Lecture 1 (ch 2)/ wk 1.1

Question 1

What makes up the CNS?

Answer 1

The brain and spinal cord

Question 2

What does the CNS arise from during embryonic development?

Answer 2

Arises from ecotodermal cells that fold over to form a neural tube

Question 3

What are nuclei?
What are tracts?

Answer 3

1) Nuclei: collections of cell bodies in CNS
2) Tract: collections/ bundles of fibers in the CNS

Question 4

1) What develops into the brain and spinal cord?
2) What forms ventricles?

Answer 4

1) Outpouchings and swellings of the neural tube develop into the brain and spinal cord
2) Fluid filled cavities form ventricles which produce CSF

Question 5

1) What can cause defects of the neural tube?
2) Give examples of neural tube defects

Answer 5

1) Lack of folic acid during pregnancy can cause neural tube defects
2) Spina bifida, anencephaly, paralysis, bowel and bladder incontinence and hydrocephalous.

Question 6

What are the 3 primary divisions of the brain?

Answer 6

1) Forebrain (prosencephalon)
2) Midbrain (mesencephalon)
3) Hindbrain (rhombencephalon)

Question 7

1) What is the largest part of the nervous system in humans?
2) What is it subdivided into? (2 things)
3) Where is it located?

Answer 7

1) The forebrain
2) Telencephalon and diencephalon.
3) Sits on top of midbrain.

Question 8

Name the 2 parts of the forebrain and what they consist of

Answer 8

1) Telencephalon: cerebral hemispheres, cerebral cortex, white matter, basal ganglia
2) Diencephalon: thalamus, hypothalamus

Question 9

1) Is the midbrain long or short? What does it connect?
2) What 3 things does the hindbrain consist of?
3) What 3 things does the brainstem consist of? What does it connect?

Answer 9

1) Midbrain: short, connects the fore and hind brains
2) Hindbrain: pons, cerebellum and medulla
3) Brainstem: midbrain, pons, medulla; connects brain to spinal cord

Question 10

What does the brainstem do? Give examples

Answer 10

Controls most of the basic bodily functions needed for survival.
Ex: **respirations, BP, HR

Question 11

1) What two parts of the brain are important in the regulation of consciousness level?
2) What 3 things are also involved in consciousness?
3) What happens if there are lesions in these two areas?
4) What is the clinical correlation?

Answer 11

1) Upper pons and midbrain
2) Cortical, thalamic and forebrain networks
3) Therefore, lesions in these areas cause lethargy and coma
4) Lesions of thalami, or large lesion/s in the hemispheres/areas above brainstem) can impair consciousness indirectly through mass effect -putting pressure on the brainstem and thereby distorting or compressing its systems

Question 12

1) What’s the primary function of the cerebellum?
2) What two things does the pons do?
3) What two things does the medulla do?
4) What do these 3 parts have in common?

Answer 12

1) Integrates sensory and other inputs from brain and spinal cord; coordinates movements from those inputs
2) Connects brain and spinal cord, and regulates level of consciousness
3) Passes information between brain and spinal cord, and regulates cardiovascular and respiratory systems
4) They’re all part of hindbrain

Question 13

1) What are the 3 membranous layers of the CNS (from external to internal)
2) Where does CSF travel?

Answer 13

1) Dura, arachnoid and pia. 2) Between the arachnoid and pia

Question 14

1) What condition can occur in the subarachnoid space?
2) What type of imaging would show this condition? What would it show is happening?

Answer 14

1) Subarachnoid hemorrhages occur in the CSF filled space between the arachnoid
and pia (subarachnoid space)
2) CT would reveal blood tracking down into the sulci following the contours of the pia

Question 15

1) Is a subarachnoid aneurysm always a spontaneous condition?
2) What is the clinical presentation of this condition?

Answer 15

1) Can be either spontaneous or traumatic
2) Presentation: sudden catastrophic headache. “Worst headache of my life.” Head feels like it is ready to explode.

Question 16

1) What typically causes spontaneous subarachnoid hemorrhages (SAHs)?
2) What is another potential cause?
3) What are the risk factors of intracranial aneurysms?

Answer 16

1) Usually caused by the rupture of an arterial aneurysm in the subarachnoid space.
2) Less often caused by other bleed at midbrain or a bleeding AVM (arteriovenous malformation)
3) Atherosclerotic disease, congenital anomalies, polycystic kidney disease, and connective tissue disorders.

