Neuroanatomy Lecture Powerpoint

Question 1

The cranial nerves with exception to CN__ are part of the ____, not the ___

Answer 1

CN II, PNS, CNS

Question 2

Neuron

Answer 2

Non-reproducing unit of nervous system composed of a body, dendrites (receivers), and axon (conductor) surrounded by a myelin sheath, has greatest sensitivity of any cells to oxygen and glucose deprivation and thus shows first signs of hypoxia or hypoglycemia

Question 3

Grey matter vs white matter

Answer 3

Grey matter is neural cell bodies located on the inner part of the spinal cord and outer part of the brain vs white matter is axons (myelin sheaths) located at the outer spinal cord or inner portion of the brain

Question 4

Sensory/afferent neurons

Answer 4

Communicate stimuli toward the CNS such as light, heat, or pressure

Question 5

Motor/efferent neurons

Answer 5

Conduct signals way from CNS mostly leading to muscle cells and other target organs

Question 6

Interneurons

Answer 6

Lie entirely within the CNS and have an integrative function to associate, process, store, and retrieve information and interconnect incoming sensory to outgoing motor pathways

Question 7

3 reasons bony anatomy is important to cranium

Answer 7

• Injury to bony anatomy can affect deeper underlying structures
• CT scans, need to be able to identify suture lines vs fractures
• Skull is a “closed box” particularly susceptible to any swelling

Question 8

List the suture lines of the skull (5)

Answer 8

Corneal - formed between parietal and frontal bone
Sagittal - Formed between the two parietal bones at the dome of the skull moving anterior to posterior
Lambdoid - formed between occipital and parietal bones
Bregma - point of intersection between corneal and sagittal sutures
Lambda - Point of intersection between sagittal suture and lambdoid sutures

Question 9

Meninges (definition and the 3 of them)

Answer 9

3 layers of tissue covering the CNS including…
The dura mater (thick outer layer of vascular connective tissue that forms dural sinuses between 2 layers periosteal and meningeal, also forming falx cerebri and tentorium cerebelli)
The arachnoid mater (nonvascular thin filamentous connective tissue that adjoins but does NOT adhere to dura allowing for subdural potential space, meanwhile subarachnoid space beneath it is where CSF and veins/arteries flow)
The pia mater (thinnest delicate layer that adheres directly to surface of brain and spinal cord invaginating along the surface)

Question 10

Epidural hematoma definition and appearance on CT

Answer 10

Arterial bleed between skull and osteum dura often in skull fractures appearing as “football shaped” bright lesion on side of head on CT scan

Question 11

Subdural hematoma definition and appearance on CT

Answer 11

Tearing of the bridging veins between the meningeal dura and arachnoid mater appearing as a crescent shaped lesion on CT scan of head

Question 12

Subarachnoid bleed definition and appearnce on CT

Answer 12

Bleed in the subarachnoid space above the pia mater that tends to layer within sulci and gyri of brain due to tearing of subarachnoid vessels that appears as layering around the invaginations of the brain on a CT scan

Question 13

Rostral vs caudal and dorsal/ventral

Answer 13

Rostral is towards the front/anterior of the brain that then shifts superiorally moving down the brain to the spinal cord, vs caudal is toward the back/posterior of the brain that then shifts inferiorally moving down the brain to the spinal cord, with dorsal and ventral being perpendicular to these points

Question 14

3 main parts of the brain

Answer 14

1) forebrain (composed of telencephalon and diencephalon)
2) midbrain (mesencephalon)
3) hindbrain (metencephlaon and myelencephaon)

Question 15

Mid brain and hind brain combine to form the….

Answer 15

…brainstem

Question 16

Parts of telencephalon (4)

Answer 16

• Cerebrum and all of its cortexes
• Basal ganglia
• Amygdala
• Hippocampus (all part of limbic system)

Question 17

Cerebrum

Answer 17

Largest portion of brain divided into 2 halves called hemispheres, communicating with each other thru corpus callosum, functions for thought, voluntary movement, language, reasoning, and perception, cerebrum is a gross division of brain that has many subdivisions and sub regions

Question 18

Cerebral cortex definition and the lobes of the cerebral cortex (4)

Answer 18

Outer layer of grey matter in the cerebrum that is highly convoluted into ridges (gyri) and grooves (sulci/fissures)

