Chapters 10 to 17 Flashcards
A stimulus that changes post synaptic neurons membrane from resting potential to -85mV is
An inhibitory stimulus
Branches that may occur along an axon are called
Collaterals
Each of the following is an example of a neuroeffector junction, except the junction between a neuron and a
Nerve cell.
A genetic disease causes the body to produce antibodies that compete withe acetylcholine for receptors on the motor end plate. Patients with this disease exhibit varying degrees of muscle weakness and flaccid paralysis in the affected muscles. If you could administer a drug the inhibits acetylcholinesterase or a drug that blocks acetylcholine which one would you use to alleviate these symptoms?
Case of competition between acetylcholine and antibodies. To ensure acetylcholine is more effective a drug that inhibits acetylcholinesterase slows breakdown of acetylcholine relieving some weakness. Acetylcholine blocker would be worse than no treatment.
During the recovery period the bodies need for oxygen is increased because
Additional oxygen is required to restore energy reserves consumed during exercise
Describe a motor unit? How many fibre units does a muscle unit contain?
A motor unit consists of all the skeletal muscle fibres controlled by a single motor neuron. They may have as few as 10 fibres or as many as 10,000
Damage to which of the following muscles would interfere most with the ability to breathe?
Intercostals
Cross bridge detachment is caused by —- binding to the myosin head.
ATP
At rest active sites on the actin are blocked by
Tropomyosin molecules
Damage to ependymal cells would most likely affect the
Formation of cerebrospinal fluid
During activities requiring aerobic endurance
Most of the muscles energy is produced in mitochondria.
Cross-bridges are portions of
Myosin molecules
A patient takes a medication that blocks ACh receptors of skeletal muscle fibres. What is this drugs effect on skeletal muscle contraction?
Reduces the muscles ability for contraction
A change in the conditions in the synaptic terminal can influence the soma as a result of —– axoplasmic transport?
Retrograde
After death muscle fibres run out of ATP and calcium begins to leak from te sacroplasmic reticulum into the sacroplasm. This results in a condition known as
Rigor Mortis
A —- is a muscle whose contraction is chiefly responsible for producing a particular movement.
Synergist.
At peak levels of muscle exertion the mitochondria can supply
Only about 1/3 of the energy required by the muscle.
A lever consists of
A rigid structure and a fulcrum.
EPSP’s ( excitatory post synaptic potentials) occur when
Ezra sodium ions enter the cell
During anaerobic glycolysis
All answers are correct
Describe the basic sequence of events that occurs as an action potential arrives at the neuromuscular junction and is transmitted to the muscle cell.
Action potential triggers exocytosis of neuro transmitters in vesicles in axon ending. Acetylcholine binds to receptors Motor and plate increase membrane permeability to sodium. AcetylCoE destroys acetylcholine ensuring that each nerve produces a single twitch. Action potential spreads both ways from end of plate across the entire surface of muscle fibre.
Active neurons need ATP to support which of the following?
All of the answers are correct
Creative phosphate
Acts as an energy reserve in muscle tissue.
Contracting the gastronemius muscles to elevate the body on the toes involves a —- lever.
Second class.
At rest the tropomyosin molecule is held in place by
Troponin molecules
A single contraction relaxation cycle in a muscle fibre produces a —-
Twitch
Decreased blood flow to a muscle could result in all of the following except
An increase in intracellular glycogen
Any stimulus that opens —- ion channel will produce a graded potential
All answers are correct
Clusters of RER and free ribosomes on neurons are called
Nissil bodies
After acetylcholinesterase acts the synaptic terminal
Reabsorbs the choline
Active sites become exposed when calcium ions bind to —
Troponin
Aerobic metabolism normally provides —– percent of the ATP demands of a resting muscle cell.
95
At a — synapse a neurotransmitter is released to stimulate the postsynaptic membrane.
Chemical.
During the recovery period following exercise all of the following are true except
Muscle fibres are unable to contract
A drug that blocks ATP production is is introduced to an isolated axon preparation. The axon is the repeatedly stimulated and recordings are made of the response. What effects would you expect to observe.
Initially normal action potentials shown. After 50,000 to 100,000 action potentials have passed less respond would be indicated from axon until it fails to respond. Cell could not replenish sodium and potassium ion gradients.
