Physio Final Exam

smooth muscles

smooth muscles

control the digestive system and other organs, found in the intestines and other organs, consist of long, thin cells

skeletal muscles/ striated muscles

control the movement of the body in relation to the environment, consists of long cylindrical fibers with stripes

cardiac muscles

heart muscles that have properties of skeletal and smooth muscles, consists of fibers that fuse together at various points

neuromuscular junction

is a synapse between a motor neuron axon and a muscle fiber

acetylcholine

release of _______________ causes the muscle to contract

one

muscle fibers receiver innervation from ___ axon

antagonistic muscles

Moving a leg or arm back and forth requires opposing sets of muscles, called

flexor muscle

one that flexes or raises an appendage (muscle)

extensor muscle

one that extends an appendage or straightens it (muscle)

fast - twitch

fibers produce fast contractions but fatigue rapidly

slow -twitch

fibers produce less vigorous contraction without fatigue

slow - twitch fibers

are aerobic and require oxygen during movement and therefore do not fatigue (nonstrenuous activities utilize______ and intermediate fibers)

fast- twitch fibers

are anaerobic and use reactions that do not require oxygen, resulting in fatigue (behaviors requiring quick movements utilized _____ fiber)

proprioceptors

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

muscle spindles

are proprioceptors parallel to the muscle that respond to a stretch: cause a contradiction of the mucle

stretch reflex

occurs when a muscle proprioceptors detect the stretch and tension of a muscle and send messages to the spinal cord to contract it

Golgi tendon organ

_ another type of proprioceptor that responds to increase in muscle tension
- located in the tendons at the opposite ends of the muscle

Golgi tendon organ

acts as a “brake” against excessively vigorous contraction by sending an impulse to the spinal cord where motor neuron are inhibited

reflexes

involuntary, consistent, and automatic responses to stimuli

ballistic movement

such as a reflex, is executed as a whole: Once initiated, it cannot be altered

central pattern generators

neural mechanisms in the spinal cord that generate rhythmic patterns of motor output.

motor program

A fixed sequence of movements that is either learned or built into the nervous system (ex. yawning)

primary motor cortex

located in the precentral gyrus in the frontal lobe

brainstem and spinal cord

axons from the precentral gyrus connect to the _________ and __________, which generates impulses that control the muscles

medulla and spinal cord

Motor neurons in the ____ and ______ control muscle contractions

primary motor cortex

•active when people intend a movement

Posterior parietal cortex

- keeps track of the position of the body relative to the world
- Damage to this area causes difficulty in coordinating visual stimuli with movement
- Important for planning movement

Premotor cortex

–Active during preparation for movement

–Receives information about a target

–Integrates information about position and posture of the body; organizes the direction of the movement in space

Supplementary motor cortex

–Organizes rapid sequence of movements in a specific order; inhibitory if necessary

–Active seconds before the movement

–Active following an error in movement so you can inhibit the incorrect movement the next time

Prefrontal cortex

–Active during a delay before movement

–Stores sensory information relative to a movement

–Necessary for you to consider the probable outcomes of a movement

Antisaccade task

inhibits a saccade, a voluntary eye movement from one target to another

Corticospinal tracts

•paths from the cerebral cortex to the spinal cord

•Two such tracts:

-Lateral corticospinal tract

-Medial corticospinal tract

lateral corticospinal tract

pathway of axons from the primary motor cortex, surrounding areas of the cortex and red nucleus to the spinal cord

medial corticospinal tract

The medial tract controls the muscles of the neck, shoulders, and trunk

Cerebellum

-A structure in the brain often associated with balance and coordination
-Important for the establishment of new motor programs that allow the execution of a sequence of actions as a whole
-critical for certain aspects of attention

cerebellar cortex

surface of the cerebellum

Purkinje cells

transmit inhibitory messages to the cells in the nuclei of the cerebellum and the vestibular nuclei in the brain stem

basal ganglia

-a group of large subcortical structures in the forebrain
-–Responsible for initiating an action not guided by a stimulus 
-driving a car

Parkinson’s Disease

-A movement disorder characterized by muscle tremors, rigidity, slow movements, and difficulty initiating physical and mental activity
-•Caused by gradual and progressive death of neurons, especially in the substantia nigra

drug L-dopa

the primary treatment for Parkinson’s and is a precursor to dopamine that easily crosses the blood-brain barrier (often ineffective)

Huntington’s Disease

-A neurological disorder characterized by various motors symptoms
-Associated with gradual and extensive brain damage especially in the basal ganglia but also in the cerebral cortex

(arm jerks, facial twitches)

Curt Richter

in 1922 he proposed that the body generates its own cycles of activity and inactivity

Endogenous Circannual Rhythms

internal mechanisms that operate on an annual or yearly cycle

Endogenous Circadian Rhythms

All animals produce _______________________, internal mechanisms that operate on an approximately 24-hour cycle

–Sleep cycle

–Frequency of eating and drinking

–Body temperature

–Secretion of hormones

–Urination

Sensitivity to drugs

circadian rhythm

The purpose of the _______________ is to keep our internal workings in phase with the outside world

Zeitgeber

German meaning “time giver”; refers to the stimulus that resets the circadian rhythm

Jet Lag

Refers to the disruption of the circadian rhythms due to crossing time zones

•Traveling west “phase-delays” our circadian rhythms

•Traveling east “phase-advances” our circadian rhythms

Shift Work

Sleep duration depends on when one goes to sleep

Suprachiasmatic Nucleus (SCN)

The main control center of the circadian rhythms of sleep and temperature

–Located above the optic chiasm and part of the hypothalamus

pineal gland

an endocrine gland located posterior to the thalamus

melatonin

a hormone that increases sleepiness

Coma

extended period of unconsciousness characterized by low brain activity that remains fairly steady

Vegetative state

person alternates between periods of sleep and moderate arousal but no awareness of surrounding

Brain death

no sign of brain activity and no response to any stimulus

locus coeruleus

a small structure in the pons whose axons release norepinephrine to arouse various areas of the cortex and increase wakefulness

Insomnia

A sleep disorder associated with inadequate sleep

Narcolepsy

A sleep disorder characterized by frequent periods of sleepiness

Periodic Limb Movement Disorder

•The repeated involuntary movement of the legs and sometimes the arms while sleeping