ch. 49 Flashcards
(118 cards)
1
Q
what do all animals have
A
a nervous system
2
Q
cnidarian examples
A
jellyfish, hydras, anemones
3
Q
nervous system of cnidarians
A
- nerve net
- neurons connected to each other in network
- activation of neurons in one area lead to activation of all or most neurons
4
Q
simplest of nervous systems
A
nerve net
5
Q
nervous system of echinoderms
A
- nerve ring around mouth connected to larger radial nerves extending to arms
- mouth and arms operate independently
6
Q
nervous system of planaria
A
- nerve cords extend by length of animal connected by transverse nerves
- collection of neurons in head form cerebral ganglia
- perform basic integration of sensory input and motor output
7
Q
nervous system of annelids
A
- same basic structure as planaria
- more neurons
- ventral nerve cords have ganglia in each segment
- rudimentary brain
8
Q
nervous system of simple mollusks
A
- similar to annelids
- pair of anterior ganglia
- paired nerve cords
9
Q
cephalization
A
increasingly complex brain in head
10
Q
brain of drosophila
A
several subdivisions with separate functions
11
Q
brain of advanced mollusks
A
brains with well-developed subdivisions
12
Q
glial cells/glia function
A
nourish, support, and regulate neurons
13
Q
what do embryonic radial glia form
A
tracks along which newly formed neurons migrate
14
Q
astrocytes
A
participate in formation of blood-brain barrier
15
Q
blood-brain barrier
A
restricts entry of most substances into the brain
16
Q
what can radial glial cells and astrocytes both act as
A
stem cells
17
Q
where does the CNS develop from
A
hollow dorsal nerve cord
18
Q
what does the cavity of the nerve cord give rise to
A
narrow central canal of the spinal cord and ventricles of the brain
19
Q
what are the spinal canal and ventricles filled with
A
cerebrospinal fluid
20
Q
cerebrospinal fluid
A
supplies CNS with nutrients and hormones, carries away waste
21
Q
gray matter
A
- neuron cell bodies
- dendrites
- unmyelinated axons
22
Q
white matter
A
- bundles of myelinated axons
23
Q
what does the spinal cord do
A
- convey info to/from brain
- generate basic pattern of locomotion
- produces reflexes independently of the brain
24
Q
reflex
A
body’s automatic response to a stimulus
25
function of PNS
- transmit info to/from CNS
- regulates movement and internal environment
26
afferent neurons in PNS
transmit info to CNS
27
efferent neurons in PNS
transmit information away from CNS
28
divisions of autonomic nervous system
1. sympathetic
2. parasympathetic
3. enteric
29
2 efferent components of CNS
autonomic nervous system and motor system
30
motor system
carries signals to skeletal muscles and can be voluntary
31
autonomic nervous system
regulates smooth and cardiac muscles, generally involuntary
32
enteric nervous system
exerts direct control over the digestive tract, pancreas, and gallbladder
33
sympathetic division
regulates arousal and energy generation (fight/flight)
34
parasympathetic division
antagonistic effects of sympathetic on target organs
- promotes calming and return to rest/digest functions
35
functions of parasympathetic divison
1. constricts eye pupil
2. stimulates salivary gland secretion
3. constricts bronchi in lungs
4. slows heart
5. stimulates activity of stomach/intestines/pancreas
6. stimulates gallbladder
7. promotes emptying of bladder
8. promotes erection of genitalia
36
3 major regions of vertebrate brain
1. forebrain
2. midbrain
3. hindbrain
37
forebrain
- processing of olfactory input, regulation of sleep, learning, and any complex procesing
38
midbrain
coordinates routing of sensory input
- receives and integrates sensory information and sends in to specific regions of the brain
39
hindbrain
controls involuntary activities and coordinates motor activities
40
what does the difference in size of particular brain regions among vertebrates show
relative importance of particular brain function
41
how many neurons and synapses in the human brain
- 100 billion neurons
- 100 trillion connections
42
anterior neural tube
gives rise to the forebrain, midbrain, and hindbrain during embryonic development
43
what form the brainstem?
