501 Neuroanatomy Quiz 1 (review and imaging)

Why should we (as SLPs) have a working knowledge of neuroanatomy and physiology?

so when there is damage in a certain area of the brain or body, we have a general conception of what to expect as well as be able to describe in layperson what is going on

What is the clinicopathologic method?

Relationship between lesion/damage and changes in behavioral function

What is the purpose of the clinicopathologic method as part of a neurological exam?

• forms the basis of a neurologic exam and clinical evals

• strong foundational understanding of typical neuroanatomy and physiology required

How has neuroimaging revolutionized neurological exams?

• clarified sites of lesions

• made diagnoses more valid and reliable

How can you tell the left vs right side of the brain on a brain scan?

What is a CT scan? (+how it works and is it static or dynamic?)

Static

• X-ray beam passed through brain, measures amount of x-ray beams that reflect off of or absorbed by body’s tissues

  • more reflection with dense tissue (bone)

  • detail can be equivalent to postmortem exam

  • Pros:

    • commonly used 

    • easily accessible

    • inexpensive

    • quick processing time

  • Cons:

    • use of x-rays/cancer risk

    • shows structures only

    • difficulty observing new and small damage

    • clarity of images (difficulty seeing soft tissues)

What is an MRI? (+how does it work and is it static or dynamic?)

Static

• uses radio waves and strong magnetic field to detect distribution of water molecules in living tissue

  • MOST WIDELY USED NEUROIMAGING TECH

  • can provide accurate tissue densities and reconstructed 3D image of brain

  • typically more sensitive to show damage/abnormalities than CT but much more expensive

  • Pros:

    • much better images

    • images in multiple dimensions

    • no x-rays

    • no preparation needed (ex no injections)

  • Cons:

    • More expensive than CT

    • patients with metal in body

    • patients must remain still for clear image

    • patients with claustrophobia may struggle with exam

What is an fMRI? (+how does it work and is it static or dynamic?)

Dynamic

• measures brain activity by detecting changes associated with blood flow

  • relies on cerebral blood flow and neuronal activation being coupled

  • when an area of the brain is in use, blood flow to that region increases

    • Pros:

      • can see structure and function at the same time (and over time)

      • safe (no contrast)

    • Cons:

      • expensive 

      • not widely utilized except in neuro research

What is a PET scan? (+how does it work and is it static or dynamic?)

Dynamic

• (positron emission tomography): measures metabolic activity in brain

  • uses radioactive glucose that is metabolized by the brain

  • more active areas metabolize glucose faster; higher radioactivity (red)

  • more accurate measure of neural activity than measuring blood flow

  • used to measure higher cognitive functions including language

  • Pros:

    • good image of location of brain activity

    • can see brain activity in different areas over time

  • Cons:

    • expensive used more often in major medical centers

    • invasive procedure because of injection

    • radioactive material used (radioactive glucose)

What is a SPECT? (+how does it work and is it static or dynamic?)

Dynamic

• (single photon emission tomography): radioactive compounds that emit gamma rays injected into individual

  • gamma rays measured as metabolized by the brain

  • constructs 3D cross sections of brain

  • can detect decreases in bloodflow in brain

  • pros: 

    • can detect increases/decreases in blood flow over time

    • less expensive than PET used in smaller medical centers

  • Cons:

    • invasive procedure because of injection

    • radioactive material used

    • resolution is less than PET

What are some common caveats to using neuroimaging?

• Not always accurate→just because lights up does not mean sole area responsible for a function

• difficult to read even if clear

• number of cross sectional slices can vary (depending on site)

• may not detect small lesions (ex: parkinsons) behavior may occur before lesions show on imaging

• limitations emphasize the continued need for behavioral neurological examinations (clinicopathologic methods)

At what point does the CNS end and the PNS begin?

What is the difference between CNS and PNS?

• CNS: brain and spinal cord (including brain stem)

• PNS: cranial nerves, ganglia outside CNS, spinal nerves

Which deals with higher level functions vs lower level? (CNS or PNS)

• brain is concerned with higher centers of control

• spinal cord contains lower centers and is concerned with reflex control

the brain is concerned with ______________ center of control

higher

the spinal cord contains _________ centers and is concerned with ___________

lower

reflex control

Besides reflex control, what is the spinal cord doing?

provides a pathway between the brain and peripheral nerves of the trunk and limbs

What is the difference between grey and white matter in the nervous system?

