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A&P Morales Fall 2017 Exam 4

Terms in this set (144)

What are the two major divisions of the nervous system?
Central nervous system (CNS) and peripheral nervous system (PNS)
What are the divisions of the motor PNS?
Somatic nervous system (voluntary) and autonomic nervous system (involuntary)
What is the autonomic nervous system division of the PNS further divided into?
The parasympathetic and sympathetic divisions
What are the two divisions of the PNS?
Motor (efferent) and sensory (afferent)
What is the difference between the motor/efferent and sensory/afferent divisions?
motor/efferent carries impulses from the CNS to the body, sensory/afferent carries impulses from the body to the CNS
Aside from the nervous system, what is the other control system of the human body?
Endocrine system, has a slow and steady control
What are the two cell types in the nervous system?
Neurons and neuroglia (supporting cells)
What does a neuron do?
Receive and transmit electrical signals
What is the role of the neuroglia?
Protect and surround neurons, its the most abundant in the nervous system
What are the three components of the neuron?
Body, axon, dendrites
Describe the body of a neuron.
Contains the nucleus, nissl bodies and the axon hillock
Describe the axon of a neuron.
Transmits action potentials away from the body, secrete's neuroT's at the axonal terminal. They arise from the axon hillock
Describe the dendrites of a neuron.
Receptive region of the neuron, convey incoming messages toward the cell body, short processes
What is anterograde movement?
Movement toward the axon terminal
What is retrograde movement?
Movement towards the soma (body) of the neuron
What are astrocytes?
Most abundant supporting cell, control the chemical environment and form supporting framework
What are microglia cells?
Specialized phagocytes that protect against foreign agents
What are ependymal cells?
Line the ventricles of the brain and central cavity of the spinal column, SECRETE CSF
What are oligiodenrocytes?
Function to wrap multiple CNS neurons with myelin
What are satellite cells?
Surround the neurons bodies in ganglia to provide support/protection
What are schwann cells?
Surround single neurons of the PNS with myelin
What are nodes of ranvier?
Also known as neurofibril nodes, they are gaps in the myelin sheath between adjacent shwann cells
What are the three functions of the myelin sheath?
Protect the axon, insulate fibers from one another, increase the speed of nerve impulse transmission
T/F: White matter found in the CNS is myelinated.
True
T/F: Gray matter in the CNS is myelinated.
False, unmyelinated
If a neuron is multipolar, what does that mean?
It has 3 or more processes
If a neuron is bipolar, what does that mean?
It has two processes
If a neuron is unipolar, what does that mean?
It has a single short process
What are interneurons?
Neurons that shuttle signals across the CNS thru pathways
What is an action potential?
Occurs when electrical signals are carried along the length of an axon reflecting the flow of ions across the membrane
What are chemical gradients?
Movement of ions from an area of high concentration to low concentration
What are electrical gradients?
Movement of ions to an area of opposite charge
What is the resting membrane potential?
The potential difference across a membrane of a resting neuron (-70mV)
What is depolarization?
Occurs when the inside of a neuron becomes less negative
What is repolarization?
Occurs when the membrane of a neuron returns to normal
What is hyper polarization?
Occurs when the inside of a neuron becomes too negative, neuron is insensitive to other incoming stimulus during this time
Describe the flow of ions during a nerve impulse.
There is a brief reversal of membrane potential that occurs in the axon. Sodium gates open and sodium enters the cell (depol.) then potassium gates open and potassium exits the cell (repol.) and resting membrane potential and chemical conditions are restored
What are graded potentials?
Short-lived, local changes in the membrane potential
What functions to restore the ionic conditions in the neuron?
Sodium/Potassium pump. 1 ATP pumps 3 Na and 2 K
What is the refractrory period?
Time during which the neuron is less responsive to a second stimulus
What is the difference between absolute refractory and relative refractory periods?
Absolute refractory means that there is no possible way to get a second action potential, relative refractory means that it is possible but that second stimulus must be stronger
What are synapses?
Occur when information is transferred
What are presynaptic neurons?
Neurons that conduct an impulse towards the synapse
What are postsynaptic neurons?
Neurons that conduct an impulse away from the synapse
What is an electrical synapse?
