Nervous System Flashcards
(227 cards)
1
Q
What does the nervous system do?
A
master communicator of the body
works with endocrine system
maintains homeostasis
2
Q
Divisions of the nervous system
A
- Central Nervous System (CNS)
- Brain and spinal cord
- Integration and command center - Peripheral Nervous System (PNS)
- Divided into sensory (afferent) and motor (efferent) divisions
- Includes 12 pairs of cranial nerves and 31 pairs of spinal nerves
3
Q
pheripheral nervous system divisions?
A
somatic nervous system
autonomic nervous system
enteric nervous system
4
Q
Somatic Nervous System
A
- “Voluntary” Nervous System
- Sensory neurons throughout the body convey information to the CNS
- All somatic sensory neurons (touch, pressure)
- Includes the special senses (vision, hearing, smell, taste, and equilibrium)
- Motor neurons conduct impulses from the CNS to skeletal muscles only
- Voluntary movements
5
Q
Autonomic Nervous system
A
- sensory neurons from viscerl organs (lungs, heart, kidneys) to CNS
- Motor neurons from CNS to cardiac, smooth, muscle and glands - involuntary
6
Q
2 main divisions of the motor nuerons?
A
- Sympathetic Division
- Supports exercise or “Fight or Flight” response - Parasympathetic Division
- Rest and Digest activities
The effectors receive innervation from both branches and have opposite actions
7
Q
Enteric Nervous System
A
- Sensory neurons monitor chemical changes and stretching of the walls of the GI tract
- Motor neurons control contractions
(peristalsis and segmentations), and
secretions (acid in stomach, hormones, etc.) - Involuntary
8
Q
Nervous system function
A
- sensory; monitor changes from inside/outside the body; retrieve stimulus/sensory input
- integration function; interpret sensory info and make decisions
- motor function; generate a response; activate effectors (muscle to contract or organ to secrete)
9
Q
Neurons
A
- generate and propagate nerve impulses
- do not replicate like other cells in the body
10
Q
Neuroglia
A
- smaller and more plentiful than neurons (25x)
- continually divide throughout life
- cannot transmit nerve impulses
- support, nourish and protect neurons
- “glue” that holds the nervous tissue together
11
Q
parts of a neuron?
A
- cell body - contains the nucleus
- dendrites - multiple “little trees”; receiving or input part of neuron
- Axon - propagates nerve impulses to another neuron, muscle or gland
12
Q
what is a functional classification of neurons?
A
classified according to the direction of nerve impulses (action potentials) travel with respect to the CNS
13
Q
What are the functional classifications of neurons?
A
- sensory (afferent) neurons - away from extremity - nerve impulses travel towards the CNS
- motor (efferent) neurons - effect action of extremity - nerve impulse is carried away from CNS
- Interneurons - within the CNS (between sensory and motor); 90% of neurons - decision makers (integration)
14
Q
what are the 4 types of neuroglia of the CNS?
A
- Astrocytes
- Oligodendrocytes
- Microglia
- Ependymal Cells
15
Q
What are the 2 types of neuroglia in the PNS?
A
- Schwann Cells - form the myelin sheath; nerve fiber regeneration
- Satellite Cells - surround the neuron cell bodies in the ganglia
16
Q
Myelin sheath
A
- protect and electrically insulate the fiber
- increase the transmission rate of the nerve impulse
17
Q
Myelin sheath in CNS?
A
Oligodendrocytes
18
Q
Myelin sheath in PNS?
A
Schwann Cells
- nodes of ranvier
- electrical impulses “jump” from node to node
19
Q
what causes Multiple Sclerosis (MS)?
A
demyelination
20
Q
Cell Bodies group together (CNS and PNS)?
A
PNS - Ganglion
CNS - nucleus
21
Q
Axons are bundled together (CNS and PNS)?
A
PNS - nerve
CNS - tract
22
Q
Gray matter
A
- contain neuronal cell bodies, dendrites, unmyelinated axons, axon terminals, neuroglia
- gray because no myelin sheath and Nissl bodies in the cell body are gray
- decision makers
23
Q
white matter
A
myelinated axons
- high speed travel
24
Q
resting membrane potential
A
- build up of negative charges inside membrane
- build up of positive charges outside membrane
- typically -70mV
- cells are “polarized” when they have a membrane potential
25
potential difference (volts)
- resting is usually negative; excess of positive charges on the outside and negative on the inside
- due to cell being more permeable to potassium than sodium; potassium passes from intercellular fluid to extracellular (leak channels) more readily than sodium from outside to inside
- sodium-potassium pump maintains balance
26
Ions Channels
- Openings in the membrane that allow specific ions to move across according to the electrochemical gradient
- Channels have "gates" to control the movement of ions
27
What are the 4 types of ion channels?
