Biopsy 5 Flashcards
Name the 5 senses.
Touch, Audition, Vision, Taste, Smell
What is ‘sensation’ ?
- registration of physical stimuli from the environment by the sensory organ
What is ‘perception’ ?
- interpretation of sensation by the brain
Somatosensation consists of ?
- Hapsis
- Nocioception
- Proprioception
Meaning of Hapsis?
Rapid or Slow?
- fine touch and pressure
- Mostly rapid
Meaning of Nocioception?
Rapid or Slow?
- pain & temperature
- Slow
Meaning of Proprioception?
Rapid or Slow?
- body awareness
- Rapid
Are dendrites in sensory receptor specialised?
Yes.
- ion channels will only opened and lead to depolarisation if stimulated by the right external stimulus
Describe the different lateralised effect caused by unilateral damage.
- Loss of Hapsis (fine touch and pressure) on the same side of the damage
- Loss of Nocioception (pain & Temp.) on opposite side of the damage
State the 3 components in Somatic sensation.
- Touch
- Pain
- Limb proprioception
What type of stimulation is Touch?
Mechanical stimulation
What type of stimulation is Pain?
Heat, chemical, mechanical stimulation
What type of stimulation is Limb proprioception?
Muscle, joint stimulation
Axons that carry ‘pain’ is myelinated or unmyelinated?
Unmyelinated
What is ‘receptive field’?
The area where there are sensory receptors that is sensitive to physical stimuli.
What determine the sensitivity of a sensory system?
Size of the receptive field.
- The smaller the receptive fields, the greater the sensitivity.
What is used to indicate how strong a stimulus is by the sensory receptors?
No. of action potential are fired
- the stronger the stimuli, the more action potentials are produced
Name the brain regions that are involved in processing the 5 senses.
- vision (occipital/temporal/parietal)
- hearing (temporal)
- touch (parietal)
- taste (frontal)
- smell (frontal)
Use of sensory pathway from periphery to cerebral cortex.
- to preserve spatial relations
Why some parts of the body have more cortical space than others?
Example of these parts.
They have more receptors.
- hands, face
What kind of sensation is Olfaction?
Chemical sensation
Describe how Olfaction work.
Scent interacts with chemical receptors —> chemical dissolve in mucosa —> interacts with cilia
The type of ion channels involved in membrane potential changes in Olfaction?
Metabotropic ion channels
Odours entering one nostril are processed by the SAME or OPPOSITE side of the brain?
Same side.
