Chapter 2 Flashcards
The Nervous System
the body’s electrochemical communication circuitry.
Characteristics of the Nervous System
Complexity: orchestration of billions of nerve cells (sing, dance, write, talk, seeing, reading..)
Integration: pulls information together
Adaptability: ability to function in a changing world.
(Plasticity): The brain’s special ability for change (the cab driver example)
Electrochemical Transmission: Brain and Nervous System work as an information processing. System powered by electrical impulses and chemical messengers
Afferent Nerves (Input)
Sensory nerves that carry information to the spinal cord. Communicate information from external environment.
(Seeing a sunset and being tired)
Efferent Nerves (Output)
Motor nerves that carry information out of the brain and spinal cord.
Neural Networks
Interconnected groups of nerve cells that integrate sensory input and motor output. Make up most of your brain.
More than 99% of nerves are in the….
Central Nervous System (the brain and spinal cord)
Peripheral Nervous System (PNS)
Connects brain and spinal cord to body, Carries out commands of CNS to execute muscular and glandular activities.
Somatic Nervous System (SNS)
consists of sensory nerves (afferent)
Autonomic Nervous System (ANS)
Involuntary bodily functions
Sympathetic Nervous System
Arouses the body to mobilize it for action
Fight or Flight
Parasympathetic Nervous System
Calms the body down
Stressors
Circumstances or events that threaten individuals and tax their coping abilities
Corticosteroids (Stress)
Powerful stress hormones. Help the brain focus on what needs to be done NOW
Acute Stress
Momentary stress over life experiences. Stress ends after event ends
Chronic Stress
Continuous stress. Even after event ends.
TRUE OR FALSE
Changing how you view stressful events, you can avoid the body’s stress responses
True
2 Types of Nerve Cells
Neurons and Glial
Neuron cells
Transmit information throughout the nervous system
Glial cells
Provide support and nutritional benefits to the nervous system
Dendrite
Tree like fibers projecting from the neuron. They receive information and orient
towards the neuron’s cell body.
Axon
Part of the nucleus that carries information away from cell body to other cells
Myelin Sheath-
a layer of cells, containing fat, that encase and insulate most axons.
Speeds up transmission of nerve pulses. Glial cells provide Myalin.
Nerve impulses
Electrical signals
Most notable ions
Sodium, Potassium
Action Potential
a brief wave of positive electrical charge that sweeps down the Axon
Lasts 1/10,000 of a second
All-or-nothing principal
nce the electrical impulse reaches a certain level of intensity (threashold) it fires, and moves all the way down the Axon without losing intensity
Synaps
Tiny spaces between neurons
Neurotransmitters
transmit or carry information across a gap
Acetylcholine
stimulates firing of neurons for muscles, learning, and memory
Alzheimers have an Acetylcholine deficiency
GABA
(Gama aminobutyric acid)- found in central nervous system
Keeps many neurons from firing
-Precise control of signal
Glumate
learning and memory
Too much can generate migraines, headaches, seizures
Norepinephrine
inhibits the firing of neurons in the central nervous system, but excites the heart, intestinal, and urogenital muscles
Dopamine
controls voluntary movement and affects sleep, mood, attention, learning, and ability to recognise rewards
Related to the personality trait of extraversion
Serotonin
regulation of sleep, mood, attention, and learning
Teams up with Acetylcholine and Norepinephrine
Key to maintaining plasticity (ability to change)
Endorphins
natural opiates that stimulate firing
Shield body from pain and elevate pleasure
Oxytocin
hormone and neurotransmitter that plays a role in the experience of love and social bonding
Stimulated by childbirth and lactation, love at first sight
Mostly a female hormone
3 ways of studying the brain
Brain lesioning, Brain imaging, Electrical recording
Hindbrain
located at the skulls rear, the lowest portion of the brain
Regulates breathing, heart rate, arousal, survival function
Main parts of the Hindbrain
the Medulla, the cerebellum and the pons
Medulla
Begins where the spinal cord enters the skull
Regulates breathing, heart rate and reflex
Cerebellum
above the medulla, and extends from the rear of the hind brain
Consists of two round structures
Controls motor function like leg and arm movements
Pons
bridge in the hind brain that connects the cerebellum and the brain stem
Brain stem
includes much of the hindbrain and the midbrain. DOES NOT INCLUDE THE CEREBELLUM
Connects the spinal cord to the reticular formation
Midbrain
located between the hindbrain and forebrain
Relays information between the brain, eyes, and ears
Reticular formation
a collection of nerves involved in patterns of behavior such as walking, sleeping and turning to attend something like a noise
Forebrain
the brains largest division and most forward part
The limbic system
A network of structures under the cerebral cortex.
