TBI

Question 1

Does the brain require insulin for metabolism?

Answer 1

No the transport protein Glut2 facilitates the transport of glucose across the plasma membrane in mammalian cells without the need for insulin.

Question 2

What is the normal range for ICP?

Answer 2

8-15mmHg

Question 3

How does O2 enter the brain cells?

Answer 3

O2 is a gas, and therefore using passive diffusion along a pressure gradient.

Question 4

How long does the brain take to use up glucose?

Answer 4

2-4mins

Question 5

What are the functions associated with each of the lobes in the brain?

Answer 5

Frontal lobe - cognitive function + voluntary movement
Occipital lobe - vision
Parietal lobe - processes sensory information - taste, touch
temporal lobe - memories, language.

Question 6

How do the scalp and skull provide protection to the brain?

Answer 6

The scalp provides some protection through the skin and hair. The main protection is the compact bone that makes up the skull.

Question 7

If the BGL is recorded as 1.1mmol/L, how would you expect the patient to present?

Answer 7

Comatosed.

Question 8

What is the munro-kellie hypothesis?

Answer 8

States that the sum of volumes of the brain, CSF and intra cerebral blood is constant. An increase in one should cause a reciprocal decrease in either one or both of the remaining two.

Question 9

Can you see a Babinski sign in infants that are younger than 2yrs?

Answer 9

No, the neural pathways have not been fully myelinated and it is normal for infants to have abnormal responses to the sole of the foot being stroked. The plantar reflex usually occurs from 1-2years of age.

Question 10

Diminished or exaggerated reflex responses can indicate what?

Answer 10

Upper (exaggerated) or lower (diminished or absent) motor neuron responses.

Question 11

What is the plantar reflex and how does it relate to a Babinski sign?

Answer 11

The plantar reflex occurs in response to the sole of the foot being stroked. This is where the big toe flexes and curls down. A response that is abnormal is known as the Babinski sign and indicates damage to the spinal cord.

Question 12

What are the 5 regions of the spinal cord called?

Answer 12

Cervical, thoracic, lumbar, sacreal, coccygeal.

Question 13

What is decussation?

Answer 13

The crossing over of the nerve pathways in the medulla or spinal cord. This is why you many see damage on the opposite side to the injured side.

Question 14

In everyday life, what does the stretch reflex assist with?

Answer 14

Maintain upright posture.

Question 15

Where does the phrenic nerve arise from?

Answer 15

c3-c5 in the neck region.

Question 16

What can trigger the blink reflex?

Answer 16

Bright light, loud noises, object moving closer to eye, sneezing, touching cornea, bitter taste.

Question 17

What vital signs might you see in a TBI?

Answer 17

Raised BP as the body tries to increase blood supply to the brain and compensatory low pulse rate.
Altered respiratory rate if medulla and pons are compressed?

Question 18

what are the two classifications of a TBI?

Answer 18

Contusions - collection of blood outside the blood vessel and can happen anywhere in the body - including brain.
Concussion - widespread trauma to the brain tissue, due to blow to the specific and specific brain bruising.

Question 19

What GCS score would indicate a mild, moderate and severe TBI?

Answer 19

Mild - 13-15 out of 15
Moderate - 9-12 out of 15
Severe - 3-8 out of 15

Question 20

What cranial nerve would be damaged that would be present in pupil dilation?

Answer 20

Cranial nerve III
Occulomotor nerver

Question 21

What is the accommodation convergence reflex?

Answer 21

Where the eyes adjust to the degree in which the light is entering the eye is bent so that it falls on the retina. When we view near objects the pupils constrict and curvature of the lens increase.

Question 22

What is a TBI

Answer 22

An acute brain injury resulting from mechanical energy to the head from external sources.

Question 23

What are 3 types of herniation that occur if ICP is raised?

Answer 23

Subfalcine herniation - brain tissue herniates across hemispheres.
Transfentorial herniation - brain tissue herniates across the tentorium cerebellium.
Tonsillar herniation - foramen magnum.

Question 24

What is the pupillary light reflex?

Answer 24

The constriction or dilation in response to change in light levels.
Constriction - parasympathetic motor neurons
Dilation - sympathetic motor neurons

Question 25

What is CPP?

Answer 25

Cerebral perfusion pressure - the pressure of blood flowing to the brain.

Question 26

How would a change in ICP lead to brain ischaemia?

Answer 26

If the ICP reaches or exceeds the mean systemic blood pressure, the blood supply to the brain will be blocked off. This will result in brain ischaemia, brain cell death and eventually brain injury.

Question 27

How does the blood brain barrier protect the brain?

Answer 27

The blood brain barrier is made up of endothelial cells, astrocyte feet and pericytes that tightly regulate ions and substances. It is highly selective semipermeable membrane. Most medications can pass through.