PSYC 372 GMU Exam 2

Curt Richter

proposed that the body generates its own cycles of activity and inactivity

endogenous circannual rhythm

an internal calendar that prepares a species for annual seasonal changes

circadian rhythm

A physiological cycle of about 24 hours that is present in all eukaryotic organisms and that persists even in the absence of external cues.

Zeitgeber

stimulus that resets the circadian rhythm

Human circadian clock generates a rhythm slightly_________ 24 hours when it has no external cue to set it

longer than

Suprachiasmatic Nucleus (SCN)

the body's way of monitoring the change from day to night.

-Main control center of the circadian rhythms of sleep and temperature

Damage to the SCN

Results in less consistent body rhythms that are no longer synchronized to environmental patterns of light and dark

retinohypothalamic pathway

the route by which retinal ganglion cells send their axons to the suprachiasmatic nuclei.

-Cells respond directly to light and do not require any input from the rods or cones

- Light resets the SCN

Two types of genes responsible for circadian rhythm

PER: Period

TIM: Timelessness

Mutation in Period Gene

PER gene result in odd circadian rhythms or decreased alertness if deprived of a good night's sleep

Melatonin

A hormone manufactured by the pineal gland that produces sleepiness.

Stage 1 sleep

- decline in brain activity;

- Alpha waves are present ;

- EEG show Irregular, jagged, and low voltage waves

Stage 2 sleep

A sleep deeper than that of stage 1, characterized by a slower, more regular wave pattern, along with momentary interruptions of "sleep spindles."

K-complex: a sharp wave associated with temporary inhibition of neuronal firing

Slow wave sleep (Stages 3 and 4)

EEGs reveal large, regular delta waves and sleepers are hard to awaken.

-Slowing of heart rate, breathing rate, and brain activity

paradoxical sleep (REM)

deep sleep in some ways, but light sleep in other ways

Rapid eye movements during sleep

When people fall asleep, they progress through stages 1, 2, 3, and 4 in _______________________.

sequential order.

Reticular formation

part of the midbrain that extends from the medulla to the forebrain and is responsible for arousal

Pontomesencephalon

contributes to cortical arousal

-Stimulation of the pontomesencephalon awakens sleeping individuals and increases alertness in those already awake

Locus coeruleus

is involved in directing attention

Orexin (hormone)

hunger-triggering hormone secreted by hypothalamus

Sleep and the Inhibition of Brain Activity

Functions of the inhibitory neurotransmitter GABA are also important for:

- Decreasing the temperature and metabolic rate

- Decreasing the stimulation of neurons

Sleep can be localized within the brain

sleepwalkers and lucid dreamers

REM is interrupted by ______________, and __________ causes you to reach REM faster

Serotonin; Acetylcholine

PGO waves are associated with

REM sleep

During REM sleep activity is _____________ in the pons and limbic system.

Increased

During REM sleep activity is __________ in the primary visual cortex, the motor cortex, and the dorsolateral prefrontal cortex.

Decreased

Sleep Apnea

inability to breathe while sleeping for a prolonged period of time

Narcolepsy

A sleep disorder characterized by uncontrollable sleep attacks. The sufferer may lapse directly into REM sleep, often at inopportune times.

Periodic Limb Movement Disorder

repeated involuntary movement of the legs and sometimes arms during sleep

REM Behavior Disorder

a sleep disorder in which a person does not lose muscle tone during REM sleep, allowing the person to act out dreams

Night Terrors

Experiences of intense anxiety from which a person awakens screaming in terror

Sleepwalking

walking or carrying out behaviors while asleep

Functions of Sleep

memory consolidation, energy conservation, helps restore bodily functions

Hibernation

Long-term torpor that is an adaptation to winter cold and food scarcity.

Parkinson's Disease

Characterized by muscle tremors, rigidity, slow movements, and difficulty initiating physical and mental activity

Immediate Cause of Parkinson's

Caused by gradual and progressive death of neurons, especially in the substantia nigra

Loss of dopamine leads to less stimulation of the motor cortex and slower onset of movements

Treatment of Parkinson's Disease

The drug L-dopa is the primary treatment for Parkinson's and is a precursor to dopamine that easily crosses the blood-brain barrier

Drugs that directly stimulate dopamine receptors

Implanting electrodes to stimulate areas deep in the brain

Huntington's Disease

Associated with gradual and extensive brain damage especially in the basal ganglia but also in the cerebral cortex

Initial motor symptoms include arm jerks and facial twitches

Readiness potential

is a particular type of activity in the motor cortex that occurs before any type of voluntary movement

we become conscious of the decision to move ________ the process has begun

After

Basal ganglia select a movement to make by ______ to inhibit it

ceasing

Movement as directed by structures of the basal ganglia

(Caudate nucleus) and (putamen) receive input from the cerebral cortex and send output to the (globus pallidus)

Globus pallidus connects to the thalamus, which sends information to the motor areas and the prefrontal cortex

