Unit 2: Biology

Central Nervous System

brain and spinal cord, body's decision maker

Peripheral Nervous System

the sensory and motor neurons that connect the central nervous system to the rest of the body

Somatic Nervous System (skeletal nervous system)

the division of the peripheral nervous system that controls the body's skeletal muscles

Autonomic Nervous System

the part of the peripheral nervous system that controls the glands and the muscles of the internal organs (such as the heart). Its sympathetic division arouses; its parasympathetic division calms.

Sympathetic Nervous System (ANS)

mobilizing its energy in stressful situations; fight, flight, freeze

Parasympathetic Nervous System (ANS)

calms you down, rest and digest

Sensory Neurons (afferent)

neurons that carry incoming information from the sensory receptors to the brain and spinal cord

Interneurons

neurons within the brain and spinal cord that communicate internally and intervene between the sensory inputs and motor outputs

Motor Neurons (efferent)

Carry outgoing information from the brain and spinal cord to the muscles and glands

Mirror Neurons

frontal lobe neurons fire when performing certain actions or observing another doing so. The brain's mirroring of another's action may enable imitation and empathy

biological psychologists

the scientific study of the links between biological and psychological processes

neuron

individual cells in nervous systems that recieve, integrate, and transmit info

dendrite

parts of a neuron that receives info

Soma (cell body)

contains the nucleus and much of cells normal organs

axon and axon terminals

A long, thin fiber that carries electrical impulses away from the neuron's cell body; The branches at the end of an axon transmit signals to other neurons or target cells.

myelin sheath

Insulating material encasing the fibers some axons; enables vastly greater transmission speed of neural impulses as the impulse hops from one node to the next; damage leads to multiple sclerosis

nodes of ranvier

gaps in the myelin sheath

sodium potassium pumps

pump positive ions out from the inside of the neuron, making them ready for another action potential

Reuptake

neurotransmitters are absorbed back into the neuron after they’ve been released

depolarization

The process during the action potential when Na+ is rushing into the cell causing the interior to become more positive.

action potential

a neural impulse; a brief electrical charge that travels down an axon (+40mV)

threshold

the level of stimulation required to trigger a neural impulse (-55mV)

all-or-nothing response

a neuron's reaction of either firing or not firing; neuron fires when excitatory signal is greater than inhibitory (passing a threshold)

refractory period

a period of inactivity after a neuron has fired

acetylcholine (ACh)

excitatory; enables muscle action, learning, and memory; Excess- muscle cramps, confusion agitation; Lack-memory problems, Alzheimer’s, muscle weakness

dopamine

inhibitory; influences movement, learning, attention, and emotion; Excess-hallucinations, impulsivity, schizophrenia; Lack-Depression, Parkinson’s (tremors, slow movement)

serotonin

inhibitory; Affects mood, hunger, sleep, and arousal; Excess-agitation, rapid heart rate; Lack-Depression, anxiety, sleep issues

norepinephrine

excitatory; helps control alertness and arousal, fight or flight state; Excess-anxiety, high blood pressure, hyperactivity; Lack-depression, low energy, poor focus

GABA

inhibitory; a major inhibitory neurotransmitter; Excess- drowsiness, cognitive impairment; Lack-anxiety, insomnia, seizures, Huntington’s disease

Glutamate

A major excitatory neurotransmitter; involved in memory; Excess-neuron damage, anxiety, hyperactivity; Lack-cognitive decline, learning issues

Endorphins

inhibitory; "morphine within"--natural, opiatelike neurotransmitters linked to pain control and to pleasure; Excess-euphoria, reduced pain sensitivity (addiction); Lack-Depression, increased pain sensitivity

agonists

increase effect of neurotransmitters

antagonists

slow down effects (destroys or blocks connections)

The Brainstem

responsible for automatic survival functions

Pons (Hindbrain)

fibers connecting the brainstem to cerebellum; involved with sleep and arousal (damage=difficulty sleeping, disruption of REM sleep)

Medulla oblongata (brain stem)(hindbrain)

attaches to the spinal cord, controls unconscious functions; circulating blood, breathing, heartbeat, maintaining muscle tone, regulating reflexes

Thalamus (forebrain)

all sensory information (except smell) must pass to get to the cerebral cortex; handles incoming and outgoing signals; damage—>synesthesia (tasting words)

Reticular Formation (midbrain)

central core of the brainstem; contributes to the modulation of muscle reflexes, breathing, and pain perception; sleep and arousal center

