Chapter 14: the Brain& Cranial Nerves Flashcards
(128 cards)
1
Q
Summarize the most important function of human brain (receive information)
A
To control the movements of the body (determine what you are going to do in the future, impact the world by planned movements )
2
Q
Three major portions of the brain
A
Cerebrum , Cerebellum, Brainstem
3
Q
is 83% of brain volume, cerebra hemisphere
A
Cerebrum
4
Q
contains 50% of the neurons; second largest brain region, located in posterior cranial fossa
10% mass of brain
motor control, movement
A
Cerebellum
5
Q
is the portion of the brain that remains id the cerebrum and cerebellum are removed, diencephalon, midbrain, pons, and medulla oblongata
A
Brainstem
6
Q
deep groove that separates cerebral hemispheres
A
Longitudinal fissure
7
Q
think folds that make up the brain
A
Gyri (gyrus)
8
Q
shallow grooves in between the folds
A
Sulci (sulcus)
9
Q
thick nerve bundle at boot, of longitudinal fissure that connects hemispheres
A
Corpus callosum
10
Q
the seat of neuron cell bodies, dendrites, and synapses
Dull white(grayish) color when fresh due to little myelin
forms surface layer CORTEXT over cerebrum and cerebellum (over all fold)
Forms NUCLEI deep within brain
A
Gray matter
11
Q
bundles of axons
Lies DEEP TO CORTICAL GRAY MATTER, opposite relationship spinal cord
Pearly white color from Myelin around nerve fibers
Composed of TRACTS, or bundles of axons, that connects one part of the brain to another, and to the spinal cord
A
White matter
12
Q
three connective tissue membranes that envelop the brain
Lies between the nervous tissue and bone
they are the DURA MATER, ARACHMOID MATER, and the PIA MATER
Protect the brain and provide structural framework for its arteries and veins
A
Meninges
13
Q
in cranial cavity; has two layers
outer PERIOSTEAL
Inner MENINGEAL
Creates DURAL SINUSES
A
Dura Mater
14
Q
equivalent to periosteal of cranial bones
A
Periosteal
15
Q
Continues into vertebral canal and forms Dural sac around spinal cord
A
meningeal
16
Q
pockets of cervical spinal fluid
A
Dural Sinuses
17
Q
transparent membrane over brain surface
spider web like
A
Arachnoid mater
18
Q
Very think membrane that follows contours of brain, even dipping into sulci
not usually visible without a microscope (so thin you cant observe)
Both involved with circulation, production and reabsorption of the CSF
A
Pia mater
19
Q
inflammation of the meninges
serious disease of infancy and childhood
Caused by bacterial and virus invasion of the CNS by way of the nose and throat
Pia mater and Arachnoid are most often affected
Bacterial___
A
Meningitis
20
Q
can cause swelling of the brain enlargement of the ventricles, and hemorrhage
comes thru blood, no blood brain barrier
swellings what kills
A
Bacterial Meningitis
21
Q
spongy mass of blood capillaries on the floor of each ventricle
A
Choroid plexus
22
Q
neuroglia that lines the ventricles and covers choroid plexus
Produces CSF
A
Ependyma
23
Q
clear, colorless liquid that fills the ventricles and canals of CNS
Bathes its external surface (purpose)
100 to 160 mL normally present at one time (replaces 4X a day)
Production begins w/ filtration of blood plasma thru the capillaries of the brain
A
Cerebrospinal fluid (CSF)
24
Q
Buoyancy
Protection
Chemical stability are functions of what
Big 3
A
CSF
25
Allows brain to attain considerable size without being impaired by its own weight
Brainfloats
Buoyancy
26
Protects the brain from striking the cranium when the head is jolted
Protection
27
Flow of CSF rinses away metabolic wastes from nervous tissue and homeostatically regulates its chemical environment
Right amount of ions Na, K, Ca
Chemical stability
28
encourage endothelial cells to move together to prevent infection ; destroy anything they don't like
Perivascular feet
29
is also a source of antibodies, macrophages, bacterial toxins, and other harmful agents
blood
30
strictly regulates what substances can get from the bloodstream into the tissue fluid of the brain
Induce the endothelial cells
Astrocytes contact capillaries
Brain barrier system
31
reach out and contact capillaries with their perivascular feet
Astrocytes (blood brain barrier)
32
Induce the ______ cells to form tight junctions that completely seal off gaps between them
endothelial (blood brain barrier)
33
Blood capillaries throughout the brain tissue
