Brain 1 Flashcards
(112 cards)
1
Q
What are the functions of the cerebrum?
A
Sensory perception Voluntary movement Memory Thought Reasoning Emotion
2
Q
What separates the left from the right hemisphere?
A
The central fissure
Or longitudinal fissure
3
Q
What type of matter is the cortex?
A
Grey matter
4
Q
What is a Gyrus?
A
A convolution in the cortex (upper ridge)
5
Q
What is a sulcus?
A
A shallow groove in the cortex
6
Q
What is a fissure?
A
A deep groove in the cortex
7
Q
What is the corpus callosum?
A
A tract of white matter that connects the 2 hemispheres
8
Q
What are the 4 lobes of the cerebrum?
A
Frontal
Parietal
Occipital
Temporal
9
Q
What are the functions of the frontal lobe?
A
Motor
Personality
Judgement
10
Q
What is the precentral gyrus? Where is it located?
A
The primary motor cortex
On the gyrus directly anterior to the central sulcus in the frontal lobe
11
Q
What are the functions of the parietal lobe?
A
Sensory perception
12
Q
What is the postcentral gyrus? Where is it located?
A
The primary sensory cortex
The gyrus directly posterior to the central sulcus in the parietal lobe
13
Q
What is the cortical homunculus
A
Pictographic representation of the sensory and motor distribution of the cerebral cortex
14
Q
What are the functions of the temporal lobe?
A
Auditory functions
Inputs from the ear
15
Q
What is Wernicke’s area? Where is it located?
A
Part of the temporal lobe where recognition of spoken and written word occur
16
Q
What are the functions of the occipital lobe?
A
Vision
17
Q
What is the tentorium? Where is it located?
A
A dural fold that separates the occipital and temporal lobe from the cerebellum
18
Q
What catastrophic event can occur with the tentorium?
A
It can tear
19
Q
Where are the speech and language centers USUALLY located? Why?
A
In the left hemisphere because they are located in the dominant side and most people are left dominant (= right handed)
20
Q
What is Broca’s area? Where is is located?
A
Broca’s area is responsible for the motor function for speech. It is located in the frontal lobe
21
Q
What is beneath the cerebral cortex (grey matter)
A
White matter - myelinated axons
22
Q
What 3 functions can the myelinated axons beneath the cortex carry out?
A
Association fibers carry information within one hemisphere.
Commissural fibers carry information between hemispheres.
Projection fibers carry information on ascending and descending tracts.
23
Q
What is the basal ganglia? Where is is located?
A
Clusters of (paired) grey matter within the mater matter of the cortex
24
Q
What are the functions of the basal ganglia
A
Crude motor
Unconscious contraction of skeletal muscles
25
Name 2 diseases of the basal ganglia
Parkinson’s
| Huntington’s
26
What structures does the diencephalon consist of?
Thalamus
Hypothalamus
Pituitary
Epithalamus
27
Where is the diencephalon located and what does it surround?
It is located between the hemispheres and it surrounds the third ventricle
28
What are the functions of the thalamus?
It is the relay center for all sensory information except smell
General awareness of sensation
29
Where does the thalamus relay sensory information to?
To the appropriate area in the cortex for further processing.
30
What are the functions of the hypothalamus?
Regulates visceral activities: cardiovascular, temperature
Water and electrolyte balance - contains the osmotic sensors and thirst center
Hunger
Emotions
Sleep/wakefulness
Endocrine functions
31
How is the pituitary connected to the hypothalamus?
By the stalk infundibulum
32
What is another name for the anterior pituitary
Adenohypophysis
33
What is another name for the posterior pituitary? Why is it called this?
Neurohypophysis. Because neurons connect the hypothalamus to the posterior pituitary
34
What is the sella turcica?
A saddle shaped depression in the sphenoid bone where the pituitary sits
35
What is the clinical significant of the sella turcica?
Give surgical access to the pituitary
36
What are the functions of the limbic system?
Emotional response
| Apex also includes olfaction, behavioral activities and memories
37
What components are included in the brainstem?
Midbrain
Pons
Medulla
38
What important structure in contained in the midbrain and what is it’s purpose?
The cerebral aqueduct. It connects the 3rd and 4th ventricle
39
What nuclei is contained within the midbrain?
Cranial nerve nuclei
40
What important centers are in the Pons?
Respiratory centers:
Apneustic
Pneumotaxic
41
What neuclei are contained in the pons?
Cranial nerve nuclei
42
What structure contains white matter fiber tracts that cross forming striations or “pyramids” that are the reason motor and sensation crosses in the brain?
Medulla
43
What important centers are located in the medulla
Cardiac - receives signals from the hypothalamus
Vasomotor center
Respiratory centers - DRG and VRG
Sneeze, swallow, cough, vomit
44
How are inhibitory signals sent to the medulla?
Via the vagus nerve
45
How are excitatory signals sent to the medulla?
Via T1-T4
46
What is the reticular activating system
A diffuse complex network of fibers in the brainstem
47
What kind of information does the reticular activating system receive?
Sensory information
48
What does the reticular activating system signal
The cortex into wakefulness
49
What occurs with absence of RAS function
Unconsciousness and unaware
50
What is believed to produce hypnosis by depressing the RAS
General anesthetics
51
Where is the cerebellum
Below the tentorium (and occipital lobe)
52
Describe the structure of the cerebellum
2 hemispheres
| Outer grey cortex with deeper white matter
53
What are the functions of the cerebellum
Equilibrium
Tone
Coordination of skeletal muscle contraction
54
What are cranial fossa?
