RAT 20 Flashcards
1
Q
What two roots attach a spinal nerve to the spinal cord?
A
Anterior Root & Posterior Root
2
Q
What fibers are contained in the anterior root?
A
Somatic & Visceral Motor
CNS->PNS
3
Q
What fibers are contained in the posterior root?
A
sensory
PNS->CNS
4
Q
How long is the spinal nerve?
A
1-2 cm
5
Q
What are the names of the two large branches of the spinal nerve?
A
Posterior Ramus
Anterior Ramus
6
Q
Is the posterior ramus sensory, motor, or mixed? Where does it travel?
A
Mixed, posterior side of the body
7
Q
Is the anterior ramus sensory, motor, or mixed? Where does the anterior ramus travel?
A
Mixed, anterior side of body/upper and lower limbs
8
Q
What is the name of the small branch that contains autonomic fibers?
A
Rami Communicates (ramus communicans)
9
Q
How many pairs of spinal nerves are there?
A
31
10
Q
What is a nerve plexus?
A
complicated network of nerves
11
Q
Which branches form a plexus?
A
Anterior rami of cervical, lumbar, and sacral spinal nerves
12
Q
Where is the cervical plexus located?
A
Deep in the neck lateral to the first through the fourth cervical vertebrae (C1->C4)
13
Q
What major nerve arises from the cervical plexus?
A
Phrenic Nerve (axons from c3->c5)
14
Q
What does the phrenic nerve innervate>
A
diaphragm
15
Q
Where is the brachial plexus located?
A
C5-T1, innervates structures within & around upper limb
16
Q
Do the anterior rami of thoracic nerves form a plexus?
A
no
17
Q
Nerves that form from anterior rami?
A
Intercostal Nerves
18
Q
Where is the lumbar plexus located?
A
L1-L4
19
Q
What is the name of the largest nerve that arises from the lumbar plexus?
A
Obturator nerve
20
Q
Where is the sacral plexus located?
A
L4-S4
21
Q
What is the name of the largest nerve that arises from the sacral plexus?
A
Sciatic Nerve
22
Q
What is the largest and longest nerve in the body?
A
Sciatic Nerve
23
Q
Describe the basic pathway for sensory information
A
- Stimulus is detected by sensory receptors of the PNS ->
- transmitted by PNS sensory neurons to the CNS ->
- Integrated and interpreted by CNS neurons.
24
Q
The conversion of a stimulus into an electrical signal
A
sensory transduction
25
Where does sensory transduction take place?
(nerve ending) Sensory receptor
26
two types of sensory receptors
Encapsulated nerve endings
Free nerve endings
27
How does pressure lead to an action potential in a somatic sensory neuron?
Pressure is applied -> Mechanically gated sodium ion channels open-> Na (sodium) will enter the axoplasm -> temporary depolarization (receptor potential) -> if enough sodium enters to reach threshold = voltage-gated sodium ion channels open
28
What is adaptation?
Different receptors respond differently to different stimuli with different speed, intensity and duration
29
will stop sending a signal even though the stimulus is still present
rapidly adaptive receptors
30
Which type of receptors continue to send a signal?
Slowly adapting receptors
31
What is the name for receptors that detect stimuli originating outside the body?
Exteroceptors
32
Exteroceptors detect
texture, temperature, color, chemical odors in air, level of light
33
What is the name for receptors that detect stimuli originating inside the body?
Interceptors
34
Interceptors detect
blood pressure, stretch of an organ (skeletal muscle or urinary bladder), concentration of certain chemicals in body fluids, body temperature
35
Based on the type of the stimuli detected, name five categories of receptors.
Mechanoreceptors
Thermoreceptors
Chemoreceptors
Photoreceptors
Nociceptor
36
What are proprioceptors?
Detects motion of position of a body or limb as to where it is
37
Most sensory neurons are what type of neuron?
Pseudounipolar
38
Where are the cell bodies of sensory neurons located?
posterior root ganglion
39
What is the peripheral process of a sensory neuron?
