Psychophysiology Lecture #2 Flashcards
1
Q
Midbrain subdivision:
A
Mesencephalon
2
Q
Tactum
A
“Roof”
- Principle structures are the:
1. Superior Colliculi
2. Inferior Colliculi
3
Q
Superior Colliculi (Tactum)
A
visual reflexes/object tracking (orienting)
4
Q
Inferior Colliculi (Tactum)
A
auditory system in ear
5
Q
Tegmentum
A
“Covering”
- Wraps around the cerebral aqueduct (connects 3rd and 4th ventricles)
Principle Structures are:
1. Periaqueductal Gray Matter (PAG)
2. Raphe (red) Nucleus
3. Substantia Nigra (black)
6
Q
Periaqueductal Gray Matter (PAG)-Tegmentum
A
Pain modulation (endogenous and exogenous opioids act here)
7
Q
Raphe (red) Nucleus-Tegmentum
A
- Coordination of sensorimotor information.
- Synthesizes serotonin.
- SSRIs are believed to largely impact the raphe nuclei.
8
Q
Substantia Nigra (black)-Tegmentum
A
Key role in dopamine production.
9
Q
Corticospinal Tract
A
Carry movement related information from the cerebral cortex to the spinal cord.
10
Q
Hindbrain subdivisions:
A
Metencephalon and Myelencephalon
11
Q
Metencephalon
A
“Afterbrain”
- Pons and Cerebellum
12
Q
Cerebellum
A
Attaches to pons by cerebellar peduncles.
- Posture, balance, fine motor movement, motor learning, proprioception.
13
Q
Pons
A
“Bridge”–translates signals between the cerebellum and cerebrum.
- Regulates breathing and arousal.
- Damage = locked in syndrome
14
Q
Medulla Oblongata
A
Part of Myelencephalon.
- Controls basic functions of the autonomic nervous system including:
1. Respiration
2. Cardiac function
3. Vasodilation
4. Reflexes like vomiting, coughing, sneezing, and swallowing.
- Damage or enlargement = respiratory failure, paralysis, loss of sensation.
15
Q
Reticular Formation
A
- Complex network of neurons located in the brain stem.
- Connections to the hypothalamus and thalamus.
- Helps support wakefulness/alertness and filters incoming information.
16
Q
Spinal Cord
A
- Connected to the brain by the brain stem.
- Long bundle of nerve tissues.
- Send motor commands from the brain to the body, send sensory information from the body to the brain and coordinates reflexes.
17
Q
4 Sections of the Spinal Cord
A
- The Cervical Spinal Cord
- The Thoracic Spinal Cord
- The Lumbar-Sacral Spinal Cord
- Cauda Equina (bundle of nerves)
18
Q
Cervical Spinal Cord
A
Sends nerves to the face and neck.
19
Q
Thoracic Spinal Cord
A
Sends nerves to the arms, chest, and abdomen.
20
Q
Lumbar-Sacral Spinal Cord
A
sends nerves to the lower body.
21
Q
A bunch of nerves
A
called cauda equina because they look like a horses’s tail–is at the bottom of the spinal cord.
22
Q
Types of Neurons in the Somatic Nervous System
A
- Sensory Neurons
- Motor Neurons
- Interneurons
23
Q
Sensory Neurons
A
Carry signals from the outer part of the body into the central nervous sytem.
24
Q
Motor Neurons
A
Carry signals from the central nervous system to the outer parts of you rbody.
25
Interneurons
Connects various neurons within the brain and spinal cord.
26
Somatic Nervous system is made up of...
1. Spinal Nerves
2. Cranial Nerves
27
Spinal Nerves
Mixed nerves that carry sensory information into and motor commands out of the spinal cord.
- Nerves leave the vertebral column and travel to the muscles or sensory receptor they innervate.
28
Afferent Axons
Part of Spinal Nerves
- Bring information inwards, towards CNS.
29
Efferent Axons
Part of Spinal Nerves
- Send information outward
30
Cranial Nerves
They are the nerve fibers that carry information into and out of the brain stem.
31
Dermatome
Areas of skin on the body that rely on specific nerve connections on your spine.
32
Myotome
Group of muscles innervated by a single spinal nerve.
33
How many pairs of cranial nerves are attached to the ventral surface of the brain?
12
34
Vagus Nerve
Regulates the functions of organs in the thoracic and abdominal cavities.
- Longest cranial nerve.
- Helps body exit "fight or flight"
35
What 2 systems does the autonomic nervous system separate into?
1. Sympathetic Division
2. Parasympathetic Division
36
Sympathetic Division
"Fight, Flight, Freeze, Fawn"
- Controls functions that accompany arousal and expenditure of energy.
- Coordinates responses to a stressor.
37
What is the Sympathetic Division also known as?
Thoracolumbar System
38
Parasympathetic Division
"Rest and Digest"
- Involved with increases in body's supply of stored energy.
- Coordinates rest and relax responses after the body has been stressed.
- Vagus Nerve responsible for calming following a stressful situation.
39
What is the parasympathetic division also known as?
Craniosacral System
40
Neurons
most basic information--processing and information--transmitting element of the nervous system.