Depressions on the inside of the skull that align with structures of the brain
55
What does the anterior fossa cover
Frontal lobe
56
What does the middle fossa cover
Temporal lobe
57
Where are the anterior and middle fossa located
Supratentorial
58
What does the posterior fossa cover
Brainstem and cerebellum
59
Where is the posterior fossa located
Infratentorial
60
Describe the lateral ventricle(s)
There are 2, one in each hemisphere
Lined with ependymal cells
Contains CSF - most CSF is created here
61
How many ventricles are there?
4
62
Where is the third ventricle located
In the diencephalon
63
Where is the fourth ventricle located
Brainstem
64
What is the interventricular foramina?
The foramina of Monroe - there are 2
| They connect the lateral ventricles with the third ventricle
65
What is the cerebral aqueduct?
Aqueduct of Sylvius
| It connects the third ventricle with the fourth ventricle
66
What are the foramina of Lushka
There are 2
| They connect the fourth ventricle with the subarachnoid space
67
What is the foramen of Magendie
There is one
| It connects the fourth ventricle with the subarachnoid space
68
What is the purpose of CSF
Performs lymph-like functions
| Cushions, buoys the CNS
69
Describe the production of CSF
It is continually produced by the ependymal cells in the choroid plexus of the ventricles (mostly the lateral ventricles). It is ultrafiltration of plasma that uses active transport
70
How much CSF is there at any given time
100-150 mL
71
Starting in the lateral ventricle, describe the flow of CSF
Lateral ventricle
Interventricular foramina - foramina of Monroe
Third ventricle
Cerebral aqueduct - aqueduct of sylvius
Foramina of Lushka and Foramen of Magendie
Fourth ventricle
Subarachnoid space
72
What is the cisterna magna
Is a space located behind the cerebellum in the posterior fossa, it communicated with the fourth ventricle via the foramina of Lushka and foramen of Magendie
73
Where does CSF circulate
Through the subarachnoid space
74
How is CSF reabsorbed
Into arachnoid villi
75
Where does CSF go once absorbed by arachnoid villi
The arachnoid villi project into the dural venous sinuses
76
How much CSF is produced each day
500 mL
77
What is the normal CSF pressure
10-15 mmHg
78
What is the significant of saying villi act like valves
The more pressure in the CSF the more the “valves” will open and allow more to be reabsobed. They also keep it flowing in one direction
79
What usually causes CSF pressure problems
Blocked reabsorption
| Formation of CSF is rarely a problem
80
What can block reabsorption of CSF
RBC
Infection
Tumor
81
What is communicating hydrocephalus
CSF flows normally from ventricles into the subarachnoid space
There is a problem with absorption - blockage of arachnoid villi or blockage of subarachnoid space
82
Where does CSF collect with communicating hydrocephalus
Inside the ventricles AND outside of the brain within the subarachnoid space
83
What is another name for communicating hydrocephalus
Non obstructive hydrocephalus
84
What is non-communicating hydrocephalus
CSF flow is blocked within the ventricles
85
Where does CSF collect with non-communicating hydrocephalus
In the ventricles behind the obstruction
86
What is another name of non-communicating hydrocephalus
Obstructive hydrocephalus
87
What is a common treatment for hydrocephalus
Ventriculo-peritoneal shunt
| Excess fluid is shunted to the abdomen and absorbed by the peritoneum
88
What is Craniosynstosis
Premature closure of the cranial sutures
89
What the the problem with carniosynostosis
Increased ICP
90
When must correct occur for craniosynostosis
Surgical correction before 1 year of age
91
What else can occur with carniosynostosis
Other craniofacial abnormalities causing a difficult airway
92
During surgical correction of craniosynostosis what should you monitor for
blood loss
Hypothermia
VAE
93
What creates the blood brain barrier
Capillaries in the brain do not have pores between adjacent endothelial cells- tight junctions
94
What cell maintains the BBB
Astrocytes
95
What other substance maintains the BBB
Endogenous steroids
96
What areas of the brain does the BBB not exist
Areas called circumventricular organs:
Part of the hypothalamus
Pineal gland
Area postrema
97
What substances are highly permeable at the BBB
water
CO2
O2
Lipid soluble substances like alcohol and anesthetics
98
What is slightly permeable at the BBB
Electrolytes
99
What substances is the BBB almost impermeable to
Non-lipid soluble substances like proteins, non lipid soluble drugs
100
What are the anesthesia implications of the BBB
Besides drug sensitivity in crossing the BBB
| If the BBB is disrupted by trauma or surgery, this allows increased cerebral edema
101
What is often given to patients with known BBB disruption
Steroids
102
What type of fluid is preferred with neuro and why
Isotonic fluid that does not contain dextrose. Dextrose is metabolized and leaves free water behind
103
Why else is glucose bad with cerebral events
High serum GLU at time of cerebral event worsens resulting neuro deficits
104
What is a general rule with fluids and neuro sx
Limit fluids but maintain hemodynamics
105
Compare crystalloids to colloid use with altered BBB
Theoretically the colloid pressure could draw in more fluid
106
What alters the BBB
```
Surgical manipulation or retraction
Renal failure to the point of uremia
HTN crisis
Seizures
Cerebral hypoperfusion
Extremes of age
```
107
What are the 3 components of anesthesia
Immobility/paralysis
Blunted stress response
Unconsciousness
108
How is unconsciousness defined
Only negatively:
Absence of wakefulness
Absence of memory
Absence of awareness
109
Define reactive
Unconscious, responsive to stimuli
110
Define aware
Conscious, responds to command
111
Define recall
Forms memory of an event
112
Are awareness and recall related
Maybe, maybe not
| Awareness is the conscious ability to respond, recall is the memory of that response. We have seen one without the other
