Ch 49 Flashcards
What kind of nervous system do Cnidarians have?
Nerve net
Simplest
Neurons connect to each other in a network
What leads to the activation of all or most nuerons in nerve net?
Activation of neurons in one area
What kind of nervous system do echinoderms have?
Nerve Ring
Around the mouth connected to larger radial nerves extending to arms
What operates independently in a starfish
Mouth and arms
What kind of nervous systems do Planaria have? (3)
1) Nerve cords
2) Connected by transverse nerves
3) Collection of neurons in head form cerebral ganglia
What kind of nervous system do annelids have?
Same basic structure as planaria
More neurons
Ventral nerve cords have ganglia in each segment
Rudimentary brain
What kind of nervous system do simple mollusks have?
Similar to annelids
Pair of anterior ganglia
Paired nerve cords
What is the trend to cephalization?
Increasingly complex brain in the head
What kind of brains do drosophila have?
Brains have several subdivision with several functions
What kind of brains do advanced mollusks have?
Brains with well developed subdivisions
What type of glia form tracks along which newly formed neurons migrate?
Embryonic Radial Glia
Which glia participates in the formation of the blood-brain barrier?
Astrocytes
What types of glial cells can act as stem cells? (2)
1) Embryonic radial glial
2) Astrocytes
What develops from the hollow dorsal cord?
CNS
What does the cavity of the nerve cord give rise to?
Narrow central canal of spinal cord and ventricles of the brain
What are the central canal and ventricles filled with?
Cerebrospinal fluid
What does the cerebrospinal fluid do?
Supplies CNS with nutrients and hormones and carries away waste
What is Grey matter made up of? (3)
1) Neuron cell bodies
2) Dendrites
3) Unmyelinated axons
What is White matter made up of? (1)
1) Consist of bundles of myelinated axons
What does the spinal cord do?
1) Conveys info to and from the brain
2) generates basic patterns of locomotion
What produces reflexes independently of the brain
Spinal cord
What does PNS do? (2)
1) transmit info to and from CNS
2) Regulates movement and the internal environment
What transmits info to the CNS
Afferent neurons
What transmit info away from CNS
Efferent Neurons
PNS two efferent components
1) Motor system
2) Autonomic system
What does the Motor system do?
Carries signals to skeletal muscles (usually voluntary)
What does the autonomic nervous system do?
regulates smooth and cardiac muscles (usually involuntary)
describe the Enteric nervous system’s function
Exerts direct controls over the digestive tract, pancreas, and gallbladder
What are the 2 different division of the autonomic nervous system?
1) sympathetic
2) parasympathetic
What does the sympathetic division do?
Regulates arousal and energy generation (flight or fight)
What does the parasympathetic division do?
Has antagonistic effects on target organs and promotes calming and return to rest and digest functions
Three major regions of the brain
1) forebrain
2) midbrain
3) hindbrain
Forebrain functions (4)
1) process olfactory input
2) regulate sleep
3) learning
4) complex processing
Midbrain function
Coordinates routing of sensory input
Hindbrain functions (2)
1) Controls involuntary activities
2) coordinates motor activities
What does size difference of brain regions reflect
the importance
the brain has how many neurons making how many connections?
100 billion which make 100 trillion connections
What give rise to the forebrain, midbrain, and hindbrain
anterior neural tube
What regions of the brain make the brainstem
midbrain and hindbrain
What does the brainstem join to
spinal cord and the base of brain
What region of the brain gives rise to the cerebellum?
hindbrain
What does the forebrain divide into
Diencephelon
Telencephalon
What does the Diencephelon region form
Forms endocrine tissues in the brain (thalamus, hypothalamus, epithalamus)
What does the Telencephalon form
the cerebrum
What does the Cerebrum control? (5)
1) Skeletal muscle contractions
2) Center for learning
3) emotion
4) memory
5) perception
SCEMP
The Cerebral cortex is vital for? (3)
1) Perception
2) voluntary movement
3) learning
What is the corpus callosum?
Thick band of axons enables the right and left cerebral cortices to communicate
What does the cerebellum coordinate
Movement and Balance
helps in learning and remembering motor skills
The diencephalon gives rise to
1) thalamus
2) hypothalamus
3) epithalamus
What is the function of the Hypothalamus? (2)
control center for:
1) body thermostat
2) biological clock
What does the brainstem consist of? (3)
1) Midbrain
2) Pons
3) Medulla Oblongata
What does the midbrain do?
Receives and integrates sensory and sends it specific regions of the brains
Major function of pons and medulla
Transfer information between PNS and midbrain and forebrain
Medulla functions (5)
1) Breathing
2) Heart and blood vessel activity
3) Swallowing
4) Vomiting
5) Digestion
What controls arousal and sleep? (3)
1) Brainstem
2) Cerebrum
3) Reticular formation
What is the reticular formation?
network of neurons formed in the midbrain and pons
What is Sleep? What do you need it for?