The lobes of the cerebral cortex include
Frontal - goal oriented, motor, cognitive functions
Occipital - visual perception
Parietal - touch, pain, limb position, size/shape perception
Temporal - perceive, localize sound, visual form/color, emotions

Question 19

Fissure vs sulci

Answer 19

Fissures are deep groves consistently present from one brain to next vs sulci are not as deep and can vary in location

Question 20

Longitudinal and transverse cerebral fissure

Answer 20

Separate left and right hemisphere and cerebrum from cerebellum, invaginated by the falx cerebri and tentorium cerebelli overlying

Question 21

Central sulcus and lateral sulcus

Answer 21

• Divides frontal from parietal lobe creating a precentral gyri and post central gyri on each side
• Divides parietal lobe from temporal lobe

Question 22

Pre-central gyrus

Answer 22

Located directly anterior to the central sulcus containing the motor cortex

Question 23

Post-central gyrus

Answer 23

Located directly posterior to the central sulcus containing the somatosensory cortex

Question 24

Frontal lobe

Answer 24

Largest lobe responsible for planning, complex movements, organizing, problem solving, and higher cognitive function, has a prefrontal cortex for higher cognitive functions and premotor and primary motor cortex (premotor modifies movement and stores muscle memory from primary motor), as well as olfactory bulb is on inferior aspect

Question 25

Frontal lobe injury can cause... (4)

Answer 25

- Lack of focus/organization - Difficulty learning new info - Loss of inhibition - Inability to retrieve recent memories

Question 26

Broca's aphasia

Answer 26

Injury to frontal lobe at the broca area (most commonly found in left hemisphere at posterior portion of inferior frontal gyrus) causes partial loss in ability to produce language (spoken, manual, or written), patients are aware that they cannot speak properly but can comprehend perfectly well (often known as motor or expressive aphasia)

Question 27

Parietal lobe

Answer 27

Integrates sensory information from perceptions of touch, pain, limb position (includes postcentral gyrus/somatosensory cortex), controls how we receive info about the environment around us such as distance and position of object

Question 28

Parietal lobe injury can cause... (4)

Answer 28

- Inability to discriminate between stimuli - Locate and recognize parts of body - Process/integrate diverse sensory info for speech and perception - Write accurately

Question 29

Temporal lobe

Answer 29

Controls audiory processing/ability to recognize words, auditory cortex allows for perception and localization of sound (receives sounds from ears and areas process info into meaningful speech or words) also perception of visual form and color, participates in processing of new memory also plays a role in mediating emotions

Question 30

Temporal lobe injury causes... (4)

Answer 30

- Left side difficulty remembering what people said - Right side may impair recalling music or pictures - Difficulty perceiving or localizing sound - Difficulty perceiving visual form and color

Question 31

Wernicke's aphasia

Answer 31

Injury to area located on the temporal lobe near the caudal end of the lateral sulcus that causes fluent but meaningless speech with comprehension generally being impaired, speech may sound fluent but pattern is disordered and illogical (global aphasia)

Question 32

Occipital lobe

Answer 32

Visual center, area allows to interpret what looking at including visual perception, differentiating form and color, and facial recognition

Question 33

Occipital lobe injury causes... (4)

Answer 33

- Visual impairment - Visual hallucinations - Impaired color perception - Inability to recognize faces

Question 34

Parts of limbic system and their function, what portion of the forebrain are they part of?

Answer 34

- Amygdala (emotional responses, hormonal secretion, emotional memory) - Hippocampus (learning and memory) - Cingulate gyrus (emotion, pain, memory) Not absolutely part of telencephalon or diencephalon

Question 35

Parts of diencephalon (3)

Answer 35

- Limbic system (sorta this sorta telencephalon) - Thalamus (relays info between cortex and brain stem, role in alert/awakeness - hypothalamus (body temp, emotion, hunger, thirst, circadian rhythm, pituitary gland control)

Question 36

Parts of mesencephalon/midbrain (2)

Answer 36

1) Tectum - more posterior component considered roof of midbrain, has the superior colliculus involved in visual reflexes and inferior colliculus involved in auditory reflexes, the 4 colliculi form the corpora quadrigema) 2) Tegmentum - floor of midbrain, network of neurons involved in many reflexive pathways, has motor centor that sends inhibitory signals to the hypothalamus