1. leak channels
2. Chemically-gated (or ligand-gated) channels
3. mechanically-gated channels
4. voltage-gated channels
28
leak channels
- more potassium leak channels compared to sodium
- membrane more permeable to potassium
- dendrites, cel bodies and axons of all types of neurons
29
Chemically-gated (ligand-gated) channels
- gates open or close due to a chemical stimulus
- neurotransmitters (acetylcholine) opens channels to allow sodium and calcium ions in and potassium ions out
- dendrites of some sensory neurons (pain receptors)
- dendrites and cell bodies of interneurons and motor neurons
30
What is the axon hillock?
where the cell body meets the axon
31
Mechanically-gated channels
- gates open or close channels due to vibrations, stretching and pressure
- found in auditory receptors, internal organ stretch receptors, pressure receptors in skin
32
If a neuroglia cell doesn't start with S where is it located?
Central nervous system
33
cells you need to know functions of are?
schwann cells and oligodendrocytes
- responsible for myelination of axons
34
study diagram on slide 245
No really go look at it!
35
Voltage-gated channels
- gates open in response to a change in the resting membrane potential
- these channels participate in the generation and conduction of action potentials in the axons of all types of neurons
36
where is grey matter located in the brain and spinal cord?
inside of spinal cord, outside of brain
37
Electrical signals in neurons?
like muscle fibers, neurons are electrically excitable. They communicate with one another using 2 types of electrical signals
38
what are the 2 types of electrical signals in neurons?
1. graded potentials
2. action potentials
39
graded potentials
- Small deviation from the resting membrane potential
- Can cause the cell to be more or less polarized
- Stimulus causes mechanically-gated and chemically-gated channels to open or close
- Graded means the signal varies in size
- Occur mainly in the dendrites and cell bodies
- Localized...only travel for short distances
40
Action Potentials
- Graded potentials are most often the stimulus for the action potential
- Action potentials can travel long distances without losing the strength of the signal
- Called propagation
- Trigger zone is often the axon hillock
- Nerve impulses travel along an axon
- rapidly occuring in sequence of evets that decrease and reverse the membrane potential and then restore it back to normal
41
thresholds for action potentials
- needs a threshold level
- According to the all-or-nothing principle, if a stimulus reaches threshold, the action potential is always the same. – A stronger stimulus will not cause a larger impulse, it will just increase the frequency
42
types of synapses?
chemical and electrical
43
What is a synapse?
- The site of communication between 2 neurons or between a neuron and an effector cell
- Most synapses between neurons are
axodendritic
44
Chemical Synapses
- Neurons are close but do not touch
- Space between neurons is called synaptic cleft
- Action potential cannot jump across
- Presynaptic neuron releases a
neurotransmitter
- Neurotransmitter diffuses through cytoplasm and binds with the membrane of the postsynaptic neuron
- Chemical stimulus causes the chemically gated channels to open and produces an electric signal in the postsynaptic neuron
- Synaptic delay is approx. 0.5 msec
45
Electrical synapses
- Action potentials conduct directly between adjacent neurons via channel proteins - tubular connexons
- Common in the brain, visceral smooth muscle, and cardiac muscle
46
What are the 2 main advantages of electrical synapses?
1. faster communication
2. synchronization - heart beat, peristalsis
47
What are the phases of action potential?
depolarizing phase followed by repolarizing phase
48
What is a synapse?
the site of communication between 2 neurons or between a neutron and an effector cell
most are ago dendritic
1. chemical synapse
2. electrical synapse
49
chemical synapse
- neurons are close but do not touch
- presynaptic neuron releases a neurotransmitter
- nuerotransmitter diffuses through cytoplasm and binds with the membrane of the postsynaptic neuron
- chemical stimulus causes the chemically gated channels to open and produces an electric signal in the postsynaptic neuron
- synaptic delay of 0.5 ms
50
what is the synaptic cleft?
space between neurons
51
electrical synapse
- action potentials conduct directly between adjacent neurons via channel proteins - tubular connexions
- common in the brain, visceral smooth muscle and cardia muscle
52
what are the 2 main advantage of electrical synapse?
faster communication
synchronization - heartbeat peristalsis
53
Spinal cord
continuation from the medulla oblongata to the conus medullar is at the disc space between L1 and L2
- filum terminale arises from the conus medullar is and anchors the spinal cord to the coccyx
- contains the major reflex center
54
where is the cervical enlargement of the spinal cord?
