Cerebral perfusion, brain anatomy and reflexes

Question 1

Cerebral perfusion is primarily driven by what?

Answer 1

PCO2

Question 2

At what oxygen pressure will O2 influence CPP?

Answer 2

Severe hypoxemia < 50 mmHg

Question 3

What is the cerebral perfusion pressure equal to (what is the equation)?

Answer 3

CPP = MAP - ICP

Question 4

What are the signs of Increased ICP (cushing reflex)?

Answer 4

• Hypertension
• Bradycardia
• Respiratory depression
• Wide pulse pressure

Question 5

When does CPP not become proportional to PCO2?

Answer 5

When PCO2 is > 90 mmHg

Question 6

What symptoms will an ACA-MCA watershed infarct cause?

Answer 6

Proximal upper and lower extremity weakness (“man-in-a-barrel” syndrome)

Question 7

What symptoms will a PCA-MCA watershed infarct give?

Answer 7

Higher-order visual dysfunction

Question 8

How is CSF drained?

Answer 8

Into cerebral veins from arachnoid granulations

Question 9

A venous sinus will present with what?
- Additionally what risk factors may they have

Answer 9

Signs/symptoms of increased ICP
- Headache
- Seizures
- Papilloedema
- Focal neurological deficits

Risk factors are hypercoagulable states e.g:
- OCP use
- Pregnant
- Factor V Leiden

Question 10

Where is the nucleus of CNXI found?

Answer 10

Spinal cord

Question 11

What is the pineal gland responsible for?

Answer 11

• Melatonin secretion
• Circadian rhythms

Question 12

What are the superior colliculi responsible for?

Answer 12

Direct eye movemtns tostimuli (noise/movements) or objects of interest

Question 13

What are the inferior colliculi responsible for?

Answer 13

Auditory

Question 14

Name the vagal nuclei

Answer 14

• Nucleus tractus solitarus
• Nucleus ambiguus
• Dorsal motor nucleus

Question 15

What is the function of the nucleus tractus solitarus?

Answer 15

• Visceral sensory info (taste, baroreceptors, gut distension)
• May play a role in vomitinfg
• CN VII, IX, X

Question 16

What is the function of the nucleus ambigus?

Answer 16

• Motor innervation of pharynx, larynx, upper esophagus (e.g swallowing, palate elevation)
• CN IX, X, XI (cranial portion)

Question 17

What is the function of the dorsal motor nucleus?

Answer 17

Sends autonomic (parasympathetic) fibers to heart, lungs, upper GI
- CN X

Question 18

What cranial nerve innervates the stylopharyngeus (elevation of pharynx/larynx)?

Answer 18

CN IX

Question 19

What are the mastication muscles?

Answer 19

• Masseter
• Temporalis
• Medial pterygoid (all close the jaw)
• Lateral pterygoids (protrude the jaw)

Question 20

What are the mastication muscles innervated by?

Answer 20

V3

Question 21

What are the 9 structures a needle must pass through in a lumbar puncture?

Answer 21

• Skin
• Fascia and fat
• Supraspinous ligament
• Intersponous ligament
• Ligamentum flavum
• Epidural space (epidural anaesthesia occurs here)
• Dura mater
• Arachnoid mater
• Subaracnoid space (CSF collection occurs here)

Question 22

When may primitive reflexes be seen in adults?

Answer 22

When a frontal lobe lesion occurs

Question 23

Describe the Moro reflexx

Answer 23

Abduct/extend arms when startled, then draw together

Question 24

Describe the Rooting reflex?

Answer 24

Movement of head toward one side if cheek or mooth is stroked (nipple seeking)

Question 25

Describe the sucking reflex

Answer 25

Sucking response when roof of mouth is touched

Question 26

Describe the palmar reflex

Answer 26

Curling of fingers if palm is stroked

Question 27

Describe the plantar reflex

Answer 27

Dorsiflexion of large toe and fanning of other toes with plantar stimulation - Babinski sign

Question 28

Descrbe the Galant reflex

Answer 28

Stroking along one side of the spine while newborn is in ventral suspension face down) causes lateral flexion of lower body toward stimulated side

Question 29

What dermatomes cover the peni;e and anal zones?

Answer 29

S2, 3, 4

Question 30

Where is the T10 dermatome?

Answer 30

Umbilicus

Question 31

Where is the T7 dermatome?

Answer 31

xiphoid process

Question 32

Where is the C4 dermatome?

Answer 32

Low collar shirt

Question 33

Where is the C2 dermatome?

Answer 33

Posterior half of the skull

Question 34

Where is the C3 dermatome?

Answer 34

High turtleneck shirt

Question 35

What nerves innervate the achilles reflexx?

Answer 35

S1, 2

Question 36

What nerves innervate the Pattelar reflex?

Answer 36

L2, 3, 4

Question 37

What nerves innervate the biceps and brachiradialis reflexes?

Answer 37

C5, 6

Question 38

What nerves innervate the tricpes reflex?

Answer 38

C6, 7, 8

Question 39

What nerves innervate the anal wink relfex?

Answer 39

S3, 4

Question 40

What nerves innervate the cremasteric reflex?

Answer 40

L1, 2

Question 41

When do the primitive reflexes disappear?

Answer 41

Within 1st year of life