Chapter 7.2 Responding to Stimuli Flashcards
The stimulus-response model
Shows the pathway through which information is transmitted in the nervous system.
What are receptors?
Special organs or cells that are able to respond to light, heat, or other external stimuli and transmit a signal to a sensory neuron.
Chemoreceptor
Sensitive to chemicals, such as odour molecules in the air. located in the nose and tongue.
Mechanoreceptor
Sensitive to touch, pressure, sound and motion.
located in the skin, the inner ear and muscles.
Pain receptor
Sensitive to chemical changes in damaged cells
located throughout the body, but mostly the skin.
Thermoreceptor
Sensitive to temperature changes located in the skin.
Photoreceptor
Sensitive to light and located in the eyes.
What is a reflex arc?
In dangerous situations, like touching a stove, we have rapid and involuntary response, the stimulus response takes a short cut through the spinal cord, the brain is informed later.
Somatic Nervous system
effect the skeletal muscles and voluntary movement.
Autonomic nervous system
effect smooth muscles, involuntary movement including peristalsis (digestion), and breathing.
Sympathetic Nervous system
Prepares body to flee or flight when facing dangerous situations.
Includes:
Dilation of pupils to clear vision
Dilation of bronchioles increasing oxygen intake
Heart rate increases – faster and stronger muscle action
Digestion is slowed
Parasympathetic Nervous system
Response to rest and digest.
Includes:
Constricts pupils
Constricts Bronchioles
Heart rate decreases - less muscle action
Stimulates digestion
