WEEK 2 - BRAIN ANATOMY & RESEARCH METHODS Flashcards
functions of the nervous system
- movement
- sensation
- regulation of bodily functions
- subjective experience and thought
CNS
brain and spinal cord
front roots of spinal cord
movement
back roots of the spinal cord
sensation
PNS
- somatic
- autonomic
somatic nervous system
sensorimotor function
- voluntary movement
- sensation vision/hearing
via cranial nerves
- sensation: haptic
(dermatomes)
dermatomes
Different exits of the spinal cord lead to different strips of skin to innervate touch in that area
ie teaches us about numbness
autonomic nervous system
connections to the heart, intestines, other organs
- sympathetic and para ns.
cranial nerves
12 nerves originating from the brain, controlling
- sensations from the head
- muscle movements in the head
- parasympathetic output to the organs
afferent nerves
carry info to the brain
sensory input
efferent nerves
Carry info from the brain
motor output
sympathetic
fight flight
arousal
parasympathetic
Rest and digest
tract
set of axons within the CNS
nerve
set of axons in the periphery
nucleus
cluster of neuron cell bodies within the CNS
ganglion
a cluster of neuron cell bodies OUTSIDE THE CNS
gyrus
protuberance/bulge on the surface of the brain
sulcus
Fold or groove that separates one gyrus from another
fissure
long, deep sulcus
myelin
type of fat, looks whiter than the cell body
gray matter
cell bodies
white matter
myelinated axons
- connecting neurons throughout the CNS/PNS
directional planes
saggital
horitzonal
coronal
ventral
toward the stomach (belly)
dorsal
toward the back (spine)
anterior
front end
posterior
rear end
roastral
forehead
caudal
back of head/neck
ipsilateral
on same side of body
contralateral
the opposite side of the body
hindbrain
medulla oblongata, pins, cerebellum
midbrain
Part of the brain stem includes sensory and motor relay nuclei
forebrain
includes hemispheres, corpus callosum, and subcortical deep structures (telencephalon and diencephalon
brainstem
combination of structures from forebrain, midbrain and hindbrain
holds up both hemispheres
medulla oblongata
enlarged extension of the spinal cord
- contributes to vital reflexes, damage is often fatal
pons (latin for bridge)
thickened part on top of the medulla (ventral and anterior)
- crossing over of many fibers in the motor and sensory pathways for contralateral motor control
cerebellum
dorsal and inferior
‘small brain’
- automated movement, balance, timing and time perception, sensorimotor coupling, attention shifting
origin of cranial nerves in the hind brain
5-12
midbrain
superior and inferior colliculi :
substantia nigra
superior and inferior colliculi :
contribute to sensory processing
substantia nigra
contributes to movement initiation
*most affected in parkinson disease
midbrain cranial nerves
2-4
forebrain
two cortical hemispheres
corpus callosum
two cortical hemispheres
cortex: bark, crumbled to increase surface (grey matter on hemispheres)
divided into 4 lobes, mostly contralateral info (opposite)
corpus colluosum
main structure connecting the hemispheres
structures underneath the cortex ‘subcortical’
thalamus
hypothalamus
pituitary gland
basal ganglia
- caudate nucleus, putamen, globus pallidus
- basal forebrain
- hippocampus
forebrain cranial nerve
first (olfactory)
- smell
thalamus (2) - one in each hemisphere
collection of smaller nuclei, sensory and motor parts
relay station: sensory input travels through the thalamus to primary sensory areas and motor output to the muscles
gating mechanisms:
- deciding what goes through and what gets attention
VERY IMPORTANT
hypothalamus
located just below thalamus
- important in behavior and hormonal regulation
- emotion, motivation
- food intake
- activity level
- sexual behavior
pituitary gland
hormone-producing gland
responds to the hypothalamus
basal ganglia
putamen, caudate, globus pallidus
motor function, and movement
disease basal ganglia involved in
damaged in parkinsons and Huntington diseases
involved in movement initiation and vigor
timing conncetion & sequence learning
hippocampus
found in the temporal lobe
crucial for memory
shrinks in patients with alziehmers diseases
SEAHORSE SHAPE
ventricles and csf
fluid coushin all subcortical structures
hollow spaces
CSF
produces by the glia cells that line the ventricles and circulate along the spinal cord
Motor nerves leave from which side of the spinal cord, dorsal
or ventral?
ventral
what structures are found in the Hindbrain:
cerebellum
medulla pons
what structures are found in the midbrain
substantia nigra,
superior and inferior colliculi, tectum,
and tegmentum.
what structures are found in the forebrain
basal ganglia, hippocampus, hypothalamus, pituitary and thalamus
Which area is the main source of input to the cerebral cortex?
thalamus
What does ventral mean?
Toward the stomach
If two structures are both on the left side, or both on the right, what is their relationship?
Ipsilateral
- What is a sulcus in the brain?