Question 17

1) Where do Berry aneurysms typically arise from?
2) Describe their appearance and how they’re connected to the vessel.
3) Which part of the aneurysm can rupture?

Answer 17

1) Arterial branch points near the Circle of Willis
2) They are balloon like outpouchings typically connected to the vessel by a stalk and
3) The dome can rupture.

Question 18

1) What percent of Berry Aneurysms occur in anterior circulation?
2) What are the 3 most common locations?

Answer 18

1) 85% of these occur in the anterior circulation (i.e.- carotid artery and branches) most commonly:
2) Anterior communicating artery, Posterior communicating artery, and Middle cerebral artery

Question 19

1) What can posterior communicating aneurysms potentially cause?
2) What are the risk factors for rupture of aneurysms?
3) What percent of patients die before the hospital? What is the overall mortality rate?

Answer 19

1) Painful CN III palsy.
2) Risk factors for rupture of aneurysms: HTN, cigarette smoking, alcohol consumption,
3) 25% patients die before hospital, 50% overall mortality rate

Question 20

1) Which is more common, a traumatic SAH (subarachnoid hemorrhage) or spontaneous SAH?
2) How does trauma lead to a SAH?

Answer 20

1) Traumatic SAH more common
2) Trauma-> ruptured vessels -> blood in CSF

Question 21

1) Where do subdural hematomas occur?
2) What are they typically caused by?
3) What are the two types of subdural hematoma?

Answer 21

1) Between dura and arachnoid
2) Typically by rupture of bridging veins
3) Chronic or acute

Question 22

1) What 3 things make up the brainstem?
2) What 3 things is the brainstem connected to?
3) What arises from here? 4) What is the brainstem packed with? What do some of these things contain?

Answer 22

1) Midbrain, pons and medulla
2) Connected to the diencephalon, cerebellum and spinal cord.
3) Most of the cranial nerves arise from here
4) Also packed with other nuclei and white matter tracts; some nuclei contain neurotransmitters

Question 23

Where do most cranial nerves arise from?

Answer 23

The brainstem

Question 24

1) What does the brainstem do? Give examples
2) What passes through the brainstem?

Answer 24

1) In charge of all vital functions needed to stay alive, ex/HR, BP, respirations; some of its nuclei contain neurotransmitters
2) ALL information passed between cerebral hemispheres and the spinal cord

Question 25

1) Where do most cranial nerves (CNs) arise from? 2) Where do spinal accessory nerves arise from? 3) What do CNs do?

Answer 25

1) Most arise from brainstem 2) Spinal accessory nerves arise from the spinal cord 3) Have motor, sensory and other specialized functions relating to the structures in the head

Question 26

List the 12 cranial nerves in order

Answer 26

1) Olfactory 2) Optic 3) Oculomotor 4) Trochlear 5) Trigeminal 6) Abducens 7) Facia 8) Vestibulocochlear 9) Glossopharyngeal 10) Vagus 11) Accessory 12) Hypoglossal

Question 27

What is the phrase to remember the order of the cranial nerves (CNs)?

Answer 27

Oh Once One Takes The Anatomy Final Very Good Vacations Are Heavenly (mnemonic from my college anatomy class)

Question 28

1) Define ventral 2) Define dorsal 3) Define rostral 4) Define caudal

Answer 28

1) Ventral – belly, toward the earth (think venomous snake) 2) Dorsal-back, towards the sky think-shark’s dorsal fin 3) Rostral-beak, towards the snout 4) Caudal-tail, towards the tail

Question 29

What is the acronym to remember whether the cranial nerves are sensory, motor, or both?

Answer 29

Some Say Money Matters, But My Brother Says Big Brains Matter More

Question 30

1) Where does orientation change in human anatomy? Why? 2) What is the orientation of the rest of the body?

Answer 30

1) In humans, CNS makes 90 degree turn at midbrain, therefore, orientation above midbrain is parallel to the ground. 2) Below midbrain perpendicular to the ground

Question 31

1) Define anterior 2) Define posterior 3) Define superior 4) Define inferior

Answer 31

1) Anterior: front 2) Posterior: back 3) Superior: top/sky-head 4) Inferior: bottom/ground-feet

Question 32

1) Define horizontal/ transverse plane 2) Define coronal plane 3) Describe sagittal plane 4) Which is the most common way to view the brain?