Release of ___________ causes the muscle to contract

acetylcholine

A neuromuscular junction is a

synapse between a motor neuron axon and a muscle fiber

Muscles are composed of

many individual fibers

Antagonistic Muscles

muscle pairs arranged to work against each other to move a joint

flexor muscle

bends a limb at a joint

extensor muscle

straightens a limb at a joint

__________ always excites skeletal muscles to contract

Acetylcholine

Fast-twitch

fibers produce fast contractions but fatigue rapidly

Slow-twitch

fibers produce less vigorous contraction without fatigue

Proprioceptors

receptors that detect the position or movement of a part of the body

Muscle spindles respond to a _________: cause a ___________ of the muscle

stretch; contraction

Golgi tendon organ responds to ___________ in muscle tension

increase

Primary motor cortex (M1) is located in the __________ which is located in the____________.

precentral gyrus; frontal lobe

Axons from the precentral gyrus connect to the _________ and the ________, which generate impulses that control the muscles

brainstem; spinal cord

Posterior parietal cortex

keeps track of the position of the body relative to the world

Premotor cortex

area of the frontal cortex, active during the planning of a movement

Supplementary motor cortex

area of the frontal cortex; active during preparation of a rapid sequence of movements

Mirror Neurons

neurons in the brain that are activated when one observes another individual engage in an action and when one performs a similar action

Messages from the brain must reach the _______ and ________ to control the muscles

medulla; spinal cord

What are the two types of Corticospinal tracts?

Lateral corticospinal tract

Medial corticospinal tract

Medial corticospinal tract

Vestibular nucleus is a brain area that receives information from the vestibular system

Axons extend from one side of the brain to the both sides of the spinal cord

Lateral corticospinal tract

Branches at the brainstem level, crossing over to the opposite side of the brain and spinal cord

Moves the digits and limbs on the opposite side of the body

Corticospinal tracts are paths from the___________ to the __________.

cerebral cortex; spinal cord

Paralysis

temporary or permanent loss of motor control

Paraplegia

paralysis of both legs and the lower part of the body

Quadriplegia

paralysis of all four limbs

Hemiplegia

paralysis of one side of the body

Tabes dorsalis

Late stage syphilis

Impaired sensation in the legs and pelvic region, impaired leg reflexes and walking, loss of bladder and bowel control.

Poliomyelitis

a viral infection of the gray matter of the spinal cord that damages cell bodies of motor neurons.

Resulting in Paralysis

Amyotrophic lateral sclerosis (ALS)

a rapidly progressive neurological disease that attacks the nerve cells responsible for controlling voluntary muscles

What are sound waves?

pressure changes in the atmosphere capable of being detected by auditory organs

What is the amplitude?

The magnitude and direction of displacement. The greater the amplitude, the louder the sound signal.

What is frequency of a sound?

the number of waves that pass a point in a certain amount of time

Timbre

quality of sound

___________ are better at hearing higher frequencies than ____________.

Children; Adults

Alteration of pitch, tone of voice, volume or timbre can convey

Emotion

outer ear

The part of the ear that collects sound waves; consists of the pinna, the ear canal, and the eardrum.

middle ear

the chamber between the eardrum and cochlea containing 3 tiny bones (hammer, anvil, and stirrup) that concentrate the vibrations of the eardrum on the cochlea's oval window

auditory pathway

outer ear (pinna) - ear drum - middle ear bones - oval window - cochlea - cochlear nucleus - superior olive - inferior colliculus - medial geniculate nucleus - auditory cortex

Inner ear

the innermost part of the ear, containing the cochlea, semicircular canals, and vestibular sacs

Oval Window transmits waves through ______________

viscous fluid

Snail shaped organ in ear

cochlea

3 fluid filled chambers of the cochlea

hint: the scala sisters like to watch videos, trailers, on twitter.

1. scala vestibuli

2. scala tympani

3. scala media

The hair cells are auditory receptors that lie between the _________________ and the __________________ of the cochlea.

Basilar membrane; Tectorial membrane

Movement of hair cells

results in excitation of the auditory nerves

place theory of pitch perception

different portions of the basilar membrane are sensitive to sounds of different frequencies

frequency theory of pitch perception

nerve impulses sent to the brain match the frequency of the sound wave

Pitch Theory

Combines both Frequency and place theory

Place theory is to ________ as Frequency theory is to ____________.

high frequencies; low frequencies

Amusia

tone deafness

Perfect pitch

Absolute Pitch

auditory cortex

the area of the temporal lobe responsible for processing sound information

Damage to the subcortical area results in

automatic deafness

Nerve Deafness

Hearing loss created by damage to the cochlea,hair cells or the auditory nerve fibers in the inner ear.

Conductive deafness

middle ear deafness

disease or infection it is often structural.

Tinnitus

ringing in the ears, may be a result of nerve deafness

What does mechanical senses respond to?

Pressure, bending & distortion of receptors

otoliths

small crystals in the fluid-filled vestibular sacs of the inner ear that, when shifted by gravity, stimulate nerve cells that inform the brain of the position of the head