Lecture 9 - The Brain And Species Senses

Question 1

Sensory Receptor Definition

Answer 1

Dendrites of Sensory Neurons

Question 2

Sensation Definition

Answer 2

Arriving Information into the CNS

Question 3

Perception Definition

Answer 3

Conscious Awareness of a Sensation

Question 4

Percentage of info that reaches conscious awareness

Answer 4

~1%

Question 5

6 General Senses

Answer 5

Temperature
Pain
Touch
Pressure
Vibration
Proprioception (Body Position)

Question 6

5 Special Senses

Answer 6

Smell
Taste
Vision
Hearing
Balance

Question 7

Difference between General/Special Senses

Answer 7

General Senses use receptors all over the body
Special Senses use receptors from specific sensory organs

Question 8

Organs used in Olfaction

Answer 8

Olfactory Organs

Question 9

2 Parts of Olfactory Organs

Answer 9

Olfactory Epithelium
Olfactory Glands

Question 10

Nerve used in Olfaction

Answer 10

Olfactory Nerve (I)

Question 11

Steps of Olfaction

Answer 11

Air swirls within nasal cavity
Lipid/Water Soluble chemicals diffuse into the mucus
Olfactory Receptors stimulated
Chemicals interact with odorant binding receptors on cilia
Binding of odorants produces action potentials
Info relayed to CNS

Question 12

Contents of Olfactory Epithelium

Answer 12

Receptor Cells
Supporting Cells

Question 13

Olfactory Gland Function

Answer 13

Secretes mucus to coat face of olfactory organs

Question 14

2 Mucus Function in Olfaction

Answer 14

Protects receptors on cilia from potent smells
Can dissolve chemicals

Question 15

Common Cold Definition

Answer 15

The overstimulation of Olfactory Glands

Question 16

Odorant Definition

Answer 16

Chemicals that stimulate olfactory receptors

Question 17

Density of Olfactory Receptor Cells

Answer 17

Between 10/20 million olfactory receptor cells packed into ~5cm2

Question 18

Pathway of info to CNS

Answer 18

Olfactory Nerve (CN I) reaches Olfactory Bulb
Axons travel along olfactory tract to olfactory cortex

Question 19

Trend in receptor density/smell

Answer 19

Higher Surface Area of Receptors = Heightened Sense of Smell

Question 20

Location of Olfactory Cortex

Answer 20

In Temporal Lobe

Question 21

Location of Taste Receptors

Answer 21

Superior surface of the Tongue

Question 22

Taste Buds Location

Answer 22

Sides of papillae

Question 23

Papillae Definition

Answer 23

Epithelial Projection of the Tongue

Question 24

3 types of Papillae

Answer 24

Filiform - No Taste Buds
Fungiform - ~5 Taste Buds
Circumvallate - ~100 Taste Buds

Question 25

Location of Fungiform Papillae

Answer 25

Front of Tongue

Question 26

Location of Circumvallate Papillae

Answer 26

Back of Tongue

Question 27

2 Contents of Taste Buds

Answer 27

Gustatory Cells Supporting Cells

Question 28

Taste Pore Definition

Answer 28

Area of where microvilli of gustatory cells extend to surrounding fluid

Question 29

6 Taste Sensations

Answer 29

Bitter Sweet Sour Salty Umami Water

Question 30

Function of Water Taste Sensation

Answer 30

Monitors hydration levels

Question 31

Water Receptor Location

Answer 31

Pharynx

Question 32

3 Steps of Taste Mechanism

Answer 32

Dissolved Chemicals contact microvilli Change in membrane potential Results in Action Potential

Question 33

Pathways of Taste Mechanism

Answer 33

Use Facial (CN VII), Glossopharyngeal (CN IX), Vagus (CN X) Cranial Nerves will synapse with medulla oblongata Info sent to the Thalamus

Question 34

Location of Gustatory Cortex

Answer 34

In Temporal Lobe

Question 35

Diameter of Eye

Answer 35

~24mm

Question 36

4 Parts of eye contacting light (in order)

Answer 36

Cornea Pupil Lens Retina

Question 37

Location of sensory neurons in the Eye

Answer 37

Retina

Question 38

Function of Cornea

Answer 38

Causes Light Refraction

Question 39

Refraction Definition

Answer 39

The bending of light as it travels from one medium to another

Question 40

Cause of Short Sightedness

Answer 40

Not enough refraction of light

Question 41

Cause of Long Sightedness

Answer 41

Too much refraction of light

Question 42

Number of rods and cones in an Eye

Answer 42

~100 Million Rods ~5 Million Cones

Question 43

2 types of Photoreceptors

Answer 43

Rods Cones

Question 44

Function of Rods (2 points)