Answer 32

1)Horizontal/axial/transverse: parallel to the floor 2) Coronal: perpendicular to floor, separates front and back 3) Sagittal: divides left from right 4) Sagittal

Question 33

1) What is the microscopic nervous system composed of? 2) What is the basic unit of signaling? Describe its anatomy

Answer 33

1) Composed of neurons (nerve cells,) glia (support cells) 2) Neurons; has a cell body, which contains a nucleus, also has dendrites and an axon

Question 34

1) Describe dendrites 2) Describe axons

Answer 34

1) Dendrites: short processes that receive inputs 2) Axons: long processes carry outputs/electrical conduction

Question 35

1) Where does neuron communication occur? 2) What do chemical synapses involve? 3) Where do electrical synapses occur?

Answer 35

1) At synapses typically from axon to dendrite 2) Chemical: involve neurotransmitters released from 1 neuron to receptors on another 3) Electrical synapses: occur through specialized junctions

Question 36

Describe action potentials

Answer 36

When an input excites a neuron, a transient voltage change can occur , lasts 1 ms, they rapidly move through the neuron/axon communicating with other neurons around it, can trigger release of neurotransmitters allowing further chemical communication

Question 37

What are axons insulated by?

Answer 37

By specialized glial cells that form a fatty layer called the myelin sheath

Question 38

1) Define neurotransmitters 2) Is there always only one neurotransmitter at a synapse? If not, what does it depend on? 3) True or false: Some NTs have different actions at different synapses

Answer 38

1) Chemicals involved in synapses 2) May have several in a single synapse depending on type of receptors present. 3) True

Question 39

1) What is the most common excitatory NT in the CNS? 2) What is the most common inhibitory NT in the CNS? 3) What neurotransmitter is responsible for skeletal, smooth and cardiac muscle contractions

Answer 39

1) Glutamate 2) GABA (gamma-aminobutyric acid) 3) Acetylcholine

Question 40

Name 4 more common neurotransmitters besides glutamate, GABA, and acetylcholine

Answer 40

Norepinephrine, dopamine, serotonin, and histamine

Question 41

1) What makes up white matter? 2) What makes up gray matter? What occurs here? 3) Define cerebral cortex 4) What is beneath the cerebral cortex? What does it do?

Answer 41

1) Myelinated axons (transmit signals over some distance 2) Cell bodies; local synaptic communications between neurons 3) Gray matter that covers the cerebral hemispheres 4) The white matter that conveys messages to and from the cortex

Question 42

1) Why does MS affect different people differently? 2) Besides the cerebral cortex, where else can gray matter be found? Give examples.

Answer 42

1) Demyelination can occur in different places 2) Gray matter can also be found in clusters deep in the hemispheres and brain stem in such structures as the basal ganglia, thalamus, and brainstem nuclei

Question 43

1) White matter is ______ to gray matter in the brain 2) What about in the spinal cord?

Answer 43

1) deep 2) In the spinal cord they are switched; the white matter is on the outside and gray is in the inside

Question 44

1) Spinal nerves come off what? 2) Motor nerves typically come off the _______ side 3) Sensory nerves typically come off the ______ side

Answer 44

1) Spinal cord (both sensory and motor) 2) Motor: anterior/ventral 3) Sensory: posterior/ dorsal

Question 45

1) How are spinal nerves named? 2) Why does the spinal cord end at L1, L2? 3) What is below this?

Answer 45

1) Named according to level of cord-cervical, thoracic, lumbar, sacral 2) During development, bony canal (vertebra) lengthen faster than spinal cord 3) A collection of nerve roots called the cauda equina (“horses' tail”)

Question 46

1) What is the clinical significance of the cauda equina? 2) What causes this cauda equina condition? 3) Is this an urgent condition?

Answer 46

1) Cauda equina syndrome; impaired function of nerve roots below L-1, L-2 2) Causes: compression from disk herniation, tumors, trauma, epidural abscess 3) Yes; needs to be treated emergently to avoid permanent defects.

Question 47

1) What part of the brain has numerous folds or crevices? What is this part also called? 2) What are these crevices called? 3) What divides the motor and sensory cortex? What is this also a boundary between? 3) What are the bumps between the crevices called?