Cerebellum (hindbrain)

back of the brainstem; coordination of movement, sense of equilibrium, balance

amygdala (limbic system)(forebrain)

involved in memory and emotion, particularly fear and aggression. (damage-can’t control emotions)

hypothalamus (limbic system)(forebrain)

regulator of biological needs (homeostasis), helps govern the endocrine system via the pituitary gland, and is linked to emotion and reward; controls ANS; biological drives=fighting, fleeing, feeding, mating

hippocampus (limbic system)(forebrain)

responsible for consolidation (conversion of info into durable memory) of memories for factual info (damage=loss of the ability to form new long-term memories)

cerebral cortex

The intricate fabric of interconnected neural cells covering the cerebral hemispheres; the body's ultimate control and information-processing center; higher brain functions (occipital, parietal, temporal, frontal lobe)

glial cells

cells in the nervous system that support, nourish, and protect neurons; ex-schwann cells

frontal lobe (Cerebral Cortex)

planning, reasoning, working memory, paying attention, solving problems, and performing movements; contains broca’s area, motor cortex (Apraxia: inability to coordinate movements)

motor cortex (frontal lobe)

an area at the rear of the frontal lobes that controls voluntary movements

broca's area (frontal lobe)

produces speech

Parietal Lobe (Cerebral Cortex)

handles somatosensory info, receives info about temperature, pressure, texture, and pain; contains somatosensory cortex

Somatosenory Cortex (parietal lobe)

area at the front of the parietal lobes that registers and processes body touch and movement sensations

Wernicke's area (parietal lobe)

language comprehension

Occipital lobe (Cerebral Cortex)

visual processing

Visual Cortex (occipital lobe)

conscious processing of sights

Temporal lobe (Cerebral Cortex)

handles auditory input, processing speech, appreciating music, and recognizing faces (right hemisphere); contains auditory cortex, Wernicke’s area, visual agnosia (objects), prosopagnosia (faces)

Auditory Cortex (temporal lobe)

the area of the temporal lobe responsible for processing sound information

Association Areas

involved in higher mental functions such as learning, remembering, thinking, and speaking

Brain Plasticity

ability of the brain to modify its structure/function following changes within the body or in the external environment

Neurogenesis

the formation of new neurons

Corpus Callosum

the large band of neural fibers connecting the two brain hemispheres and carrying messages between them

Split Brain

a condition resulting from surgery that isolates the brain's two hemispheres by cutting the fibers (mainly those of the corpus callosum) connecting them

Left Hemisphere Functions

sequential processing, analytic thought, logic, language, science and math

Right Hemisphere Functions

Analysis of left visual field, stereognosis (left hand), emotional coloring of language, spatial abilities, rudimentary speech

cognitive neuroscience

the interdisciplinary study of the brain activity linked with cognition (including perception, thinking, memory, and language)

dual-processing

the principle that information is often simultaneously processed on separate conscious and unconscious tracks

thyroid gland

affects metabolism

Parathyroid

help regulate the level of calcium in the blood

adrenal glands

inner part helps trigger the fight or flight response; secretes epinephrine in times of stress

testosterone

Hormone involved in the development of make reproductive tissues and secondary sexual characteristics

estrogen

hormone responsible for reproductive development

pancreas

Regulates the level of sugar in the blood

behavioral genetics

the study of the effects of heredity on behavior

Molecular Genetics

the subfield of biology that studies the molecular structure and function of genes

epigenetics

the study of environmental influences on gene expression that occur without a DNA change

basal ganglia

control movement, proprioception (perceive the location and movements of our body parts), learning, and emotional processing (recognizing facial expressions in others)

Phineas Gage

physical makeup to brain changes who we are as people

Nerves

bundles of neuron fibers (axon) that are routed together in the PNS

Endocrine System

glands that secrete chemicals into the bloodstream that help control bodily functioning (in charge of the adrenaline effect)

Hormones (Endocrine System)

chemical messengers; travel through body much slower than neurotransmitters; regulate many physical and behavioral functions

Pituitary Gland (In Hypothalamus)

releases the hormones in the body

Repolarization

K+ exit the cell

Resting Potential

sodium potassium pump active, -70mV; negative charge inside the neuron which is essential for the neuron to respond to stimuli

Broca’s Aphasia

can’t produce speech, can comprehend

Wernicke’s Aphasia

can’t comprehend language, can produce speech

Hindbrain

pons, medulla oblongata, cerebellum

Forebrain

Cerebral cortex, limbic system, basal ganglia

midbrain

contains an area integrating sensory processes (vision and hearing), dopamine center of the brain

Limbic System (forebrain)

behavioral and emotional responses; associated with emotion and motivation; under cerebral cortex, above brainstem

Case Study H.M.

a patient under Dr. William Scoville who believed that removing H.M.'s hippocampus would alleviate his epileptic seizures. While the surgery was successful, it led to H.M. suffering from anterograde amnesia, in which he could no longer form or keep new memories.

EEG

Electroencephalograph; measures brain waves/electrical activity; seen a lot in sleep studies; measures brain activity

CT/CAT Scan-Computed Tomography

uses x-rays to create a 3 dimensional image; nice view of soft tissue as well as dense bone structure

PET Scan-Positron Emission Tomography

radioactive glucose to see functioning of the brain or where is activity occuring in the brain

MRI-Magnetic Resonance Imaging

magnets/radio waves to see structure of the soft tissue

fMRI-Functional Magnetic Resonance Imaging

measures brain activity by detecting associated changes in blood flow

TMS-Transcranial Magnetic Stimulation

Magnets are used to alter electrical signals in the brain