Unit 2: Biology Flashcards
Identify key research contributions of scientists in the area of heredity and environment. Charles Darwin?
Evolution thru “natural selection” (the weaker die out - inherited/adaptive traits better enabling survival/reproduction in an environ. will exceed other trait variations/be passed down) explained the Origin of Species
Predict how traits and behavior can be selected for their adaptive value.
favorable traits and behavior will be passed on, while undesirable traits will die off
our genes predispose us to act in ways that enhance their chances of surviving/ spreading, this motive underlies all our behavior.
Discuss the effect of the endocrine system on behavior.
glands secrete hormones (chemical messengers) -> thru bloodstream effects diff tissues + the brain & body development
Hormones based syst. influences our interests (sex, food, agression), maturity moods, feelings, and behavior
Pituitary gland (master gland): most influential gland, under hypothalamus’ influence, regulates growth & controls other glands (influence brain & behavior) -ex: pituatary triggers sex gland to release sex hormones
Adrenal glands, secretes hormones (epinephrine & norepinephrine) that help arouse body during stress, hormones increase heart rate, blood pressure, & blood sugar + fight-or-flight response to energize body, hormones & feelings linger after emergency
Central nervous system
(brain and spinal cord): body’s decision maker
Peripheral nervous system
(PNS - sensory & motor neurons that connect the CNS to rest of body, gathers info
Autonomic (w/ in PNS)
(controls self-regulated action on internal organ muscles & glands (ex: heart, influences heartbeat, usually operates on its own, another ex: digestion))
Sympathetic (arousing & uses energy)
Parasympathetic (calms & conserves energy )
Somatic (w/ in PNS)
(enables voluntary control of skeletal muscles)
Sensory Input &
Motor Output
Sensory Input
carries incoming messages from tissues/sensory receptors inwards (afferent)
Motor Output
(controls skeletal muscles) - carry messages outward (efferent)) from brain/spinal cord to muscles & glands
All-or-none response
a neuron’s reaction to either firing (w/ a full-strength response) or not firing, speed does not change
Refractory period
in neural impulses, brief resting pause that occurs after a neuron has fired; subsequent action potentials cannot occur until axon returns to resting state
Threshold
level of stimulation required to trigger a neural impulse, the brain+ all nervous system operate w/ neurons that receive & send electrochemical signals to communicate
resting potential
positive ions outside, negative ions inside
action potential
a neural impulse; brief electrical charge that travels down axon
sodium potassium pumps
allows positive ions and negative ions to get back to their original positions (resting potential)
The Nervous system
body’s speedy electrochemical communication network, consists of all nerve cells of peripheral & CNS
The Limbic system
neural syst (includes hypothalamus, amygdala, & hippocampus) located below cerebral hemispheres; associated w/ emotion & drives
between brain’s older parts & newest brain areas, hypothalamus controls nearby pituitary gland (from endocrine syst)
Reflex
simple, automatic response to a sensory stimulus(ex: knee-jerk response)
Neurons have 5 parts
Cell Body/Soma, Dendrites, Axon, Myelin Sheath, Axon terminal branches
Cell Body/Soma
Contains a nucleus, cell’s life support center
Dendrites
(listen)
Bushy, Branch like extensions that RECEIVE/unite electrical messages from other neurons/cells, conducts impulses toward cell body
Axon
(speak) Neuron extension that passes messages thru its branches to other neurons or to muscles/glands
Myelin Sheath
Layer of fatty tissue, wraps around axon in sections of some neurons, speeds up message transmission (neural impulses hop from one node to the next),
protect nerve fiber from damage, insulating sheath, speeds up the neural message
Axon terminal branches
Tips at the end of the axon, containing terminal buttons which hols synaptic vesicles that store neurotransmitters, forms junctions w/ other cells, sends signals to other neuron
Synapse (not apart of neuron)
junction between axon tip of the sending neuron & the dendrite or cell body of the receiving neuron
Identify the basic process of transmission of a signal between two neurons.
