be involved in a reflex?
Four Three Two Five One
2
The deep groove that separates the two hemispheres of the cerebrum is called the _______.
pons central sulcus thalamus longitudinal fissure cerebellum
Longitudinal fissure
Which of the following substances is NOT prevented from entering brain tissue due to the tight junctions that form the blood-brain barrier?
Potassium ions Nonessential amino acids Urea Proteins Essential amino acids
Essential amino acids
Which of the following is NOT a central nervous system glial cell?
Neuron Ependymal cell Oligodendrocyte Astrocyte Microglia
Neuron
An action potential i) occurs when the local potential reaches threshold, ii) obeys the all-or-none rule, iii) proceeds with constant magnitude from one point to another, iv) is characterized by a series of depolarizations/repolarizations along the membrane.
All the above statements are correct. Only (i), (ii), and (iii) are correct. Only (i) and (iii) are correct. Only (iv) is correct. Only (ii) and (iv) are correct.
All are correct
Between successive Schwann cells, there are gaps in the myelin sheath called _______.
axon hillocks nodes of Ranvier Nissl granules neuron cell bodies axons
Nodes of Ranvier
Damage to which cranial nerve(s) may impair the sense of taste?
Hypoglossal (N XII)
Facial (N VII)
The facial (N VII) and the glossopharyngeal (N IX)
Glossopharyngeal (N IX)
The facial (N VII) and the glossopharyngeal (N IX)
The _______ produce cerebrospinal fluid.
crura cerebri adenohypophyseal glands meninges choroid plexuses corpora quadrigemina
choroid plexuses
The cerebellum aids in maintenance of _______.
emotional behavior visual acuity binocular vision speech balance and posture
Balance of posture
The corpus callosum connects the _______.
lateral lobes of the cerebellum hippocampi with the mammillary bodies hypothalamus to the pons cerebellum to the pons and medulla right and left cerebral hemispheres
right and left hemispheres
The dendrite of a neuron _______.
conducts nerve impulses away from the neuron cell body AND is the larger cell process of a multipolar neuron
conducts nerve impulses toward the neuron cell body
is the only cell process of a multipolar neuron
conducts nerve impulses away from the neuron cell body
conducts nerve impulses toward the neuron cell body
Sensory neuron cell processes (dendrites) carry a stimulus toward the neuron cell body.
Which of the following cranial nerves supplies motor fibers to the pharynx that promote swallowing and saliva production, and carries sensory impulses from taste buds of the posterior tongue and from pressure receptors of the carotid artery?
Hypoglossal nerve (N XII) Facial nerve (N VII) Trigeminal nerve (N V) Glossopharyngeal nerve (IX) Vagus nerve (N X)
Glossopharyngeal nerve (IX)
Which of the following statements regarding the nerve impulse is TRUE?
If a stimulus is strong enough, hyperpolarization causes membrane polarity to be completely reversed, and an action potential is initiated.
Ionic conditions are restored after repolarization by the actions of the sodium-potassium (Na+-K+) pump, whereby two Na+ ions are ejected for every three K+ ions carried back into the cell.
A stimulus changes the permeability of a “patch” of the membrane, and sodium ions (Na+) diffuse rapidly into the cell.
During repolarization, sodium ions diffuse rapidly into the cell.
The external face of the resting membrane is slightly negative, and its internal face is slightly positive.
A stimulus changes the permeability of a “patch” of the membrane, and sodium ions (Na+) diffuse rapidly into the cell.
