Quiz 7 Vocab Study

aerobic

- requiring the use of oxygen during movements

anaerobic

- not aerobic
- proceeding without using oxygen at the time of a reaction

antagonist muscles

- movement requires the alternating contraction of opposing sets of muscles
- composed of flexor and extensor muscles

cardiac muscles

- heart muscles that have properties of skeletal and smooth muscles (smooth muscles: control the digestive system and other organs)

extensor

- an antagonistic muscle
- extends an appendage or straightens it

fast-twitch fibers

- skeletal muscles type
- produce fast contractions but fatigue rapidly
- anaerobic, using reactions that do not require oxygen resulting in fatigue
- *slow-twitch fibers: produce less vigorous contraction without fatigue

Golgi tendon organs

- proprioceptor that responds to increases in muscle tension
- located in the tendons at the opposite ends of the muscle
- acts as a “brake” against excessively vigorous
contraction by sending an impulse to the spinal cord where motor neurons are inhibited

muscle spindle

- proprioceptors parallel to the muscle that respond to a stretch: cause a contraction of the muscle
- *proprioceptor: receptors that detect the position or movement of a part of the body

neuro muscular junction

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

skeletal or striated muscles

- control movement of the body in relation to the environment

basal ganglia

- group of large subcortical structures in the forebrain
- initiates actions not guided by a stimulus
- comprised of the caudate nucleus, putamen, globus pallidus
- caudate nucleus and putamen receive input from the cerebral cortex and send output to the globus pallidus
- globus pallidus connects to the thalamus, which relays information to the motor areas and the prefrontal cortex, inhibiting the thalamus
- selects a movement to make by ceasing to inhibit it
- *subcortical: below the (cerebellar) cortex

mirror neurons

- active during both preparation of a movement and while watching someone else perform the same or similar movement

posterior parietal cortex

- part of the cerebral cortex
- keeps track of the position of the body relative to the world
- important for planning movement

premotor cortex

- part of the cerebral cortex
- active during preparation for a movement, then receives information about a target, then integrates information about position and posture of the body and organizes the direction of the movement in space

primary motor cortex

- part of the cerebral cortex
- located in the precentral gyrus located in the frontal lobe

huntington

- protein that codes Huntington's disease
- occurs throughout the human body, although its mutant form produces no known harm outside the brain
- the mutant form impairs neurons and glia in several ways, including effects on mitochondria and potassium channels

Huntington's disease

- neurological disorder characterized by jerky arm movements
and facial twitches and later by tremors, writhing movements, and psychological symptoms

L-dopa

- the primary treatment for Parkinson’s
- is a precursor to dopamine that easily crosses the blood-brain barrier

MPTP

- a drug similar to heroin that when converted to MPP accumulates in, and then destroys, neurons that release dopamine, partly by impairing the transport of mitochondria from the cell body to the synapse (causing Parkinson's disease)

Parkinson's disease

- a movement disorder characterized by muscle tremors, rigidity, slow movements, and difficulty initiating physical and mental activity
- associated with an impairment in initiating spontaneous movement in the absence of stimuli to guide the action
- 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
- symptoms also include depression, memory and reasoning deficits, loss of olfaction, and other cognitive deficits

stem cells

- immature cells that are capable of differentiating into other cell types
- used in a theoretical approach where they are guided in their
their development so that they produce large quantities of
L-dopa, and then transplanted into the brain to treat Parkinson's disease