Long axon, sensory receptor and peripheral process ends near the neuron’s cell body
40
What is the central process of a sensory neuron?
- Exits the cell body and travels through the posterior root of the spinal cord to end the posterior horn
41
What two factors determine the speed of transmission of axons?
Diameter of the axon & thickness of myelin sheath
42
Is proprioceptive information transmitted quickly or slowly?
quickly
43
Is temperature information transmitted quickly or slowly?
slowly
44
Is pain information transmitted quickly or slowly?
slowly
45
Which area contains more sensory neurons, the fingertips or the forearm?
fingertips
46
Which has a larger sensory field, sensory neurons on the fingertip or on the forearm?
Forearm
47
Describe how you would measure the two-point discrimination threshold.
Two stimuli are placed closely together on the skin, stimuli are then moved apart until the subject can feel two distinct points
48
A dermatome is a segment of skin determined by the
spinal nerve that serves it
49
What is referred pain?
Pain that originates in an organ and is perceived as cutaneous pain
50
why does referred pain happen
Visceral sensation travels along the same pathways as the somatic sensations
51
What are the two layers of the retina?
Outer pigmented epithelium & inner layer with photoreceptors
52
two types of receptors
rods & cons
53
What cells synapse with the photoreceptors? What types of cells are these?
Horizontal cells -> Bipolar cells
54
What cells are next in the pathway? What do their axons form?
Amacrine cells, retinal ganglion dendrites
55
What do cones detect?
color
56
In what type of light do cones function best?
bright lights
57
What area has a high concentration of cones?
fovea centralis
58
what area of the retina lacks cones
edge of the retina
59
what type of vision occurs due to the retina edge lacking cones
high acuity vision
60
What do rods detect?
Light
61
In what type of light do rods function best
low intensity/dim light
62
What part of the retina lacks rods?
fovea centralis
63
due to the fovea centralis lacking rods what vision is caused
peripheral vision
64
What are the basic parts of a rod & cone?
1. Synaptic terminals: the most anterior portion that contact bipolar cells
2. Cell bodies with nuclei
3. Inner segments that contain mitochondria and the typical cellular organelles
4. Outer segments that are the side closer to the pigmented layer
65
What is found in the outer segment?
Flattened discs that absorb light, formed from parts of the plasma membrane
66
What pigment is found in the disc membrane of a rod?
Rhodopsin
67
What are the two components of rhodopsin?
Opsin and retinal
68
How many types of cone pigments are there?
3
69
how can an entire range of colors be perceived?
react slightly overlap in wavelengths
70
What causes color-blindness?
Person lacking a functional gene for one of more cone pigments
71
What is the most common form of color-blindness
Red/green
72
Why is colorblindness more common in males?
Red/green cone pigment is located on the x chromosome
73
In terms of sending signals, how is the visual system fundamentally different than the other special senses?
Special senses are off until turned on
74
In terms of sending signals, how is the visual system similar to the other special senses?
Visual system is on (in the dark when photoreceptors are depolarized) UNTIL turned off (when light hyper-polarizes the photoreceptor and it stops releasing neurotransmitters)
75
How does the number of photoreceptors compare to the number of ganglion cells?
There are 105 million receptors but 1 million retinal ganglion cells –
76
Why is vision so sharp in the fovea?
a ganglion cell receives input from only a single photoreceptor
77
Why is peripheral vision less detailed?
The retinal ganglion cannot determine exactly which one of the photoceptors has been stimulated, so the brain does not receive previse visual info
78
What is a visual field?
The area one can observe with one or both eyes when focusing on a central point
79
What is the optic chiasm?
x-shaped structure formed by meeting of the optic nerves at the midline
80
What occurs at the optic chiasma?
where some of the axons of the optic nerve cross to the other side of the brain
81
What are optic tracts?
Axons that leave the optic chiasma
82
.What are optic radiations?
Axons of the lateral geniculate neurons grouped together
83
Where do the axons of the optic radiations typically terminate?