• Grey matter: cell bodies (primarily)

  • processing information; clusters of cell bodies can create structures

• white matter: mylinated axons

  • transmit information

grey matter is the _______________ and is responsible for _______________

cell bodies

processing information

white matter is _____________ and is responsible for _____________

myelinated axons

transmit/move information

Is there more white or grey matter on the inside/deeper in the brain?

there is more white than grey matter on the inside

also there is more grey matter on the outside

Label the lateral side of the brain and its major landmarks

What are 2 primary functions of the frontal lobe?

movement

higher level cognitive functions—> attention, cognitive processing and thinking etc

What does the frontal lobe include?

the prefrontal cortex which is crucial for attention, cognitive processing and thinking

What are 2 primary functions of the temporal lobe?

auditory processing

language comprehension

What is the function of the parietal lobe?

general sensation

includes somatosensation because postcentral gyrus is here

What is included in somatosensation?

touch, taste, temperature, pain and pressure

What is the primary function of the occipital lobe?

visual processing

(includes primary visual cortex)

What are the 3 types of cerebral connections?

Projection fibers

Association fibers

Commissural fibers

What are association fibers (and example)?

horizontal orientation

to and from regions of same hemisphere (ex: arcuate fasiculus—> connects wernickes and brocas so can communicate)

What are commissural fibers (and example)?

transverse orientation

from one hemisphere to the other (ex: corpus callosum—> connects 2 hemispheres)

What are projection fibers (and example)?

Vertical orientation

to and from cortex(surface) to the brainstem/spinal cord (ex: corona radiata)

What is the theory of “localization of function”?

Different cortical regions associated with different mental functions

Label the different Broca’s areas

What is area 4 and its functions?

Primary motor cortex

Responsible for executing motor plan and sending plan down as electrical signals to be carried out by muscles of face, legs, etc

Last place motor information touches before leaving brain

What are the areas 1-3? What are their functions?

Primary somatosensory cortex

First place in the brain that receives raw somatosensation (touch, taste, pressure, pain and temperature)

What are areas 41 and 42? What are their functions?

Primary auditory cortex

First place to receive raw auditory information from ears

Sound localization (where is the sound coming from)

Detects if the sound is speech or not (ex fan noise vs speech)

What is area 17? What is its function?

Primary visual cortex

Receives raw visual info (the shapes, colors, shading, etc)

What is area 28? What is its function?

Primary olfactory cortex (located on medial side of temporal lobe)

First place to receive raw smell information from nasal cavity that triggers hair cells

What are the cortical speech association areas? What do they do?

Help to plan motor (speech) movements

Areas 44-47 (opercular gyri)

Area 44, 45 Broca’s area

NOTE: the cortical motor speech association areas work first and create the motor plan before sending it to the primary motor cortex (where motor plan is executed)

What helps process a speech plan and is the heavy lifter?

Broca’s area 44 and 45

What are the sensory association areas? And what do they do?

“Elaboration of sensation”

Areas 5-7: general somatic association

Area 22: auditory association/language processing (wernicke’s area)—> decodes what are you hearing

Areas 18 and 19: visual association—> decodes what are we seeing?

what are areas 18 and 19? Function?

Visual association area—>decodes what we are seeing

(sensory association area)

what are areas 5-7

general somatic sensation

(sensory association area)

what is area 22

auditory association/language processing (wernicke’s area)—> decodes what are you hearing

(sensory association area)

What are unimodal association areas (and example)?

1 type of information is processed

Adjacent to primary motor/sensory areas

Ex: visual association area—> next to primary visual cortex

What are polymodal association areas? (And example)

close to unimodal areas; process 2 or more kinds of sensory info; matches current sensory info with past

What are the supramodal association areas? (And example)

highest level of processing (perception)

neural processing not directly with motor/sensory functions

primarily in prefrontal area, perisylvian cortex, limbic lobe

What is the function of the limbic system “lobe”?

Group of structures that generate emotional and visceral responses

Also involved in establishing memories and motivation for communication

While cingulate gurus is part of the cortex, limbic system is considered the “lobe”

most subcortical structures are _______________but connect with ________________

cell bodies (grey matter)

white matter

What is the function of the thalamus?

• paired egg shaped mass of subcortical grey matter, located on either side of 3rd ventricle

  • integrates all types of sensation in the nervous system except olfaction (smell)

  • relays info to/from cortex, cerebellum, limbic system and basal ganglia

  • RELAY CENTER FOR SENSORY INFO THAT IS COMING UP TOWARDS BRAIN

the thalamus is the __________for all ______________ info coming into CNS

EXCEPT _______________

relay station

sensory

smell

the thalamus is located on either side of the ________________

3rd ventricle

the hypothalamus is located _________ and _______ to thalamic nuclei

medial

inferior

the hypothalamus makes up what?

the floor of the 3rd ventricle

the hypothalamus is critical for ______ and _________ function

autonomic

endocrine

the hypothalamus is close to the brain stem and regulates ______________ including?

bodily (functions)

-body temperature

-food and water intake

-sexual and sleep behavior

hypothalamus ALSO helps regulate what kind of behaviors

emotional behaviors

escape behaviors (fight or flight)

basal ganglia is responsible for helping to program and control _______________________________

voluntary and stereotypic movements (walking)

where does the basal ganglia receive primary input from?

motor cortex and thalamus

the basal ganglia sends primary output back to __________ via ___________

motor cortex

thalamus

what is the loop the basal ganglia is involved in?

cortex—> basal ganglia—>thalamus—>cortex

subcortical structures are made of __________ matter

grey matter (cell bodies)

What are the functions of the hypothalamus?

