BB Physiology

Question 1

what do you test blood pressure with

Answer 1

phygmomanometer cuff

Question 2

what happens when a sphygmomanometer cuff is inflated around the arm

Answer 2

When a sphygmomanometer cuff is inflated around the arm, the local pressure transmitted to the ulnar, radius and median nerves reversibly blocks the axons (nerve “fibres”) within them

Question 3

how do you cut of the nerve supply to the arm

Answer 3

• Place the cuff on the subject’s right arm above the elbow.
• Raise the arm above the head to drain the blood from the arm for about 10 seconds; then rapidly raise the pressure in the cuff to 180mmHg with the arm still in the air.
• When the circulation has been occluded, allow the subject to lower their arm and rest it on the bench.
• Keep this pressure maintained for the duration of the experiment, i.e. 20 minutes
• When you release the cuff, keep hold of the subject so that he cannot injure himself by falling if he should feel faint.
• Make sure you ask the subject how they feel.

Question 4

what tests should be performed every 5 minutes

Answer 4

Sensory functions

a. ) Touch: Lightly brush the skin of the forearm, hand and fingers with cotton wool. Note whether the subject can detect the stimulus and whether it feels different from normal. Test two-point discrimination at 5mm on the finger tips. Test with Von Frey hairs on the forearm.
b) Joint sense: Lightly grasp the terminal joint of the thumb on its lateral and medial surfaces with your fore finger and thumb. Flex or extend the joint a few degrees. Can the subject detect the direction of movement?
c) Pain: test by prodding with a sterile lance on the dorsum of the finger below the nail base or on the back of the wrist. (Use a new sterile lance for each subject). Do not draw blood from the subject.
d) Vibration: test by putting a vibrating tuning fork on the bony protuberances of the upper limb (elbow, wrist, knuckles).

2. Motor functions

Can muscles still be moved? If so, is control impaired or lacking in comparison with the other arm? Do distal muscles appear weaker or more uncoordinated than proximal ones?