CNS Flashcards
1
Q
Functions of the Nervous System
A
- Sensory input: helps us to feel things, like pressure and pain
- Motor output: helps us to move our skeletal muscles
- Integration: integrate those two things tgthr
2
Q
Central Nervous System (CNS)
A
- includes: brain and spinal cord
- functions: integration, processing, and coordination of sensory input and motor commands, higher functions (intelligence, memory, learning, emotion)
3
Q
Peripheral Nervous System
A
- includes: neural tissue outside brain and spinal cord (cranial nerves, spinal nerves, ganglia)
- functions: links all regions of body to CNS (can’t have a memory to hold something w/o the peripheral NS), delivers sensory info to CNS, carries motor commands to peripheral tissues
- it delivers memories and sensations to the brain
4
Q
What two sections are apart of the PNS?
A
- Sensory (Afferent)
- bring info IN to CNS
- info is going At the brain
- Motor (Efferent)
- sends info OUT of CNS
- E for exiting
5
Q
Neuroglia
A
- supporting cells
- catering to every whim of our neuron
6
Q
Ependymal cells
A
- simple cuboidal epithelium lining ventricles
- will make CSF
7
Q
Microglia
A
- phagocytes of the CNS
- come in and gobble up any foreign invaders
- gobble up any waste tissue or scar tissue
8
Q
Astrocytes
A
- structural and nutritional support for form blood-brain barrier (star-shaped cell)
9
Q
Oligodendrocytes
A
- produce myelin for the CNS (cell with few branches)
10
Q
Dendrites
A
- receive impulses from other cells (many per cells)
11
Q
Cell body
A
- aka soma, aka perikaryon
12
Q
Rough ER
A
- also called nissel substance in nerves
- surround the nucleus
- making lots of diff proteins called neurotransmitters
- ribosomes = help transcribe and translate those proteins
13
Q
Axon
A
- one per cell
- sends impulses away from neuron to axon terminal
14
Q
Why do neurons need nutritional and structural support?
A
- neurons are long lived and don’t divide
- if we lose a neuron, we can’t make a new one
15
Q
What is mainly astrocytes and oligodendrocytes and are relatively short lived and divide and replace all the time?
A
- neuroglia
- we make lots of these
16
Q
What brain tumors arise from neuroglia and are not derived from neurons?
A
- meningiomas and glioblastomas
17
Q
Chemical synapse
A
- neurotransmitters are released from axon terminal into synaptic cleft and bind to receptors on second neuron (or muscle or gland)
- form of exocytosis
18
Q
Electrical synapse
A
- ions pass from one cell to another thru gap junctions
- charged particles create electricity
- they will go thru gap junctions and talk to second neuron
19
Q
Myelin
A
- membranous sheath that covers axons
- increase speed of action potential propagation
- going to insulate axon
- not all axons are myelinated
20
Q
Gray matter
A
- unmyelinated regions of CNS
- neuron cell bodies, dendrites, some neuroglia
- in brain called cortex
- superficial to white matter in the brain but deep to white matter in the spinal cord
21
Q
White matter
A
- myelinated region of CNS
- axons and glia
- bundles of axons called “tracts” in CNS
22
Q
Spinal cord
A
- functions: sensory and motor innervation of body 2-way conduction of signals btw body and brain
- major center for reflexes (don’t necessarily need a signal to go all the way up to the brain)
- reflex: Dr. Hammering your quadricep tendon and your knee kicks up
- location: from foramen magnum to level of 1st/2nd lumbar vertebra
23
Q
Cerebrum
A
- sensory, motor, and association areas
- higher cognitive functions occur here -> memory
- thinks part of the brain
24
Q
Cerebellum
A
- adjusts motor activities based on sensory information
- fine tune movement based on info we received
25
Diencephalon
- thalamus, hypothalamus
- sensory info relay, visceral control
26
Brain stem
- midbrain, pons, medulla oblongata
- relay center
- directs nerves where to go
27
What does the cerebrum have?