Primary visual cortex
84
What is the consensual pupillary response
When both pupils constrict
85
if both pupils do not constrict it means ___
Damage, optic nerve, or brainstem damage
86
What is stereoscopic vision?
Depth perception
87
What are the three regions of the ear?
Outer, middle, inner ear
88
Elastic cartilage covered with skin and fleshly lobule
- Funnels sound waves into external auditory canal
auricle
89
Funnels sounds waves toward the tympanic membrane
External auditory canal
90
“eardrum” epithelium and connective tissues that separates the outer ear from the middle ear
Tympanic membrane
91
secrete (ear wax) which lubricates & waterproofs the external auditory canal and tympanic membrane as well as traps debris and sweeps it out of the auditory canal
Ceruminous glands & cerumen
92
What substance fills the middle ear?
Air-filled chamber in temporal bone lined with mucous membrane
93
What structure connects to the middle ear?
Pharyngotympanic tube (auditory tube)
94
What part of the throat does it connect to?
Nasopharynx (throat posterior to the nasal cavity)
95
What causes your ears to “pop”?
air pressure in the external auditory canal changes relative to the middle ear which cause tympanic membrane to stretch and bulge inward or outward
96
how does yawning or swallowing cause ears to pop
- Yawning or swallowing opens the pharyngotympanic tube and equalizes pressure in the middle and outer ears
97
What are the three auditory ossicles?
malleus incus and stapes
98
what structure do the auditory ossicles connect to?
connected by synovial joints and form a bridge that extends from the middle ear to the inner ear.
99
function of auditory ossicles
Malleus is connected to the cone-shaped tympanic membrane and the stapes is attached to an oval membrane in the medial wall called the oval window. The ossicles amplify and convert sound waves in. the air into fluid movement
100
what are the two tiny muscles in the ear
tensor tympani muscle
stapedius muscle
101
Tensor tympani muscle function
pulls and tenses the tympanic membrane
102
Stapedius muscle function
reduces movement of the ossicles as a unit
103
What are the three regions of the inner ear? What is the basic function of each?
Vestibule and Semicircular Canals: detect head movement and position
104
What is a labyrinth?
Network of winding passages
105
mazelike series of tunnels
Bony labyrinth
106
lines the inner walls of the body labyrinth
Membranous labyrinth
107
What is endolymph and where is it found?
Fluid with higher concentration of potassium ions than sodium ions
Found within the membranous labyrinth
108
What is perilymph and where is it found?
Between the bony labyrinth and membranous labyrinth and has a higher concertation of sodium ions than potassium ions
109
What is the vestibule?
Houses two portions of the membranous labyrinth
110
What structures are found in the vestibule? (
Utricle and saccule
111
What is the (utricle and saccules) basic function?
Chambers contain receptor cells that detect head tilting and linear movement
112
What are the semicircular ducts?
Detect rotational movement of the head in any plane (anterior, posterior, and lateral)
113
How are the three ducts oriented to each other? What is the benefit of this?
Oriented at right angles to one another
- Detect rotational movement of the head in any plane (anterior, posterior, and lateral)
114
Swollen bulb at the base of each duct which contains receptor cells in contact with neurons
ampulla
115
opening of the cochlea
cochlear duct
116
structure connecting to the cochlear duct
saccule
117
What are the three ducts in the cochlea? What type of fluid is in each?
Scala vestibuli: perilymph
Scala tympani: perilymph
Cochlear duct (scala media): endolymph
118
What are the membranes that separate the ducts in the cochlea?
Cochlear duct and scala vestibuli: vestibular epithelium
Cochlear duct and scala tympani: basilar membrane
119
Which membrane supports the organ of hearing?
Basilar membrane
120
term for the organ that supports the organ of hearing
Spiral organ (organ of Corti)
121
What nerve is formed from the axons extending from the organ of hearing?
Vestibulocochlear nerve (cochlear nerve) and then form the spiral ganglion