STEP 1- Neurons receive signals (chemical, light, pressure, heat) through the dendrites (connected to CELL BODY*receive messages from cells)
STEP 2- THRESHOLD is reached (excitatory signals outnumber inhibitory by minimum amount)
STEP 3-Neuron fires action potential in “all or none” response
STEP 4- DEPOLARIZATION occurs: gates open and positive sodium ions rush in, changing negative charged axon sections in a domino effect
STEP 5- Action potential (electrical charge) travels down axon to axon terminals
STEP 6- Axon terminals release neurotransmitters (chemical messengers) into synapse (space between neurons) where they combine with receptor sites on the next neuron
Reuptake mechanisms
Excess neurotransmitters are reabsorbed by the sending neuron
Agonist
molecule that increases a neurotransmitter’s action
May increase production/release of neurotransmitters/block reuptake in synapse
Some might be similar enough to neurotransmitter to bind to its receptor & mimic its excitatory/inhibitory effects
Antagonist:
molecule that inhibits/blocks a neurotransmitter’s action by blocking production/release
Can occupy/block receptor site but can NOT stimulate receptor
Hindbrain
lowest brain segment, regulates basic body functions and consists of: cerebellum, medulla, pons, and reticular formation
Cerebellum
the “little brain” at the rear of the brainstem; sensory input, coordinating voluntary movement & balance, & supports nonverbal learning & memory
Brainstem - 3 parts
oldest part & central core of brain. Begins where spinal cord swells as it enters the skull; responsible for automatic survival functions
Medulla, Pons, Reticular Formation:
Medulla
the base of the brainstem, controls heartbeat & breathing
Pons
helps coordinate movement & control sleep
Reticular Formation:
helps control arousal
Midbrain
middle brain segment, involved w/ motor control, vision, hearing, arousal, sleep, temperature regulation, & transmission of sensory information
Forebrain - 5 parts
highest brain segment, consists of: thalamus, hypothalamus, hippocampus, amygdala, and cerebrum
Cerebrum:
Thalamus
Limbic System
Amygdala:
Hippocampus:
Hypothalamus:
Thalamus
(sensory control center, directs messages to sensory receive areas in cortex & transmits replies to cerebellum & medulla)
Cerebrum
The NEWEST & largest part of the human brain; contains the cerebral cortex.
Amygdala
linked to emotion
Hippocampus
linked to conscious memory
hypothalamus
controls maintenance functions such as eating, helps govern endocrine syst; linked to emotion & reward!!
Basal Ganglia
controls movement, balance, implicit memory, and a little bit of emotion.
Frontal lobes
ront of brain; speaking, muscle movements. Making plans/judgements (motor cortex)
Parietal lobes
at top of brain;receives sensory input for touch & body position (sensory cortex)
Occipital lobes
at back of brain; portion of cerebral cortex lying at the back of head; includes areas that receive info from visual fields(visual cortex)
Temporal lobes:
at both sides of brain; auditory areas receiving info from opposite ears (auditory cortex)
Cerebral cortex
ultimate control & info processing center, interconnected neural cells covering cerebral hemispheres
Motor cortex
area at rear frontal lobes, controls voluntary movements (frontal lobes)
Somatosensory cortex:
(front of parietal lobes), registers/processes touch & movement sensations
Visual cortex
processes visual information (occipital lobes)
Auditory cortex
(temporal lobes), receives info from ears
Association areas:
not involved in primary motor or sensory functions; involved in higher mental functions (learning, remembering, thinking, speaking)
Hemisphere
One of two symmetrical halves (left and right) of the brain, specialized for particular functions.
Left eye & left hand - Right hemisphere
controls the left hand side of body & receives info from left visual field controlling creativity, context and recognition of faces, places and objects
Right eye & right hand - Left hemisphere
controls the right hand side of the body and receives info from the right visual field controlling speech, language & recognition of words, letters/numbers.
If someone sees a cake on their LEFT visual side they will….
say they can’t see anything (bc only right hemisphere can see cake but left hemisphere can’t thus u can’t say u saw a cake)
If someone sees a cake on their RIGHT visual side, they can….
Verbally say they see a cake (left hemisphere)
sometimes when info is given to both sides, the different hemispheres will….
LEFT hemisphere may respond verbally what is seen on the right side
RIGHT hemisphere may respond another way like pointing to a word or touching what is seen on left side
2 answers = opposing & incompatible bc they answer differently
Some ppl have specializations REVERSED
left hemisphere (usually has language)
Right hemisphere (for some ppl language is here)
Typically LEFT-HANDED ***
Lateralization
: The localization of some functions in one of the two hemispheres.
Wernicke’s area
The region in the temporal lobe of a person’s dominant hemisphere that controls speech comprehension.
Broca’s area
The region in the frontal lobe of a person’s dominant hemisphere that controls speech production.
