Physiology neuro Book

Question 1

Major neural pathways in spinal cord

Answer 1

Corticospinal- motor - desiccate at medulla
Dorsal- touch, vibration, proprioception - desecrate at medulla
Spinothalamic- crude touch, pain and temp desiccate at level where leaves

Question 2

Best clinical sign of compartment syndrome

Answer 2

Extreme pain on passive stretch

Question 3

Ulcer forming from head trauma

Answer 3

Cushing ulcer - can form from operations or strokes too

Question 4

Afferent limb to cranial reflexes

Answer 4

Cough- vagus
Clink- V1
Sneeze- V2
Jaw- V3
Gag- IX

Question 5

Primary aim after major head injury

Answer 5

To prevent hypoxia, hypercapnia and hypotension

Question 6

Cells on SA node

Answer 6

B1
M2

Question 7

Calculating Cerebral perfusion pressure

Answer 7

MAP- ICP

Question 8

Effects of raised ICP

Answer 8

Hypertension
Low HR
Irregular breathing
Eventually- pupillary constriction due to compression of 3rd CN

Question 9

MAP calculation

Answer 9

1/3 (systolic-diastolic) + diastolic

Question 10

When does auto regulation of CPP become impaired and when is there a bad outcome

Answer 10

In head injury

Occurs at 60-150

Question 11

Volume of CSF

Answer 11

150ml

Question 12

Order of CSF flow

Answer 12

Lateral
Foreamen on monro
3rd
Aqueduct of slyvius
4th
Lateral foreman of Luschka
SAS

Question 13

Resting membrane potential, threshold and depolarisation potential

Answer 13

-70- -95mv
-55
To +40mv

Question 14

Conduction speed of myelinated and unmyelinated

Answer 14

Myelinated 50-100m/s
Unmyelinated 1m/s

Question 15

Brainstem death criteria

Answer 15

Pupils fixed
No corneal
Absent vestibule ocular reflex
No motor
Absent gag
Absent resp disconnected from ventilator

No sedation, muscle relaxants, electrolyte distubrances, normothermic

Question 16

CO2 effect on cerebral blood vessels

Answer 16

High- vasodialtion

Question 17

Timeline of spinal shock

Answer 17

Usually above T6
Happens instantly
Recovers after a few days/months

Question 18

Types of nervous cells

Answer 18

Microglia- scavenger- phagocytosis

Schwann- myelin peripheral
Oligo- myelin CNS
Astrocytes- most common, supportive, maintaining environment and BBB

Question 19

Neurotransmitters for autonomic system

Answer 19

Ach- pre ganglionic on nicotinic

Post- noradrenaline for symp
Ach para- Muscarinic

Adrenal medulla- noradrenalin from pre ganglionic symp directly

Question 20

Location of pre ganglionic autonomic fibres

Answer 20

Symp- T1-L2 Lateral horns

Para- BS and sacral

Question 21

Definition of motor unit

Answer 21

All the motor fibre a motor neurone innervates

Question 22

What determines finer muscle control

Answer 22

The lower the innervation ratio

I.e less motor units to nerve

Question 23

Different tissue around and within nerves

Answer 23

Endoneurium - surrounds peripheral nerves with capillaries and lymphatics

Perineurium- strong mechanical- surround bundles of fascicles

Epineurium- joins fascicles together- biggest

Question 24

Types of nerve fibres

Answer 24

A and C

A- subtypes- a,b, y, d
Typically large and medium
a- motor
b- sensory
y-muscle
d- pain, temp

C umyeliainted- pain