C4-T1
55
Where is the lumbar enlargement of the spinal cord?
T9-T12
56
spinal cord protection
cord is completely surrounded by the vertebra
meninges; 3 layers; CSF acts as a shock absorber
intervertebral discs
57
meninges
spinal meninges are continuous with the cranial meninges
Extend to the level of S2
58
what is the innermost layer of the meninges?
pia mater
59
What is the middle layer of the meninges?
arachnoid mater
60
what is the outermost layer of the meninges?
dura mater
61
what is the epidural space?
between the dura mater and vertebra
epidural injection - local anaesthetic
62
what is the subdural space?
between the dura and arachnoid maters
interstitial fluid
63
what is the subarachnoid space?
between the arachnoid and pia maters
contains CSF (shock absorber)
64
diagrams slide 285-288
don't be lazy go look
65
What vertebral level is a spinal tap performed at in an adult patient?
L3 and L4
avoid spinal cord - go below it
- would insert lower on a child
- prefer L3/4 in an adult as there is less tissue than L4/5
66
What layer does a spinal tap go to?
subarachnoid space - to access CSF
67
spinal nerves
31 pairs
- where the nerves exit the spine through the intervertebral foramina
68
How many nerve pairs in C-spine?
8
69
How many nerve pairs in T-spine?
12
70
How many nerve pairs in L-spine?
5
71
How many nerve pairs in Sacrum?
5
72
How many nerve pairs in coccyx?
1
73
spinal nerve positioning
not all segments are aligned with their respective vertebra
roots of lumber, sacral, and coccygeal nerves descend on an angle to exit their respective foramina - cauda equina
74
spinal nerves formed by 2 roots?
1. Posterior (dorsal) root - sensory
2. Anterior (ventral) root - motor
all spinal nerves are MIXED
75
What is the Dorsal root made up of?
contain only axons of sensory neurons
76
What is the dorsal root ganglion?
collection of cell bodies of sensory neurons
- swelling
77
diagram slide 296
epidural space
subarachnoid space
78
Internal anatomy of spinal cord?
white matter - anterior median fissure; posterior median sulcus
Gray matter - "H" or butterfly
79
what is the difference between a fissure and a sulcus?
fissure is deeper than a sulcus
80
gray matter in the spinal cavity
posterior dorsal horn
lateral horn
anterior ventral horn
Commissure - cross bar of "H"
Central canal - small hole in the middle of the commissure - extends the entire length go the spinal cord - filled with CSF
81
Posterior (dorsal) horn (gray matter)
incoming sensory neurons
cell bodies and unmyelinated axons of interneurons
82
Anterior (ventral) horn (gray matter)
contain somatic motor nuclei
- nerve impulses for contraction of skeletal muscles
83
what are nuclei of the spinal cord?
clusters of cell bodies in the CNS
84
Lateral horn (gray matter)
present only in T and L segments
autonomic and enteric motor nuclei
- clusters of cell bodies of motor neurons that regulate the heart, glands and smooth muscle
85
What is white matter?
myelinated axons
sensory tracts are ascending
motor tracts are descending
86
What columns are white matter divided into?
posterior (dorsal) column
lateral column
anterior (ventral) column
- these columns contain tracts - bundles of axons in CNS
87
Posterior column (white matter)
ascending tract (sensory)
88
Lateral and anterior columns (white matter)
both ascending and descending (sensory and motor)
89
Study slide 304 and 305 diagrams
good diagram
90
Nerve plexus
- spinal nerves branch into rami after passing through the intervertebral foramina
- branches of the spinal nerves (anterior rami) do not go directly to the area they supply (except for the intercostal nerves)
91
what are the different plexus networks?
cervical
brachial
lumbar
sacral
coccygeal
92
cervical plexus
*C1 TO C5*
- head, neck, superior part of chest and shoulders
- *phrenic nerves arise from the cervical plexus at the levels of C3, C4 and C5*
- sternocleidomastoid
- erector spine
- levator scapulae
93
What do phrenic nerves do in cervical plexus?
supply motor neurons to the diaphragm
94
C3 to C5 keeps what alive?
the diaphragm
95
What is referred pain distribution?
