Neurophysiology (slides 1-55) Flashcards
Above the midbrain, Rostral is A)anterior B)posterior C)superior D)inferior
A) anterior
Above the midbrain, Ventral is A)anterior B)posterior C)superior D)inferior
D) inferior
Above the midbrain, Caudal is A)anterior
B)posterior
C)superior
D)inferior
B)posterior
Above the midbrain, dorsal is A)anterior B)posterior C)superior D)inferior
C)superior
Below midbrain Rostral is ______ and Caudal is ______.
Superior (head)
Inferior (tail)
Below the midbrain ventral is _____ and dorsal is____
Anterior (front of body)
Posterior (back of body)
Ipsilateral
Two points on same side of midline
Contralateral
Two points on opposite sides of midline
Soma
Cell body of the neuron
Neurites
Thin cellular processes extending from soma
Axon
Carries action potential away from soma
Dendrites
Receive impulses from other neurons
Gray matter
-Neuronal cell bodies in CNS (gray because no myelin)
Cortex
Thin sheets of neurons, usually at the brain surface and most often used in reference to the cerebral cortex
Nucleus
Term referring to collection of neurons
Clearly defined mass of neurons, usually large and deeply placed in brain
Locus
Clearly defined groups of neurons, but smaller than a nucleus
Substantia
Less well-defined group of neurons
Ganglion
Applied to collections of neurons in PNS (exception: basal ganglia)
White matter
General term for axon groups in CNS (whit because it has myelin)
Tract
Collection of axons with common origin
Capsule
A group of axons connecting the cerebrum and brain stem
Comissure
A collection of axons that connects one side of the brain to the other
Leminscus
A “ribbon-like” tract
Nerve
A bundle of axons in the PNS (expection: optic nerve)
Layers of the meninges from superficial to deep
Dura mater
Arachnoid mater
Pia mater
Where is CSF located?
Subarachnoid space
Afferent nerves
Sensory info from periphery to CNS
Peripheral Nervous System made up of:
- Neurons & glia outside the meninges
- Spinal nerves
- Cranial nerves
- sensory receptors
Efferent nerves
Carry info from CNS to periphery
True of false: Motor nerves are afferent
False, motor nerves are efferent nerves that carry info to skeletal muscles
What are the subdivisions of the autonomic nervous system?
- sympathetic
- parasympathetic
- enteric
What is the somatic nervous system
Sensory and motor communications between CNS and skin, skeletal muscles and joints
What is the rest and digest system?
Parasympathetic
What is the fight or flight system?
Sympathetic
Which system controls the walls of the GI tract?
Enteric nervous system “gut brain”
Cerebrum (two cerebral hemispheres) receives input and controls movement from which side of the body?
Contralateral side
Cerebellum is mainly responsible for what two things?
Muscle coordination and balance (think when you get drunk)
What part of the brain is responsible for the regulation of vital body functions?
Brain stem
Dorsal root carries ___ info ____ the spinal cord
Afferent, toward
Ventral root carries _____ info ___ the spinal cord
Efferent, away from
Surface area of the brain is increased through ____ and ____
Folds (gyri) and fissures (suci)
Which structure controls thoughts, perceptions and voluntary actions?
Cerebrum
What is another term for cerebrum
Cortex, refers to surface of gray matter
Lower part of the forebrain is the ________
Diencephalon (thalamus and hypothalamus)
What structure is the relay station for sensory pathways?
Thalamus
Corpus callosum
Provides the link between hemispheres
True or false: hypothalamus lies ventral to the thalamus
True- ventral means below
Which structure is considered the command center for the ANS?
Hypothalamus
Four F’s of hypothalamus include
Feeding
Fighting
Fleeing
F**king
What are the two major midbrain structures?
Tectum and tegmentum (cerebral peduncles)
Superior and inferior colliculus are structures of the ____ in the midbrain
Tectum
Superior colliculus receives sensory input from what body structure?
Eyes; involved in eye movement
Inferior colliculus is the relay station for sensory input from what part of the body?
Ear
What are the two structures within the tegmentum (cerebral peduncles)
Red nucleus
Substantia Nigra
What three structures make up the hindbrain
Cerebellum
Pons
Medulla
Ataxia
Damage to the cerebellum causing jerky movements; poorly coordinated
Descending tracts of the cerebellum are responsible for ____
Movement
Ascending tract of cerebellum are responsible for ____
Proprioception aka position sense
Site of decussation (crossing over) of motor tracts
Medullary pyramids
How many pairs of cranial and spinal nerves are there?
