Week 4/Brain + Biology Flashcards
Central Nervous System (CNS)
-Brain and spinal cord
-What is encased in bone
The brain is the commans center and the spinal cord is the pathway for messages
Peripheral Nervous System (PNS)
Network of nerves connecting the CNS to the body’s organs and muscles
what does the nervous system do?
transmits signals between the brain and the rest of the body, including internal organs.
What does the Peripheral nervous system include?
Somatic and Autonomic system
Autonomic Nercvous system
Heart muscle, smooth muscle, and glands. Involuntary muscle
Somatic Nervous system
Voluntary Skeletal Muscles
What does the Autonomic Nervous System include?
Parasympathetic and sympathetic division
Parasympathetic division
rest and digest
sympathetic division
active and alert
Basic components of a neuron
Dendrites, Cell body, axon, and terminal buttons
Dendrites
receive incoming signals
Axon
extended fiber of a neuron through which nerve impulses travel from the soma to axon terminals and terminal buttons
Terminal buttons
bulblike structure that have a chemical substance responsible for passing signal to next neuron
Synapse
where chemical communication occurs
Neurons do not touch each other, they communicate by sending chemicals into the synapse (i.e., tiny gap between terminal buttons of sending neuron and dendrites of receiving neuron)
Resting Neuron- Resting Membrane potential
theelectricalchargeinsidetheneuro
isslightlymorenegativethanthe
electricalchargeoutside
Phase one of firing
When aneuronreceiveschemicalsignalsfromnearbyneuronsthroughitsdendrites, thesechemicalsignalsimpactlocalionchannels,and influence thepolarization
(+/-charge) oftheneuron.
Excitatory
decrease negative charge inside cell and thus increase likelihood of neuron firing
depoloraize
Inhibitory
increase negative change inside cell and thus decrease likelihood of neuron firing
Hyperpolarize
what happens after signals are recieved and the decrease negative chahrge in the cell occurs
If the excitatory inputs outnumber the inhibitory ones by enough, then the positive charge of the cell reaches a threshold and an action potential is generated
Action potential
-55mv threshold
The action potential is an electrical ripple that travels down axon.
When the neuron fires positive ions rush (i.e., sodium ions) into neuron.
from - to +
What happens after the action potential?
Immediately after positive ions stopped from entering cell and positive ions rush out of cell, causing membrane potential to be negative once again.
Finally channels close and at this point membrane is slightly more negative than resting potential, called relative refractory period
What happens after the refractory potential?
Then balance of positive and negative ions restored to resting potential
Neurotransmitters
Neurotransmitters are chemical messengers that transmit signals between nerve cells (neurons) in the brain and throughout the body
Action potential in the neurons
Pre-synaptic neuron-axon terminal connects to the post-synaptic neuron of the dendrite spine.
Phineas Gage
Damage to the frontal lobe. He survived, but Left frontal lobe damage started to exhibit personality changes
Until recently with more advances in technology much of what we know about the brain is from brain damage
Localization assumption:
psychological functions are localized in specific and distinct brain regions.
big assumptions
Brainstem
housesthenervesthatcontrolthemostbasicfunctionsofsurvival,suchasheartrate,breathing,swallowing.
spinal cord
sends motor commands from the brain to the body, send sensory information from the body to the brain, and coordinate reflexes.
Midbrain
- Nerve pathway of the cerebral hemispheres; contains auditory and visual reflex centers.
acting as a sort of relay station for auditory and visual information.
Pons
– “Bridge” where fibers cross (horizontally) across brain, and connects to the cerebellum. Sleep.
Medulla
Connects spinal cord and brain. Controls breathing, blood pressure, heart rate, and some reflexes (coughing, gagging, swallowing, and vomiting).
Basic life support
Reticular formation
projects up into cerebral cortex and affects alertness and involved in inducing and terminating different stages of sleep
Cerebellum
Coordinates voluntary muscle movements, balance, posture.
does not produce them but it smooths them out
Limbic system
above brainstem and lying under the cerebral cortex . Important for emotion and motivation
Hypothalamus
-Motivated behavior or the 4 “F’s”: Fighting, Fleeing, Feeding, and Romance
-Hormone regulation
-Survival and reproduction
Thalamus
-Receives sensory information for vision and touch.
-Organizes and routes information to the appropriate cortical areas.
Amygdala
-Motivation and emotion, aggression, and emotional memory
-Controls responses to emotionally salient situations and stimuli
Hippocampus
-Stores new memories by interacting with temporal lobe
-Interacts with amygdala to make emotional memories.
-Important for storing new memories
Basal ganglia
Crucial for planning and producing movement. Receive input from cerebral cortex & send to motor centers of brain stem
Cerebral cortex
outter layer of the cerebral hemispheres (the wrinkly part). Complex mental activity
Occipital
dedicated entirely to vision
Temporal
hearing, memory, language (Wernicke’s area) , smell
Parietal
-Body sensation (somatosensory cortex) – touch, pressure, temperature, pain
-Fine sensation – judgment of texture, weight, size, shape
sensations
-Spatial awareness
Wernicke region
what: language comprehension
contains motor neurons involved in the comprehension of speech. Word salad, random words dont make sense. Impared comprehension speech is clear.
- Temporal lobe
Frontal
-Motor control (motor cortex)
-“Higher” cognition (planning, decision making, problem solving, selective attention)
-Personality
-Language (Broca’s Area)Damage cannot produce words. Routine language not here ( counting cursing)
Brain plasticity
Brain plasticity is a property of the human brain that allows it to change in response to experiences or injuries. As age increases, brain plasticity decreases due to the various influences the brain has already undergoes throughout life.
Brocas
WHAT: Broca’s area is responsible for speech production, including the articulation of words, grammar, and the motor control needed to produce speech.
- difficulty producing speech, which can be slow and labored ( comprehension remains intact)
○Primary sensory cortex
processing sensory information and providing us with the ability to perceive and respond to our environment
-Pariental lobe
primary motor cortex function
voluntary muscle movement
frontal lobe
Steps from sensation to perception
1.Signal Occurs
2.Sensory receptors detect
3. Transduction ( Physical properties of stimuli translated into neural impulses for brain to process)
4. Thalamus (Sensory information pre-liminary processing in thalamus (except smell)
5.Cerebral cortex (Thalamus relays information to region in cerebral cortex associated with sense processing (e.g., occipital lobe for vision).
6. Perception ( Perception processing begins in cerebral cortex)
Brain plasticity
refers to the brain’s ability to reorganize itself by forming new neural connections in response to learning, experience, or injury
Perception is actively constructed and goal directed
○ Inattentional blindness
○ Change blindness