Corpus Callosum
(axon fibers connecting the 2 cerebral hemispheres + carrying messages between them)
Paul Broca
investigated speech disorders; cerebrum region responsible for speech production = named after him (Broca’s area in left frontal lobe) + associated speech disorder (Broca’s aphasia aka expressive aphasia).
Carl Wernicke
Investigated speech disorders, cerebrum region responsible for speech comprehension was named after him (Wernicke’s area in the left temporal lobe), + associated speech disorder (Wernicke’s aphasia, aka receptive aphasia).
Split-brain research
Surgical cutting of the corpus callosum to study the effects of disconnecting the right and left brain hemispheres (cutting the fibers and connecting them) - specifically, the independent functioning of the two hemispheres
involves sending messages to only one side of the brain
demonstrates right and left brain specialization
Electroencephalograph (EEG)
device that monitors/records waves of electric activity w/ in brain; measured by electrodes placed on the scalp
MRI:
Stands for “magnetic resonance imaging”;
ppl sit/lie down in a chamber that uses magnetic fields & radio waves to provide brain structure map (soft tissue/brain anatomy)
MEG (magnetoencephalography)
a head coil records magnetic fields (magnetic activity) from natural electrical currents
Functional MRI (fMRI)
An imaging technique for revealing blood flow & brain activity by comparing successive MRI scans; shows brain function & structure
measures blood flow to regions by comparing continuous MRI scans
PET (positron emission tomography) scan
tracks where a temporarily radioactive form of glucose goes while a person is performing a given task (visual display of brain activity)
CT scan
x-rays of the head generate images that may locate brain damage
Lesioning
tissue destruction; brain lesion - naturally/ experimentally caused destruction of brain tissue
Roger Sperry
research w/ Gazzaniga on split-brain patients, helped to improve understanding of brain lateralization (left/right hemisphere = diff functions)
Neuroplasticity
is the brain’s amazing capacity to change and adapt, refers to brain’s physiological changes that happen bc of our interactions with our environment
factor in recovery from brain injury, basis for much of our cognitive & physical rehabilitation practices, part of rehabilitation is aimed at trying to rebuild connections among the nerve cells — or neurons: this “re-wiring” of the brain can make it possible for a function previously managed by a damaged area to be taken over by another undamaged area
Michael Gazzaniga
conducted split-brain research; understanding of functional lateralization in the brain; how the cerebral hemispheres communicate
William James
Functionalism, psychology should aim to understand how consciousness helps organisms adapt to their environments
Sigmund Freud
Psychoanalysis, therapy approach included dream interpretation, which he believed could reveal insights abt unconscious mind
Acetylcholine(ACh)
A neurotransmitter involved in learning, memory, and muscle action,
w/ Alzheimer’s, ACh producing neurons degenerate
Dopamine:
A neurotransmitter involved in mood, movement, attention, and learning.
Oversupply linked to schizophrenia
undersupply linked to tremors & decreased mobility in Parkinson’s disease
Serotonin:
A neurotransmitter that affects mood, hunger, sleep & arousal
undersupply linked to depression
some drugs used to raise serotonin levels - used to treat depression
Gamma amino butyric acid (GABA):
The primary inhibitory neurotransmitter in the nervous system.
undersupply linked to seizures, tremors, & insomnia
Norepinephrine
A neurotransmitter important in controlling alertness, wakefulness, mood, and attention.
undersupply can depress mood
Glutamate
The main excitatory neurotransmitter in the central nervous system; important for learning and memory.
oversupply can overstimulate brain
producing migraines/seizures
Reuptake inhibitors
Drugs that prevent a neurotransmitter from being reabsorbed by presynaptic axons, causing greater activation of postsynaptic receptors.
Selective serotonin reuptake inhibitors (SSRIs):
Drugs that prevent the reabsorption of serotonin, leading to greater activation of serotonin receptors.
Endorphins
neurotransmitter that influence perception of pain/pleasure
oversupply of opiate drugs can suppress the body’s natural endorphin supply
what did Phineas Gage’s cast study find?
the frontal lobe was directly involved in personality
what did Phineas Gage’s cast study find?
the frontal lobe was directly involved in personality
Left hemisphere
controls the right hand side of the body and receives info from the right visual field controlling speech, language & recognition of words, letters/numbers.
sometimes when info is given to both sides, the different hemispheres will….
LEFT hemisphere may respond verbally what is seen on the right side
RIGHT hemisphere may respond another way like pointing to a word or touching what is seen on left side
2 answers = opposing & incompatible bc they answer differently
