Option Module: Neurobiology and Behavior Flashcards
(77 cards)
1
Q
Neocortex
A
- most advanced part of the brain
- large in intelligent animals- dolphins, primates
- takes up 2/3 of human brain
- develop language, abstract thought, consciousness, imagination
- two hemispheres- left and right
- right side controls left side of body. Left side controls right side of body
- right: concerted with artistic, spatial, musical thoughts
- left- concerned with linear, rational, verbal aspects
- part of the cerebral cortex
2
Q
Embryogenesis
A
development of fertilized egg to fully developed organism
3
Q
3 layers of embryonic tissues
A
- ectoderm- outer layer, becomes brain, nerve, tissue
- mesoderm- middle, becomes skeletal, reproductive, muscle,
- endoderm- inner layer, becomes gut
4
Q
Process of neural tube formation
A
- neural tube will eventually become the brain and spinal cord
5
Q
What is neurulation?
A
the transformation of the neural plate into the neural tube, which marks the beginning of the formation of the central nervous system
- occurs in the 3rd week of embryonic development
6
Q
Explain the process of neurulation.
A
- neural plate forms become elevated and form neural folds
- neural folds fuse together, and form neural tube
- during fusion, cells on crest of neural tube detach, forming the neural crest (forms peripheral nervous system)
- if fusion does not occur by day 27, result is spina bifida
7
Q
When does spina bifida occur?
A
when the neural folds don’t fuse to form neural tube by day 27
8
Q
What does the neural tube hold?
A
neurons of the central nervous system (carry messages)
glial cells- don’t carry messages in brain
9
Q
Explain the process of neurogenesis
A
- differentiation from neuroblast to neurone
- neuroblasts- immature cells that become neurons
10
Q
What is neurogenesis?
A
development of a neuroblast to a neuron
11
Q
What are glial cells?
A
- originate in neural tube
- physical and nutritional support of neuron
- provide scaffolding network where immature neurons and nerve cells can migrate along
- ex Schwann cells, provide insulation
12
Q
Axon Growth
A
- growth cone on tip of axon directs direction of axon growth
- when axon contacts unfavorable surface, it contracts. In favorable surface, it continues to grow
- grow 1 mm/ day
- when neurons reach final location, they make synaptic connections with target cells
- target cells secrete cell adhesion molecule (CAM), which bind to CAM receptors on growth cone of axon. Axon elongates in that direction.
- Target cells can secrete chemotrophic factors into the extracellular environement that growth cone detects. Chemoattractive (stimulate elongation) v Chemorepellent (repel axon)
13
Q
What makes motor neurons different from others?
A
- they extend their axons out of the CNA (brain and spinal chord)
- gives mammal ability to control voluntary muscular movement
14
Q
Explain the topic of multiple synapses.
A
- each neuron will attempt to synapse with adjacent neurons
- if synapses are unused, they gradually retreat
- learning new information– making new connections between axons
- CAM molecule, immunoglobin, helps axons bond with other axons
15
Q
Neural Pruning
A
- removal of simple connections and replacing them with more complex wiring made in adulthood
- eliminating axons that aren’t being used
- improved of brain efficiency
- microglia, type of glial cell, prunes synapses
16
Q
Neural Plasticity
A
- influenced by age, environment, heredity
1. functional- ability of brain to move functions from damaged area to undamaged
2. structural- ability of brain to change physical structure as a result of learning
17
Q
2 types of neural plasticity
A
functional- ex tennis player paralyzed left arm. Eventually arm will work because functions transferred to healthy region of brain
structural- london taxi drivers have larger hippocampus
18
Q
Neural Plasticity during stroke
A
- functional and structural brain reorganization occurs during recovery
- new connections between axons
- neurogenesis
- differentiation of immature glial cells
19
Q
5 things to label in brain diagram
A
- cerebral hemisphere
- hypothalamus
- cerebellum
- Medulla oblongata
- Pituitary gland
20
Q
Function of cerebral hemispheres
A
integrating center for complex functions: learning, memory, emotion, intelligence, motor function
21
Q
Function of hypothalamus
A
maintains homeostasis, controls pituitary gland
monitors and controls: circadian rhythms (daily sleep/wake cycle), homeostasis, appetite and thirst, other bodily urges
22
Q
Function of Cerebellum
A
- 2 hemispheres with a highly folded surface
- coordinates unconscious functions- movement and balance
23
Q
Function of Medulla Oblongata
A
controls automatic and homeostatic activities: swallowing, digestion, vomiting, breathing, heart activity
24
Q
Function of Pituitary Gland
A
controlled by hypothalamus
secrete hormones
25
What is fMRI
- functional magnetic resonance imaging
| - show us active parts of brain by seeing blood flow in the brain
26
What is the corpus callosum?