C 3, 4, 5
- sensory stimuli from diaphragm often interpreted as pain over shoulder and lower neck
96
Brachial plexus
- formed by the anterior rami of C5-C8 and T1
97
what are the major nerves supplied by the brachial plexus?
- musculocutaneous
- axillary
- radial
- median
- ulnar
- long thoracic
98
wrist drop is damage to what nerve?
radial nerve
99
what does median nerve damage cause?
median nerve palsy
100
what does damage to the ulnar nerve cause?
ulnar nerve palsy - last 2 fingers stuck partially bent
101
What is the lumbar plexus?
- *roots from L1-L4*
- anterior part of lower limbs
- femoral, obturator, saphenous nerves
102
What causes winging of the scapula?
damage to the long thoracic nerve
103
What is the sacral plexus?
- *L4 - S4*
- *sciatic nerve*
- posterior part of lower limbs
104
where does the sciatic nerve branch?
branches into tibial and common fibular nerves at the knee
105
What are dermatomes?
- area of skin supplied by sensory neurons form a single spinal nerve
- useful to determine neurological levels
106
What are reflexes?
spinal cord is the integration centre for some reflexes
107
what are 2 examples of reflexes?
1. patellar reflex
2. plantar reflex; babinski sign - toes fan out and great toe moves upwards, normal for infant but abnormal for adults
108
How do you best demonstrate the intervertebral foramina of C-spine?
45 oblique C-spine with 15-20 degree angle (Caudad or Cephalic dependant on AP/PA)
109
How do you best demonstrate the intervertebral foramina of T-spine?
True lateral
110
How do you best demonstrate the intervertebral foramina of L-spine?
True lateral
111
How do you best demonstrate the intervertebral foramina of sacrum?
AP Axial Coccyx
112
What are the parts of the brain?
1. cerebrum
2. diencephalon
3. brain stem
4. cerebellum
113
What are the parts of the diencephalon?
1. thalamus
2. hypothalamus
3. epithalamus
114
What are the parts of the brain stem?
1. midbrain (mesenceohalon)
2. pons
3. medulla oblongata
115
Diagrams slides 329-332
Go learn the parts of the brain
116
What is the protection of the skull?
skull and meninges
117
what are the meninges?
1. pia mater
2. arachnoid mater
3. dura mater
118
what is Pia mater?
adheres tightly to the surface of the brain
- including the gyro and sulci
119
what is the arachnoid mater?
subarachnoid space
does not adhere tightly to the Pia mater at all times
- forms cisterns
arachnid villi
- finger like extensions that project into the dural venous sinuses
- one way valves that allow CSF into the blood
120
What sits anterior to the Pons?
clivus - sella turcica - pituitary gland
121
what is dura mater?
2 layers (spine only has 1)
- periosteal layer (outer)
- meningeal layer (inner)
fused together except where they surround venous sinuses
*no epidural space in the brain* - there is in the spinal cord
122
what are the extensions of the dura mater?
falx cerebri
falx cerebelli
tentorium cerebelli
123
what is the falx cerebri?
- separates the 2 cerebral hemispheres
- in longitudinal fissure
- attaches anteriorly to the crista galli
124
What is the falx cerebelli?
separates the 2 hemispheres of the cerebellum
125
what are cisterns of the arachnoid mater?
pockets of CSF
126
what is tentorium cerebelli?
separates the cerebrum from the cerebellum
127
Which brain bleed it he most life threatening? subdural, epidural or subarachnoid?
Subarachnoid is most life threatening as it is a ruptured brain aneurism
epidural is arterial is more dangerous than subdural as subdural is venous
128
Diagrams slide 338 and 339
study them so you don't fail
Seriously go now
129
what is located within the sinuses of the brain?
venous blood
130
What is located within the sinuses of the facial bones?
air
131
Brain blood flow
the brain represents only 2% of total body weight but receives about 20% of the body's blood supply and consumes 20% of the O2 and glucose (even when resting)
132
Where does the internal carotid artery supply the brain?
supplies the anterior and middle parts of the brain
133
Where does the vertebral artery supply the brain?
supplies the posterior part of the brain
134
Where does the internal jugular vein drain blood from?
blood drains from the dural venous sinuses and deeper veins into the internal jugular vein
135
What is the blood brain barrier?