| Capillaries of the choroid plexus (of the ventricles)
Two points of entry must be guarded (Blood brain barrier)
34
to water , glucose, and lipid-soluble substances such as oxygen, carbon dioxide, alcohol, caffeine, nicotine, and anesthetics ( pass thru blood barrier easily)
Obstacle for delivering medications such as antibiotics and cancer drugs (don't pass thru blood brain barrier )
Blood barrier system is highly permeable
35
places in the third and fourth ventricles where the barrier is absent
Blood has direct access to the brain ( 3rd & 4th Ventricle)
Enables the brain to monitor and respond to fluctuations in blood glucose, pH, osmolarity, and other variables
Circumventricular organs (CVOs)
36
Hindbrain – Pons, Cerebellum, and Medulla oblongata
Midbrain – Midbrain
Forebrain – Thalamus, Hypothalamus, and Cerebrum
Brain parts from an embryological perspective
37
Thalamus, Hypothalamus, and Cerebrum
Forebrain
38
Midbrain
Midbrain
39
Pons, Cerebellum, and Medulla oblongata
Hindbrain
40
Begins at foramen magnum of the skull
Slightly wider than spinal cord
All nerve fibers connecting the brain to the spinal cord pass through the medulla
Contains cardiac, vasomotor, and respiratory centers
Medulla Oblongata
41
```
Cardiac center
Adjusts rate and force of heart
Vasomotor center
Adjusts blood vessel diameter
Respiratory centers
Control rate and depth of breathing
Reflex centers (autonomic ally)
For coughing, sneezing, gagging, swallowing, vomiting, salivation, sweating, movements of tongue and head
```
Functions of the Medulla Oblongata
42
Adjusts rate and force of heart
Cardiac center
43
Adjusts blood vessel diameter
Vasomotor center
44
Control rate and depth of breathing
Respiratory centers
45
For coughing, sneezing, gagging, swallowing, vomiting, salivation, sweating, movements of tongue and head
Reflex centers
46
Pathways in and out of cerebellum
Contains additional nuclei concerned with sleep, respiration, posture
is the function of
Pons
47
Short segment of brainstem that connects the hindbrain to the forebrain
Contains continuations of the reticular formation
(middle of everything ; midbrain& forebrain)
Midbrain
48
Loosely organized web of gray matter that runs vertically through all levels of the brainstem
SOMATIC MOTOR CONTROL
Integrates visual, auditory, and balance and motion stimuli into motor coordination functions of
Group of grey matter that goes thru all parts of brain
Cardiovascular control
Pain modulation(ramping &duliness of pain )
Sleep and consciousness(walking or putting you to sleep)
Habituation(Dulls stimuli higher stimuli )
Reticular Formation
49
The largest part of the hindbrain and the second largest part of the brain as a whole
Consists of right and left cerebellar hemispheres connected by vermis
Cortex of gray matter with folds (folia) and four deep nuclei in each hemisphere
Contains more than half of all brain neurons—about 100 billion
Cerebellum
50
Monitors muscle contractions and aids in motor coordination
Planning and scheduling tasks(4th dimension)
Evaluation of sensory input
Spatial perception and comprehension of different views of three-dimensional objects belonging to the same object
Timekeeping center(4th d)
Predicting movement of objects
Ex. Basketball goal
Cerebellum Functions
51
ovoid mass on each side of the brain perched at the superior end of the brainstem beneath the cerebral hemispheres
Composed of at least 23 nuclei
(cerebral Cortex to the Cerebellum)
Thalamus
52
“Gateway to the cerebral cortex”: filters information on its way to cerebral cortex
Plays key role in motor control by relaying signals from cerebellum to cerebrum and providing feedback loops between the cerebral cortex and the basal nuclei (discussed later)
Involved in the memory and emotional functions of the limbic system (discussed later)
Functions of the Thalamus
53
Major control center of autonomic nervous system and endocrine system
Plays essential role in homeostatic regulation of all body systems
Hypothalamus
54
Hormone secretion
Controls anterior pituitary
Regulates growth, metabolism, reproduction, and stress responses
Hormone secretion
Controls anterior pituitary
Regulates growth, metabolism, reproduction, and stress responses
Autonomic effects
Influences heart rate, blood pressure, gastrointestinal secretions, motility, etc.
