Neuroanatomy Flashcards

1
Q

what are afferent signals?

A

signals that move from the body to the brain (sensory)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

what are efferent signals?

A

signals that move from brain to body (motor)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

what is the central nervous system (CNS)?

A

the brain and the spinal cord

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

what is the peripheral nervous system (PNS)? what other systems does it contain?

A
  • nervous tissue outside the brain and spinal cord
  • somatic and autonomic nervous system
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

what is the somatic nervous system? what do it’s afferent and efferent signals do?

A
  • conscious sensation and movement in relation to the outside world
    • afferent - sensation of the outside world, touch
    • efferent - movement in relation to the outside world
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

what is the autonomic nervous system? what do it’s afferent and efferent signals do?

A
  • unconscious afferent and efferent signals
    • afferent - sensation of internal environment (blood acidity, how much stomach is stretched)
    • efferent - movement of internal environment without our conscious involvement
      • sympathetic NS
      • parasympathetic NS
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

what are the efferent systems of the autonomic nervous system? do they work bilaterally?

A
  • sympathetic and parasympathetic nervous systems
  • there is a unilateral sympathetic response across the body and extreme lateralization of response
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

what does the sympathetic nervous system do?

A
  • mobilizes energy, fight or flight, main goal is to be ready for some action, maximize and mobilize energy/resources on hand
    • heart pounds more to bring more O2 to the brain
    • body starts creating more energy, ATP to use
    • blood constricts to the core and the brain to prevent bleeding in limbs
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

what does the parasympathetic nervous system do?

A
  • conserves energy, rest and digest, main goal is to store energy for later, digest faster
  • not always mutually exclusive or in opposition to one another
    • ex. healthy sexual activity
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

what are cell clusters?

A

cell clusters - grey matter regions
- nucleus, nuclei (CNS) vs. ganglion/ganglia (PNS)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

what are bundles?

A

bundle of axons - white matter regions
- tract (CNS) vs. nerve (PNS) vs. fibres (all)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

what are the anatomical directions when referring to quadrapedal animals?

A
  • anterior (rostral) - head of the animal, posterior (caudal) - end of spinal cord of the animal
  • dorsal/superior - spine side, ventral/inferior - stomach side
  • lateral - towards the outside of the body, medial - towards the line of symmetry
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

what are the anatomical directions when referring to the bipedal neuroaxis of humans?

A
  • anterior - head (including the midbrain), posterior - end of spinal cord
    • after the midbrain, it switches
    • anterior - front of our face,
    • posterior - back of our head
  • dorsal- spine side, ventral - stomach side
    • we don’t use the terms superior/inferior for the midbrain to botton of spine
    • after the midbrain, it switches
    • dorsal/superior - top of the head, ventral/inferior - bottom of the brain
  • lateral - towards the outside of the body, medial - towards the line of symmetry
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

what is a coronal section?

A

cutting to separate front half of brain from the back half

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

what is a horizontal section?

A

cutting to separate the top of the brain from the bottom half

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

what is a mid-sagittal section?

A

cutting to separate sides of the brain down the middle

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

what is a sagittal section?

A

any cut separating the sides of the brain

18
Q

what is the composition of the spinal cord from anterior to posterior?

A
  • cervical, thoracic, lumbar, and sacral vertebrae protect the spinal cord
  • intermittent projections form spinal cord because the spinal cord is protected by bones and the axons bundle together to squeeze through between bones
19
Q

why does the spinal cord narrow as you go down the spine?

A
  • narrows as you go down since the efferent neurons on the lower end leave to control parts of the body
    • barely any sensory information coming in at the bottom of the spinal cord
    • sensory axons increase as you move up the spinal cord
20
Q

what is the cauda equina?

A

sack of nerve roots at the lower end of the spinal cord that leave the spinal cord to connect to other parts of the body

21
Q

what does the composition of grey and white matter look like in the spine? what are the different parts responsible for?

A
  • grey matter is on the inside and shaped like an H, white matter surrounding
    • opposite of how white matter and grey matter are organized in the brain
  • dorsal side of spinal cord is responsible for sensory information and ventral side is responsible for motor information
  • motor cell bodies - cell bodies are in the grey matter of the spinal cord
  • sensory cell bodies - cell bodies are in the ganglia outside the spinal cord (dorsal root ganglia)
22
Q

why is the segment of damage of the spinal cord important?

A
  • spinal cord damage is related to segment of damage
  • closer to brain → worse damage
    • affects all the motor and sensory axons/cell bodies below it
23
Q

what are the 3 major divisions in the brain?

A
  • forebrain, midbrain, hindbrain
  • all appear in early development
24
Q

what are the 5 major divisions in the brain?

A
  • forebrain - telencephalon, diencephalon
  • midbrain - mesencephalon
  • hindbrain - metencephalon, myelencephalon
25
Q

what are the functions of the myelencephalon? what directional terms are we using?

A

dorsal is along our back, posterior is towards our feet, anterior is towards the top of our head

  • medulla - is the junction between spinal cord and brain, has lots of tracts and myelinated axons
  • responsible for involuntary control of life-sustaining functions
  • reticular formation - runs from myelencephalon to mesencephalon (midbrain to hindbrain)
  • responsible for arousal, wakefulness, arousal and sleep
26
Q

what are the functions of the metencephalon? where are the different regions?

