Week 2 Flashcards
1
Q
Central Nervous System
A
Brain and Spinal Cord
2
Q
Peripheral Nervous System
A
Cranial nerves, ganglia outside CNS, spinal nerves
3
Q
Two Types of Sensory Input
A
External (sensory) and Internal (visceral)
4
Q
Where input goes, motor output leaves
A
Central nervous system: Brain and Spinal Cord.
Integration occurs
5
Q
Two Types of Motor Output
A
Somatic Nervous System
Autonomic Nervous System
6
Q
Somatic Nervous System Acts on
A
Skeletal Muscles
7
Q
Autonomic Nervous System Acts on
A
Sympathetic and parasympathetic system (as well as enteric nervous system in digestive tract)
8
Q
Pathway from CNS to effector organ
A
CNS –preganglionic fiber–> autonomic ganglion (Preganglionic neurotransmitter) –postganglionic fiber–> Varicosity (Postganglionic neurotransmitter) –> Effector Organ
9
Q
Sympathetic and Parasympathetic Preganglionic neurotransmitter and Receptor
A
Acetylcholine, All Nicotinic Receptors
10
Q
Sympathetic Postganglionic Neurotransmitter
A
Norepinephrine/Epinephrine
11
Q
Sympathetic Effector Organ Receptors
A
Adrenergic Receptors (a1, a2, B1, B2, B3)
12
Q
Parasympathetic Postganglionic Neurotransmitter
A
Acetylcholine
13
Q
Parasympathetic Effector Organ Receptors
A
Muscarinic Receptors (M1, M2, M3, M4, M5)
14
Q
General Response of Parasympathetic and Sympathetic
A
Para: Rest and Digest
Sym : Fight or Flight
15
Q
Parasympathetic and Sympathetic: Pupils
A
Para: Constrict
Sym: Dilate
16
Q
Parasympathetic and Sympathetic: Saliva
A
Para: Stimulate
Sym: Inhibit
17
Q
Parasympathetic and Sympathetic: Heartbeat
A
Para: Slow (Vagus)
Sym: Increase
18
Q
Heartbeat Responses
A
Stimulate Vagus: slows
Stimulate Sympathetic nerves: Increase
Cut Sympathetic: Slows
Cut Sympathetic and Parasympathetic: Increase
19
Q
Which autonomic system has more basal activity on the heart
A
Parasympathetic – when both nerves cut, heart rate increases rather than remains unchanged
20
Q
Parasympathetic and Sympathetic: Airways
A
Para: Constrict
Sym: Relax
21
Q
Parasympathetic and Sympathetic: Stomach and Intestine Activity
A
Para: Stimulate
Sym: Inhibit
22
Q
Parasympathetic and Sympathetic: Glucose Release (Liver)
A
Sym: Stimulate
23
Q
Parasympathetic and Sympathetic: Gall bladder
A
Para: Stimulate
Syn: Inhibit
24
Q
Parasympathetic and Sympathetic: Bladder
A
Para: contract (voiding)
Sym: Inhibit
25
Parasympathetic and Sympathetic: Genitals
Para: Erection
Sym: Ejaculation
26
Sympathetic Spinal Nerves
T1-T12
27
Sympathetic Splanchnic Nerves
L1, L2
28
Parasympathetic Cranial Nerves
IX, Vii, III, X
29
Parasympathetic Spinal Nerves
S1-S4
30
Grey Matter
Cell bodies and dendrites
Cerebrum (outside-corex)
31
White Matter
Axons with myelin
Inside and in tracts
32
Ventricles
In middle of white matter, hollow spaces in brain
33
Brainstem
Composed of Midbrain, Pons, and Medulla
Control of cardiovascular, respiration, digestion
34
Cerebellum
Balance, skilled movement
35
Hypothalamus
Temperature, Thirst, Hunger, Endocrine
36
Thalamus
Sensory Relay, Emotion, Arousal
37
Basal Nuclei
Motor control, addiction, habits
38
Cerebral cortex
Sensory, motor, association, thinking, etc.
39
Protection of the CNS
- Bony structures (cranium (skull) encases brain, Vertebral column surrounds spinal cord)
- Cerebrospinal Fluid (CSF) in ventricles formed by selective transport fluids
- Blood-brain barrier - tight junctions between capillary endothelial cells
40
Cerebral Spinal Fluid
Made by tissue that lines the ventricles (hollow spaces) in the brain. It flows in and around the brain and spinal cord to help cushion them from injury and provide nutrients.
41
Blood-Brain Barrier
-Tight junction in capillary wall
-Astrocyte processes
-carrier-mediated transport
-lipid soluble substances can get through?
