Unit 3: Sensory and Motor

Question 1

Mechanoreceptor

Answer 1

Mechanical stimulus (touch, vibration)

Question 2

Chemoreceptors

Answer 2

Chemical stimulus (taste, smell, chemicals bind to receptors)

Question 3

Electromagnetic

Answer 3

Electric stimulus (light/eyes, magnetic/birds)

Question 4

Thermoreceptors

Answer 4

Heat stimulus (snake heat vision)

Question 5

Pain receptors

Answer 5

In skin, signals body that something is damaged

Question 6

Sensory Transduction

Answer 6

Convert stimulus into language of nervous system (generates AP from release of neurotransmitters)

Question 7

Sensory Transmission

Answer 7

convert stimulus into AP (intensity determined by AP frequency)

Question 8

Integration and Perception

Answer 8

Brain tries to make sense of stimulus

Question 9

Orientation

Answer 9

Gravity-based mechanic, physical structures (statoliths in insects) move with gravity, triggering sensory hair cells

Question 10

Human inner ear

Answer 10

Utricle, saccule, connect to 3 rings of different planes, contain gel-like capsule called cupula which is filled with fluid, hair cells, and otoliths (rocks).

When head is tilted, otoliths move inside capsule and trigger hair cells, determining orientation.

Question 11

Sound

Answer 11

Waves enter outer ear, traverse auditory canal, and strike tympanic membrane, which sends vibrations along malleus, incus, and stapes bones, and through the cochlea’s oval window.

The Cochlea contains hair cells that vibrate based on sound wave intensity and frequency. Different hair cells detect different pitches.

At the end of the cochlea, vibration hits the round window.

Question 12

Depolarization

Answer 12

Hair cells move in direction of sound wave

Question 13

Hyperpolarization

Answer 13

Hair cell movement rebounds

Question 14

Volume-
Pitch-

Answer 14

Intensity
Frequency

Question 15

Motor Output 1
AP reaches muscle cell from motor neuron

Answer 15

Vesicles fuse with membrane and release neurotransmitters (Acetylcholine/Ach) into synaptic cleft. Ach binds to receptors on muscle cell, triggering a new action potential.

Question 16

Motor Output 2
New action potential in muscle cell

Answer 16

Travels down T-tubule to enter the sarcoplasmic reticulum (SR).

SR releases Ca2+ into cytosol.

Question 17

Motor Output 3
SR releases Ca2+ into cytosol

Answer 17

Ca2+ binds to troponin complex, causing it to rotate and expose the myosin binding sites on the actin fibers.

Question 18

Motor Output 4
Myosin binding sites on actin are exposed

Answer 18

Heads of myosin fibers bind to actin and pull, causing the sarcomere to shorten and the whole muscle to contract.

Question 19

Muscle relaxation occurs when

Answer 19

Ach gets broken down