Week 4 and 5

Question 1

Peripheral sensory info is needed to?

Answer 1

• Construct a map of our body
  
  • Make adjustments to changes in the environment
  • Helping control posture and sequences of movements

Question 2

4 main receptor sites for sensing movement

Answer 2

Muscle
Tendons
Joints
Skin

Question 3

Define muscle sense

Answer 3

• Sensory info arising in the muscles and tendons

Question 4

Define Proprioceptio

Answer 4

Refers to all sensory inputs from the musculoskeletal system

Question 5

Define kinesthesia

Answer 5

• The sense of the position and movements of limbs

- The ‘sixth sense’

Question 6

Define rapidly adapting

Answer 6

• Receptors decrease firing rate while stimulus is applied at the same strength

Question 7

Define slowly adapting

Answer 7

• Receptors continue to fire throughout the stimulus duration at the same or slower rates

Question 8

Pacinian Corpuscle - rapidly or slowing adapting?

Answer 8

Rapidly

Question 9

Define Ruffini Endings - rapid or slow

Answer 9

• Slowly adapting

- Responds to steady indentation of skin with sustained discharge

Question 10

Meissner corpuscle - rapid or slow

Answer 10

• Rapidly adapting

- Higher activation threshold than Pacinian

Question 11

Merkel’s Disc - rapid or slow

Answer 11

• Slowly adapting

- Signals changes in intensity and steady-state values

Question 12

Free Nerve endings - rapid or slow

Answer 12

• Slowly adapting
  
  • Simple receptor, unmyelinated
  • Responds to noxious stimuli

Question 13

Define receptive field

Answer 13

• Area of skin served by a sensory unit

Question 14

define intensity discrimination

Answer 14

ability to judge stimulus strength

Question 15

Depth of skin indentation = ?

Answer 15

tactile sensitivity

Question 16

spatial discrimination

- where is it highest and lowest

Answer 16

• Differentiate between locations of point stimuli
  
  • Two point discrimination test
  • Highest in finger tips
  • Lowest on back

Question 17

spatial discrimination depends on what two things

Answer 17

Size and overlap of receptive fields

Question 18

Define extrafusal fibres

Answer 18

Muscle fibres that do the work

- innervated by alpha motor neuron

Question 19

Define intrafusal fibres

Answer 19

Modified muscle fibres gathered in small bundles and surrounded by a capsule

Question 20

Muscle spindle densities

- where is the highest and lowest

Answer 20

highest

• hand, food, neck
• some leg muscles

Lowest

• shoulder
• thigh

Question 21

Define golgi tendon organ

Answer 21

The Golgi tendon organ is a tree-like sensory ending enclosed in a spindle-like connective tissue capsule, that lies near the junction of a tendon with a muscle

Question 22

4 type of joint receptors

Answer 22

Type 1 - 4

Question 23

Explain each type joint receptors

Answer 23

Type 1: 
	- Slowly adapting 
Type 2:
	- Large
	- Rapidly adapting 
Type 3: 
	- Found in ligaments near capsule 
	- High threshold and rapidly adapting
	- Resemble GTO 
Type 4:
	- Free nerve endings 
	- Unmyelinated fibres

Question 24

two afferent pathways?

Answer 24

Dorsal column pathway
Spinothalamic pathway
- lateral and anterior

Question 25

3 function zones of the spinal cord

Answer 25

1. Dorsal (posterior): sensory 2. Ventral (anterior): motor Middle - association

Question 26

Define interneurons

Answer 26

- provide excitatory & inhibitory connections between primary sensory neurons & motor neurons in the ventral horns of the same or opposite side

Question 27

Explain reflex arc

Answer 27

1. Sensory receptors (detect the stimulus) 2. afferent nerve (conveys sensory signal centrally) 3. Integrative synaptic centre (analyses sensory input) 4. Efferent nerve (conducts motor output to periphery) 5. Motor effector (carries out response)

Question 28

3 reflex loop types

Answer 28

M1 - short loop M2 - long loop M3 - voluntary

Question 29

3 inhibitory reflexes

Answer 29

GTO Joint Cutaneous

Question 30

Define withdrawal reflex

Answer 30

The withdrawal reflex is a spinal reflex intended to protect the body from damaging stimuli.

Question 31

Define knee jerk reflex

Answer 31

A sudden involuntary forward movement of the lower leg that can be produced by a firm tap to the tendon located just below the kneecap

Question 32

Define cross extensor reflex

Answer 32

The crossed extensor reflex is a contralateral reflex that allows the body to compensate on one side for a stimulus on the other. For example, when one foot steps on a nail, the crossed extensor reflex shifts the body's weight onto the other foot, protecting and withdrawing the foot on the nail.