42
Most capillaries
Possess water-lined pore
43
Brain highly dependent on
Constant blood supply
- brain cannot produce ATP in absence of oxygen
-Brain uses only glucose (and ketone bodies during starvation) for fuel (small amount of glycogen stored in astrocytes)
- brain damage results if brain is deprived of oxygen for more than a few minutes (stroke)
44
Four lobes of cerebral corex
occipital, temporal, parietal, frontal
45
Occipital lobe
Back of brain- contains visual association area (vision)
46
Temporal lobe
middle of brain- auditory association area
(hearing, smell)
47
Parietal lobe
Near back of brain on top- contains somatosensory cortex and somatosensory association area (body sensory, touch, taste, speech, reading)
48
Frontal lobe
Front of brain- contains frontal association area and motor cortex (motor activity, speech, memory, planning)
49
Hearing hotspot
Middle of brain - auditory cortex in temporal lobe
50
Seeing words hotspot
Back of brain - visual cortex in occipital lobe
51
Speaking words hotspot
Middle top of brain- motor cortex in frontal lobe
52
Generating words hotspot
Front of brain- broca's area in frontal lobe
53
Central sulcus
Split down middle of brain between primary motor cortex and somatosensory cortex
54
Hommunculus
Visual representation of what parts of the brain correspond to each body part (sensory humunculus similar to motor humunculus)
55
Four distinct structures of the brain
Brainstem, Diencephalon, Cerebellum, Cerebrum
56
Medulla
In Brainstem. Autonomic center for regulating heart, lungs, and digestive system
57
Hypothalamus
In Diencephalon. Temperature, hormones, hunger, thirst, sexual behaviors
58
Thee parts of cerebellum
Vestibulocerebellum, Spinocerebellum, Cerebrocerebellum
59
Vestibulocerebellum
Bottom and top (closest to brainstem) - Maintenance of balance, control of eye movements
60
Spinocerebellum
Top (middle) - Regulation of muscle tone, coordination of skilled voluntary movement
61
Cerebrocerebellum
Bottom- Planing and initiation of voluntary activity, storage of procedural memories
62
Hypothalamus
- Integrating center for homeostatic functions (body temp, thirst and urine output, food intake)
- Controls anterior pituitary hormone secretion
- Produces posterior pituitary hormones (Stimulates uterine contraction and milk ejection)
63
Pathway for coordinated movement
frontal lobe plans --> premotor cortex prepares for movement --> primary motor cortex activates movement pathways --> cerebellum receives input from premotor cortex, primary motor cortex and sensory input from parietal lobe SS cortex and cordinates --> coordinated movement comes from premotor and primary motor cortex
64
Saltatory Conduction
Occurs along myelinated axon. Action potential jumps between nodes of ranvier and increases speed of conduction
65
Axons synapse on
- Other neurons
- Muscle cells (skeletal, cardiac, smooth)
- Glands
66
Neuromuscular junction
Occurs between motor neuron and skeletal muscle
1. action potential reaches presynaptic terminal
2. open voltage-gated Ca2+ channels, causing an influx into the motor neuron
3. Acetylcholine released
4. Acetylcholine diffuses across synaptic cleft
5. ACH binds to ACH receptors on post-synaptic membrane and opens channels (ligand-gated sodium channels)
6. Acetylcholine broken down by acetylcholinsterase
67
Synaptic cleft
Space between presynaptic terminal in motor neuron and postsynaptic membrane (skeletal muscle) in which acetylcholine diffuses across
68
Botulism
Blocks ACH release at neuromuscular junction
69
Cobratoxin
Blocks ACH receptors at neuromuscular junction on ligand-gated sodium channels in postsynaptic membrane
70
Curare
Blocks ACH receptors at neuromuscular junction on ligand-gated sodium channels in postsynaptic membrane
71
Nerve gas (sarin)
Blocks acetylcholinesterase (harmful at neuromuscular junction)
72
Black Widow Toxin
Makes pores in motor neuron membrane at neuromuscular junction
73
Acetylcholine Action and Location
Excitatory to skeletal muscles; excitatory or inhibitory at neurons
Central NS, Peripheral NS, Neuromuscular junction
74
ACH can cause 2 different effects
This is due to two different receptors that bind ACH
75
Muscarine
ACH receptor that slows heartbeat
Inhibited by atropine
76
Nicotine
ACH receptor that causes muscle contraction
Inhibited by curare
77
Norepinephrine Action and Location
Excitatory or Inhibitory*
Central NS, Peripheral NS
78
Glutamate Action and Location
Excitatory*
Central NS
79
GABA Action and Location
Inhibitory*
Central NS
80
Met-enkephalin Action and Location
Inhibitory
Central NS
81
Integration of responses within the nervous system can be done by
Different neurotransmitters released by multiple presynaptic neurons causing varied responses in postsynaptic neuron
82
How do action potentials cause diversity of actions
- Frequency of action potentials
- A neuron may go to different locations and alter function in multiple other neurons
- Multiple neurotransmitters in different neurons (although, single neuron, single neurotransmitter)
- A single neurotransmitter can bind to different receptors
- Multitude of responses (IPSP, EPSP) than can alter the membrane potential of a neuron
