Chapter 2: Biology & Behavior Flashcards
2 Main Components with the Nervous System
1- Central Nervous System (CNS)
2- Peripheral Nervous System (PNS)
Central Nervous System includes
the brain and the spinal cord
Peripheral Nervous System includes
nerves that connect the CNS to the rest of the body
Sensory neurons
receive information about the environment from the sensory system and convey it to the brain for processing
Motor neurons
carry information from the CNS to move; provide mechanism regulated by the spinal cord and brain
Interneurons
reside in the brain and spinal cord; act as bridges connecting sensory and motor neurons
Types of Neurons
sensory=>interneurons=>motor
What are the 2 functional branches of the PNS?
1- somatic nervous system
2- autonomic nervous system
Somatic Nervous System
includes sensory and motor nerves; controls the skeletal muscles responsible for voluntary movement
Autonomic Nervous System
controls involuntary processes; has 2 divisions that help us respond to and recover from stressful or crises:
1- Sympathetic Nervous System
2- Parasympathetic Nervous System
Sympathetic Nervous System
“fight or flight”
Parasympathetic Nervous System
calm down when danger has passed
Know the structures of the neuron
Dendrite
receives messages from other cells
Axon
carries messages to other cells
Synaptic gap
fluid-filled space between end of axon terminals and surface of the next cell
Soma
responsible for nutrients
Myelin sheath
coats and insulates the axon
Axon terminal
branches at the end of the axon
Action Potential
if the neuron is stimulated by neighboring cells, channels in its membrane begin to open up, starting at the dendrites; an influx of Na+ changes the voltage from -70mV to -55mV (threshold potential); the voltage then rises rapidly, increasing from -55mV to +30mV
Resting Potential
the electrical potential of a neuron “at rest”; concentration of Na+ outside the cell is much greater than the inside; -70mV
Excitatory Signals
if enough sending neurons signal the receiving neuron to pass along the message, their combined signal becomes excitatory and fires
Inhibitory signals
inhibit neuron from releasing a signal through the axon
All-or-None
a neuron either fires or doesn’t
Acetylcholine
involved in the action of muscles, learning, and memory; low levels in the brain are linked to Alzheimer’s disease
Serotonin
regulates mood, sleep and attention; linked to depression and anxiety symptoms
Dopamine
controls voluntary movement, attention, learning, and rewards
Endorphins
natural opiate; shields the body from pain, elevates feelings of pleasure
What structures are involved in the limbic system?
- thalamus
- hypothalamus
- amygdala
- hippocampus
Thalamus
relays sensory information to the appropriate places of the cortex
Hypothalamus
sleep, wake cycle; appetite; sexual behavior
Amygdala
“aggression” and fear
Hippocampus
formation of new memories
Structures of the brainstem/hindbrain
- pons
- medulla
- cerebellum
- midbrain
Pons
sleep, wake cycle
Medulla
life-sustaining processes- breathing, heart beat, digestion
Cerebellum
responsible for muscle coordination and balance; Latin for “little brain”
Cerebral Cortex
muscle coordination/movement
4 lobes of the brain
1- parietal
2- occipital
3- frontal
4- temporal
Parietal lobe
integration of sensory information like touch and temperature
Occipital lobe
processing of visual information
Frontal lobe
higher-level cognitive activities like language, emotions, and decision making
Temporal lobe
hearing and language comprehension
Corpus callosum
the thick band of nerve fibers connecting the right and left cerebral hemispheres; allows the left and right sides of the brain to communicate and work together to process information
Left hemisphere
language
Right hemisphere
sight
What are hormones?
chemical signals that travel throughout the blood
Glutamate
excitatory neurotransmitter; plays a central role in learning and memory; too much= strokes and too little= symptoms of schizophrenia
Norepinephrine
helps prepare the body for stress; regulating arousal and sleep
GABA
inhibitory neurotransmitter; plays a role in controlling sleep and wakefulness
Main organs involved in the endocrine system
- pancreas
- pineal gland
- pituitary gland
- adrenal glands
Pancreas
controls the level of sugar in the blood
Pineal gland
secretes melatonin
Pituitary gland
master gland, secretes human growth hormone and regulates other endocrine glands
Adrenal glands
located on top of each kidney, helps us deal with stress
Microglia cells
defend the brain from infection and inflammation
Astrocyte cells
restore the barrier between the brain and blood and support communication between neurons
Oligodendrocytes and Schwann cells
provide the myelin sheath enveloping the axons of some neurons