Question 37

Cerebellum

Answer 37

Part of metencephalon located on posterior-inferior portion of brain that functions in coordination of voluntary movement, balance, posture, motor learning and reflex memory

Question 38

Pons

Answer 38

Part of metencephalon that relays sensory info between forebrain and hindbrain, houses cranial nerve nuclei V-VIII, contains pneumotaxic centers that help regulate respiration

Question 39

Medulla oblongata

Answer 39

Part of the myelencephalon, most inferior portion of brainstem that gradually transitions into spinal cord, relays nerve signals between the two, helps regulate several autonomic functions of the body including respiration, blood pressure, heart rate, digesjtion, and voluntary functions such as vomiting, sneezing, coughing, and gagging

Question 40

Cerebrospinal fluid (CSF)

Answer 40

Formed by choroid plexus in the 4 ventricles, 2 lateral ones and a 3rd and 4th that then empty into the subarachnoid space creating a protective fluid filled chamber against concussive trauma that also bathes and removes waste products

Question 41

CSF pathway

Answer 41

- Lateral ventricles - interventricular foramina - 3rd ventricle - cerebral aquaduct - 4th ventricle - 2 lateral and one median aperture - subarachnoid space - circulation - reabsorption via arachnoid villi - superior sagittal sinus

Question 42

Circle of Willis Components

Answer 42

- 2 vertebral arteries combining to form the basilar artery - Off the basilar artery see anterior inferior cerebellar artery, pontine arteries, and superior cerebellar arteries - Basilar terminates into 2 posterior cerebral arteries - branching off each posterior cerebral artery is a posterior communicating artery - Internal carotids ascending meet with this, sending off middle cerebral artery branches as well as anterior cerebral artery branches - Anterior communicating artery is a small link between the anterior cerebral arteries

Question 43

Anterior cerebral artery

Answer 43

Derived from the internal carotids, supplies very deep portions of the anterior cerebrum including midline structures reaching all the way back posteriorally to midline of parietal lobe as well, has collateral supply due to anterior communicating artery and is thus rare to have ACA infarct

Question 44

2 divisons of middle cerebral artery

Answer 44

- MCA superior and inferior division (superficial division) supplies outer cortex portion of cerebrum - Lenticulostriate arteries supply the inner portion of brain,

Question 45

What artery is most common site of stroke?

Answer 45

Middle Cerebral artery and its branches lenticulostriate and superficial divisions

Question 46

Venous drainage system of the brain

Answer 46

No arterial/venous counterpart, cerebrum, midbrain, pons, cerebellum, and rostral medulla drain via the dural sinuses while spinal cord and caudal medulla drain directly into systemic circulation

Question 47

Arachnoid granulations

Answer 47

Small projections that extend into the dural sinus to allow csf to remove waste products

Question 48

Venous drainage of the brain components (9)

Answer 48

Superior sagittal - runs along the ceiling of the skull anterior to posterior eventually draining into the confluens of sinuses Inferior sagittal sinus - runs along the same path as superior but is located deep in the cerebrum, empties into the straight sinus upon merging with the great cerebral vein of galen Great cerebral vein of galen - Large midline vessel inferior to inferior sagittal sinus that forms the straight sinus upon merging with the inferior sagittal sinus Straight sinus - posterior continuation from the inferior sagittal sinus, combines with superior sagittal sinus to form the confluens of sinuses Transverse sinuses - derived from the confluens of sinuses and travel bilaterally along the posterior wall of the skull before entering into the sigmoid sinus Sigmoid sinuses - 2 s shaped sinuses that receive blood from the transverse sinuses and superior petrosal sinuses and drain into the internal jugular vein Cavernous sinuses - drain the eye area and empty into inferior and superior petrosal sinuses Inferior petrosal sinuses - derived from cavernous sinuses and drains directly to internal jugular Superior petrossal sinuses - derived from canvernous sinuses and drains to sigmoid sinus upon meeting with the transverse sinuses