- Tight junctions are formed between the brain tissue and capillaries
- Astrocytes are thought to have an important function
- Semi-permeable membrane
136
What is the BBB permeable and impermeable to?
- Allows O2, CO2, steroid hormones, alcohol, caffeine, water, and glucose to cross
- Prevents proteins, toxins, most antibiotics from crossing
137
What may breakdown the BBB?
- Trauma, inflammation, certain toxins may cause a breakdown of the BBB, permitting the passage of normally restricted substances into the brain tissue
138
What is the BBB's purpose?
- The BBB protects brain cells from harmful substances and pathogens by serving as a selective barrier to prevent passage of many substances from the blood into the brain
139
What is the CSF?
- Fluid that continually circulates through the cavities in the brain (ventricles) and spinal cord (central canal) and around the brain and spinal cord in the subarachnoid space
- Mainly water (clear, colourless)
- Contains small amounts of oxygen, glucose, proteins, ions
140
what are the functions of the CSF?
1. Mechanical protection – shock absorber
2. Homeostatic Function – pH of CSF affects cerebral blood flow and pulmonary ventilation
3. Circulation – minor exchange of nutrients and wastes between the blood and adjacent nervous tissue
141
where is the CSF produced?
Produced in *Choroid Plexus* (network of capillaries) in walls of the ventricles
142
where is the CSF found?
**CSF is found in the ventricles, cisterns, subarachnoid space of the brain and spinal cord, and central canal of the spinal cord**
143
where is the CSF reabsorbed
Reabsorbed in the arachnoid villi (stick into the dura venous sinuses)
144
reabsorption to production ratio
Typically, reabsorption and production are equal
- About 500 ml of CSF produced daily
- About 125 ml of CSF present in the body at any given time
145
What happens if reabsorption is affected of CSF?
If reabsorption is affected…hydrocephalus
- Infants, the fontanels are open so the skull enlarges
- Adults, the skull is fused, so this becomes a life-threatening condition
146
What are the lateral ventricles of the brain?
- Lateral Ventricles (2)
- Largest of the ventricles
- C-shaped structures containing CSF
- One in each hemisphere passing through frontal, parietal, temporal, and occipital lobes
- Anterior (Frontal) horn, body, posterior (Occipital) horn, inferior (Temporal) horn
- Anterior/Frontal horns communicate with the Third Ventricle through the interventricular foramina
- Play a crucial role in cushioning the brain
147
What is the Third ventricle?
- Mid-line, slit-like structure within the diencephalon
- Communicates with the Fourth Ventricle via the Cerebral Aqueduct
148
What is the Fourth Ventricle?
- Posterior to the Pons (anterior part of the cerebellum)
- Communicates with the subarachnoid space via 3 openings in the roof; Median aperture (1); Lateral apertures (2)
- Becomes the central canal of the spinal cord
149
diagrams slide 353-358
go look silly, like right now
150
where does a vp shunt drain to?
ventriculoperitoneal space
- dumps fluid into peritoneal space in the abdomen to be resorbed into the body
151
How do you obtain image of slide 350
RPO
180 SID
Grid
Small focal spot
75 kVp
152
Diagram 355 - describe flow of CSF through brain and spinal cord
************** VERY IMPORTANT **************
153
what does the 4th ventricle become?
central canal of spinal cord
154
When you are viewing a CT scan you are always viewing it from?
the foot end
155
what is a cistern?
extra CSF stored
156
what is the cerebrum (cerebral hemispheres)?
- “Seat of intelligence” - Read, write, speak, make calculations, remember the past, plan for the future
- Superior portion of the brain
- Makes up over 80% of brain mass
- Divided into equal right and left hemispheres by the Longitudinal Fissure
- Each hemisphere acts on sensory and motor functions of the opposite side of the body
- Further divided into Lobes by the bones that cover it; Frontal, Parietal, Temporal, Occipital
157
cerebrum landmarks in the gray matter?