A
  • pons - on the ventral side (belly)
    piece of big white matter with afferent and efferent axons, info continuing from spinal cord and medulla
  • responsible for ability to feel and ability to move
  • cerebellum - on the dorsal side (back)
  • 10% of brain volume and more than 50% of - neurons needed for sensory and motor coordination
27
Q

what are the functions of the mesencephalon? where are the different regions?

A
  • tectum - dorsal (back) side, has the superior colliculi (eye movement in response to visual stimuli) and inferior colliculi (head movement in response to sound)
  • responsible for how we move our eyes and bodies in relation to sights and sounds
  • parinaud’s syndrome - inability to move eyes, especially upwards
  • tegmentum - ventral (belly) side, related to movement in relation to motivation
  • contains reticular formation, periaqueductal grey (behaviour linked to fear/emotions), dopamine-producing regions, and red nucleus
  • dopamine-producing regions = substantial nigra (damage=parkinsons), and ventral tegmental area
  • red nucleus has key role in movement related to species-specific behaviour
  • drug addiction is related to strong activation of tegmentum
28
Q

what are the functions of the diencephalon? where are the different regions?

A
  • now switched to dorsal as top of the head and ventral as chin
  • thalamus - dorsal, receives all sensory info except olfaction
  • projection neurons stop and create a synapse so there is an opportunity to modify signal
  • corticothalamic loops responsible for consciousness (receives from and sends to the cortex)
  • responsible for sensation, movement, and consciousness
  • hypothalamus - ventral, controls the pituitary gland
  • other diverse functions such as sex, aggression, feeding, sleep, etc
29
Q

what are the functions of the telencephalon? where are the different regions?

A
  • is the cerebral cortex and underlying structures
  • damage here is wide-ranging in it’s symptoms
  • outer layer = cerebral cortex, cortex, neocortex
30
Q

what are the different types of convolutions?

A
  • gyrus/gyri - folds outward
  • sulcus/sulci - folds inwards
    • if sulci are very prominent or important, they are also called fissures
  • they are not functionally meaningful but damage may show up in one and not the other
31
Q

how are the two hemispheres separated?

A
  • the hemispheres are separated by the longitudinal fissure
  • connected by a few tracts (commissures)
  • corpus callosum - largest commissure of white matter connecting the hemispheres of the brain
32
Q

what fissures separate the lobes of the brain? what are some important areas around these fissures?

A
  • central fissure separates frontal and parietal lobes
    • precentral gyrus - gyrus in front of central fissure (motor)
    • postcentral gyrus - gyrus behind the central fissure (somatosensation)
  • lateral fissure separates temporal lobe from frontal/parietal
    • the insula - deep inside the lateral fissure under the first layer of cortex (older piece of cortex)
    • involved in taste and emotions of disgust
33
Q

what is the limbic system?

A
  • mainly the amygdala, hippocampus, and cingulate cortex
  • is between the cortex and the brain stem
  • amygdala is important in emotion and learning and behaviour
  • hippocampus is important for long term memory, spatial navigation
  • cingulate cortex is a long piece of grey matter surrounding the corpus collosum
    • is an older cortex, has less layers
  • symptoms from damage can vary from region to region
34
Q

what is the basal ganglia?

A
  • deeper gray matter structures
  • includes striatum (caudate + putamen) and globus pallidus
    • sometimes others (subthalamic nucleus)
  • nucleus accumbens is a subregion of striatum/caudate, sometimes called ventral striatum
    • involved in motivation, movement, reward-seeking
  • critical in movement, skills, habits, decision making
    • muscle memory
35
Q

what is the anatomy of the cortical layers of the telencephalon?

A
  • neocortex has 6 layers, outermost is layer 1 and innermost is layer 6
  • motor cortex and somatosensory cortex each have 6 layers
    • same number of layers, but layers differ in thickness
  • layer 4 - major input layer, somatosensory cortex has a thicker layer 4
  • layer 5 - major output layer, motor cortex has a thicker layer 5
  • there are different types of neurons (projection or interneurons) at different layers
36
Q

what are the main support structures of the brain?

A

blood, meninges, cerebrospinal fluid

37
Q

how does blood flow into and through the brain?

A
  • right/left internal and vertebral carotid arteries are the only blood supply to the brain
  • relatively limited supply, damage to the arteries has devastating results
    • neurons in the brain die if they don’t get blood for 4 minutes
  • blood supply cut off = no reserves, no oxygen, no ATP, brain failure
    • parts of the brain get blood from a single artery
38
Q

what is the blood brain barrier

A
  • in the rest of our body, gaps in capillary walls (pores) allow entrance and exits
    • in the brain, we have no pores, we have tight junctions in the capillaries
  • we also have astrocytes wrapped around capillaries to protect the brain
    • mediate entrance into the brain
39
Q

what are the layers of the meninges?

A
  • three main layers: duramater, arachnoid mater, pia mater
    • from outside to inside, thickest to thinnest
  • between arachnoid mater and pia mater, there is a thin layer of fluid (CSF)
40
Q

what is cerebrospinal fluid? where is it produced and where does it go?

A
  • constantly produced by the brain in the lateral ventricles
  • lateral ventricles → third ventricle → fourth ventricle through aqueducts
    • some goes into brain and some down into central canal (spinal cord)
    • passage occasionally gets blocked
  • can be used to transport nutrients or get rid of waste
  • primarily for protection, works like an air bag
    • stops the brain from being compressed and slows down impact