Abundant, star-shaped cells
Form barrier between capillaries and neurons to maintain the blood-brain barrier and control the brain’s chemical environment (ions, nutrients, etc)
Astrocytes
Mobile cells roaming through neural tissue, similar to macrophages
Remove cellular debris, waste products, and pathogens
Microglia
Form the epithelium-lined fluid-filled passageways in spinal cord and brain
Produce, monitor, and circulate CSF
Ependymal cells
Wrap around nerve fibers in the central nervous system to produce myelin sheaths
Oligodendrocytes form concentric layers of lipid-rich material called myelin sheath around axons
Grey Matter
Unmyelinated axons not completely covered by myelin
Regions of CNS with cell bodies and unmyelinated axons are gray matter
White matter
Myelinated axons have myelin sheath
Regions in CNS with myelinated axons are white matter
Form myelin sheath in the peripheral nervous system
Schwann cells
Protect neuron cell bodies
Satellite cells
Neurons
Neurons = nerve cells
Cells specialized to transmit messages from one part of the body to another – these messages are called nerve impulses
Neurons are amiotic
Receive stimuli from environment or other neurons
Dendrites
Contains nucleus and other organelles
Cytoskeleton contains filaments that extend into dendrites and axon
Cell bodies
Carries information away from cell body toward other cells
Axon
Axonal Terminal
Axonal terminals contain vesicles with neurotransmitters
End of axon terminal adjacent to synapse (where neuron communicates with another cell)
whitish, fatty material produced by schwann cells (in periphery) and oligodendrocytes (CNS) to cover axons
Myelin Sheath
The purpose of the myelin sheath is to:
The purpose of the myelin sheath is to:
protect and insulate the nerve fibers
increase the transmission (speed) of the nerve impulse
Somatic sensory neurons
External receptors detect changes in external environment
Proprioceptors monitor body position and movement
Somatic sensory neurons
External receptors detect changes in external environment
Proprioceptors monitor body position and movement
The function of sensory neurons in the CNS is ______
The 3 types of sensory neurons in the CNS are _____, ________ & ________
Deliver information from receptors to CNS along afferent fibers
Somatic sensory neurons
External receptors detect changes in external environment
Proprioceptors monitor body position and movement
Visceral sensory neurons
Internal receptors monitor internal conditions
Special sensory neurons
From the 5 special senses
Interneurons
Receive sensory information from PNS and from other interneurons in CNS
Responsible for memory, planning, and learning
The function of a motor neuron is _________
The 2 types of motor neuron are _______ & ______
Carry information from CNS to effectors along efferent fibers
Somatic motor neurons
Innervate skeletal muscle under voluntary control
Visceral motor neurons
Innervate smooth muscle, glands, cardiac muscle, adipose tissue
Function of a neuron
Responds to stimuli and creates a nerve impulse – this is called irritability
Transmits impulses to other neurons – this is called conductivity
Depolarization
When the cell is becoming more positive
-80 to +30
Repolarization
Cell becoming more negative
Define reflex and reflex arc
Reflex - rapid, predictable, and involuntary response to a stimulus
Occurs over pathways called reflex arcs
Reflex arc - direct route from a sensory neuron, to an interneuron, to an effector
Somatic Reflexes
Somatic reflexes
Activation of skeletal muscles
Autonomic reflexes
Heart rate and blood pressure regulation Regulation of glands Digestive system regulation Pupillary reflex Saliva and goosebumps
Deep Tendon Reflexes
Biceps – antecubital - flexion
Patellar – knee cap - flexion
Superficial Reflexes
Corneal - blink
Pupillary – pupil reaction
Plantar – toes down
Babinski – toes up & fan - abnormal
Primitive Reflexes
Grasp – hold hand/finger and don’t let go
Sucking
Regions of the brain
Cerebrum – divided into two central hemispheres
Diencephalon
Brain stem
Cerebellum
Calcium triggers _______ in production of neurotransmitters
exotysosis
Surface lobes of the cerebrum include
Frontal lobe
Parietal lobe
Occipital lobe
Temporal lobe
Three main regions of cerebral hemisphere
Three main regions of cerebral hemisphere
Cortex (gray matter)
White matter
Basal nuclei (deep pockets of gray matter)
4 lobes and their functions are
Frontal Lobe - concentration, judgment, abstract thinking, personality, motor function (primary motor area)