83
Invertebrate evolution of nervous system involves
Increasing cephalization (concentration of sense organs, nervous control, etc., at the anterior end of the body, forming a head and brain)
84
Vertebrate evolution of nervous system involves
Increase in body weight corresponds to increase in brain size
85
Evolutionary trend of brain
Expand, more complex
Although, some of the primitive regions such as the brainstem are similar
86
Number of neurons in sensory receptors
1x
87
Number of neurons involved in integration in CNS
200,000x
88
Number of neurons in effector organs (motor system)
10x
89
Internal sensory pathways
Blood chemistry, pressure, temperature
Nerves from many internal organs (referred pain)
Input generally goes to medulla and other primitive areas of the brain
90
Baroreceptors
Monitor blood pressure - provide data on blood pressure to medulla
Carotid artery baroreceptor
Aortic baroreceptor
91
Carotid arteries
Deliver blood to brain (both sides of neck)
92
Baroreceptors report to
Medulla oblongata (vasomotor center and cardioinhibitory center)
Carotid artery baroreceptor connects via glossopharyngeal nerve
Aortic baroreceptor connects via vagus nerve
93
Medulla oblongata acts on
Heart via vagus nerve
Blood vessels via sympathetic neuron
94
Changes in action potentials in neurons from carotid baroreceptors during differing blood pressures
Carotid sinus nerve impulses increase in frequency with increased blood pressure and impulses decrease in frequency with decreased blood pressure
95
Cardiovascular center
- In medulla
- regulates blood pressure by feedback circuit to heart and blood vessels
- Sends output to sympathetic neurons to release NE on heart and release epinephrine from Adrenal (increases heart rate and stroke volume -> increases cardiac output and therefore blood pressure; Constricts specific arterioles --> increases resistance and therefore blood pressure)
- Sends output to parasympathetic neurons to release ACH on heart: decreases heart rate and atrial contractility which decreases blood pressure
96
The sympathetic and parasympathetic nervous system acts on
Smooth muscle
Cardiac muscle
Exocrine muscle
Some endocrine glands
97
Stimuli in digestive tract acts on
Enteric nervous system, which then acts only on digestive organs
98
Afferent division
The sensory (afferent) division carries sensory signals by way of afferent nerve fibers from receptors in the central nervous system (CNS)
99
Efferent division
The efferent or motor division transmits impulses from the CNS out to the peripheral organs to cause an effect or action.
100
Autonomic nervous system regulates
Visceral activities (circulation, digestion, thermoregulation, pupil size,...)
Most visceral organs are innervated by both sympathetic and parasympathetic nerve fibers (dual innervation)
Two divisions exert opposite effects
101
Sympathetic system
Preparation for strenuous physical activity in emergency situations
102
Parasympathetic system
General housekeeping activities in relaxed situations
103
Parasympathetic postganlionic fibers release
ACH (cholinergic fibers)
104
Sympathetic postganglionic fibers release
norepinephrine (NE) (adrenergic fibers)
105
Varicosities
Terminal branches of postganglionic fibers have
varicosities for diffuse release of neurotransmitters
106
Adrenal medulla
Modified sympathetic ganglion which releases NE and epinephrine into the blood
107
Which division of the autonomic nervous system has longer preganglionic fibers
Parasympathetic
108
Cholinergic nicotinic receptors
- On postganglionic cell bodies in all autonomic ganglia
- Open nonspecific cation channels when ACh binds
- More Na enters than K leaves, resulting in depolarization
109
Cholinergic muscarinic receptors
- On effector cells of parasympathetic systemn
- Five subtypes linked to G proteins that activate second messenger systems when ACh binds
110
5 dfferent types of muscarinic receptors
M1, M2, M3, M4, M5
The muscarinic agonists cause receptor activation; the antagonists produce receptor blockade
111
Thoracolumbar sympathetic nerves*
The sympathetic nervous system originates in the thoracolumbar region of the spinal cord. This system is responsible for stimulating fight-or-flight responses in the body, which heighten senses, mobilize energy, and temporarily pause physiological processes like digestion and voiding
112
Adrenergic receptors
On effector cells of sympathetic system
Epinephrine or NE binding coupled to G proteins
113
Types of Adrenergic receptors
a1, a2, B1, B2, B3
114
a1 receptor
bind to NE >> E, excitatory response, smooth
muscle of some blood vessels, vasoconstriction (GI tract, kidney)
115
α2 receptors
bind to NE > E, inhibitory response
116
β1 receptors
bind equally to epinephrine and NE, excitatory
response – heart, increase heart rate & heart contractility
117
β2 receptors
bind to epinephrine, inhibitory response – decrease
motility of GI tract, bronchodilation bronchioles of lungs
118
β3 receptors
binds epinephrine and norepinephrine, stimulatory
response - fat cells, lipolysis
119
Types of internal sensory input
Baroreceptors
Chemoreceptors
120
Types of external sensory input
Visual
Touch
Hearing
Smell