- divided in to left and right hemispheres
- has gyri (bumps) and sulci (grooves)
- divided into lobes named after overlying bone (frontal, parietal, temporal, occipital)
28
Longitudinal fissure
- separates right and left hemispheres
29
Central sulcus
- separates frontal and parietal lobes
30
Lateral sulcus
- sylvian fissure
- separates temporal lobe from frontal and parietal lobes
31
Major sensory areas
- primary sensory cortex: is in postcentral gyrus of parietal lobe (most of our sensory information)
- primary visual cortex: is in occipital lobe
- primary auditory cortex: is in temporal lobe (hearing sense)
- look at slide for pictures
32
Major motor areas
- primary motor cortex: precentral gyrus of frontal lobe
- Broca’s area: in left frontal lobe controls motor movements for speech
33
Major association areas
- wernicke’s area: in the left parietal and temporal lobes is involved with recognizing and comprehending language (written and spoken)
- association = meaning that you hear something from your auditory sense and then associate it w/ a meaning
34
Broca’s aphasia
- effects the ability to produce speech
35
Wernicke’s aphasia
- effects the ability to understand language
- can put tgthr words into a sentence but don’t mean anything
36
Classification of white matter in the brain
- association fibers: travel within a hemisphere
- comissural fibers: travel btw hemispheres
- projection fibers: travel from spinal cord to brain and vice versa
37
Corpus callosum
- a bundle of myelinated axons connecting right and left hemispheres
38
What does the cerebellum look like/do?
- has folia: lea-like folds that increase surface area
- white matter of cerebellum called arbor vitae
- function: maintains balance and posture by automatically adjusts motor activities based on sensory info
- controls motor activity
39
Thalamus
- involved sensory information relay and processing
- relay things from the spinal cord to the cerebral cortex or down the other way
40
Hypothalamus
- main visceral (organ) control center
(Emotions, autonomic functions, hormone production, body temperature, hunger/thirst, formation of memory)
41
Midbrain
- helps to process visual and auditory info
- maintains consciousness
42
Pons
- connects brain stem to cerebellum
- relays sensory information to cerebellum and thalamus
- subconscious somatic and visceral motor control (things you can control w/o thinking abt it)
43
Medulla oblongata
- connects brain to spinal cord
- relays sensory info to thalamus
- autonomic centers regulate visceral function
44
Meninges
- connective tissue membranes that surround the brain
45
Cerebrospinal fluid
- cushions the brain and provides immunologic protection
46
Blood-brain barrier
- formed by astrocytes protects brain from blood-borne toxins and pathogens
47
3 layers of connective tissue that covers the brain: Dural Mater
- double layer of defense CT. Dural venous sinuses inside. Periosteum (dark yellow) and Meningeal layers (light yellow)
48
3 layers of connective tissue that covers the brain: arachnoid mater
- deep to dura
- spidery mother
49
3 layers of connective tissue that covers the brain: Pia Mater
- delicate, adheres directly to surface of brain
- astrocytes help this layer of CT adhere directly to the brain
50
False cerebri
- separates right and left hemispheres
51
Falx cerebelli
- separates cerebrum from cerebellum
52
Dural venous sinuses
- drain venous blood from brain back to systemic circulation (internal jugular vein)
- systemic circulation: all the blood that’s pumping thru your body basically not relegated to a single organ
- in btw meningeal and periosteum layer of dura mater
- look at picture in slides
53
Ventricles of the Brain
- lateral ventricles (first and second) with cerebrum
- cerebral aqueduct: connects 3rd and 4th ventricles
- third ventricle within diencephalon
- fourth ventricle: btw pons and cerebellum
54
Flow of CSF
1. CSF is produced by ependymal cells of the choroid plexus (“roof” of ventricles)
2. Flows to subarachnoid space
3. Absorbed into dural sinuses via arachnoid granulations (projections of arachnoid mater into dural sinus)
55
Hydrocephalus
- excess production or improper drainage of CSF
- extra fluid puts pressure on neural tissue
- placement of shunt to drain excess fluid