Parietal lobe - sensory processing (somatic) – pain, cold, light touch, position
Temporal – receptive area (hearing, smell)
Occipital – vision interpretation
Primary somatic sensory area
Receives impulses from the body’s sensory receptors
Pain, temperature, light touch
Located in parietal lobe posterior to central sulcus
Sensory homunculus is a spatial map
Left side of the primary somatic sensory area receives impulses from right side (and vice versa)
Specialized areas of the cerebrum include
Primary motor area Broca's Area Anterior association areas Posterior association areas Cerebral areas involved in special senses Visual area (occipital lobe) Auditory area (temporal lobe) Olfactory area (temporal lobe)
Primary motor area
Primary motor area
Sends impulses to skeletal muscles
Located in frontal lobe
Motor neurons form corticospinal (pyramidal) tract, which descends to spinal cord
Motor homunculus is a spatial map (see previous slide)
Broca’s Area
Broca’s area (frontal lobe)
Involved in our ability to speak (vocalize words)
Usually only in left hemisphere
Anterior association areas
Higher intellectual reasoning and social behavior
Posterior association areas
Posterior association areas
Recognizing patterns and faces; blending all inputs into an understanding of the “whole situation”
Basal nuclei (ganglia)
Basal nuclei (ganglia)—islands of gray matter buried within the white matter Regulates the information coming from the primary motor cortex going to the thalamus and then spinal cord
Central sulcus
Central sulcus - Separates frontal lobe from parietal lobe
Contains primary motor cortex (anterior) – sends motor impulses to periphery – in frontal lobe
Contains primary sensory cortex (posterior) - receives impulses from peripheral sensory receptors – in parietal lobe
Lateral sulcus
Separates frontal lobe from temporal lobe
Parieto-occipital sulcus
Separates parietal lobe from occipital lobe
Thalamus
Thalamus
Relay station for sensory impulses
Transfers impulses to the correct part of the cortex for localization and interpretation
Hypothalamus
Under the thalamus Important autonomic nervous system center Helps regulate body temperature Controls water balance Regulates metabolism Houses the limbic center for emotions Regulates the nearby pituitary gland
Epithalamus
Epithalamus
Houses the pineal body (an endocrine gland)
Includes the choroid plexus - CSF
Parts of the Brain Stem
Parts of the brain stem
Midbrain
Pons
Medulla oblongata
Midbrain
Midbrain
Composed mostly of tracts of nerve fibers to convey ascending and descending impulses (between cerebrum and spinal cord)
Also contains visual and auditory reflex centers
Pons
Pons
Mostly composed of fiber tracts
Includes nuclei involved in the control of breathing
Medulla Oblongata
Medulla Oblongata The lowest part of the brain stem - merges into the spinal cord Contains critical control centers Heart rate control Blood pressure regulation Breathing Swallowing Vomiting
Reticular formation
Diffuse mass of gray matter along the brain stem
Involved in motor control of visceral organs
Reticular activating system (RAS)
Plays a role in awake/sleep cycles and consciousness
Filter for incoming sensory information
Deliver information from receptors to CNS along afferent fibers
Sensory Neurons
Somatic sensory neurons
Visceral sensory neurons
Internal receptors monitor internal conditions
Special sensory neurons
From the 5 special senses
External receptors detect changes in external environment
Proprioceptors monitor body position and movement
Somatic sensory neurons
Internal receptors monitor internal conditions
Visceral sensory neurons
Somatic reflexes
Activation of skeletal muscles
Autonomic reflexes
Heart rate and blood pressure regulation Regulation of glands Digestive system regulation Pupillary reflex Saliva and goosebumps
regions of the brain
Cerebrum – divided into two central hemispheres
Diencephalon
Brain stem
Cerebellum
Lobes of the cerebrum
Fissures (deep grooves) divide the cerebrum into lobes Surface lobes of the cerebrum Frontal lobe Parietal lobe Occipital lobe Temporal lobe
Function of the Frontal Lobe
- concentration, judgment, abstract thinking, personality, motor function (primary motor area)
functions of the Parietal lobe
- sensory processing (somatic) – pain, cold, light touch, position
function of the temporal lobe
Temporal – receptive area (hearing, smell)
function of the Occipital lobe
Occipital – vision interpretation
