Anatomy Chapters 21 And 22

Front 1

3 main requirements of sensory systems

Back 1

1. Stimulus
2. Receptors
3. Brain

Front 2

Stimulus

Back 2

Signal from environment

Front 3

receptors

Back 3

detects stimulus - converts it to a neural impulse

Front 4

Brain

Back 4

recieve impulse, integrate it, produce a perception of the stimulus

Front 5

General senses

Back 5

Found throughout body
Can be somatic or visceral

Front 6

Somatic general senses

Back 6

concious, voluntary
tactile, thermal, pain, preprioception

Front 7

Visceral general senses

Back 7

unconcious, involuntary
Conditions in internal organs

Front 8

Special senses

Back 8

Vision, hearing, taste, smell, balance
-Head oriented

Front 9

Types of stimuli we can respond to:

Back 9

Light, (electromagnetic spectrum), heat/cold, pressure/pain, mechanical energy (soundwaves), soundwaves

Front 10

Two types of receptors

Back 10

1. Neurons
2. Unique cells

Front 11

Two types of neurons:

Back 11

1. Free nerve endings
2. Encapsulated nerve endings

Front 12

Free Nerve Endings

Back 12

Naked dendrite detects stimulus, initiates impulses
-smell, pain, temperature, tickle, itch

Front 13

Encapsulated Nerve Endings

Back 13

Dendrites wrapped in c.t. capsule
-e.g. Meissner/Pacinean corpuscles
-Pressure, vibration, touch

Front 14

What do encapsulated nerve endings enhance?

Back 14

-enhance sensistivity/
selectivity of receptor (this stimulus but not that one)

Front 15

Unique Cells

Back 15

Recieves stimulus, communicates signal to adjoining neuron
~Rods/cons in eye
-Taste buds in mouth
-Hair cells in ear

Front 16

The 3 Tactile Sensations

Back 16

1. touch
2. pressure
3. vibration

Front 17

Touch

Back 17

Found in skin, different receptors for fine or crude touch

Front 18

Pressure

Back 18

Deformation of deep tissue in skin
-Pacinean corpuscles have to be squeezed to feel this sensation

Front 19

Vibration

Back 19

Touch and pressure receptors that are stimulated repeatedly

Front 20

Thermal Sensations

Back 20

Cold Receptors:
Inside s. basale, activated by 10-40 C
Heat Receptors:
In dermis (deeper in skin then cold receptors), activated by 32-48 C

Front 21

What does temperatures <10 or >48 trigger?

Back 21

Trigger pain receptors, not cold/heat receptors. The body doesn't care if it's hot or cold, it just wants to get out.

Front 22

Fast Pain Receptors

Back 22

a pain sensation
1. Near the skin
2. Sense sharp, quick pain
3. Fairly abundant, often w/ reflex (no brain)

Front 23

Slow Pain Receptors

Back 23

a pain sensation
1. Deeper in body
2. Builds slowly, aching/throbbing

Front 24

Proprioception

Back 24

Provides info on location/movement of body parts

Front 25

Receptors in muscles

Back 25

-Muscle spindles (LL corkscrew fibers)
-Info on degree of streching in a muscle

Front 26

Receptors in tendons

Back 26

-Tendon organs
-Info about tension on tendon as muscle contracts

Front 27

Receptors in joints

Back 27

-Joint kinesthetic receptors
-Info about position and movements of joints

Front 28

How is sensory information relayed to brain?

Back 28

3 neuron pathway
1st order neuron to
2nd order neuron to
3rd order neuron

Front 29

1st Order Neurons

Back 29

Carry signal from site of stimulation to brain stem/s. cord

Front 30

2nd Order Neurons

Back 30

Carry signal from brain stem/s.cord to thalamus

Front 31

3rd Order Neurons

Back 31

Carry signal from thalamus to appropriate part of cerebrum

Front 32

Where do the signals go when they get to the brain?

Back 32

3rd order neurons arrive in post-central gyrus for interpretation

Front 33

Special Senses

Back 33

-Receptors are distinct and localized in specific parts of head
-Neural pathways variable

Front 34

Olfaction

Back 34

-Receptors (1st order neurons) are cilia on dendrites of bipolar neurons
-Sits on cribiform plate on ethmoid bone

Front 35

Neuron pathway for olfaction:
Synapse

Back 35

synapse = the axon of 1st order and dendrites of 2nd order in olfactory bulb

Front 36

Some of the 2nd order travel to ________ ________(awareness of smells, emotions due to smells)

Back 36

Limbic system

Front 37

Some of the 2nd order neurons travel to _________, allowing discrimination of odors.

Back 37

cerebrum

Front 38

Why do some of the 2nd order neurons in olfactino bypass the thalamus?

Back 38

Because smell is such an old sense evolutionarily.