Active state for brain
Needed for survival, learning, and memory
What does the Reticular formation control regarding sleep?
Control timing of sleep periods: characterized by REM and vivid dreams
What controls timing of sleep periods?
Neurons of the reticular formation
Sleep intensity and duration is regulated by
Biological clock and regions of forebrain
Dolphin sleep
Only brain half sleeps at a time
Cycles of sleep and wakefulness are examples of
Circadian Rhythms
rhythms that rely on biological clock, a molecular mechanism that directs _______. (2)
1) periodic gene expression
2) cellular activity
In mammals circadian rhythm is coordinated by
Suprachiasmatic nucleus (SCN)
Acts as a pacemaker
Where is the SCN located?
in the hypothalamus
What generates emotions in the brain
1) Amygdala
2) Hippocampus
3) Thalamus
hAt of emotions
What are the structures used for emotion called
Limbic system
Most important structure of emotion in the memory
Amygdala
Mass of nuclei near base of cerebrum
Generating emotion requires interactions with?
Different parts of the brain
Enables a display of metabolic activity through injection of radioactive glucose
Positron emission tomography (PET)
Brain activity is detected through changes in local concentration
Functional magnetic resonance imaging
(fMRI)
Cerebrum (cerebral cortex) is essential for? (5)
1) Language
2) Communication
3) Memory
4) Consciousness
5) Awareness of our surrounding
Four regions of cerebrum
1) Frontal
2) Temporal
3) Occipital
4) Parietal
Where does cerebral cortex receive input from
sensory organs and somatosensory receptors
Somatosensory receptors
Provide information about touch, pain, pressure, temperature and position of muscle
What directs different types of input to distinct locations
Thalamus
What helps plan actions and movement
prefrontal cortex
How are neurons arranged in somatosensory cortex and motor cortex?
According to the part of the body that generates input or receives commands
Patients with damage in _______ in the frontal lobe can understand language but cannot speak
Broca’s area
Damage to ________ causes patients to be unable to understand language, though they can still speak
Wernicke’s area
Left brain contribution
Analysis
Logic
Idea
Facts
Math
Training
Right brain contribution
Creativity
Intuition
Arts
Creation
Feeling
Imagination
The differences in hemisphere function are called
Lateralization
How do the two hemispheres work together by communicating through the fibers of?
Corpus Callosum
What may frontal lobe damage cause
Impair decision making and emotional responses but leave intellect and memory intact
Embryonic development of nervous system (4)
1) regulated gene expression and signal transduction determine where neurons form
2) neurons compete for growth-supporting factors in order to survive
3) Half the synapses that form during embryo development survive into adulthood
4) Final phase, synapse elimination occurs
Ability of the nervous system to be modified after birth
Neuronal plasticity
What do changes in neuron usage cause?
Strengthening or weakening of signaling at a synapse
Developmental disorder involves a disruption in activity remodeling at synapses
Autsim
Children affected with autism display (3)
1) Impaired communication
3) Impaired social interaction
2) Repetitive behavior
What is essential in the formation of new memories?
neuronal plasticity
How is short term memory is accessed
Hippocampus
In Long term memory,
the links in the hippocampus are replaced by connections in the cerebral cortex
How to get better memory
sleep
What contributes to disease of the nervous system
Genetic and environmental factors
Disorders of the nervous system (5)
1) Schizophrenia
2) depression
3) drug addiction
4) alzheimer disease
5) Parkinson’s disease
What are the characteristics of Schizophrenia? (2)
1) Hallucinations
2) delusions
What does schizophrenia affect? (2)
1) Affects neuronal pathways that use dopamine as neurotransmitter
2) Alter glutamate signaling
What are the 2 forms of depression?
1) major depressive disorder
2) bipolar disorder
Major depressive disorder characteristic
lack of interest or pleasure
Bipolar disorder characteristic
1) manic phases (high-mood)
2) depressive phases (low-mood)
Treatment for depression
Include drugs increase the activity of biogenic amines in the brain
The brain rewards _______ with _______
Motivation with pleasure
Why are drugs addictive
Increase brain reward system
affect the dopamine pathway
What is Drug addiction?
Long lasting changes in reward circuitry
What is Alzheimer disease?
Mental deterioration characterized by confusion and memory loss
What does Alzheimers increase with?
Increases with age
What is Alzheiemers associated with?
Associated with formation of neurofibrillary tangles and amyloid plaques in the brain
What is Parkinson’s disease?
Motor disorder caused by death of dopamine secreting neurons in the mid brain
What are the characteristics of Parkinson’s disease?
1) Muscle tremors
2) flexed posture
3) shuffling gait
Parkinsons disease treatment
L dopa