Rapid conduction, held together by gap junctions
What is a chemical synapse?
Release and receive neuroT's, transmission across the synaptic cleft
What is the slowest step of neural transmission?
Synaptic delay
What is reuptake?
The diffusion or degradation of a neuroT by an enzyme resulting in its inability to produce a continuous effect
What is an inhibitory postsynaptic potential (IPSP)?
Occurs when a neuroT binds at an inhibitory synapse
What is an excitatory postsynaptic potential (EPSP)?
Occurs when a neuroT arrives at its receptor
What is temporary summation?
Occurs when multiple single EPSP repeat rapidly to initiate an action potential
What is spatial summation?
Occurs when one group of multiple EPSP's initiate an action potential
What is acetylcholine (Ach)?
A neuroT released at the NMJ in muscular tissue and autonomic nervous system, cholinergic synapse
What is acetylcholinesterase (AchE)?
Enzyme that degrades the functionality of Ach
What are biogenic amines?
NeuroT found in the CNS, controls emotions, sleep cycle, and behaviors. Examples are norepi, dopamine, serotonin
What are amino acids?
Primary inhibitory neuroT in the CNS, example is GABA
What is a neuropeptide?
NeuroT that acts as a natural opiate, reducing our perception of pain
What does the neural plate arise from?
The neural ectoderm
The neural plate grows to form the neural groove which fuses to form the neural tube which then forms into the...
Brain and spinal cord
The forebrain is known as the...
Prosencephalon
The midbrain is known as the...
Mesencephalon
The hindbrain is known as the...
Rhombencephalon
The prosencephalon divides into two different parts, what are they?
Telencephalon and diencephalon
The rhombencephalon divides into two different parts, what are they?
Metencephalon and myelencephalon
What are the three main divisions of the brain?
Cerebrum, cerebellum, and brain stem
Describe the meningeal layers.
Bone, dura mater, subdural space, arachnoid mater, subarachnoid space (houses blood vessels), pia mater
What is the main function of the cerebrum?
Higher thought processes
What is the main function of the cerebellum?
Produce smooth coordinated muscle activity
What is the main function of the brain stem?
Relay station for messages to and from the brain, controls reflexes
What does cerebrospinal fluid (CSF) do?
Cushions to protect the CNS, nourishes the brain, removes waste, carries chemical signals
What are gyri?
The ridges in the brain
What are sulci?
Shallow grooves in the brain
What are fissures?
Deep grooves in the brain
What are ventricles?
Large chambers in the brain that contain CSF
What is the choroid plexus?
Cluster of capillaries in the ventricles the produce CSF and remove waste from CSF
Neural tissue is separated from the general circulation by the...
Blood-brain-barrier (BBB)
What are the four lobes of the brain?
Frontal, parietal, temporal, occipital
The left hemisphere of the brain controls what kind of functions?
Language, math, logic
The right hemisphere of the brain controls what kind of functions?
Visual-spatial skills, emotions, artistic skills
Gray matter comprises __% of the brains mass
40
The cerebral cortex controls...
Conscious thinking and understanding
What are the three functional areas of the cerebral cortex?
Motor, sensory, and association
What does the motor cortex of the cerebrum control?
Voluntary movements
What does the sensory cortex of the cerebrum control?
Conscious sensation
What does the association cortex of the cerebrum control?
Interprets sensory information or coordinates a response
The sensory cortex of the cerebrum is further broken down into what areas?
Primary somatosensory cortex, somatosensory association cortex, and visual/auditory cortex
The motor cortex of the cerebrum is further broken down into what areas?
Primary motor cortex, premotor cortex, and speech (broca's) area
What is the primary motor cortex responsible for?
Conscious control of precise voluntary skeletal muscle movements
What is the premotor cortex responsible for?
Controls patterened motor skills, its a memory bank and plans movements
What is broca's area responsible for?
Directs the muscles of the tongue, only present in the left side of the brain
What is the primary somatosensory cortex responsible for?
Receives info from skin and skeletal muscles, exhibits spatial discrimination
What is the somatosensory association cortex responsible for?
Analyzing sensory information and understanding of stimulus
What is the visual/auditory area responsible for?
Receive and interpret sensory information
What cortex is involved in intellect, recall, personality, conscience and reasoning?
