lab one - eeg/wii NS physiological introduction

electroencephalogram (EEG)

• Recording of electrical (membrane) potential differences between various cortical areas - known as brain waves

• Place electrodes on the scalp that are connected to an apparatus

cortical neurons

• Excitatory postsynaptic potentials

• Inhibitory postsynaptic potentials

alpha waves

subject has eyes closed and are relaxed (8-13 Hz)

beta waves

mentally alert and awake (14-30 Hz)

theta waves

during sleep or children that are awake (4-7 Hz)

delta waves

deep sleep (<4 Hz)

gamma waves

may be associated with higher mental activity (30-50)

consciousness

Encompasses conscious perception of sensations, voluntary initiation and control of movement, and capabilities associated with higher mental processing

1. Involves simultaneous activity of large areas of the cerebral cortex

2. Superimposed with other types of neural activity

3. Holistic and interconnected (information for thought can be claimed from many locations in the cerebrum simultaneously)

syncope

loss of consciousness

sleep types

• Non-rapid eye movement

  • 4 stages

• Rapid eye movement

sleep

partial unconsciousness is known as sleep - a cyclical process that lasts 90 minutes

*what are the stages of sleep on an EEG?

• Stage 1: Beta and alpha activity decreases; theta activity increases

• Stage 2: irregular theta activity; sleep spindles and increase in K complexes

• Stage 3 and 4: increase in delta activity

reflex arc photo on page 281

know it!

1. receptor

structure that receives the stimulus

2. afferent (sensory) neuron

the neuron taking the response TO the CNS

3. integration center (brain or spinal cord)

central point

efferent (motor) neuron

the neuron taking the response from the CNS to the site

effector (structure causing the effect)

if the effector is a skeletal muscle, the reflex is a somatic reflex. if the effector is a gland, smooth muscle, or cardiac muscle, the reflex is called a visceral or autonomic, reflex

chemoreceptors

respond to changes in the chemical environment

barorecepters

respond to changes in pressure (bp)

mechanoreceptors

respond to mechanical stimuli (touch, hearing, or equilibrium)

nociceptors

transmit the sensation of pain

photoreceptors

detect light

proprioreceptors

detect changes in tension (joint tension)

thermoreceptor

detect changes in temperature

left hemisphere role in language

• Broca’s area: speaking language

• Wernicke’s area: understanding language

right hemisphere role in language

Produces body language through gestures and tone of the voice

types of memory - procedural

related to skill memory

types of memory - motor

related to the ability to repeat the same muscle movements

types of memory - emotional

related to sentiments of an event

types of memory - declerative

the memory of facts (words, names, faces, dates)

• short term: limited to 7-8 parts of info

• long term: larger sumes of information

rehearsing and repeating allows you to go from short term to long term memory

what effect does damage have on the brain?

damage to the brain can cause drowsiness, disorientation, inattentiveness, loss of consciousness, and even seizures

seizure

absence-loose consciousness of environment as their expression goes blank for a few seconds

• Torrent of electrical discharges from groups of brain neurons that interrupt normal functioning

• Experience sensory hallucinations before seizure begins

• Absence seizure

• Tonic-clonic seizure: most severe and result in convulsions

psychophysiology

• Branch of science concerned with physiological bases of psychological processes

• Skin conductance or electrodermal response (EDR)

• Skin temperature, heart rate, muscle activity, eye movement, blood pressure and respiratory rate

how certain states of mind affect how the body functions

electrodermal response (EDR)

• Galvanic skin response (GSR) or skin conductance level (SCL)

• Eccrine sweat glands respond to a person’s mental state more than they do to temperature increase

• When filled with fluid, skin resistance decreases and skin conductance increases

frontal lob affect

• Consciousness of what you are doing as well as decision making on tasks or our environment

parietal lobe affect

Integrating sensory information particularly spatial awareness and navigation

occipital lobe

• Deals with vision and our ability to locate objects in the environmental as well as details about those objects

temporal lobe

• Auditory perception and memory acquisition

brain stem

vision-based reflexes

cerebellum

coordination of voluntary movement

attention

• Top-down: goal oriented 

• Bottom-up: reflexive attention to sensory information

distraction

The divided attention of an individual from a particular task onto the source of the distraction

inattentive blindness

• Someone is distracted and becomes “blinded” to sensory information that would likely process without the distraction

• Dangerous during driving

this is from the book from now on

get hype?

what are the two fundamental properties nervous tissue shows?

irritability: potential of a nerve to respond to some kind of stimulus (chemical, mechanical, electrical)

conductivity: movement of a nerve impulse along the length of the neuron

reflex

a motor response to a stimulus without conscious thought (involuntary, predictable responses to stimuli)

what is the structure of a reflex arc?