Answer 47

1) Cerebral cortex (aka hemispheres) 2) Sulci = crevices 3) The central sulcus; also a boundary between frontal and parietal lobes 4) Gyri = bumps

Question 48

What are the 4 lobes of the cerebral cortex?

Answer 48

Cerebral hemispheres have 4 lobes: frontal, temporal, parietal, and occipital

Question 49

1) Describe the location of the frontal lobe 2) Describe the location of the temporal lobes in relation to the frontal lobe 3) What separates the frontal lobe and temporal lobes?

Answer 49

1) In the front, extends back to the central sulcus 2) Inferior and lateral to frontal lobe 3) A deep fissure called Sylvian (or lateral) fissure (a deep sulcus)

Question 50

1) Where is the parietal lobe in relation to the central sulcus and Sylvian fissure? 2) Where is the occipital lobe in relation to the parietal lobe? What separates it from the parietal lobe when viewed medially?

Answer 50

1) Parietal lobe: posterior to the central sulcus and superior-posterior to the Sylvian fissure 2) Posterior to parietal; separated by parieto-occipital sulcus when viewed medially

Question 51

1) What are the cerebral hemispheres separated by? 2) What connects the two hemispheres?

Answer 51

1) The interhemispheric/sagittal/ longitudinal fissure 2) Corpus callosum (a C shaped band of white matter)

Question 52

What are the primary sensory and motor areas (4)?

Answer 52

1) Primary somatosensory cortex 2) Primary motor cortex 3) Primary visual cortex 4) Primary auditory cortex

Question 53

1) Where is the primary motor cortex? What is it immediately anterior to? 2) What does the primary motor cortex control? 3) Where is the primary somatosensory cortex? What does it control?

Answer 53

1) Lies in precentral gyrus in frontal lobe, immediately anterior to central sulcus. 2) Controls movement to opposite side of body. 3) Lies in postcentral gyrus in the parietal lobe; involved in sensation for the opposite side of the body

Question 54

1) Motor areas lie ________ to somatosensory areas 2) What lobe is the primary visual cortex in?

Answer 54

1) anterior 2) In occipital lobe

Question 55

1) Describe the location of the primary auditory cortex 2) How are sensory and motor pathways usually organized?

Answer 55

1) Primary auditory cortex- transverse gyri of Heschl —2 fingerlike gyri inside the Sylvian fissure on superior surface of each temporal lobe 2) Usually topographically organized (adjacent receptors on motor surfaces are mapped to adjacent fibers in white matter pathways and to cortex ex/ motor and somatosensory regions controlling the hand are next to the arm, etc)

Question 56

Is the primary auditory cortex lateralized?

Answer 56

It's less lateralized and input from opposite ear is slightly stronger, but not clinically detectable

Question 57

1) What is the cerebral cortex composed of? How many layers is this, and what is it made of? 2) What do the inner layers project to? 3) What do the inner layers control? (8 things)

Answer 57

1) Neocortex; contains 6 cell layers (I-VI) containing neurons and axons. 2) Project to thalamus, brainstem, spinal cord and basal ganglia 3) Touch, movement planning, thoughts, vision, speech, emotions, hearing, taste and behavior

Question 58

1) What is the most important motor pathway? 2) Where does this pathway begin?

Answer 58

1) Corticospinal tract/ “pyramidal tract” 2) Begins in primary motor cortex where neurons project axons through cerebral white matter and brainstem to the spinal cord

Question 59

1) What do the primary motor and somatosensory cortexes represent? 2) Why? 3) Why is this important? 4) What does the visual cortex represent?

Answer 59

1) The opposite side of the body to where they are located. 2) The somatosensory and motor pathways cross over in the nervous system 3) Knowing this information helps guide clinicians to area of abnormality 4) Visual input from opposite visual field; the left half of visual field for each eye is mapped to right visual cortex

Question 60

1) What percent of fibers in the corticospinal tract cross over to control movement on the opposite side? 2) What is this crossing over called and where does it occur? 3) What happens if there's a lesion above this? What about below?