Prefrontal
What does the thalamus do?
It is a relay station for information going to the sensory cortex
What does the hypothalamus do?
Controls autonomic functions, body temp, circadian rhythm, secretes hormones
What does the epithalamus do?
Consists of choroid plexus and pineal gland
What does the pineal gland secrete?
Melatonin
What three components form the diencephalon?
Thalamus, hypothalamus, epithalamus
What is the basal nuclei?
Masses of gray matter found within the cortical white matter, functions to plan/organize/coordinate muscle movements and maintain posture
What does cerebral white matter do?
Myelinated fibers that bundle into large tracts to communicate between the cerebral cortex and all other areas of the brain
Describe the projection fibers of the cerebral white matter
Connect the hemispheres to the lower brain or spinal cord
Describe the association fibers of the cerebral white matter
Connect the different part of the same hemisphere to each other
Describe comissures
Connect the corresponding gray matter of the two hemispheres allowing them to act as one
The brain stem is responsible for what reflex?
Startle reflex, survival behaviors
The cardiovascular and respiratory centers are found in the...
Medulla
The vestibular complex is located in the...
Medulla
What are the two functional brain systems?
Limbic and reticular
The limbic system is responsible for...
Moods, behavior, motivation, anger, danger, fear. Interacts with the prefrontal cortex
What does the reticular system do?
Sends impulse to cerebral cortex to keep is conscious and alert enabling one to focus
What happens when there is too little RAS activity?
Poor memory and little self control
What happens when there is too much RAS activity?
Hyperactive personality
What happens when there is no RAS activity?
Coma
What do alpha waves indicate on an EEG?
Regular/rhythmic idle brain
What do beta waves indicate on an EEG?
Irregular, person is awake and thinking
What do delta waves indicate on an EEG?
Deep sleep and RAS is damped
Sleep is regulated by what portion of the brain?
Hypothalamus
What are the two major types of sleep?
Non-rapid eye movement (NREM) and Rapid eye movement (REM)
What are the four stages of NREM?
1. Eyes closed, relaxed but easily wakened
2. EEG pattern irregular
3. Sleep deepens, vitals decline
4. EEG is delta waves and all skeletal muscles are relaxed
What is REM sleep?
Alpha waves and increased vitals, skeletal muscles inhibited and dreaming takes pace
What is narcolepsy?
A lapsing abruptly from awake into a sleeping state
What is insomnia?
Chronic inability to obtain needed amount of sleep
What are the three principles of memory?
Storage, processing, memory traces
Where does memory processing take place?
Hippocampus
What are memory traces?
Chemical or structural changes that encode memory
How many pieces of information can you hold in your short term memory?
7
What is the range of the spinal cord?
From foramen magnum to L1
How many spinal nerves are there?
31
What is the Conus Medullaris?
Bottom tip of the spinal cord that turns into the cauda equina
What is the filum terminale?
Fibrous extension of the pia mater that anchors the spinal cord to the coccyx
The gray matter of the spinal cord is split into two halves, what are they?
Dorsal and ventral
The dorsal root of the gray matter in the spinal cord is responsible for...
Sensory information
The ventral root of the gray matter in the spinal cord is responsible for...
Motor information
Dorsal root and ventral roots fuse to form...
Spinal nerves
The white matter of the spinal cord is split into 3 different directions/pathways, what are they?
Ascending, descending, transverse
The ascending pathway of the white matter in the spinal cord contains...
1st, 2nd, and 3rd order neurons
First order neurons function to...
Carry impulses from skin to the cord
Second order neurons function to...
Carry impulses from the cord to the thalamus or cerebellum
Third order neurons function to...
Carry information from the thalamus to the sensory cortex
Descending pathways in the white matter of the spinal cord are divided into two groups, what are they?
Direct (pyramidal) and indirect (extrapyramidal)
Direct pathways in the descending pathways of the white matter in the spinal cord are responsible for what kind of movements?
Fast and skilled movements
Indirect pathways in the descending pathways of the white matter in the spinal cord are responsible for what kind of movements?
Balance, posture, large movements, head/neck/eye movements
Quadrapelgia
Injury to the cervical region
Parapelgia
Injury between T1 and L1
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