midbrain and part of the hindbrain
44
where is the brainstem
joins with spinal cord at base of brain
45
what does the rest of the hindbrain give rise to
cerebellum
46
what does the forebrain divide into
1. diencephalon
2. telencephalon
47
diencephalon
forms endocrine tissues in brain
48
telencephalon
becomes cerebrum
49
what does the cerebrum control
- skeletal muscle contraction
- center for learning
- emotion
- memory
- perception
50
outer layer of the cerebrum
cerebral cortex
51
function of cerebral cortex
- perception
- voluntary movement
- learning
52
corpus callosum
thick band of axons that enables the right and left cerebral cortices to communicate
53
what does the cerebellum coordinate
- movement
- balance
- learning
- remembering motor skills
54
what does the diencephalon give rise to
1. thalamus
2. hypothalamus
3. epithalamus
55
hypothalamus
control center that includes the body's thermostat and central biological clock
56
brainstem composition
- midbrain
- pons
- medulla oblongata
57
major function of pons and medulla
to transfer information between the PNS and the midbrain/forebrain
58
medulla function (automatic)
- breathing
- heart/blood vessel activity
- swallowing
- vomiting
- digestion
59
what do the brainstem and cerebrum control
arousal and sleep
60
what is sleep for the brain
an active state
61
function of sleep
essential for survival and may play a role in the consolidation of learning and memory
62
reticular formation
network formed mainly of neurons in the midbrain and pons
- controls arousal and sleep
63
function of reticular formation
timing of sleep periods characterized by rapid eye movements and vivid dreams
64
bottlenose dolphins and sleep
- can swim while sleeping
- EEG data suggest that only one side of brain sleeps at a time
65
circadian rhythms
daily cycles of biological activity
- cycles of sleep and wakefulness
66
biological clock
molecular mechanism that directs periodic gene expression and cellular activity
67
what are biological clocks typically synchronized to
light and dark cycles
68
what coordinates circadian rhythms
group of neurons in the hypothalamus called the suprachiasmatic nucleus
- acts as pacemaker
69
what does generation and experience of emotions involve
limbic system:
- amygdala
- hippocampus
- parts of thalamus
70
amygala
mass of nuclei near the base of the cerebrum that is most important to the storage of emotion in the memory
71
PET (positron-emission tomography)
enables display of metabolic activity through injection of radioactive glucose
72
fMRI (functional magnetic resonance imaging)
brain activity detected through changes in local oxygen concentration
73
largest structure in the human brain
cerebrum
74
function of cerebrum
- language
- cognition
- memory
- consciousness
- awareness of our surroundings
75
4 regions/lobes of brain
1. frontal
2. temporal
3. occipital
4. parietal
76
where does cerebral cortex receive input from
sensory organs and somatosensory receptors
77
somatosensory receptors
provide information about touch, pain, pressure, temperature, and the position of muscles and limbs
78
what directs different types of input to distinct locations
thalamus
79
beginnings of somatosensory system
receptors located in the skin, joins, ligaments, muscles, and fascia
80
2 types of somatosensory receptors
1. exteroceptive - dermis
2. proprioceptive - within body
81
where does integrated sensory information pass to
prefrontal cortex, which helps plan actions and movements
82
neuron arrangment in somatosensory cortex and motor cortex
arranged according to the part of the body that generates input or receives commands
83
damage to Broca's area
can understand language but cannot speak
84
damage to Wernicke's area
unable to understand language, but can still speak
85
lateralization
differences in hemisphere function
86
how do 2 hemispheres work together
by communicating through the fiber of the corpus callosum
87
frontal lobe damage results in...
impaired decision making and emotional responses, but leave intellect and memory intact
88
what do the frontal lobes have a substantial effect on
executive functions
89
steps of embryonic development of nervous system
1. regulated gene expression and signal transduction determine where neurons form
2. neurons compete for growth-supporting factors to survive
3. only half the synapses that form survive into adulthood
4. synapse elimination
90
neuronal plasticity
ability of nervous system to be modified after birth
- changes can strengthen/weaken signaling at synapse
91
autism
developmental disorder that involves a disruption in activity-dependent remodeling at synapses
- impaired communication/social interaction
- repetitive behaviors
92
what is essential to the formation of memories
neuronal plasticity
93
where is short-term memory accessed
hippocampus
94
where is long-term memory formed
links in hippocampus replaced by connections in the cerebral cortex
95
when is some consolidation of memory thought to occur?
during sleep
96
disorders of the nervous system
- schizophrenia
- depression
- drug addiction
- Alzheimer's disease
- Parkinson's disease
97
how much of the world's population suffers from schizophrenia
1%
98
symptoms of schizophrenia
- hallucinations
- delusions
99
schizophrenia
- affects neuronal pathways that use dopamine as a neurotransmitter
- Amy also alter glutamate signaling
100
2 broad forms of depressive illness
1. major depressive disorder
2. bipolar disorder
101
major depressive disorder
patients have persistent lack of interest or pleasure in most activities
102
bipolar disorder
manic (high-mood) and depressive (low-mood) phases
103
treatments for depression
drugs that increase the activity of biogenic amines in the brain
104
brain's reward system
rewards motivation with pleasure
105
why are some drugs addictive
increase activity of brain's reward system
106
addictive drugs
cocaine, amphetamine, heroin, alcohol, tobacco
107
what is drug addiction characterized by
compulsive consumption and an inability to control intake
108
what do addictive drugs enhance
activity of dopamine pathway
109
what does drug addiction lead to
long-lasting changes in the reward circuitry that cause a craving for the drug
110
Alzheimer's disease
mental deterioration (dementia) characterized by confusion and memory loss
111
what does incidence of Alzheimer's increase with
age
112
what is Alzheimer's associated with
formation of neurofibrillary tangles and amyloid plaques in the brain
113
is there a cure for Alzheimer's?
no, but some drugs relieve symptoms
114
Parkinson's disease
motor disorder caused by death of dopamine-secreting neurons in the midbrain
115
what is Parkinson's disease characterized by
muscle tremors, flexed posture, shuffling gait
116
cause of Parkinson's disease
no identifiable cause, although one form is known to have a genetic basis
117
118
can Parkinson's disease be cured
no but can be treated
- dopamine-related drug called L-dopa can reduce severity
- potential cure: implantation of dopamine-secreting neurons into the brain