Answer 60

1) About 85% 2) Pyramidal decussation; at junction of medulla and spinal cord 3) Lesions above will cause contralateral weakness; below will cause ipsilateral weakness

Question 61

1) Define upper motor neurons 2) What do they synapse onto? Where are these located? 3) Where do these neurons leave the CNS from and where do they go?

Answer 61

1) Motor neurons that project from the cortex down to the spinal cord or brainstem 2) Onto the lower motor neurons, which are located in the anterior horns of the ventral gray matter of the spinal cord 3) Axons project out of the CNS via spinal roots or cranial nerves to reach the periphery

Question 62

1) What do the cerebellum and basal ganglia do? 2) What do they receive input from? What do they modulate? 3) What do they project back to? 4) Where else does the cerebellum receive input from?

Answer 62

1) Help refine motor outputs 2) The motor cortex; modulate output from corticospinal tract and other descending motor pathways. 3) They project back to the cortex via the thalamus 4) Brainstem and spinal cord

Question 63

1) Lesions in the cerebellum cause what? 2) What do lesions in the basal ganglia cause? 3) Give 2 examples of the effects of basal ganglia lesions

Answer 63

1) Movement disorders (especially balance and coordination= ataxia) 2) Hypokinetic movement disorders 3) Slow and rigid as in Parkinsonism or hyperkinetic as in Huntington’s disease “dancelike” involuntary movements

Question 64

The two pathways in the spinal cord for sensation are called what?

Answer 64

Somatosensory pathways (posterior and anterior)

Question 65

1) Huntington's causes what kind of movement? 2) What type of movement does Parkinson's cause?

Answer 65

1) Hyperkinetic 2) Hypokinetic

Question 66

What are the two pathways in the spinal cord for sensation? What 3 things do they each convey?

Answer 66

1) Posterior column pathway: conveys proprioception, vibration sense, and fine touch 2) Anterolateral pathway: conveys pain, temperature sense, and crude touch

Question 67

1) What anterolateral pathway axons cross over to the other side of the spinal cord? 2) Where does this pathway synapse? 3) Where does this pathway terminate?

Answer 67

1) Axons from the secondary sensory neurons 2) The thalamus 3) The primary somatosensory cortex​

Question 68

What is conveyed by both somatosensory pathways? Why?

Answer 68

Touch sensation; so a lesion in one pathway does not completely eliminate touch sensation

Question 69

Where are primary sensory neuron cell bodies found?

Answer 69

In the dorsal root ganglia (NOT the CNS)

Question 70

1) Define posterior column pathway. What 3 things does it carry information about? 2) Where does it enter? 3) Where does it ascend? 4) Where does it end up?

Answer 70

1) Sensory motor neurons carrying information about proprioception, vibratory sense and fine touch. A somatosensory pathway. 2) Enters the spinal cord via the dorsal roots 3) Ascends ipsilateral white matter dorsal/posterior column [all the way up to] 4) The dorsal column nuclei in the medulla. here they synapse to secondary sensory neurons whose axons cross over to the other side of the medulla

Question 71

Where does the posterior column pathway continue onto after synapsing to secondary sensory neurons?

Answer 71

Continues up on the contralateral side to the thalamus into the primary somatosensory cortex.

Question 72

1) Define anterolateral pathway. What 3 things does it carry information about? 2) Where does it enter the spinal cord? 3) Where do these axons initially synapse?

Answer 72

1) Primary sensory neurons carry information about pain, temperature sense and crude touch. A somatosensory pathway. 2) The dorsal root 3) Synapse in the gray matter.

Question 73

1) What does the thalamus do? What structures does it interact with? 2) Is it gray or white matter? Describe its location

Answer 73

1) A relay center; almost all pathways (sensory and non-sensory) that project to cerebral cortex synapse in the thalamus first 2) A gray matter structure deep within the white matter, just above the brainstem, behind the basal ganglia

Question 74

1) What shape is the thalamus? How many nuclei does it have? 2) What exists in each sensory modality of the thalamus? 3) Where does it relay information to?

Answer 74

1) Egg shaped, consists of multiple nuclei. 2) Each sensory modality has a different nuclear area for synapses before the information is relayed 3) The cortex.

Question 75

1) What sense is not relayed through the thalamus? 2) Where does it go instead? 3) What does the thalamus encompass?

Answer 75

1) Olfaction 2) Directly to the olfactory cortex. 3) The pineal gland

Question 76

Where is the pineal gland? What does it do?