Important for memory and emotion
2 principal structures of the limbic system
Amygdala, Hippocampus
Hippocampus
special role in the storage of memories
Extensive damage to the hippocampus results in the inability to remember new memories
Amygdala
almond shaped structure inside the brain towards the base (one on each side)
Involved in the discrimination of objects needed for survival
Food, mates, social rivals
The thalamus
A structure that sits on top of the brain stem, in the central core of the brain.
Serves as a relay station
Sort information and send to the appropriate place
Ex input from the cerebellum, output to a motor area of the cerebral cortex
The basal ganglia
A cluster of neurons that sits below the cerebral cortex and atop the thalamus.
Work with the cerebellum and cerebral cortex to control and coordinate voluntary movement
The hypothalamus
A small structure just below the thalamus.
Monitors eating, drinking, sex
Regulates the bodies internal state
Responsible for the secretion of hormones and neural outputs
Ex- blood near the hypothalamus increases by 1-2 degrees, the hypo increases circulation to the sweat glands to cool off
The cerebral cortex
The outer layer of the brain.
Part of the forebrain, most recent development in the evolutionary scheme
Cortex means ‘Bark’ (tree bark)
Responsible for the most complex functions such as thinking and planning
Neocortex
makes up 80% of the cortex
Size of neocortex strongly related to size of social group where organisms live
Lobes
the cortex is divided into 2 halves called hemispheres, each sphere has 4 lobes
4 lobes of the brain
Occipital, Temporal, Frontal, Parietal
Occipital lobe
located at the back of the head, responds to visual stimuli
Color, shap, and motion
Temporal lobe
part of the cerebral cortex above the ears
Hearing, language, and processing memory
Numerous connections to the limbic system
Damage here results in issues with long term memory
Frontal lobe
cerebral cortex behind forehead
Involved in personality, intelligence, control of voluntary muscles
Prefrontal cortex
at the front of the motor cortex
Involved in higher cognitive function such as planing, reasoning, and self control
Parietal lobe
top and toward the rear of the head
Involved in registering spacial location, attention, and motor control
Ex- judging how far to throw a ball
Somatosensory cortex
located at the front of parietal lobes
processes information about body sensations
Motor cortex
located at the rear of the frontal lobes
Processes information about voluntary movements
Association cortex
Makes of 75% of the cerebral cortex
Regions of the cerebral cortex that integrate sensory and motor information
Highest functions such as thinking and problem solving happen here
Each sensory system has its own association area in the cerebral cortex
Largest portion of the association cortex is located in the frontal lobes
Brochs area
area of the brain that plays in important role in speech.
Wernicks area
damage here causes problems with comprehension
Corpus callum
large bundle of Axon connecting the two hemispheres together
Endocrine system
consists of glands that regulate the activities of certain organs by releasing their chemical products into the blood stream
Glands
organs or tissues in the body that create chemicals that control many bodily functions
What does the brain’s hypothalamus connect
the nervous system with the endocrine system
Hormones
produced by the endocrine system, are chemical messengers
Pituitary gland
pea sized gland just beneath the hypothalamus
Controls growth and regulates other glands (Master gland)
Adrenal glands
located on top of the kidneys
Regulate mood and energy
Secrete adrenalin and norepinephrine
Pancreas
ocated under the stomach
Performs digestive and endocrine functions
Produces insulin
Ovaries and testes
produce sex hormons
Important role in developing sexual characteristics
3 types of brain repair
Collateral sprouting, Substitution of function, Neurogenesis
Collateral sprouting
when axons of healthy neurons adjacent to the damaged cell grow new branches
Substitution of function
the damaged regions function is taken over by another area of the brain
Neurogenesis
new neurons are generated
Brain grafts
implants of health tissue into damaged brains
Stem cells
primitive cells that have the capacity to develop into most types of human cells
The human body contains how many types of cells
220
