Nervous System Flashcards
What is the sensory function of the nervous system and where is this carried out?
Receiving information; the PNS
What is the integrative function of the nervous system and where is this carried out?
Processing the information; the CNS
What is the motor function of the nervous system and where is this carried out?
Acting on the information; the PNS
What is the function of motor neurons?
Carry information away from the nervous system towards effectors
What is an effector and what are the types of effectors?
Organs that can act upon the information transmitted by motor neurons; muscles and glands
What category of neurons carry information away from the CNS?
Efferent neurons (to the effectors)
What category of neurons carry information towards the CNS?
Afferent neurons
Give and example of an efferent and an afferent neuron.
Efferent: motor neurons
Afferent: sensory neurons
What is the simplest example of a nervous system activity?
Reflex
What is a reflex?
A direct motor response to sensory input that occurs without conscious thought
What type of reflex involves only two neurons and one synapse?
Monosynaptic reflex arc
Describe an example of a monosynaptic reflex arc.
Muscle stretch reflex: a sensory neuron detects stretching of a muscle and transmits an impulse to a motor neuron cell body in the spinal cord that synapses with the muscle causing it to contract
What two things happen when a physician taps a patellar tendon, and what is this an example of?
The quadriceps contract and the hamstrings relax; reciprocal inhibition
What about the sensory neuron involved in the patellar tendon tap allows the reciprocal inhibition to occur?
The sensory neuron that detects the stretching synapses with both the motor neuron for the quadriceps and with an inhibitory interneuron
What is an inhibitory interneuron?
Forms an inhibitory synapse with a motor neuron inner sting the hamstring muscle
What is the simplest example of the integrative role of the nervous system?
An interneuron
How are we aware of an action that occurs without the involvement of the brain, like a reflex?
The sensory neuron also branches to form a synapse leading to the brain and her sensory information is received after the action is taken
What are the two main divisions of the nervous system and their components?
CNS: brain and spinal cord
PNS: all nerves and sensory structures outside of the brain and spinal cord
What are the the two divisions of the PNS and what function do they serve?
Somatic: voluntary control of skeletal muscle
Autonomic: involuntary control of glands and smooth muscle
What are the two divisions and functions of the autonomic division of the PNS.
Sympathetic: “flight or fight”
Parasympathetic: “rest and digest”
Many sympathetic effects result from the release of what hormone into the bloodstream by what organ?
Epinephrine/adrenaline by the adrenal medulla (on top of the kidney)
What effects does the parasympathetic division have on the digestive system?
Stimulates digestion
Glands and motility: stimulation
Sphincters: relaxation
What effects does the sympathetic division have on the digestive system?
Inhibits digestion
Glands and motility: inhibition
Sphincters: contraction
What effects does the parasympathetic division have on the urinary system?
Stimulates urination
Bladder: construction
Urethral sphincter: relaxation
What effects does the sympathetic division have on the urinary system?
Inhibits urination
Bladder: relaxation
Urethral sphincter: contraction
What effects does the parasympathetic division have on the bronchial smooth muscle?
Closes airways
Bronchial smooth muscle: constriction
What effects does the sympathetic division have on the bronchial smooth muscle?
Opens airways
Bronchial smooth muscle: relaxation
What effects does the parasympathetic division have on the cardiovascular system?
Heart rate and contractility: decreased
What effects does the sympathetic division have on the cardiovascular system?
Heart rate and contractility: increased
Blood flow to skeletal muscle: increased
What effects does the sympathetic division have on the skin?
Sweating and general vasoconstriction Emotional vasodilation (blushing)
What effects does the parasympathetic division have on the eye?
Pupil: constriction
Muscles controlling lens: near vision accommodation
What effects does the parasympathetic division have on the eye?
Pupil: dilation
Muscles controlling lens: accommodation for far vision
What effect does the sympathetic division have on the adrenal medulla?
Release of epinephrine
What effect does the parasympathetic division have on the genitals?
Erection/lubrication
What effect does the sympathetic division have on the genitals?
Ejaculation/orgasm
In which division of the nervous system can one find the most neuronal cell bodies?
CNS
What are bunches of neurons called within the CNS and the PNS?
CNS: nuclei
PNS: ganglia
What is the brown section of the CNS?
[insert figure 9 on page 50]
Cerebral cortex
What is the pink section of the CNS?
[insert figure 9 on page 50]
Corpus callosum
What is the green section of the CNS?
[insert figure 9 on page 50]
Thalamus
What is the light blue section of the CNS?
[insert figure 9 on page 50]
Hypothalamus
What is the yellow section of the CNS?
[insert figure 9 on page 50]
Midbrain
What is the dark blue section of the CNS?
[insert figure 9 on page 50]
Cerebellum
What is the orange section of the CNS?
[insert figure 9 on page 50]
Pons
What is the small red section of the CNS?
[insert figure 9 on page 50]
Pituary gland
What is the purple section of the CNS?
[insert figure 9 on page 50]
Medulla
What is the larger red section of the CNS?
[insert figure 9 on page 50]
Spinal cord
What are the three divisions of the brain?
Hindbrain, midbrain, forebrain
What is the clear liquid that the CNS floats in and what functions does it serve?
Cerebrospinal fluid (CNS); shock absorption and exchange of nutrients and waste with the CNS
What protects the spinal cord?
CSF and the vertebral column
What are the three parts of the hindbrain?
Medulla, pons, cerebellum
Where is the medulla located?
Below the pons and connecting to the spinal cord
What is the general function of the medulla?
Involuntary functions
Where is the pons located?
Below the midbrain and above the medulla
What is the general function of the pons?