Answer 76

1) In the center of the brain 2) Receives information about light and dark and secretes melatonin as needed

Question 77

1) What is controlled by the hypothalamus? 2) What makes up the diencephalon?

Answer 77

1) Autonomic, neuroendocrine, limbic and other circuits, body temp, hunger, thirst, fatigue, sleep 2) Thalamus and hypothalamus

Question 78

1) Where is the association cortex? 2) What does it do?

Answer 78

1) Contained within the cerebral cortex 2) Processes higher order information

Question 79

1) Where is Broca's area? 2) What is it adjacent to? 3) What does it do? 4) What happens if there's a lesion in this area?

Answer 79

1) Located in frontal lobe of left hemisphere 2) Adjacent to areas of motor control of the lips, tongue, face, larynx 3) Controls language production/speaking. 4) Lesions inhibit speaking, but not understanding of language (expressive or motor aphasia)

Question 80

1) Motor planning is distributed among many areas of the association cortex. What does this mean in regards to lesions? 2) What type of lesions cause hemineglect (patients ignore objects or even their own body parts to one side)

Answer 80

1) That lesions in the cortex can cause apraxia (uncoordinated or disassociated movements.) 2) Right parietal lesions

Question 81

1) What is the largest lobe? What does this mean? 2) What would lesions in the frontal lobe cause?

Answer 81

1) The frontal lobe; it contains the largest amount of the association cortex. 2) Many different problems with personality (lack of judgement, inappropriate joking, inhibition) and cognition

Question 82

1) Where is the primary visual cortex? 2) What do lesions in this cortex cause? 3) What about seizures in this area?

Answer 82

1) In the parieto-occipital lobe 2) Inability to recognize faces, or colors or persistence or reappearance of an earlier viewed object. 3) Seizures cause visual hallucinations.

Question 83

Name 6 arteries that compose the circle of Willis. Know their locations

Answer 83

1) Internal carotid arteries 2) Anterior cerebral arteries (ACAs) 3) Posterior cerebral arteries (PCAs) 4) Posterior communicating arteries (PCOMs) 5) Vertebral arteries 6) Middle cerebral arteries (MCAs)

Question 84

1) Where is Wernicke's area? What does information does it process? 2) Describe how it receives this information

Answer 84

1) Located in the dominant (usually left) hemisphere-area of language comprehension.​ 2) Language first perceived by auditory (if hearing) or visual (if reading) cortexes. Cortical association fibers then communicate to Wernicke’s area.​

Question 85

Name 4 elements of the association cortex

Answer 85

1) Wernicke's area 2) Broca's area 3) Frontal lobe 4) Primary visual cortex

Question 86

Broca's area is in what direction in relation to Wernicke's area?

Answer 86

Broca's is anterior

Question 87

What part of the brain is responsible for motor planning?

Answer 87

The association cortex

Question 88

What is CN1?

Answer 88

Olfactory

Question 89

What is CNVII?

Answer 89

Facial

Question 90

What does the cerebellum do?

Answer 90

Coordinate movement

Question 91

What pathway conveys proprioception, fine touch, and vibration?

Answer 91

Posterior

Question 92

What structure secretes melatonin?

Answer 92

Pineal gland

Question 93

What structure is responsible for expressive language?

Answer 93

Broca's

Question 94

What structure is responsible for receptive language?

Answer 94

Wernicke's

Question 95

Damage to what structure causes hypo or hyperkinetic movement?

Answer 95

Basal ganglia

Question 96

What drains blood from the brain?

Answer 96

Internal jugular

Question 97

Where is the pyramidal decussation?

Answer 97

Junction of medulla and spinal cord

Question 98

What supplies blood to the anterior portion of the brain?

Answer 98

Internal carotid arteries

Question 99

What supplies blood to the posterior brain?

Answer 99

Basilar arteries

Question 100

What pathway conveys pain, temperature, and crude touch?

Answer 100

Anterolateral

Question 101

True or false: Adjacent parts of the body are mapped to adjacent parts of the cerebral cortex

Answer 101

True

Question 102

Where is the primary motor cortex?

Answer 102

Precentral gyrus

Question 103

What lobe has the primary visual cortex?

Answer 103

Occipital

Question 104

What produces the CSF?

Answer 104

Choroid plexus