• Located medial and inferior thalamic nuclei, makes up floor of 3rd ventricle

  • critical for autonomic and endocrine function

  • regulates emotional behaviors as well as escape behaviors

  • regulates bodily functions including body temp, food and water intake, sexual and sleep behavior)

What are the functions of the basal ganglia?

• collection of subcortical nuclear structures helping to progream and control voluntary and stereotypic movements (walking)

• receives primary input from motor cortex and thalamus

• sends primary output back to motor cortex via thalamus-makes a circuit or loop (4 different kinds of loops)

What are the functions of the cerebellum?

• “little brain”, located posterior to brainstem, inferior to cerebrum, 2 hemispheres

  • coordinates and refines motor movements on ipsilateral side

  • large role in postural stability and in motor learning

  • also thought to have minor role in cognitive processing as connections found to prefrontal cortex

the cerebellum is located ________ to the brainstem (has attachments) and _________ to the cerebrum (not directly attached)

posterior

inferior

the cerebellum _______________and ___________ motor movements

coordinates and refines

What are the functions of the brainstem?

• maintains essential life functions

  • regulation of body temp

  • respiration

  • swallowing

  • digestion

  • cardiac function

what are the 3 parts of the brainstem?

midbrain

pons

medulla

the midbrain contains ___________ , ___________, and __________

crus cerebrum

tectum

colliculi

superior colliculi are for ___________

inferior colliculi are for ____________

vision

hearing

the pons connect to the _______ and contain several _________________

cerebellum

cranial nerve nuclei

the medulla contains ______________ and the point of ____________________ for neuron tracts and also contains some cranial nerve __________

pyramids (tracts of neurons)

decussation (crossing over)

nuclei

the brainstem controls flow of info between ________ and ____________________

brain

rest of body

What are the functions of the spinal cord?

• gray H shaped core surrounded by white quadrants

  • myelinated axons make up white matter and cell bodies make up gray matter

  • posterior horns=dorsal horns→ sensory (afferent)

  • anterior horns=ventral horns→ motor (efferent)

posterior horns are the _____________

which do what?

dorsal horns

bring in sensory info

aka sensory (afferent)

anterior horns are the ___________

which do what?

ventral horns

push motor info out

aka motor (efferent)

efferent/descending tracts are…

-typically motor (movement)

-exit to muscles, viscera, etc

-EXITING

afferent/ascending tracts are…

-typically sensory

-arrive to CNS from sensory nerves

-ARRIVING

What are the different structures of the limbic system?

• cingulate gyrus

• hippocampus (memory)

• amygdala (emotion)

• mammillary bodies

• fornix

Why is the limbic system called “lobe”?

Because the cingulate gyrus is located on the surface/cerebral cortex, but the rest of the structures are subcortical

What are the different structures of the basal ganglia?

• caudate nucleus (head, body, tail)

• putamen

• globus pallidus

• subthalamic nucleus

• substantia nigra

What are the different parts of the brainstem?

• Midbrain: contain tectum and colliculi (bumps on tectum)

• Pons: connects to cerebellum and contains several cranial nerve nuclei

• Medulla: contains pyramids (tracts of neurons) and is point of decussation (crossing over) for corticospinal neuron tracts; also contains some cranial nerve nuclei

How does a reflex arc work? (What are the steps?)

1. arrival of stimulus and activation of receptor (hand on hot stove)

2. activation of a sensory neuron

3. information processing in CNS (sensory neuron synapses with CNS)

   1. also the info crosses over and is sent up to the brain as well

4. activation of a motor neuron

5. response by effector (move hand)

facts about reflex arc

interaction between CNS and PNS

lower level of processing information

does NOT need to be first send to the cortex for action to be triggered (but info does subsequently get sent to the cortex)

What are the efferent tracts?

Primary motor projection areas are EFFERENT (EXIT)—> send motor commands out

What are afferent tracts?

Primary sensory reception areas are AFFERENT (arriving)

What is the difference between efferent and afferent tracts of the nervous system?

Efferent (MOTOR) tracts are exiting while afferent (SENSORY) tracts are arriving

What are the divisions of the PNS?

Cranial nerves (12 pairs)

Spinal (peripheral) nerves (31 pairs)

Peripheral parts of autonomic nervous system

What are the 3 divisions of the autonomic nervous system (ANS)?

Enteric nervous system: controls swallowing and digestion

Sympathetic nervous system: alerts body to stimulus (fight or flight)

Parasympathetic nervous system: returns body back to “pre-alert”levels

enteric nervous system controls what?

swallowing and digestion

sympathetic nervous system does what?

alerts body to stimulus (fight or flight)

parasympathetic nervous system does what?

returns body back to “pre-alert” levels

“re-regulates”