Question 49

___ total vertebrae, how many of each?

Answer 49

``` -33 7 cervical 12 thoracic 5 lumbar 5 fused sacral 4 fused cocyx ```

Question 50

Spinal column functions (6)

Answer 50

Protection, attachment, structural support, flexibility/mobility, extension, production and storage of RBC and minerals

Question 51

C1

Answer 51

Also known as the atlas, this is the 1st cerivcal vertebra that functions to support the skull, ring of bone that has no vertebral body associated but does have superior articular facets to articulate with the occipital condyles of the skull

Question 52

C2

Answer 52

Also known as the axis, features a dens or odontoid process allows head to pivot and rotate around, has the first semblance of a vertebral body

Question 53

Thoracic vertebrae

Answer 53

Increased sized of body vertebrae compared to cervical spine, these also serve as the articulation points of the ribs (2 ribs coming off each of the 12), has thick spinous process sticking directly dorsally and thick transverse processes for the site of ligament and muscle attachment

Question 54

Lumbar vertebrae

Answer 54

Increased vertebral body size to bear majority of weight, often see nerve root compression in this area

Question 55

sacrum and coccyx

Answer 55

Groups of 5 and 4 fused bones, respectively, forming an articulation of the pelvic girdle and tail bone, respectively

Question 56

Intervertebral disks

Answer 56

Function to help disperse the weight of the spinal column, composed of jelly like interior known as nucleus pulposus and cartilagenous exterior the annulus fibrosis (herniation occurs when the nucleus pulposus protrudes out of the intervertebral disk)

Question 57

anterior longitudinal ligament

Answer 57

Most anterior ligament of the spinal column, located in front of the vertebral bodies running superiorally along each body of the spine

Question 58

Posterior longitudinal ligament

Answer 58

Anterior to spinal cord travelling in canal but right up against posterior of vertebral bodies running superiorally along each body of the spine

Question 59

Ligamentum flavum

Answer 59

yellow ligament, located beneath the lamina of the spinal column, first defining structure right before the dura that runs superiorally along the entire length of the spinal column

Question 60

vertebral column stability determination and how do they heal?

Answer 60

If 2 or more columns are injured (fracture or ligament tear, etc.), considered unstable, if one then considered stable -all take a long time to heal due to low blood supply

Question 61

3 columns of the spine and their components

Answer 61

Posterior column composed of spinous processes, transverse processes, lamina, facet joints, pedicles, and posterior ligaments of the spine Middle column composed of posterior longitudinal lig, posterior annulus fibrosis, and posterior vertebral body Anterior column ant longitudinal lig. anterior annulus fibrosis, anterior vertebral body

Question 62

Each pair of spinal nerves exit between adjacent vertebrae except for this one

Answer 62

C1

Question 63

C7 and above exits ___ corresponding vertebral body, C8 exits below ___, T1 downward exits ____ corresponding vertebral body

Answer 63

above, C7, below

Question 64

Spinal cord commencement level and termination level in the spinal column, what is it called where it terminates? What are the fibers after that? What is the filum terminale?

Answer 64

- At foramen magnum, L1 or L2 - Conus medullaris - Cauda equina - An extension of pia matter past the conus medullaris within the cauda equina down to the coccyx that functions to anchor the spinal cord floating in CSF

Question 65

Arterial supply to the spinal cord (3)

Answer 65

Anterior spinal artery - single artery derived from branches of the vertebral arteries, moves downward along the anterior surface of the spinal cord and supplies the grey matter and majority of the spinal cord as well despite only being one Posterior spinal arteries - Paired arteries derived from branches of the vertebral arteries, move downward along the posterior surface of the spinal cord Anterior and posterior radicular arteries - travel out laterally to the nerve root from the segmental arteries within the spinal cord

Question 66

CNS contains ___ neurons (what type?) while PNS contains ___ and ___ neurons

Answer 66

Relay or interneurons, sensory, motor

Question 67

Motor end plate

Answer 67

site of contact between an axon and a muscle fiber where neuromuscular junction is, Ach is transmitted across here to stimulate muscle cells

Question 68

Schwann cells

Answer 68

Cells of the PNS that produce myelin around an axon

Question 69

Oligodendrocytes

Answer 69

Cells of the CNS that produce myelin around an axon

Question 70

Parts of the metencephalon (2)

Answer 70

- Pons | - Cerebellum

Question 71

