Sensory and motor system Flashcards
Where in the body is somatosensation?
All over the body
What information does the somatosensory system give us?
Tells us what body is up to and what’s going on in environment by providing bodily sensations such as touch, temp, pain, position in space, movement of joints
What does an increased number of receptors mean?
Increased sensitivity to stimulation
Skin is the largest sensory organ. What are the two types of skin that humans have?
- Hairy skin - relatively low sensitivity
- Glabrous skin - doesn’t have hair follicles but contains large number of sensory receptors, sensitive to wide range of stimuli
What is the name of the test that reveals differences in skin sensitivity across the body?
Two point-discrimination test
Which part of the body is the most sensitive? Why is this?
Fingertips
Higher density of mechanoreceptors
Receptors with small receptive fields
Brain devotes a lot of resources
What are the three main types of somatosensory receptors and what do they perceive?
- Nocioception - perception of pain and temperature
- Napsis - perception of fine touch and pressure (e.g. grasp, manipulate)
- Proprioception - perception of the location and movement of the body
Fill in the gaps about nocioreceptors…
1.Free nerve ______
2. Sharp/____ pain and _____/cold
3. Damage to _____ or surrounding cells release ________ that stimulate dendrite and produces an action potential
- endings
- dull, heat
- dendrite, chemicals
Fill in the gaps about haptic receptors…
1. Dendrite attached to _____, connective tissue or dendrite encased in ______ of tissue
2. Distinguish _____, pull, vibration, flutter, ________
3. _______ stimulation produces action potential
4. Composition of ______ determines the type of _________ energy conducted
- hair, capsule
- touch, indentation
- Mechanical
- capsule, mechanical
Fill in the gaps about proprioceptors…
Movements _____the receptors to _______ stimulate dendrites and produces an action potential
stretch, mechanically
Somatosensory receptors tell us what two things about a sensory event?
- When it occurs
- Whether it is still occurring
What is a rapidly adapting receptor?
Body sensory receptor that responds briefly to the beginning and end of a stimulus on the body
What is a slowly adapting receptor?
Body sensory receptor that responds as long as a sensory stimulus is on the body
What stimulus do slow adapting receptors signal the presence of? Give an example.
Long sustained stimulus
e.g. pain, long pinch
What stimuli do rapid adapting receptors signal the presence of? Give an example.
Motions of object on skin, gives good response to repeated stimuli
e.g. vibration, tickle