General Psychology-Biology & Behavior

Published by admin on

Two main forms of communication in the nervous system
Neurons travelling through the central nervous system and the peripheral nervous system
Neuron
A specialized nervous cell that allows for communication throughout the body
Dendrites
Receive information from other neurons
Axon Terminal
Transmits a signal
Axon
Nodes of Ranvier
Myelin Sheath
Afferent (Sensory) Neurons
Neurons specialized for receiving information about the environment from the sensory systems and transmitting this information to the brain for further processing
Efferent (Motor) Neurons
Neurons specialized for transmitting information from the CNS to other parts of the body, such as muscles and glands
Interneurons
i. Found in the spinal cord
ii. Act as bridges connecting sensory and motor neurons
The Spinal Cord Reflex
The pain from the burning heat of the candle flame stimulates the afferent nerve fibers, which carry the message up to the interneurons in the middle of the spinal cord. The interneurons then send a message by means of the efferent neurons and tell the hand to jerk away
Facts About Neurons
a. We are born with 100 billion neurons
b. Neurons do not regenerate
c. How does alcohol kill neurons?
i. Long term alcohol abuse → B-Vitamin thiamine deficiency → Wernicke-Korsakoff syndrome → result in loss of neurons in brain
d. Plasticity is the ability for healthy neurons to take over the functions of dead or damaged neurons
Purpose of Glial Cells
To support, nourish and protect neurons; produce myelin that covers axons; cleans up waste products
What is the message of a neuron?
A neural impulse (electricity)
Does a single neuron send a constant message?
No. It must be activated
Is any single neuron constantly charged?
Yes
Resting Potential
-70mV, State in which a neuron is not transmitting a nerve impulse. A neuron in this state has a net negative charge relative to its outside environment, and this state of potential energy prepares it to be activated by an impulse from an adjacent neuron.
Threshold
-55mV, Level of stimulation needed to trigger a neural impulse
Action Potential
30mV , A neural impulse; a brief electrical charge that travels down an axon.
All-or-None Law
The principle that either a neuron is sufficiently stimulated and an action potential occurs or a neuron is not sufficiently stimulated and an action potential does not occur
Refractory Period
the time after a neuron fires or a muscle fiber contracts during which a stimulus will not evoke a response
Dopamine
Primary Roles: Movement, thought processes, Rewarding sensations
Associated Disorders: Parkinson’s Disease, Schizophrenia, Drug addiction
Acetylcholine
Primary Roles: Learning, memory, muscle contraction
Associated Disorders: Alzheimer’s
Serotonin
Primary Roles: Emotional states, sleep
Associated Disorders: Depression
Norepinephrine
Primary Roles: Physical arousal, learning, memory
Associated Disorders: Depression, stress
Endorphins
Primary Roles: Pain perception, positive emotions
Associated Disorders: Opiate addiction
GABA
Primary Roles: Inhibition of brain activity
Associated Disorders: Anxiety disorders
SSRI’s
Selective Serotonin Reuptake Inhibitors are medications that can help reduce symptoms of depression in some people
Somatic Nervous System
The branch of the PNS that includes sensory nerves and motor nerves; gathers information from sensory receptors and controls the skeletal muscles responsible for voluntary movement
Autonomic Nervous System
The branch of the PNS that controls involuntary processes within the body, such as contractions in the digestive tract, and activity of glands
i. Can work with somatic NS to provide voluntary control
Parasympathetic Nervous System
Rest and digest
Reactions: Constrict pupils, stimulates tear glands, inc salivation, constricts bronchi, inc digestive function, allow bladder contraction, dec heart rate
Sympathetic Nervous System
Fight, Flight or Freeze
Reactions: Dec in salivation, inc heart rate, dec digestive function, dilates bronchi, inhibits bladder contraction, pupil dilation and inhibition of tear glands
Pituitary Gland
Endocrine gland attached to the base of the brain that secretes hormones that affect the function of other glands as well as hormones that act directly on physical processes.
The master gland
Thyroid Gland
Regulates the rate of metabolism through the secretion of thyroxin
Adrenal Glands
Involved in responses to stress as well as the regulation of salt balance
Why do we care about neurons in psychology?
Neurons need to be firing in order for us to have behaviors/mental processes (sense information & respond to it)
i. When neurons fire → we feel, respond
Why do we care about hormones in psychology?
When neurons fire and we experience an emotion → our bodies communicate what is needed to respond → urges to perform certain behaviors externally and internally
CT scans
cross sectional images of the brain in many different images
MRI
Using radio frequency waves, the MRI produces cross sectional images of the brain; detects tumors, bleeding, infections, and the size and shape of various brain structures
EEG
Detects electrical energy in the brain and displays information that can be interpreted
PET scans
Uses radioactive glucose; scanner sensitive to radioactivity, detects active areas of the brain, which have absorbed the most sugar
fMRI
Captures changes in brain activity
Hindbrain
bottom of the brain; most protected part; most important part needed for life
Pons
relays messages between the cerebellum and the cortex
Cerebellum
controls balance and maintains muscle coordination
Reticular Formation
selective attention
Medulla Oblongata
Breathing, swallowing, and heart rate
Limbic System
Several brain structures involved in: learning, emotion, memory & motivation
Hypothalamus
Links brain and endocrine system; regulates hunger, thirst, sleep, and sexual behavior
Thalamus
Part of the forebrain that relays information from sensory organs to the cerebral cortex
Amygdala
Influences our motivation, emotional control, fear response, and interpretations of nonverbal emotional expressions
Hippocampus
plays a role in our learning, memory, and ability to compare sensory information to expectations
Cerebral Hemispheres
The two specialized halves of the brain. For example, in right-handed people, the left one is specialized for speech, writing, language, and calculation; the right one is specialized for spatial abilities, visual face recognition, and some aspects of music perception and production.
Forebrain
Cerebral Cortex, Limbic system, Thalamus, basal ganglia, and hypothalamus make up this region of the brain
Corpus Collosum
Collection of nerve fibers that connect the two cerebral hemispheres and allows information to pass from one side to the other
Cerebral Cortex
Receives and processes sensory information and directs information and directs movement. Center for higher order processes such as thinking, planning, and judgment.
Frontal Lobe
Motor function, high order function, planning, reasoning, judgment, impulse control, memory
Temporal Lobe
Organization of sensory input, auditory perception, language and speech production, as well as memory association and formation
Parietal Lobe
Processes sensory information that had to do with taste, temperature, and touch
Occipital Lobe
Receives and processes visual input from the retina
Split-Brain Research
research on hemispheric specialization that studies individuals in whom the corpus callosum has been severed
o The right side of the brain processes globally, and controls emotional expression, spatial perception, recognition of faces, patterns, melodies, and emotions.
o The left hemisphere, the left side of the brain, seems to control language, writing, logical thought, analysis, and mathematical abilities. The left side also processes information sequentially, controls spoken language in most individuals.
Categories: General Psychology