thick band of axons connecting right and left hemispheres of brain
- white matter
27
Functions of left hemisphere
areas important for forms of communication
28
Functions of right hemisphere
receives and analyzes information comes from all senses
29
PET scanner
- position emission tomography scanner
| - identify areas of brain activated by neurotransmitters and drugs
30
What is a lesion?
area of damage or tissue death causing functions to be impaired
31
Limbic System
- "emotional brain" or "old mammalian brain"
- emotions and memories combine to mark behaviors as positive or negative
- unconscious value judgments made
- role in salience (what grabs your attention), spontaneity, creativity
32
Parts of the Hindbrain
- oldest part of human brain (evolutionary)
| - in charge of primal instincts and basic functions. Instincts of survival, dominance, mating, respiration
33
What symptoms will someone have when they're addicted to a substance?
- want more and more
- spend lots of time and energy getting substance
- withdrawal symptoms
- return to substance when stressed
34
Peripheral nervous system
includes parasympathetic system and sympathetic system
35
Sympathetic system
- important in an emergency
- "flight or fight"- increase heart rate, dilate bronchi and pupils, restrict blood flow to digestive system
- noradrenaline neurotransmitter
- excitatory
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Parasympathetic system
- important in returning to normal
- response is to relax- decrease heart rate, constrict bronchi and pupil, blood flow to digestive system
- acetylcholine neurotransmitter
- inhibitory
37
What is the pupil reflex?
- type of cranial reflex- no connection to spinal chord
38
Brain Death definition and diagnosis
- brain and brainstem have irreversibly lost all neurological function
- movement of extremities- arms or legs
- eye movement-eyes must remain fixed, showing lack of brain- to motor nerve reflex
- corneal reflex- eye doesn't blink when swabbed
- pupil reflex- no constriction when light shone on eyes
- gag reflex- tube down throat to test
- breathing response
- do EEG test- measures brain activity
- do CBF test- measures blood flow
39
What does life support regulate?
- body temperature
- fluid retention
- blood pressure
40
What tests confirm brain death?
EEG and CBF
41
Pupil reflex
- circular muscle contracts and radial muscle relaxed- pupil gets smaller/ parasympathetic
- circular muscle relaxes and radial muscle contract- pupil gets bigger/ sympathetic
42
Parasympathetic control of iris
- optic nerve receives message from retina.
- Photoreceptors synapse with bipolar neurons and ganglion cells
- electrical signals sent to pretectal nucleus of the brainstem
- signal sent to Edinger-Westphal nucleus (axons that run back to the eye)
- oculomotor nerves synapse on ciliary ganglion
- axons of ciliary ganglion stimulate circular muscle to contract
43
Cerebral Cortex
- largest part of mature brain
- left and right hemisphere
- thin layer of grey matter that covers the cerebral hemisphere
- language, visual processing, motor movement, complex thought
- made u of unmyelinated neurones
44
Relationship between right and left cerebral hemisphere
- left CH controls muscle contraction in right side of body and vice versa
45
Neuron metabolism
- glucose is primary energy source
- delivered in blood
- used up rapidly during mental activity
46
Mechanoreceptors
sense mechanical deformation
| - ex pressure receptors detect change in blood pressure in arteries
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Chemoreceptors
- respond to chemical substances
| - chemoreceptors in blood vessels monitor pH changes
48
Thermoreceptors
- respond to change in temperature
| - cold thermoreceptors on skin respond when temperature drops
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Photoreceptors
- respond to light energy, found in eyes
| - rod cells respond to dim light. Cone cells respond to bright light
50
What are bipolar neurones
cells in the retina that carry impulses from a rod or cone cell to the ganglion cell of the optic nerve
51
Rod Cells
- absorb all wavelengths of visible light
- present in retina, none in fovea
- connected in groups to single bipolar neuron
- function well in dim light and are more sensitive to light (scotopic vision)
- achromatic color
52
Cone Cells
- absorb red, blue, green light
- many in fovea
- connected to individual neuron
- less sensitive to light and function well in bright light (photopic vision)
- chromatic color
53
How do we see?
- light rays pass through pupil, focused on retina
- photoreceptors send impulses to bipolar cells then to ganglion cells in optic nerve
- optic nerve sends signal to visual cortex- where it is processed and image is inverted
54
How do we hear?
