-
Neurotransmitters
- Brain
- chemicals that are housed
- in the axon terminals
-
Junction
between the axon and the dendrite
Synapse
-
Synaptic cleft
The small gap at this junction
-
The Central Nervous System
–comprised of the brain and spinal cord
- –Often referred to as the command
- center
-
Peripheral Nervous System
- •The system of neurons in the
- periphery, outside the brain and spinal cord, make up the peripheral nervous
- system (e.g.. neurons going to the arms, legs, internal organs, and other body
- parts)
- •Further broken down into the
- Somatic (SNS) and Autonomic nervous systems (ANS)
-
Somatic Nervous System
- –The somatic system involves neurons in
- the remaining periphery of the body.
-
•Autonomic Nervous System
- –Autonomic system involves neurons going
- to parts of the body that are considered to be automatic in their function. For
- example, we don’t have to remind our intestines to work, our hearts to beat, or
- our lungs to take air in and out.
- •The ANS is further broken down into the sympathetic
- division and
- the parasympathetic
- division.
-
Sympathetic Divisions
- The
- sympathetic system activates when our autonomic system needs to be excited.
- •The extra blood flow and oxygen to the
- muscles prepare the body to protect itself and allow us to either escape from
- the danger or fight to overcome the danger (flight-or-fight reaction).
-
Parasympathetic Division
- •what
- keeps the body calm and allows the heart rate, blood pressure, and respiration
- to function at a resting state.
-
Brainstem
- •The oldest part of the brain and is
- responsible for automatic survival processes such as arousal and consciousness.
- •brainstem also plays an important role in
- attention.
- •All information from the body passes
- through the brainstem on its way to the brain
-
Structures of the Brainstem
–Medulla
–Pons
–Reticular formation
-
Medulla
- •controls such vital automatic functions
- as heartbeat, breathing, and blood pressure.
-
Pons
•Survival functions controlled are sleep, arousal, and cardiac reflexes.
-
Reticular Formation
- -a bundle of nerves that is responsible for arousal and regulating the sleep–wake
- cycle
-
Cerebellum
-regulates the body’s movement and balance. It is also involved in learning processes
-
Thalamus
- •acts as a sensory relay station that
- processes and relays sensory information between the cortex and the brainstem.
-
Limbic system
- •group of body structures responsible for
- emotions, memory, and motivated behaviors.
- –hippocampus, amygdala, and hypothalamus.
-
Hippocampus
- •responsible for the formation of new
- memories, as well as spatial memory and navigation.
-
Amygdala
-almond-shaped mass of nuclei that controls emotional responses such as rage and fear.
-
Hypothalamus
- •located below the thalamus, regulates
- body temperature, circadian rhythm, hunger, and thirst.
- -The
- hypothalamus also plays a role in regulating the release of hormones in the
- pituitary gland
- -Also the brain structure that influences the endocrine system through its control of the pituitary
- gland. The pituitary gland regulates growth and is often referred to as “the master gland” because it secretes hormones that
- regulate other glands.
-
Cerebral Cortex
- •The cerebral cortex contains several
- important divisions, including the sensory/motor cortices and the association
- cortex.
-
Cerebral Cortex Divisions
•Sensory cortex
•Motor cortex
•Association
•Frontal lobe
•Parietal lobe
•Occipital lobe
•Temporal lobe
-
Sensory Cortex
- -responsible
- for processing information in the brain related to the five senses.
-
Association Areas
- -Association areas of
- the cerebral cortex are responsible for higher mental processes including
- thinking, language, learning, and information processing.
- -A popular task involving association areas is completing the crossword puzzles
- found in the daily newspaper
-
Motor Cortex
- -receives information from neurons
- throughout various areas of the body and in turn produces the body’s voluntary
- movements
-
Frontal Lobes
• These functions are are planning, movement, and speech.
-
Parietal lobes
- •The parietal cortex is located in the area at the top of the brain toward the middle.
- •Chief among the functions associated with this cortical region is the processing of tactile sensory information.
-
Occipital Lobe
- •The occipital lobes are located at the
- back of the skull and just below the parietal lobes.
- •Within this region, the brain receives
- and processes basic visual information.
- •The occipital lobes receive, organize,
- and integrate basic characteristics of objects in our visual fields that are
- helpful in our understanding of them, such as color, shape, size, and so on.
-
Temporal lobe
- •Temporal lobes play an integral role in
- the production and processing of language.
- -Damage
- to the left temporal lobe often results in Wernicke’s aphasia (unable
- to understand or comprehend speech)
-
Endocrine System
- –Regulates the release of hormones from
- glands.
- -Once released into the bloodstream, hormones impact changes in various
- body organs, including the brain, as well as in various bodily function
-
Adrenal glands
- -release
- epinephrine and norepinephrine in
- response to autonomic nervous system actions to help the body respond to stress
- or emergencies
- -located
- above the kidneys
-
Thyroid Gland
- -large
- gland in the neck that secretes hormones that regulate the rate of metabolism
-
Parathyroids
- -small glands located in the neck, release
- hormones that regulate calcium levels in the blood and in bones.
-
Pancreas
- -located below the stomach near the small
- intestines
- -regulates blood glucose levels
-
Phrenology
- •phrenologists felt the bumps on an
- individual’s head and used that information to determine the individual’s
- traits and characteristics
-
Lesion
studies
- •parts of animal brains are cut in order
- to determine which functions are affected
-
Split-brain
research
- •Cutting the corpus callosum was
- first used to treat epileptic seizures in those individuals who had severe
- epilepsy
-
Nervous System
- •The nervous system is
- involved in all psychological processes, whether affective, behavioral, or cognitive.
- -Comprised
- of billions of nerve cells called neurons, the brain cells responsible for
- transmitting signals (neural impulses) throughout the body.
-
Neurons
- •Neurons receive signals from sensory receptors in the
- body, process them, and transmit them as neural impulses throughout the nervous
- system and back to the body.
- In
- addition to processing memories, thoughts, and emotions, neurons are
- responsible for regulating life sustaining functions: heartbeat, breathing, and
- body temperature.
-
Major Parts of a Neuron
Cell Body, Axon, Dendrites
-
Cell Body
•contains the nucleus of the neuron
-
Dendrites
- -short,
- busy structures that are connected to the cell body
-
Axon
- •receives messages from the cell body,
- then transmits the signal to axon terminals
- –a fatty substance called myelin. Neural
- impulses of myelinated axons are 10x faster than the impulses of unmyelinated
- axons.
-
Resting
Potential
- –When neurons are not transmitting
- information they are “at rest” and polarized. If the neuron is not stimulated,
- the electrical charge will remain constant at about -70 millivolts (mV).
-
Action Potential
- –When the electrical charge of a neuron
- reverses to become more positive on the inside than the outside (+50 mV), an action
- potential
- occurs.
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