Relay station and balance
Where is the cerebellum located?
Behind the pons and below the cerebral hemispheres
What is the general function of the cerebellum?
Movement coordination
What is the result of damage to the cerebellum?
Poor hand-eye coordination and balence
What is the general function of the midbrain?
Eye movement
What parts or the brain constitute the brain stem?
Medulla, pons, and midbrain
What is the function of the brain stem?
Contains important processing centers and relays information to or from the cerebellum and cerebrum
What are the two parts of the forebrain?
The diencephalon and the telencephalon
What are the two parts of the diencephalon?
Thalamus and hypothalamus
What is the location and general function of the thalamus?
Near the middle of the brain below the cerebral hemispheres and above the midbrain; integrating center and relay station
What is the general function of the hypothalamus?
Homeostasis and behavior
All parts of the CNS up to and including the diencephalon form what shape?
A single symmetrical stalk
What does the telencephalon consist of?
Two separate cerebral hemispheres
What differences are there between the functions of the right and left hemispheres?
The left hemisphere controls the motor functions of the right side and vice versa; the left side is dominant in most people and is generally responsible for speech, while the right side is more concerned with visual-spatial reasoning and music
What connects the two cerebral hemispheres?
A thick bundle of axons called the corpus callosum
What are the two components of the cerebrum?
Cerebral cortex- outer layer of grey matter composed of trillions of somas
Inner core of white matter composed of myelinated axons
What are the general functions of the cerebral cortex?
Perception, skeletal muscle movement, memory, thought, language, and consciousness
What are the four pairs of lobes of the cerebral cortex?
Frontal, parietal, temporal, and occipital lobes
Label the four pairs of lobes of the cerebral cortex
[insert figure 10 on page 52]
[insert figure 10 on page 52]
What is the specialized subfunction of the frontal lobes?
Voluntary movement and problem solving
What is the specialized subfunction of the parietal lobes?
Involved in general sensations and gustation
What is the specialized subfunction of the temporal lobes?
Auditory processing, short-term memory, and emotion
What is the specialized subfunction of the occipital lobes?
Visual processing
What two areas of the cerebral cortex are shown in the red section of the brain?
[insert figure 10 on page 52]
Motor homunculus and the frontal eye field
What area of the cerebral cortex is shown in the blue section of the brain?
[insert figure 10 on page 52]
The sensory homunculus
What area of the cerebral cortex is shown in the orange section of the brain?
[insert figure 10 on page 52]
Wernicke’s area (language comprehension)
What area of the cerebral cortex is shown in the dark blue section of the brain?
[insert figure 10 on page 52]
Broca’s area (speech production)
What are basal nuclei composed of and where are they located?
Grey matter; deep within the cerebral hemispheres
What is the general function of the basal nuclei?
Movement
How do the basal nuclei and the cerebellum work together to process and coordinate movement initiated by the primary motor cortex?
The basal nuclei is inhibitory and the cerebellum is excitatory
Emotion, memory, and learning
What is the general function of the limbic system?
Where is the limbic system located and what substructures does it include?
Between the cerebrum and the diencephalon; the amygdala, the cingulate gyrus, and the hippocampus
What is the function of the cranial nerves and how many are there?
Convey sensory and motor information to and from the brainstem; 12 pairs
What is the function of he spinal nerves and how many are there?
Convey sensory information to and from the spinal cord; 31 pairs
What type of nerve is the vagus nerve?
Cranial nerve
What division of the autonomic nervous system is the vagus nerve?
The parasympathetic division
What is true of all somatic motor neurons?
They innervate skeletal muscle cells, use ACh as their neurotransmitter, and their cell bodies are in the brain stem or ventral portion of the spinal cord
[insert part of figure 12 on page 55]
What is true of all somatic sensory neurons?
They have long dendrite extending from a sensory receptor toward the soma, which is located just outside of the CNS in a dorsal root ganglion; the first synapse is in the CNS
[insert part of figure 12 on page 55]
What is a dorsal root ganglion?
A bunch of somatic and autonomic sensory neuron cell bodies located just dorsal to the spinal cord
How many dorsal root ganglia are there?
A pair for every segment of the spinal cord
Which part of the nervous system, CNS or PNS, are the dorsal root ganglia located and why?
The CNS; while protected within the vertebral column, the dorsal root ganglia are outside of the meninges
What two types of efferent neurons does the autonomic nervous system consist of?
A preganglionic and postganglionic neuron
Where is the cell body of a preganglionic neuron?
The brainstem or the spinal cord
Sympathetic: thoracolumbar (thoracic and lumbar spinal cord)
Parasympathetic: craniosacral (brainstem and sacral spinal cord)
Where is the axon of the preganglionic neuron in the autonomic system sent and what does it synapse with?
To an autonomic ganglion, located outside of the spinal column, and it synapses with a postganglionic neuron
What neurotransmitter is released by all autonomic preganglionic neurons?
Acetylcholine (ACh)
What do all parasympathetic postganglionic neurons release?
Acetylcholine
What do nearly all sympathetic postganglionic neurons release?
Norepinephrine
What are the effectors of the somatic system and the autonomic system?
Somatic: Skeletal muscles
Autonomic: all visceral organs, like heart bladder, stomach, blood vessels, ect..
Describe the anatomical organization of PNS effects
Insert picture (page 55)
What are the relative lengths of the preganglionic axon in the sympathetic and the parasympathetic nervous system?
Sympathetic: short
Parasympathetic: long
(Para long pre)
What are the relative lengths of the postganglionic axon in the sympathetic and the parasympathetic nervous system?
Sympathetic: long
Parasympathetic: short