Gyri, Sulci and fissures
158
Gyri
Convolutions
- Precentral - anterior central sulcus
- Postcentral - posterior central sulcus
159
Sulci
Shallow grooves
- lateral
- **central**
160
Fissures
Deep grooves
- longitudinal
161
Diagram 361-362
understand the sulci, gyri and fissures
162
What is the cerebral cortex?
billions of neurons - gray matter
- gyri, fissures and sulci can be identified on the cortex
163
what is the basal nuclei?
gray matter deep within the cerebrum
1. caudate nucleus
2. lentiform nucleus
- Subconscious control of skeletal muscle tone
- Coordination of learned movement
- Important in starting, stopping and monitoring movement
- Plays a role in initiating and terminating cognitive processes
164
where do you find the caudate nucleus?
follows the curve of the lateral ventricle
165
where do you find the lentiform nucleus?
posterior and lateral to caudate nucleus
166
Slide 364 identify caudate nucleus and lentiform nucleus
Go - important
167
What is the white matter of the cerebrum?
Deep to the cortex is white matter composed of tracts of neurons that connect parts of the brain to each other and the spinal cord
168
what is the corpus callosum?
A bundle of white matter tracts that connects the right and left hemispheres of the cerebrum
169
what is a tract?
a bundle of axons - CNS
170
what is a bundle of axons in PNS?
nerves
171
slide 366 and 368 - be able to label diagram
don't give up silly
172
What are the lobes of the cerebrum?
- frontal
- parietal
-occipital
-temporal
- insula
173
What is the frontal lobe?
- *Primary motor area is located at the “precentral gyrus”* - consciously move skeletal muscle
- Premotor cortex: Learned motor skills
- Broca’s speech area
- Reasoning
174
What is the Broca's speech area?
- Typically only on left side
- Speaking
175
What is the Parietal lobe?
Primary somatic sensory area
- Postcentral gyrus
- Integrate and interpret senses
- Can recognize pain, temperature or a light touch
Area for taste
Wernicke’s Area
176
What is the wenicke's area?
Only on left side
General interpretive area
- Interprets the meaning of speech
177
What is the temporal lobe?
- Also contains Wernicke’s area (left side only)
- Primary olfactory area*
- Primary auditory area
178
What is the occipital lobe?
primary visual area
179
What is the insula?
additional area of gustation (taste)
180
What is the Thalamus?
* relay system*
- The thalamus is located superior to the midbrain and contains nuclei that serve as relay stations for all sensory impulses (except smell) to reach the Primary Sensory Area
- Also transmits information from the cerebellum to the Primary Motor Area
181
What is the diencephalon?
- Sits on top of brain stem - enclosed by hemispheres
Major structures
- Epithalamus
- Pineal gland
- Thalamus (80%)
- Hypothalamus
- Pituitary Gland
Surrounds the 3rd Ventricle
182
Hypothalamus
- Projecting from the hypothalamus is the hypophysis (or Pituitary Gland)
- *It controls the Autonomic Nervous System (ANS).*
- It coordinates between nervous and endocrine systems.
- It controls body temperature (measured by blood flowing through it).
- It regulates hunger/thirst
- It regulates circadian rhythms (24-hour clock)
- It regulates emotional and behavioural patterns: Rage, aggression, pain, and pleasure
183
Epithalamus
Superior and posterior to the thalamus
Superior to the 3rd ventricle
Pineal gland - Secretes melatonin - Promotes sleepiness
habenular nuclei - emotional responses to odours
184
What is the limbic system?
*forms the emotional brain* - pleasure, pain, anger, fear and affection
- Encircles upper part of brain stem, inner border of cerebrum, and floor of diencephalon
- Links the conscious, intellectual functions of the cerebral cortex with the unconscious and autonomic functions of the brain stem
- Memory storage and retrieval
- “motivator”
185
Brain stem
midbrain, pons and medulla oblongata
186
Midbrain
- Most superior part of brain stem (between Pons and Diencephalon)
- Controls the reflex center for eye movement
- Coordinates head and neck movement in response to visual and auditory stimulus
- The cerebral aqueduct passes through the midbrain connecting the 3rd ventricle with the 4th ventricle
187
Pons
- Together with the medulla, areas in the pons help control breathing
- Anterior to the 4th Ventricle
188
White matter in the medulla oblongata?
- Contains ascending and descending tracts to spinal cord
- It has two external bulges called the pyramids formed by the largest motor and sensory tracts in the body.
