NS: Senses/Stimulus

Question 1

Sensations

Answer 1

• Dectection of stimuli by sensory receptors which send action pot. using sensory neurons to the brain

Question 2

Perception

Answer 2

When brain is aware of sensations, it interprets them, giving perception of stimuli

Question 3

Sensory Transduction

Answer 3

stimuli converted into neural signals

Question 4

Sensory Receptors

Answer 4

• Grouped witin sensory organs (ear,eyes,nose, mouth)
• Receive stimulus and transfer to sensory neuron by producing NT
• stronger stimulus=stronger depolarization of sensory neurson
• higher frequency of action pot. = strong stimulus

Question 5

Strength of stimulus is based on

Answer 5

frequency of action pot.

-higher frequency = stronger stimulus

Question 6

Mechanoreceptors

Answer 6

• Sense physical deformation
• some r sensory neurons that send action pot. to CNS
• some r epithelial cells that have cilia (hair) that bend to release action pot.

Question 7

Meissner’s corpuscles

Answer 7

• respond to light touch and light pressure
• located just below skin surface
• concentrated in sensitive areas

Question 8

Pacinian corpuscles

Answer 8

• Respond to deep pressure or vibration

- deep in skin

Question 9

Stretch Receptors

Answer 9

• in organs and muscle tissue

- can be distended

Question 10

Hair cells

Answer 10

• specialized epithelial cells (skin cells)

- when bent, it will depolarize membrane and release Ca sending NT to sensory neuron

Question 11

Chemoreceptors

Answer 11

• General Receptors: transmit info about total state concentration
• Specific Receptors: respond to individual kinds of molecules

Question 12

Smell

Answer 12

• Olfactory receptor cells on olfactory epithelia (skin in nose)
• odorant molecules bind to specific receptors and signal transduction pathway is triggered, send action pot. to brain

Question 13

Pathway of smell

Answer 13

1. Odorant
2. dissolve in mucous
3. attach to protein receptor
4. depolarize olfactory nerve
5. olfactory bulb
6. temporal lobe

Question 14

Electromagnetic Receptors

Answer 14

• detect various forms of electromagnetic energy (infrared, electricity, magnetism)
• Eye has photoreceptors that sense different wavelengths of light
• allow us to see colour and in the dark

Question 15

Thermoreceptors

Answer 15

• Respond to hot or cold by activating or inhibiting enzymes which alter membrane channels
• Skin thermoreceptors: sense outside environment, located on skin
• Core thermoreceptors: sense inside temp. located in brain
• stimulate behaviours: change in blood flow, shivers/panting, seek shade/sunlight

Question 16

Pain Receptors

Answer 16

• aka nocireceptors
• respond to lots of heat, pressure or chemicals released from damaged tissue (acids and prostaglandins)
• aspirin prevents production of prostaglandins
• send info to: cerebrum - interpret pain, limbic system - memories and emotions w/ pain, Reticular formation - increase alertness (response to pain)

Question 17

Taste

Answer 17

• Papillae (bumps on tongue) house taste buds that respond to salt, sweet, sour, and bitter
• Taste detect dissolved chemicals and smell detects airborne chemicals
• Sensory Receptors on taste buds have microvilli which binds food molecules, causing depolarization of sensory neuron
• when full, smell n taste receptors altered, decrease in ability to bind food/smell molecules, less awareness or interest in food

Question 18

Pathway of taste

Answer 18

1. Taste Buds
2. Cranial Nerve
3. thalamus
4. parietal lobe