Answer 44

Predominate periphery vision Detect absence/presence of light

Question 45

Function of Cones (2 points)

Answer 45

Predominate Central vision Detect colour

Question 46

Photopigments Definition

Answer 46

Light sensitive molecule in Photoreceptors

Question 47

Rhodopsin Definition

Answer 47

Main component of Photopigments

Question 48

2 Components of Rhodopsin

Answer 48

Opsin Retinal

Question 49

Rhodopsin reaction to light

Answer 49

In the presence of light, Rhodopsin splits This alters the flow of electrical current Thus, action potential is produced

Question 50

5 Steps of Vision Mechanism

Answer 50

Light refracted by Cornea Light interacts with photopigments in photoreceptors Rhodopsin splits Electrical flow is altered Action Potential is produced

Question 51

Pathways of Vison Mechanism

Answer 51

2 Optic Nerves (CN II) reach Diencephalon Nerves cross over in optic chasm Pass through the Superior Colliculus Nerve Reach Thalamus on the opposite side of the brain Info reaches visual cortex

Question 52

Binocular Vision Definition

Answer 52

Field of view where both eyes are used

Question 53

Location of Visual Cortex

Answer 53

In Occipital Lobe

Question 54

Receptors used in Hearing/Balance

Answer 54

Mechanoreceptors

Question 55

3 Parts of the Ear

Answer 55

External Ear Middle Ear Inner Ear

Question 56

Location of Hearing Receptors

Answer 56

Cochlea

Question 57

Location of Balance Receptors

Answer 57

Semicircular Canals

Question 58

3 Components of Auditory Ossicles

Answer 58

Malleus Incus Stapes

Question 59

Tympanic Membrane Definition

Answer 59

Membrane separating Middle Ear from ear canal

Question 60

Auditory Ossicle in contact with Tympanic Membrane

Answer 60

Malleus

Question 61

4 Components of Cochlea

Answer 61

Vestibular Duct Cochlear Duct Tympanic Duct Organ of Cocti

Question 62

2 windows in Bony Labyrinth of Cochlea

Answer 62

Round Window = Base of Tympanic Duct Oval Window = Base of Vestibular Duct

Question 63

Components of Organ of Cocti

Answer 63

Basilar Membrane Tectorial Membrane

Question 64

Movement of Stereocilia in Organ of Cocti

Answer 64

Vibration causes movement of tectorial membrane Causes movement of cilia on receptors Generates action potential

Question 64

6 Steps of Hearing Mechanism

Answer 64

Sound waves arrive at Tympanic Membrane Movement of Tympanic Membrane causes displacement of auditory ossicles Movement of Stapes at the Oval window establishes pressure waves in perilymph of the vestibular duct Basilar membrane distorted Vibration of Basilar Membrane causes hair cell vibration against Tectorial Membrane Action Potential Generation

Question 65

Auditory/Equilibrium Pathways

Answer 65

Sensory Neurons located in spiral ganglion Use Vestibulocochlear Nerve (CN VIII) Enter Medulla Oblongata Pass through Inferior Colliculus, Thalamus to reach Auditory Cortex

Question 66

Layers of Semicircular Canals

Answer 66

Bony Labyrinth Perilymph Membranous Labyrinth Endolymph

Question 67

3 Semi-circular Canals

Answer 67

Anterior Posterior Lateral

Question 68

Steps of Mechanism of Balance

Answer 68

Receptors respond to rotational movement Movement leads to Fluid in cupula Hair Cells in Cupula move Action Potential Generation

Question 69

2 Otoliths

Answer 69

Utricle = Horizontal Linear Accelerations Saccule = Vertical Linear Accelerations

Question 70

Function of Otoliths

Answer 70

Sense Gravity and Linear Acceleration

Question 71

4 Functions of Vestibular Nuclei

Answer 71

Integrate sensory information arriving from each side of the head Relay information to cerebellum Relay information to cerebral cortex Send commands to motor nuclei in brain stem and spinal cord