Nervous System & Sensory System Flashcards
Two main types of electrical signals for Neurons?
Graded potentials - input signals
Action potentials - output signals
What is the site of communication between two excitable cells called?
Synapse
What is the main difference between Graded and Action potentials?
Action Potentials are generated by regenerative activation of voltage-gated ion channels, over a certain level (threshold)
What are the 3 Sensory Systems in vertebrates?
Somatosensory System (senses external environment)
Visceral Sensory System (senses internal environment)
Special Sensory Systems (senses external environment)
What is the 4 things (sensory coding) the nervous systems is able to identify when a stimulus activates a sensory receptor
Modality
Location
Intensity
Duration of Stimulus
3 types of Sensory Receptors on your body surface and how are these conveyed and to where?
Mechanoreceptors
Thermoreceptors
Nociceptors
Signals from these receptors are conveyed via the thalamus to the cerebral cortex
Where are Temperature Receptors generally found?
What is the range of temperatures that are tissue-damaging? (These signals are perceived as pain!
Free nerve endings, mainly in the skin, lining of oral cavity and surface of tongue.
Tissue-damaging signals perceived as pain temperature is 43C
What are Nociceptors on the body surface and what stimuli do they pick up?
Free nerve ending receptors that respond to tissue-damaging stimuli. And perceived by the brain as pain.
Can be Chemical, Mechanical or Thermal stimuli
Mechanoreceptors detect what kind of things?
Pressure and Vibration Cell Stretch (osmoreceptors) Balance (equilibrium) Sound Muscle Length and Tension Joint Position and Movement
Chemoreceptors detect what and where?
Chemicals binding to specific receptors on cell membrane.
Eg. CO2, pH, various organic and inorganic molecules
What is “Adequate Stimulus”?
The modality to which receptor responds best
Are signals which travel to the “Cerebellum” consciously or unconsciously perceived?
Unconsciously
5 Basic tastes in humans
Umami Salty Bitter Sour Sweet
There are 3 types of receptor cells, what are they and what tastes do they detect?
Type 1 - support or glial-like cells
Type 2 - receptor cells detect either Sweet, umami or bitter tastes
Type 3 - presynaptic cells detect sour taste
Name the 3 layers of the eye and what are within them.
Outermost Layer
- Sclera
- Cornea
Middle Layer
- Choroid
- Ciliary body
- Lens
- Iris
Innermost Layer
-Retina