- Decussation of the pyramids occur (means crosses over) - Right side of the brain controls voluntary movements on the left side of the body
189
What cranial nerves are associated with the midbrain?
3 and 4
189
Gray matter of the medulla oblongata
Functions
- Cardiac center adjusts rate & force of heartbeat
- Vasomotor center adjusts blood vessel diameter
- Respiratory centers control rate & depth of breathing
- Reflex centers for coughing, sneezing, gagging, swallowing, vomiting, salivation, sweating, hiccupping, movements of tongue & head
190
What cranial nerves are associated with the pons?
5-8
191
What cranial nerves are associated with the gray matter of the medulla oblongata?
8-12
192
What is the cerebellum?
- occupies the posterior cranial fossa
- cerebellar hemispheres
193
Are nerves 1 and 2 associated with the brainstem?
no
194
cerebellum gray matter?
Folia - slender, parallel folds
Cerebellar Nuclei - deep within the white matter
195
Cerebellum functions
- Regulates posture and balance
Smooths and coordinates contractions of skeletal muscles
- Skilled muscular activities
- May have a role in cognition and language processing
196
What is ataxia?
- Loss of the ability to coordinate movements
- MS, Parkinson’s, tumours,
- ALCOHOL
197
Cranial Nerves
12 pairs
Part of the PNS
Each has a name and a roman numeral
The number indicates the order from which they arise from the brain, going from anterior to posterior
Some are special sensory nerves only, some are motor nerves only, and some are mixed (both)
198
Oh, Oh, Oh, To Touch And Feel Very Good Velvet, AH!
olfactory, optic, oculomotor, trochlear, trigeminal, abducens, facial, vestibulocochlear, glossopharyngeal, vagus, accessory, hypoglossal
199
What is nerve 1?
Olfactory nerve - sensory
200
What is nerve 2?
optic nerve - sensory
201
What is nerve 3?
Oculomotor nerve - motor
- innervates 4 of 6 intrinsic muscles of eye
202
which cranial nerves control eye movement? where do they pass through?
3, 4 and 6 - they all pass through the superior orbital fissure
203
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sensory, sensory, motor, motor, both, motor, both, sensory, both, both, motor, motor
204
What is nerve 4?
trochlear nerve - motor
205
What is nerve 5?
trigeminal - mized
Sensory - contains opthamalic, maxillary and mandibular divisions
motor - contains mandibular division
206
V1
opthamalic - superior orbital fissure
- only sensory
207
V2
maxillary - foramen rotundum
- only sensory
208
V3
mandidular - foramen ovale - both sensory and motor
209
What is nerve 6?
Adsucens - motor
210
What is nerve 7?
facial - mixed
- motor component innervates all muscles of facial expression
- innervates glands
- sensory input from anterior 2/3 tongue
211
What is nerve 8?
Vestibulocochlear nerve - sensory
- vestibular: equilibrium and balance
- cochlear: sense of hearing, input from signal organ
212
What is nerve 9?
Glossopharyngeal - mixed
- innervates tongue and pharynx, involved in swallowing and gag reflex
- sensory: taste from posterior 1/3 of tongue
213
What is nerve 10?
vagus - mixed
- critical component of the parasympathetic nervous system
- innervates visceral organs of the thorax and abdomen
214
what is the longest cranial nerve?
the vagus nerve (X)
215
what does glossal mean?
tongue
216
what is the vagus nerves impact on the parasympathetic nervous system?
- lowers heart rate and blood pressure
217
what does the innervation of visceral organs of the thorax and abdomen due to the cranial nerve do?
- stimulates digestive processes and promotes peristalsis
218
Which nerve rests and digests?
the vagus nerve - rests heart rate and stimulates digestive processes
219
What is nerve 11?
accessory - motor
220
What is nerve 12?
hypoglossal - below the tongue - 12
221
Diagram slide 86 of brain
be able to label this entire diagram
- can't see olfactory nerve as it is above olfactory bulb
222
where does the optic tract go?
occipital lobe
223
the dot of the trigeminal nerve is labelled is?
sensory part of the trigeminal nerve
224
Diagram slide 87
brain lecture
225
Where does the olfactory tract end up?
temporal lobe
226
where does the optic nerve pass through?
lesser wing of the sphenoid through the optic foramen
