Neuro Anatomy Quiz 1. 2016 :) Flashcards
2 main arteries that supply the brain
internal carotid, vertebral
where does the ACA ( anterior cerebral arteries) come from?
internal carotid and it supplies part of the cerebrum
where does the MCA ( middle cerebral arteries) come from?
internal carotid to lateral sulcus branches off to lateral cerebral cortex
where does the PCA (posterior cerebral arteries) come from?
basilar artery ( vertebral artery below the pons)
the anterior, middle, an posterior arteries supply blood to what
cerebral cortex
the anterior cerebral artery supplies what part of the cerebral cortex
medial, anterior and superior portions of the cerebral hemisphere
middle cerebral artery supplies what part of the cerebral cortex
primarily the lateral surface of the cerebral hemisphere
posterior cerebral artery supplies what part of the cerebral cortex
posterior portion as well as the inferior aspect of the medial surface of the cerebral hemispheree
the main supply arteries that make up “ Circle of Willis” :)
- Internal carotid artery (left and right)
- Basilar artery
- Ensures that the brain has a large blood supply
Describe and discuss the function of the Circle of Willis
Provides multiple paths for oxygenated blood to supply the brain if any of the other suppliers of oxygenated blood are constricted by physical pressure, occluded by disease, or interrupted by injury.
Describe the general blood flow return to the heart
Series of sinuses in the cerebrum collects the deoxygenated blood
To the jugular veins
To lungs where they are deoxygenated to the heart
what do the meninges do?!
protects CNS, provides blood supply to skull
How many layers of meninges are there and what are they! :)
Dura Mater: Outermost layer, fibrous tissue(tough mother)
Arachnoid mater: Layer under the dura mater, filled with a bed of collagen, has trabeculae (spider)
Pia Mater: Innermost layer, it lines the sulci and gyri, very fine thin layer (tender mother)
Latin names for meninges and what they mean
Dura Mater: Means “Tough mother”
Arachnoid mater : Means “Spider”
Pia Mater: means “tender mother”
order of impulse travelling across a neuron
dendrites, axon( nodes of ranvier and schwan cells, myelin sheath), axon terminal
define neuroglial cells
These are the cells that form myelin, protect, support, and maintain equilibrium in your nervous system
define nerve impulse
signal across nerve fibre
define resting membrane potential
It is where a neuron is at rest, there are relatively more sodium ions outside the neuron and more potassium ions inside that neuron
next one is long info don’t need to read
a. Myelinated axons contain Schwann cells that produce myelin. The myelin is discontinuous with gaps called Nodes of Ranvier. Myelin is a lipid substance that acts as an insulator.
b. The speed of conduction also relies on the thickness of the myelin sheath as well as the diameter of the axon. Greater myelination and larger diameter axons conduct action potentials faster.
c. Nerve fibers are classified according to their size. Type A fibers are large diameter myelinated fibers that quickly conduct action potentials (15-120 meters/second).
d. Type B fibers are medium diameter myelinated fibers that conduct action potentials more slowly than Type A fibers. Type B fibers can conduct action potentials from 5-15 meters/second.
e. Type C fibers have a small diameter and are unmyelinated fibers that conduct action potentials at 2 meters/second or less. Type B and C fibers are found in the autonomic nervous system.
Random stuff about action potential
- Identify the main steps of action potential - Threshold, Depolarization, Repolarization, Refractory Period, Resting State.
- Function and Location of Myelin: runs along the axon to help transmit and send impulses faster
- Define Saltatory Conduction: increases the speed of the impulse by “jumping” the impulse from the node of ranvier to node of ranvier
- Define neurotransmitters & Describe how these are released - chemical messengers which transmit signals across a chemical synapse. They exchange information at the synapse located between the dendrite and the axon terminal.
- Describe excitatory and inhibitory potentials -Excitatory: increase the likelihood that the neuron will fire an action potential. Inhibitory: stop/decrease the likelihood that the neuron will fire an action potential.
how many cranial nerves are there
There are 12 Cranial Nerves. 11 originate from the diencephalon, 1 from the frontal lobe. They sense touch, pain, and vision.
function of autonomic nervous system
- Maintains homeostasis (glands, smooth muscle, and cardiac muscle)
- Controls involuntary movement (eg: breathing, heart rate, digestion, etc.)
2 systems in the ANS
•Sympathetic
◦Fight or flight system; excites the body or gets the body going.
•Parasympathetic
◦Rest and digest; calms the body down
what sympathetic does
◦Dilates pupil
◦Stimulates viscous saliva
◦Stimulates sweat
parasympathetic
◦Contracts pupil
◦Stimulates watery saliva
◦Decreases heart rate
what do horns do
where synapse happens an info goes in an out
What are Neural Receptors?
A sensory receptor is a sensory nerve ending that responds to a stimulus in the internal or external environment of an organism
Different sensory receptors that detect stimuli
Chemoreceptors: that sense changes in chemical concentration.
• Pain receptors (nociceptors): that sense tissue damage. do not adapt to stimuli
• Thermoreceptors: that sense changes in temperature.
• Mechanoreceptors: that sense mechanical deformation of tissue.
• Proprioceptors: that sense changes in position of joints.
• Stretch receptors: that sense changes in tissue length.
• Photoreceptors: that sense changes in light intensity.
different types of sensory receptors that detect stimuli
a. Touch and pressure are sensed by free nerve endings and Merkel’s discs as well as Meissner’s, Pacinian, and Ruffini corpuscles.
b. Pacinian corpuscles detect heavy pressure and vibration
c. Ruffini corpuscles are sensitive to pressure and skin movement.
d. Merkel’s discs sense fine touch and pressure
e. There are warm and cold receptors. Warm receptors are receptive to temperatures greater than 25 degrees C.
f. Cold receptors are receptive to temperatures 10-20 degrees C
g. Pain receptors or nociceptors are the free nerve endings. Pain receptors do not adapt to stimuli.