1. receptor (the structure that receives the stimulation)

2. afferent (sensory) neurons (the neuron taking the stimulus to the CNS)

3. integration center (brain or spinal cord) OR interneuron

4. afferent (motor) neuron (the neuron taking the response from the CNS)

5. effector (the structure causing an effect)

what is it called if the effector is a skeletal muscle?

somatic reflex

what is it called if the effector is a gland, smooth muscle, or cardiac muscle?

visceral, or autonomic, reflex

polysynaptic reflex arc

Involves many neurons with many synapses

monosynaptic reflex arcs

reflex that only involves two neurons, a sensory neuron and a motor neuron, with one synapse between them

what do reflexes depend on to occur?

a stimulus, an environmental cue, a receptor that is sensitive to the stimulus, a sensory neuron, a motor neuron, and an effector

what does the polysynaptic reflex arc have in addition to the required features?

an integration center located between the sensory and motor neuron

what do the integration centers do?

take information to the brain via ascending tracts in the spinal cord

what indicates damage to the nervous system

decreased or exaggerated response

hypoflexic

shows less than average response

hyperflexic

shows a more than average response

hypothyroidism

reflexes are depressed

what kind of reflexes are most commonly used in expirements?

stretch reflexes

• receptors are in the muscle spindle

• stretching the muscle causes an increase in action potentials in the sensory neuron and the subsequent synapse with the motor neuron

• this causes action potentials in the motor neuron and stimulates the muscle, causing contraction of the muscle that is stretched

• patellar reflex

patellar reflex

tests the conduction of the femoral nerve - a monosynaptic reflex arc (one with a sensory neuron directly synapsing with a motor neuron)

triceps brachii reflex

tests the radial nerve - causing a twitch of the tricep muscle

biceps brachii reflex

tests the musculocutaneous nerve - results in bicep twitch

calcaneal tendon reflex

tests the tibial nerve - causes a plantar flexion of the foot

eye reflexes

The autonomic blinking of an eye is important to keep material away from the outer layer of the eye, known as the cornea

extensor plantar response or babinski reflex

the extension of the hallux (big toe) in response to stroking the plantar surface of the foot

• normal in infants under one BUT abnormal in adults (indicates damage to the pyramidal tracts and is important in determining spinal damage)

• in infants, reflex is due to incomplete myelination of some nerve fibers

what should happen with adults when stroking the plantar surface of the foot?

flexor plantar response

*what is the threshold voltage in nerve conduction?

minimum voltage required for nerve conduction

*what is maximum recruitment voltage in nerve conduction?

maximum muscle contraction - obtained when all neurons of a particular nerve are stimulated

which structure receives stimuli from the external environment and relays it to the sensory neuron?

what is another name for an efferent neuron?

motor neuron

define reflex

in what kind of reflex are there just two neurons?

monosynaptic

polysynaptic reflexes have something not found in monosynaptic reflexes, what is it?

integration center

in terms of number of synapses, what kind of reflex is a patellar reflex?

what action occurs with hyperflexic response? hypoflexic response?

how do we classify organs in the body?

• general senses: touch, pain, and pressure that can be felt by many parts of the body

• specific senses: sight, smell, and taste that are perceived only by specific, localized receptors

punctuate distribution

the idea that sense receptors are not uniformly distributed throughout the body but are absent, or few in number, in some parts of the body, while densely clustered in others (i think this means your mouth ears and eyes are all on your head)

what can’t happen without environmental input or stimulus (listed by type or modality)?

perception

what are examples of modality in stimuli?

light, heat, sound, pressure, and specific chemicals

receptors

Receiving units of the body that respond to stimuli - they transform the stimulus to neural signals that are transmitted by sensory nerves and neural tracts to the somatosensory cortex, or other areas of the brain, which interpret the message

what is special about the skin?

the skin has multiple types of receptors (pressure, pain, temperature, and touch)

what two receptors allow for the perception of very light touch stimuli?

meissner corpuscles, in the upper portion of the dermis, and merkel discs, located in the upper dermis and lower epidermis

what receptors in the skin detect deep touch or pressure?

pacinian (lamellated) corpuscles

how do warm and cold receptors work together in the skin?

they equally fire when at a comfortable temp, but when in one extreme, pain receptors are stimulated (naked nerve endings in the dermis that respond to environmental stimuli)

what can you use to determine the relative density of the receptors in the skin?

two-point discrimination test

how are receptors classified?

according to the length of time they can perceive stimulus

tonic receptors

constantly perceive stimuli

phasic receptors

adapt to stimulus

referred pain

perception of pain in one area of the body when the pain is actually somewhere else

an area with a great number of nerve endings is the upper lip. what can you predict about the ability of the upper lip to distinguish two points?

distinguish the functions of Pacinian corpuscles, meisnner corpuscles, and pain receptors in the skin.

what perception is senses when experiencing extreme temperatures?

are there more cold and warm receptors in the skin? what adaptive advantage might there be for an unequal number of receptors of one kind?

Adaptation occurs on some sensory stimulation. why is this important?

why do pain receptors fuction as tonic receptors?

in terms of receptor density, describe why it is difficult to find the same location on the forearm when your eyes are closed

in reference to the sense organs, what is a modality?

what kinds of receptors are sensitive to the following modalities?

light

touch

temperature

sound

smell

what kind of receptor is responsive to extremely hot sensations