A post synaptic neuron will have an EPSP when
Chemically regulated sodium channels are open and sodium is diffusing into the cell
After heavy exercise if energy reserves in a muscle are depleted —– occurs
An oxygen debt
At the normal resting potential of a typical neuron it’s sodium- potassium exchange pump transports
3 intracellular sodium ions for 2 extra cellular potassium ions
A sesamoid bone occasionally found within the lateral head of the gastrocnemius is
The fabella
All of the following originate in the scapula except the
Pectoralis major
An infection by the bacterium clostridium tetani can cause the disease called —-
Tetanus
A fascicle is
A group of muscle fibres that are encased in the perimysium.
Damage to the pectoralis major would interfere with a persons ability to
Adduct the humerus
Because skeletal muscle contractions demand large quantities or ATP skeletal muscles have
Many mitochondria and rich blood supply
Deteriorating changes in the distal segment of an axon as a result of a break between it and a soma is called —– degeneration
Wallerian
An —- can be described as a broad tensions sheet
Aponeurosis
A muscle produces its highest tension when in complete —
Tetanus
During repolarization of a neuron
Potassium ions move out of the cell
A muscle that flexes the spinal column is the
Rectus abdominals
Compounds that alter the rate of neurotransmitter release by the presynaptic neuron or change the postsynaptic cells response to neurotransmitters are called ——
Neuro modulators
A muscle whose name in the suffix glossus would be found within or attached to the
Tongue
Communication between axons and muscle fibres occurs at specialized synapses called —–
Neuromuscular junctions
A shift of the resting transmembrane potential toward 0 mV is called
Depolarization
A weight lifter strains to lift a heavy weight and there is no movement of the persons arms holding on to the weight. This type of contraction is called a —- contraction.
Isometric.
A muscle that dorsiflexes the foot is the
Tibialis anterior
A threshold stimulus is the
Depolarization necessary to cause an action potential.
During abdominal surgery the surgeon makes a cut lateral to the linea alba. The muscles that would be cut is the
Rectus abdominius
A muscle that assists the muscle that is primarily responsible for a given action is a —
Synergist
Cholinergic synapses release neurotransmitters
Acetylcholine
A muscle producing tension that peaks and falls at intermediate stimulus rates is said to be in
Incomplete tetanus
At each End of the muscle the collagen fibres of the epimysium and each perimysium and endomysium come together to form a
Tendon.
A muscle that inserts on the body of the mandible is probably involved in
Chewing
A single motor neuron together with all the muscle fibres it innervates is called
A motor unit
A neuron that receives neurotransmitter from another neuron is called
The post synaptic neuron
Axons terminate in a series of fine extensions known as
Telodendria
Adrenergic synapses release the neurotransmitter
Norepinephrine
All of the following are innervated by the facial nerve except for the — muscle
Levator palpebrae superiosis
A movement charges in response to a potential difference is called a
Current
After a stroke what type of glial cell accumulates within the affected brain region?
Microglia
A resting muscle generates most of its ATP by
Aerobic metabolism of fatty acids
Active site o the actin become available for binding after
Calcium bonds to troponin
Deep muscles are called
Profundus
An antagonist to the gastronemius is the
Tibialis anterior
A —- is a rigid structure that moves Ina fixed point
Lever
During the Cori cycle in the liver
Glucose is produced from lactic acid.
Cerebrospinal fluid
is secreted by ependymal cells
A tract of white matter that connects the hippocampus with the hypothalamus is the
fornix.
A patient develops a tumor of a cranial nerve that leads to difficulty in speaking from a loss of tongue movement. Which cranial nerve is affected?
hypoglossal
Divisions of the cerebral hemispheres that are named after the overlying skull bones are
lobes.
A(n) ________ reflex has at least one interneuron placed between the sensory and motor neurons.
polysynaptic
A viral disease that destroys the cells of the anterior gray horn will
lead to skeletal muscle weakness or paralysis.
Cortical regions that interpret sensory information or coordinate motor responses are called ________ areas.
association
All of the following are true of neural reflexes, except that they
cannot be modified by the brain.
Damage to the superior colliculi would interfere with the reflex ability to
react to a bright light.
During embryonic development, which of the following secondary brain vesicles will form the cerebrum?
telencephalon