Front 39

Gustation

Back 39

Taste: Only 5 different tastes can be recognized:
Sweet, salty, bitter, sour, umami and maybe water

Front 40

Gustation receptors

Back 40

Receptors are cells on tongue, soft palate, pharynx, and epiglottis
-Group of cells = TASTE BUD
-Microvillus of cell extends up through a pore, picks up chemical signals

Front 41

Neuron pathway for gustation:
Receptors and synapse

Back 41

Receptor cells excited by chemicals, send signal to 1st order neurons
-via c.n. VII and IX
-synapse in medulla

Front 42

The 2nd order neurons of gustation go from the medulla to one of two places:

Back 42

1. Limbic System:
Pleasure/dislike to taste
2. Thalamus:
3rd order to cerebrum
Taste discrimination

Front 43

The two accessory structures of eye:

Back 43

1. Muscles that control eye movement
2. Lacrimal apparatus- make/ release/drain tears

Front 44

Muscles that control eye movement

Back 44

-Six extrinsic eye muscles-produced fine tuned eye movements
-controlled by motor neurons c.n. III, IV, and VI

Front 45

Lacrimal Apparatus purpose and 3 main structures

Back 45

makes drains tears
1. Lacrimal gland
2. Lacrimal canals (collects tears)
3. Lacrimal sac (stores then drains tears to nasal cavity)

Front 46

Lacrimal glands

Back 46

Produces tears
-water, salts, antibacterial enzymes
-moistens, cleans eye surface

Front 47

Outer tunic of eyeball

Back 47

Sclera = white of eye, c.t.
Cornea = clear front of eye, epithelial cells and some c.t.

Front 48

The 3 sublayers of the middle tunic of eyeball (vascular)

Back 48

1. Choroid
2. Ciliary Body
3. Iris

Front 49

Choroid

Back 49

-Well-vascularized
-Provides nutrients to inner eye

Front 50

Ciliary body

Back 50

-Anterior to choroid, extends almost to cornea
-Muscles, ligaments that alter shape of lens for focusing near/distance.

Front 51

Iris

Back 51

-Colored part
-Smooth muscle regulates how much light enters eye through pupil

Front 52

The lens of the eye is attached to the __________ body and changes shape to focus light on back of ________ for clear vision.

Back 52

Ciliary, retina

Front 53

Inner tunic of the eyeball

Back 53

-Lines the posterior portion of eye
-Photoreceptors (rods/cons) and 2 layers of neurons

Front 54

Neuron pathway for vision:
Receptors / 1st order

Back 54

Rods/cons stimulated
1st order = bipolar cells stimulate (first neuron layer)

Front 55

Neuron pathway for vision:
2nd order neuron

Back 55

2nd order = Ganglion cells form optic nerve (second neuron layer)

Front 56

What regulates synapses between bipolar and ganglion layers?

Back 56

Amacrine and horizontal cells

Front 57

The two optic nerves cross at a point called the ______ ________. Some _______ sides, some _______.

Back 57

Optic chiasm
Switch, don't

Front 58

Neuron pathway for vision:
3rd Order Neuron

Back 58

-Signals travel to the thalamus
-New neuron carries signal to cerebrum

Front 59

Hearing uses ________/______/
_________. While euilibrium uses ___________ ear.

Back 59

external/middle/inner
inner

Front 60

3 structures of the external ear:

Back 60

1. Pinna (earflap funnels sound waves)
2. External auditory meatus (Carries sound waves into ear)
3. Tympanic membrane (Vibrates when sound waves hit it)

Front 61

Middle Ear

Back 61

Ossicles:
3 bones in contact with tympanic membrane and each other.

Front 62

The order of the ossicles in the middle ear is:_____, _____, ______. These bones _______ and ________ the signal.

Back 62

Malleus, incus, stapes
Vibrate and augment

Front 63

The ______ lays agaisnt the _______ window.

Back 63

Stapes, oval

Front 64

The 3 parts of the inner ear:

Back 64

1. Oval window
2. Cochlea
3. Hair cells (receptors)

Front 65

Oval Window

Back 65

Vibrations against this membrane displaces the fluid in cochlea in ear

Front 66

The fluid within the cochlea is called the _____________.

Back 66

Parilymph

Front 67

Movement of __________ moves hair cells embedded in walls of ___________

Back 67

Parilymph
Cochlea

Front 68

Hair cells = ____________ cells. Send signals to ________ (c.n. ______)

Back 68

Receptor
Neurons
VIII

Front 69

How much hair cells move = ___________

Back 69

Volume = (loud vs. soft)

Front 70

Which hair cells get moved = ___________

Back 70

tone/pitch

Front 71

Groups of hair cells are called ____________

Back 71

Organ of Corti

Front 72

Two structures for equilibrium within vestible:

Back 72

1. Saccule
2. Utricle

Front 73

The saccule and utricle

Back 73

One senses verticle exceleration, the other senses horizontal exceleration

Front 74

Semicircular canals

Back 74

3 in x,y and z planes of head

Front 75

Hair cells in regard to equilibrium:

Back 75

All the structures of equilibrium have perilymph and hair cells

Front 76

Neuron pathway for hearing/equilibrium:
______ neuron pathway from ear to ____________

Back 76

four
cerebrum

Front 77

Neuron pathway for hearing/equilibrium:

Back 77

1. in c.n. VIII to
2. in nuclei of medulla to
3. in inf. colliculi to
4. in thalamus to
*cerebrum