Thermoregulation
Hypothalamic thermostat monitors body temperature
Food and water intake
Rhythm of sleep and waking
Controls 24-hour (circadian) rhythm of activity
Emotional behavior
Anger, aggression, fear, pleasure, and contentment
Functions of hypothalamic nuclei
55
largest and most conspicuous part of the human brain
Seat of sensory perception, memory, thought, judgment, and voluntary motor actions
Two cerebral hemispheres divided by longitudinal fissure
Connected by white fibrous tract, the corpus callosum
Gyri and sulci: increase amount of cortex in the cranial cavity(Increase surface area)
Some sulci divide each hemisphere into five lobes named for the cranial bones overlying them
Cerebrum
56
Frontal lobe
Voluntary motor functions
Motivation, foresight, planning, memory, mood, emotion, social judgment, and aggression
Parietal lobe
Receives and integrates general sensory information, taste, and some visual processing
Occipital lobe
Primary visual center of brain
Temporal lobe
Areas for hearing, smell, learning, memory, and some aspects of vision and emotion
Insula (hidden by other regions)
Understanding spoken language, taste and sensory information from visceral receptors
Five lobes of the Cerebrum
57
Voluntary motor functions
Motivation, foresight,
planning, memory, mood, emotion, social judgment, and aggression
Frontal Lobe
58
Receives and integrates general sensory information, taste, and some visual processing
Parietal lobe
59
Primary visual center of brain
Occipital lobe
60
Areas for hearing, smell, learning, memory, and some aspects of vision and emotion
(Limpic system)
Temporal lobe
61
Understanding spoken language, taste and sensory information from visceral receptors
(comes from gut)
Insula (hidden by other regions)
62
Association tracts
Projection tracts
Commissural tracts
Three types of tracts for Cerebral White Matter
63
Connect different regions within the same cerebral hemisphere
Association tracts
64
Extends vertically between higher and lower
brain
(up and down )
Projection tracts
65
Cross from one cerebral hemisphere through bridges called commissures
Most pass through corpus callosum
Enables the two sides of the cerebrum to communicate with each other
(left to right)
Commissural tracts
66
Cerebral cortex
Basal nuclei
Limbic system
Cerebral gray matter found in three places
67
Neural integration is carried out in the
gray matter of the cerebrum
68
layer covering the surface of the hemispheres
Only 2 to 3 mm thick
Cortex constitutes about 40% of brain mass
(Outer most layer, lots of Neurons, pack many neurons into tight space)
Cerebral cortex
69
six-layered tissue that constitutes about 90% of the human cerebral cortex
Relatively recent in evolutionary origin
(organization- system of neurons)
Neocortex
70
masses of cerebral gray matter buried deep in the white matter, lateral to the thalamus
Involved in motor control
(motor function movement)
basal nuclei
71
```
important center of emotion and learning
Most anatomically prominent components are:
Cingulate gyrus
Hippocampus
Amygdala
```
Also structures have centers for both gratification and aversion
Gratification
Aversion
Limbic system
72
in the medial temporal lobe; memory
Hippocampus
73
immediately rostral to the hippocampus; emotion
Amygdala
74
sensations of fear or sorrow
Aversion
75
sensations of pleasure or reward
Gratification
76
Higher brain functions—sleep, memory, cognition, emotion, sensation, motor control, and language
Involve interactions between cerebral cortex and basal nuclei, brainstem, and cerebellum
******Functions of the brain do not have easily defined anatomical boundaries
Integrative functions of the brain focus mainly on the cerebrum, but involve combined action of multiple brain levels
Integrative Functions of the Brain
77
monitors surface electrical activity of the brain waves
Useful for studying normal brain functions as sleep and consciousness
In diagnosis of degenerative brain diseases, metabolic abnormalities, brain tumors, etc.
Electroencephalogram (EEG)
78
Awake and resting with eyes closed and mind wandering
Suppressed when eyes open or performing a mental task
(Relitive to an Adult; syignals per sec)
Alpha waves 8 to 13 Hz
79
Eyes open and performing mental tasks
| Accentuated during mental activity and sensory stimulation
Beta waves 14 to 30 Hz
80
Drowsy or sleeping adults
If awake and under emotional stress
right before sleep or if under stress
Theta waves 4 to 7 Hz
81
Deep sleep in adults
Delta waves (high amplitude)
82
Brain glycogen and ATP levels increase in non-REM sleep(replenish ATP &glycogen)
Memories strengthened in REM sleep (hippocampus and thalamus)
Synaptic connections reinforced( adenine)
Purpose of Sleep
| Who do we sleep?
83
Bed rest alone does not have the restorative effect of sleep—why must we lose consciousness?
To stay safe
84
the range of mental processes by which we acquire and use knowledge
Such as sensory perception, thought, reasoning, judgment, memory, imagination, and intuition
Be familiar with following functions and the areas of the brain that allow for a particular component of cognition.