- the inner ear (malleus, incus, stapes) receive vibrations from the tympanic membrane.
- vibration passed to the fluid in the cochlea
- fluid in the cochlea causes hair cells to vibrate
- when sterocilia on hair cells bend, produces an electrical impulse that is carried to the auditory nerve
- travels to brain
55
Explain blackcaps study
- collected and raised blackcaps- migrate to UK or Spain
- recorded migration
- followed migration patterns of parents
- so it's genetic
56
Innate behavior
- independent of environmental context
- controlled by genes
- inherited
- developed by natural selection
- increases chance of survival and reproduction
57
Learned Behavior
- dependent on environmental context
- not controlled by genes
- not inherited
- developed in response to environmental stimuli
- may/may not increase chance of survival
58
What is taxis?
- movement in response to stimulus
- positive- moving towards light
- negative- moving away from light
- ex- phototaxis, chemotaxis, gravitaxis
59
What is kinesis?
- movement in response to non-directional stimulus
- not moving away or towards
- orthokinesis (changes speed) or klinokinesis (turns constantly)
60
Pain Reflex
- pain receptors receive stimulus and generate nerve impulse in the sensory neurons
- sensory neurons carry impulse toward spinal cord
- sensory neuron axon enters spinal cord and sends chemical message across synapse to relay neuron
- relay neuron synapses with motor neuron
- motor neuron carries impulse to effector (organ that performs the response)
61
Explain Pavlov's experiment
```
UCS- food
UCR- salivation
NS- ringing of bell
After training:
CS- ringing bell
CR- dogs salivating when hearing bell
```
62
Birdsong learning phases
1. Memorization
- born with crude template that is specific to species
- first 100 days- bird will modify inherited template based on songs he's heard
2. Motor phase
- bird practices singing the song
- shapes song to match what he's heard
- sings copy of song heard
63
Cholinergic Synapses
- stimulate skeletal muscle
- Acetylcholyn
- signals cause relaxation- parasympathetic system
- Acetylcholinesterase breaks down Acl in synapse preventing it from being permanently bound to Na+ receptor
64
Adrenergic Synapses
- causes fight/flight response
- sympathetic system
- ex- cocaine and amphetamines
- depolarizes postsynaptic neuron
- Noradrenaline neurotransmitter
65
Some effects of drugs on the brain
- block receptors at post-synaptic membrane
- block release of neurotransmitter
- enhance release of neurotransmitter
- block removal of neurotransmitter
66
LSD effects
- chemically resembles serotonin and binds to serotonin receptors
67
Heroin
- mimics natural opiates and binds to opiate receptors, turning off dopamine inhibition
- dopamine floods synapse, producing immediate feelings of sedation
68
Cocaine
- blocks removal of dopamine from synaptic cleft
| - dopamine binds again and again and overstimulates cell
69
Marijuana
- THC mimics anandamide and binds to cannabinoid receptors
| - dopamine flood synapse
70
Meth
- mimics dopamine and taken into cell by dopamine transporter
- meth enters dopamine vesicles in presynaptic knob, forcing dopamine molecules out
- dopamine leaves cell and is trapped in cleft, binds to receptors, overstimulating cell
71
Alcohol
- interacts with GABA receptors to make them more inhibitory
| - binds to glutamate receptors, preventing excitement of cell
72
Ecstacy
- mimic serotonin and taken up by serotonin receptors
- serotonin transporters work in reverse, remove serotonin from cell
- serotonin trapped in cleft, binds to receptors, overstimulating cell
73
What is addiction and effects?
body develops tolerance and needs more substance to produce same results- desensitivization
- withdrawal: depression, craving state of euphoria
- alcohol withdrawal: seizures, fatal, delirium
74
Ethology v Psychology
Ethology
- study of organisms behavior in natural conditions
- field work
Psychology
- studies behavior in controlled conditions
75
Altruistic Behavior
- results in decrease of fitness of altruist and increase of fitness in close relative
- more closely related, more likely to display
76
Altruistic Behavior Squirrel
- geldings ground squirrel
- if predator approaches, high pitched call alerts the rest
- alarm squirrel more likely to be killed
- if close relatives dead, F doesn't sound alarm
77
Altruistic Behavior Bat
- vampire bat
- die if no food for 2 days in row
- if bat fails to find food, another in cluster (small group) will regurgitate
- ex of reciprocal altruism
- survival for both bats increased