12 pairs of cranial
31 pairs of spinal
Which nerve is considered part of the CNS and why?
Optic n. By its located within the meninges
All cranial nerves serve head and neck region expect which nerve?
Vagus, travels down to diaphragm
If volume in brain increases there is risk of intracranial pressure which in turn, decreases brain ___
Perfusion
What are the 3 components of brain ECF
Blood plasma
Interstitial fluid (in contact with neural cells and glia)
CSF within ventricular and subarachnoid space
What makes CSF?
Choroid plexus epithelium
CSF is drained into venous system via ________
Arachnoid granulation
Functions of CSF
- Shock absorber
- Assist in maintenance of constant internal environment of CNS
- route for removal of metabolites in the brain
Blood Brain Barrier made up of
Capillary endothelial cells connected by tight junctions. The end foot (podocyte process) of Astrocytes also promote the BBB.
_____ _____ soluble solutes can get through the BBB (capillary endothelial membranes). Give examples
Highly Lipid soluble
Ex: O2, CO2, urea, nicotine, ethanol
Non lipid solubles are unable to diffuse into the brain , what is the exception & how does it get through?
Glucose enters via GLUT-1 carriers
What are circumventricular organs? And examples.
Areas of brain that lack BBB. Directly exposed to solutes in blood.
Ex:
-ogranum vasculosum laminae terminalis (OVLT)
-posterior pituitary
-pineal gland
How does OVLT generate a fever?
Leakiness in OVLT allows circulating cytokines to signal the body to body temperature control to generate a fever
Definition and example of Unipolar, Bipolar and Multipolar neurites
Uni- single neurite ( primary sensor neurons)
Bi- two neurites (retinal bipolar cell)
Multi- three or more neurites *most common
Ex: spina motor neuron
Organization of dendrites follow what two patterns
Pyramidal neurons or Stellate (star-shaped) neurons
Do Golgi type I Neurons have short or long axons?
Long axons (project from one region of nervous system to another)
Do Golgi type II neurons have short or long axons?
Short axons (contribute to local circuits in a region)
In what area of the axon are action potentials readily triggered and why?
Initial segment (aka spike initiation zone) due to high levels of voltage gated Na channels
What is the majority type of neurons in the body? Primary sensory neurons, interneurons or motor neurons?
Interneurons (only form connections with other neurons)
What happens at the terminal bouton?
Aka axon terminal ; point of synapse.
What is the axon proper?
The section of the axon that IS myelinated and can extend over long distance.
Axons with larger diameters have lover ______ and faster ________.
Lower electrical resistance and faster conduction velocities
What is Wallerian degeneration
The degeneration of the distal part of a neuron after being cut.
Transport of materials in the axon is mediated by ______
Cytoskeleton
What are the three parts of the cytoskeleton involved with axoplasmic transport?
Microtubules (run longitudinally, train tracks)
Microfilaments (polymers of actin molecules)
Neurofilaments (long protein molecules)
How does anterograde transport of microfilaments work?
Soma to axon terminal (movement of vesicles with neurotransmitters)
What is retrograde transport?
Axon terminal towards cell body (uptake of growth factor at axon terminal by endocytosis)
What are considered the “box cars” on the train tracks in regards to axoplasmic transport?
Motor proteins
Name of support cells that support neurons
Neuroglia
Name of neuron cells that provide immunity
Microglia
What cells produce and maintain myelin sheath in CNS?
Oligodendrocytes
What cells make myelin sheath in PNS?
Schwann cells
What cells provide scaffolding and are part of the BBB?
Astrocytes
In synaptic transmission: Action potential from axon depolarizes the axon terminal causing what to happen next?
Ca entry into axon terminal via ca voltage gated channels.
In synaptic transmission: once Calcium enters the axon terminal, what occurs next?
Exocytosis!!!!! (Remember if u see calcium think contraction of muscle, or exocytosis)
Exocytosis of vesicles carrying neurotransmittters occur.
Neurotransmitter signaling is terminated by removal from synaptic cleft via what 3 mechanisms? Which is most common?
- Diffusion
- enzymatic degradation
- reuptake of neurotransmitter