Cognition
85
planning our responses and personality; ability to execute appropriate behavior
(most of how we think/ separates us from other species)
Frontal lobe association (prefrontal cortex) area
86
identifying stimuli
Temporal lobe association area
87
perceiving stimuli
Parietal lobe association area
88
acquiring new information
learning
89
information storage and retrieval
memory
90
eliminating trivial information; as important as remembering
forgetting
91
Learning
Memory
forgetting
Information management entails
92
defects in declarative memory: inability to describe past events
Amnesia
93
ability to tie one’s shoes
Procedural memory
94
unable to store new information
Anterograde amnesia
95
person cannot recall things known before the injury
Retrograde amnesia
96
(temporal lobe) important memory-forming center
Does not store memories
Organizes sensory and cognitive information into a unified long-term memory
-most important memories & sends to cerebral cortex decides what is important ( thalamus does same thing)
Hippocampus
97
Long-term memories are stored in various areas of the cerebral cortex and other gray matter (stores memory)
Cerebral Cortex
98
Vocabulary and memory of familiar faces stored in superior
temporal lobe
99
Memories of one’s plans and social roles stored in the
| plans
prefrontal cortex
100
helps learn motor skills (Procedural memory)
Cerebellum
101
Emotional feelings and memories are interactions between
prefrontal cortex and hypothalmus (limpic system)
102
seat of judgment, intent, and control over expression of emotions
Prefrontal cortex
103
___come from hypothalamus and amygdala
| Nuclei generate feelings of fear or love
Feelings
104
receives input from sensory systems and stores and integrates emotional memory
one output goes to hypothalamus & other output to prefrontal cortex
Amygdala
105
influencing somatic and visceral motor systems
| Heart races, raises blood pressure, makes hair stand on end, induces vomiting
One output goes to hypothalamus
106
important in controlling expression of emotions
Ability to express love, control anger, or overcome fear
Lie detector tests
Other output to prefrontal cortex
107
_shaped by learned associations between stimuli, our responses to them, and the reward or punishment that results
Behavior
108
limited to the head and employ relatively complex sense organs
```
Vision
Hearing
Equilibrium
Taste and smell
(info we receive to brain)
```
Special senses
109
distributed senses
General (somatosensory, or somatic) senses
110
olfactory association area
bottom of frontal lobe
111
visual association are, primary visual cortex
occipital lobe
112
Primary auditory cortex, auditory association area
temporal lobe
113
Several sites where sensory input is first received and one becomes conscious of the stimulus
Central sulcus
incoming information
Primary sensory cortex or Postcentral Gyrus
114
nearby to sensory areas that process and interpret that sensory information
Association areas
115
which resembles an upside-down sensory map of the contralateral side of the body
Sensory homunculus—diagram of the primary Somatosensory cortex (post central gyrus)
116
point-to-point correspondence between an area of the body and an area of the CNS
ex. toe to brain
Somatotopy
117
Intent to contract muscles begins in Motor Association (premotor) (plans how much force) . Program and plan sent to primary motor cortex which is in the precentral gyrus.
Primary motor cortex or Precentral Gyrus
118
**Permits recognition of spoken and written language and creates plan of speech
When we intend to speak, Wernicke area formulates phrases according to learned rules of grammar
Wernicke area
119
**Generates motor program for the muscles of the larynx, tongue, cheeks, and lips
Broca area
120
the difference in the structure and function of the cerebral hemispheres
Cerebral lateralization
121
categorical hemisphere
Specialized for spoken and written language
Sequential and analytical reasoning (math and science)
Breaks information into fragments and analyzes it in a linear way
Left hemisphere
122
representational hemisphere
Perceives information in a more integrated holistic way
Seat of imagination and insight
Musical and artistic skill
Perception of patterns and spatial relationships
Comparison of sights, sounds, smells, and taste
Right hemisphere
123
Advantage?
| of Cerebral Lateralization
Multitasking; ex squirrel thinks about prettier while looking for food
124
using a series of conventional x-rays to image the body in numerous sections rather than one 2d image.
X-Ray Computed Tomography (CT scan)
125
visualize increases in blood flow when brain areas are active
Injection of radioactively labeled glucose
Busy areas of brain “light up”
Positron emission tomography (PET) and MRI
126
swallowing of radioactive glucose molecule Carbon 11 unstable positron electron(+) releases gamma radiation waves and that's what the machine detects
PET
127
looks at increase in blood flow to an area (additional glucose is needed in active area)—magnetic properties of hemoglobin depend on how much oxygen is bound to it (additional oxygen is there due to additional blood flow)
Quick, safe, and accurate method to see brain function
Functional magnetic resonance imaging (fMRI)
128
shifts molecules magnetic +/- the machine detects those but how this happens is that the
blood flow neurons needs astrocytes glutmate to glutamine , glucose makes ATP increases blood flow to area w/ more oxygen on hemoglobin which increases oxygen to area and magnetic field detects by that action
MRI