41
4 Main Structures of Neurons
1. Cell bodies (Soma)
2. Dendrites
3. Axons
4. Terminal Buttons
42
Multipolar Neurons
Most common, one axon to multiple trunks.
43
Bipolar Neurons
Interneurons, one axon and one dendritic tree, soma in middle of axon.
44
Unipolar Neurons
One stalk, usually sensory.
45
Soma
Contains the nucleus, shape varies in different kinds of neurons. AKA Cell Body
46
Dendrites
Branches to the soma of a neuron; receives information transmitted across synapse.
47
Axons
Carries information from cell body to terminal buttons/axon terminal.
48
Axon Hillock
Gate keeper of whether an action potential is strong enough.
49
Myelin Sheath
Surrounds axons and insulates them.
- Produced by oligodendrocytes.
- Decrease = Demyelinating Disease (multiple sclerosis, AIDP)
50
Terminal Buttons/Axon Terminals
- Buds at the end of a branch of axon; forms synapses with another neuron.
- Secrete chemicals called neurotransmitters.
51
Synapse
- Points of contact between neurons where information is passed from one neuron to the next.
- Form between axons and dendrites.
52
What do synapses consist of?
1. Presynaptic Neuron
2. Synaptic Cleft
3. Post Synaptic Neuron
53
Glial Cells
"Glue"
- Provide nutrients to neurons
54
What are the 3 main types of glial cells?
1. Microglia
2. Astrocytes
3. Oligodendrocytes
55
Microglia
Smallest, cleaning up dead cells and protecting brain from microorganisms/toxins.
- Damage/Toxins = microglial cells produce inflammatory mediators to call other cells to the injury --> promote and perpetuate the inflammatory response --> can worsen neurodegeneration (keeping area inflammed)
56
Astocytes
Star shaped, neuron "glue"--holds them together, engulf debris, provide nourishment via transfer of fuel--neurons use a lot of energy but cannot store it.
- Provide electric insulation for unmyelinated neurons.
57
Oligodendrocytes
Produces myelin in the form of a tube by wrapping itself around the axon, forms sheath in segments.
58
Blood Brain Barrier (BBB)
Selectively permeable.
- Blocks all molecules except those with lipid soluble.
59
Area Postrema
Weakest region in BBB (vomiting); has an additional barrier.
60
Chemotherapy and BBB
Chemo increases inflammatory cytokine production which weakens blood brain barrier therefore increasing crossing.
61
New name for chemobrain
Cancer Related Cognitive Impairment
62
Diffusion
Movement of molecules from region of high concentration to low to achieve equilibrium.
63
Electrostatic Pressure
Force exerted by attraction or repulsion to move ion from place to place.
64
Electrolytes
Substances that break into 2 parts with opposing electrical charges.
65
Cations
positive (sodium Na+ and potassium K+)
66
Anions
negative (Chloride CI-)
67
Sodium Potassium Pump
Protein molecules embedded in the membrane.
- Works to keep the ion concentration stable even as ions cross the membrane at rest.
- Continuously pushes Na+ out of the axon = maintains resting potential.
68
Resting/Membrane Potential
A resting neuron's voltage across its membrane.
- Resting potential is determined by concentration gradients of ions across the membrane and by membrane permeability to each type of ion.
69
Action Potential
Rapid bursts of depolarization followed by hyper-polarization.
- Occurs because of diffusion and electrostatic pressure.
70
Depolarization
Reduction of membrane potential (less negative on inside)
- Decrease in electrical charge = decrease in membrane potential.
71
Threshold of Excitation
Set point to produce an action potential = .55mV
72
Hyperpolarization
Increase in membrane potential.
73
Conduction of Action Potential
- Remains constant in size--all or none law.
- Normally one-way traffic from soma end to boutons.
- Refractory period.
- Strength is based on rate of firing--rate law.
74
Saltatory Conduction
In myelinated fibers, depolarization and repolarization processes occur from one node of ranvier to the next instead of the entire area of the membrane.
--> economic and speedy.
75
Synaptic Transmission
Primary means by which neurons communicate across synapse.
76
Synaptic Cleft
22mm wide space between pre and post synaptic membrane.
77
Creation of Action Potential in Next Cell
- Neurotransmitter exerts effects by attaching to binding sites/receptors.
- Binding open neurotransmitter-dependent ion channels.
- Opening of channels = generates electrical impulse.
- Opening propagates pre-synaptic signal = creates a post-synaptic potential.
78
Types of Postsynaptic Potentials
1. Excitatory (EPSP)
2. Inhibitory (IPSP)
79
Excitatory (EPSP)
sodium channel opened, depolarizing.
80
Inhibitory (IPSP)
Potassium channel opened, hyper polarizing.
81
Termination of Postsynaptic Potentials
1. Reuptake
2. Enzymatic Deactivation/Degradation
82
Reuptake
an extremely rapid removal of a neurotransmitter from the synaptic cleft by the terminal button.
83
Enzymatic Deacativation/Degradation
Accomplished by enzyme that destroys molecules of the neurotransmitter.
