1) Pheromone is a chemical (hormones) released by one animal that affect the behaviour
or physiology of another animal
a. Yes humans have pheromones.
2) Main olfactory system is a sensory system used for olfaction, that detect and
recognise chemicals that come In contact with its membrane
3) Accessory olfactory system is a system used for olfaction that sense fluid-phase
4) Cribriform plate is a bone at the base of the rostral part of the brain
a. Olfactory cranial nerve
5) - Lee-Boot effect = The slowing and eventual cessation of estrous cycles in groups of
female animals that are housed together
-Whitten effect = The synchronization of the menstruation cycles of a group of
females, which occur in the presence of a pheromone in a male’s urine
-Vandenbergh effect = The earlier onset of puberty seen in female animals that are
housed with males
-Bruce effect = Termination of pregnancy caused by the odour of a pheromone in the
urine of another male
- As a type of alarm to warn other member of the same species to either flight of fight
- To warn others of their territory
- For courtship or attract an opposite sex
- To leave a trail so that other member of the same species can follow
6) Amplitude = Movement of the sound wave
Loudness = How big the wave is/How much the wave is compressed
Frequency = Number of cycles per unit time Pitch = The perceived frequency of sound
7) Figure 7.3 = The auditoryApparatus
Figure 7.4 = The Cochlea
Figure 7.5 = Basilar membrane
8) Hair cells are the receptive cells of the auditory apparatus. The hair cells form synapse
with dendrites of bipolar neurons whose axons bring auditory information of the
9) When the cilia (singular: cilium) detect sound, the tip link that connects the cilia will
be stretch. When the tip links are stretch, the sodium channel would open slightly
which would allow Na+ to enter. This would cause depolarization. If the hair cells
bend towards the longest hair, the tip link would open wider thus, more Na+ can enter
and the rate of activity would increase.
On the other hand, if the hair cells are mashed together, the sodium channel would
close and lesser Na+ can enter thus the rate of activity would decrease.
10) The vestibular system provides the sense of balance, sense of spatial orientation,
maintenance of head in an upright position and adjustment of eye movement in
compensation for head movement.
11) The somatosensory system composed of the receptors and processing centres to
produce touch, temperature, body position and pain.
12) Figure 7.19 = The somatosensory pathway
Figure 7.20 = The three component of pain
13) Cutaneous receptor is a type of sensory receptors found in the dermis or epidermise.
Free nerve ending = Detect temperature, mechanical stimuli (touch, pressure) or pain
Hair-folicle receptor = Meissner’s corpuscle = Touch sensitive (sensitive to light touch), changes in texture &
Pacinian corpuscle = Mechanical stimuli, deep pressure & fast vibration
14) The free ending nerve would react to intense pressure, heat or acid. The pain receptors
such as nociceptors (response to intense pressure) is a high threshold
mechanoreceptors would receive these signal. Receive stimulus would then enter the
spinal cord and would immediately cross over to the other side of the spinal cord
before going up the brain and to the thalamus.
Pain can be perceived by both physically and emotionally.
15) Different receptors process different taste thus, we can taste many different flavours.
a. Salt (sodium chloride)
i. When we eat salty food, there are more salt in our mouth
ii. When the sodium enters the channel in the taste bud, we would have