A groove that separates one gyrus from another
- What is the function of the dorsal roots of the spinal cord?
They receive sensory input.
What does the parasympathetic nervous system control?
Vegetative activities
Which of these controls breathing, heart rate, and salivation?
The cranial nerves
hippocampus in what region
forebrain
Which structure provides most of the direct input to the cerebral cortex?
C. Thalamus
What do the ventricles contain?
Cerebrospinal fluid
cortical lobes
occipital lobe
parietal
temporal
frontal
cortical cell layers
6 different layers
Axons differ in lengths and thickness depending on cortical areas and primary function
organized into the type of neurons
types of neurons
sensory (input)
interneurons (relay)
motor (output)
primary sensory areas
first point of reception of sensory info after thalamus
information from specific senses is processed in so-called primary sensory areas and further processed detail elsewhere
landmark gyri and sulci
the wrinkled surface of the cortex
landmark fissures, sulci and gyri
longitudial fissure
central sulcus
lateral fissure
precentral gyrus
post central gyrus
occipital lobe
visual cortex
crossed visual fields, one hemisphere receives input from two eyes
(both sides process info from contralateral visual field)
damage occipital lobe
cortical blindness
parietal lobe
contains postcentral gyrus: primary somatosensory cortex
- processing touch and pain sensations, sensor info from muscles and joints
- integrating info from eye, head and body positions
spatial and numerical information
somatosensory homunculus
little human
body represetnation on the somatosensory strip in parietal cortex: somatotphy
not everybody part is represented equally (some parts are more sensitive)
temporal lobe
auditory areas
complex aspects of visual perception
memory (hippocampus)
frontal lobe
contains precentral gyrus: primary motor cortex
prefrontal cortex: contributes to many functions
- working memory
-planning
- response inhibition or inhibition, impulse control
binding problem
integration problem
unified perception across senses seems to happen when 2 sensations happen at the same placr and time
NOT YET FULLY EXPLAINED
dementia
brain damage
dementia gyri gets smoother
brain damage
atrophy
tumor
vascular (stroke)
developmental disorders
toxicity
infections
surgery (ie, epilepsy)
transcranial magnetic stimulation TMS
knocks out specific region: stimulates a lesion
- non invasive, reversible
*unnatural situtation
EEG
electrodes in a cap, measure small electrical currents on thee scalp
currents are results of many action potential
MEG
measures magnetic fileds due to the same electrical currents
position emission tomography
measures decay of an injected radioactive tracer, shows where the blood is going
fMRI
measures level of oxygen in the blood changed as brain areas become more active
electrical signals tests
EEG
MEG
blood circulation and oxygen use tests
positron emission tomography
fmri
correlation methods
CT
can show brain structure using x rays and an injected contrast tracer
MRI
without the functional
makes high resolution 3d images of the brain
expensive
Which lobe of the cerebral cortex includes the primary audi-
tory cortex?
temporal lobe
Which lobe of the cerebral cortex includes the primary
somatosensory cortex?
Parietal lobe
Which lobe of the cerebral cortex includes the primary visual
cortex?
occipital
Which lobe of the cerebral cortex includes the primary
motor cortex?
frontal lobe
What are the functions of the prefrontal cortex?
posterior portion: control of movement
middle potion: working memory, cognitive control, emotion
anterior portion: compares various types of info for making a decision
- What is meant by the binding problem, and what is neces-
sary for binding to occur?
The binding problem is the question of how the brain
combines activity in different brain areas to produce
unified perception and coordinated behavior.
Binding requires identifying the location of an object and perceiv-
ing sight, sound, and other aspects of a stimulus as being
simultaneous.
When the sight and sound appear to come
from the same location at the same time, we bind them
as a single experience.
What is the main way in which mammalian species vary in their cerebral cortex?
Brains differ in their size and degree of folding.
In which of these ways do primates differ from elephants in their cerebral cortex?
A. Primates have more neurons per unit volume.
What is the relationship between columns and laminae in the cerebral cortex?
Each column crosses through one lamina after
another.
Where is the primary visual cortex?
Occipital lobe
Where is the primary somatosensory visual cortex?
Parietal lobe
Where is the primary auditory cortex?
Temporal lobe
Where is the primary motor cortex?
Frontal lobe
The main functions of the prefrontal cortex include which of the following?
Working memory and weighing the pros and cons of a
possible action
What is the binding problem?
The question of how we perceive separate sensations
as part of a single object
What is the difference between a lesion and an
ablation?
lesion is damage to a structure
. An ablation is
removal of the structure.
For example, a blood clot might
produce a lesion, whereas surgery could produce an
ablation.
What are the similarities and differences between MRI and
fMRI?
Both methods measure the responses of brain
chemicals to a magnetic field.
MRI shows the anatomy of
the brain.
The fMRI method shows which brain areas are
most active at the moment.