Parts of myelencephalon (1)

Answer 71

Medulla oblongata

Question 72

Small vertebral bodies in the cervical spine lack ___ but make up for it with ____. They have ___ processes but lack ____ processes

Answer 72

strength to bear weight, great mobility, spinous, transverse

Question 73

Pedicle

Answer 73

Stub of bone that connects the vertebral body to the lamina forming a vertebral arch to house the spinal cord

Question 74

Lamina

Answer 74

Part of vertebra that is located directly on either side of the spinous process

Question 75

An injury to which column of the vertebrae is most likely to result in unstable classification and why?

Answer 75

Middle column - it is connected to the anterior and posterior columns and is thus a lot more vulnerable!

Question 76

Healthy curvature of the spine

Answer 76

Cervical should be lordotic, thoracic should be kyphotic, and lumbar should be lordotic

Question 77

Venous supply to the spinal cord (4)

Answer 77

Posterior spinal vein - single traveling vein located between the posterior spinal arteries Anterior spinal vein - single traveling vein located alongside the anterior spinal artery Posteriorlateral veins - 2 traveling veins located lateral to each of the posterior spinal arteries Radicular veins - travel with the radicular arteries

Question 78

Spinal columns

Answer 78

The dorsal, 2 lateral, and anterior areas of white matter within the cross section of the spinal cord

Question 79

Spinal tracts

Answer 79

Ascending or descending pathways for sensory or motor signaling located within the different spinal columns (anterior, 2 lateral, or dorsal)

Question 80

Spinal horns

Answer 80

The dorsal, ventral, and lateral projections of grey matter within the spinal cord composed of cell bodies and interneurons on a bisection

Question 81

Spinal roots

Answer 81

Either dorsal and ventral, bundles of neurons that enter or exit the spinal cord laterally at a certain nerve root level

Question 82

Spinal cord dorsal root

Answer 82

Afferent sensory root that carries sensory information to the spinal cord from the spinal nerve somewhere in the periphery

Question 83

Spinal cord ventral root

Answer 83

Efferent motor root that carries motor information from the spinal cord to an effector site in the periphery

Question 84

Lateral horn function

Answer 84

Houses cell bodies of preganglionic sympathetic neuron fibers

Question 85

Corticospinal tract cross over at the level of ___

Answer 85

the medulla

Question 86

Corticospinal vs corticobulbar tracts

Answer 86

Corticospinal is motor efferent nerves associated with spinal nerves from the cerebral cortex vs corticobulbar is similar but composed of non oculomotor cranial nerve motor functions from where the cranial nerves originate on the brain surface slightly lower down in the medulla itself, only about 50% of them deccusate compared to the 90% of the corticospinal but for the sake of this class just say they both cross over at medulla

Question 87

Upper vs lower motor neuron

Answer 87

Upper body originates in the brain at the motor cortex, crosses over midline at the medulla, and then goes down in the white matter of spinal cord before synapsing into the gray matter lower motor neuron body in the lateral horn, and then leaves via the anterior horn to the target muscle

Question 88

Signs of upper motor neuron lesion on motor exam (6)

Answer 88

- spasticity - increased tone - positive babinski sign - clonus - hemiparesis/weakness - increased tone and reflexes

Question 89

Signs of lower motor neuron lesion on motor exam

Answer 89

- Flaccid muscles with atrophy - fasciculations - paralysis - decreased tone and reflexes

Question 90

Spinothalamic tract (what 3 things is it responsible for and where does it cross)

Answer 90

- Responsible for pain, temp, and crude touch - Crosses over at the level of the spinal cord and then travels up the contralateral side to the thalamus and cerebral cortex

Question 91

Posterior/dorsal column tract (what 3 things is it responsible for and where does it cross)

Answer 91

- Responsible for position, vibration, and fine touch | - Travels up ipsalateral side of spine where signal entered and crosses over at medulla then to thalamus and cerebrum

Question 92

Components of reflex arc

Answer 92

- Receptor - sensory neuron - CNS interneuron that immediately responds faster than message to brain - motor neuron - effector muscle or gland

Question 93

2 divisions of PNS

Answer 93

Sensory and motor

Question 94

2 divisions of sensory PNS

Answer 94

Somatic sensory (skin limb and body wall) and visceral sensory (internal organ sensations)

Question 95

2 divisions of motor PNS

Answer 95

Somatic motor (voluntary) and visceral motor (autonomic)

Question 96

2 divisions of ANS

Answer 96

Parasympathetic (bladder contraction) and sympathetic (bladder relaxation)