Muscle and Nervous Tissue Review
The structural classification of neurons is based on the number of processes that extend from the neuron cell body. Match these definitions to the correct term.
1. Many dendrites and a single axon = Multipolar neuron 2. One dendrite and one axon = Bipolar neuron 3. One process with two branches; one extending to the CNS, one extending to the periphery = Unipolar neuron
Place the events involved in muscle contraction in the correct order.
1.) A nerve impulse causes ACh release at a neuromuscular junction 2.) ACh binds receptors on the motor end plate, initiating a muscle impulse 3.) Calcium ions bind to troponin, causing tropomyosin to move and expose active sites 4.) Myosin heads attach to actin and form crossbridges 5.) A cyclic "attach, pivot, detach, return" event occurs 6.) Calcium ions are moved back into the sarcoplasmic reticulum by ATP 7.) Driven pumps-myofilaments passively return to their original state
Place a single word into each sentence to make it correct. Not all terms will be used.
1.) An unmyelinated fiber has voltage-gated ion gates along its entire LENGTH. 2.) An action potential at the TRIGGER zone causes sodium to diffuse into the cell. 3.) This results in membrane DEPOLARIZATION. 4.) The depolarization causes a REPITITION that excites the entire membrane. 5.) This continues until the traveling SIGNAL reaches the end of the axon.
Check all that are characteristics of cardiac muscle.
1.) Cells are long and cylindrical. 2.) Cells are short and branching. 3.) Cells have multiple nuclei at the periphery of the cell. 4.) Cells have one or two nuclei in the center of the cell.
Place the organizational level of muscle tissue in order, beginning with the entire muscle and ending with the smallest component.
1.) Muscle 2.) Fascicle 3.) Muscle Fiber 4.) Myofibril 5.) Myofilament
Match the type of muscle tissue with its brief description.
1.) Striated and multinucleated = Skeletal 2.) No striations and involuntary = Smooth 3.) Autorhythmic with gap junctions = Cardiac
Fill in the blanks with the terms provided. Not all terms will be used.
1.) The peripheral nervous system is further subdivided into an afferent (sensory) division and an efferent (MOTOR) division. 2.) The afferent or sensory division transmits impulses from PERIPHERAL ORGANS TO THE CNS. 3.) The efferent or motor division transmits impulses FROM THE CNS OUT TO THE PERIPHERAL ORGANS. 4.) The motor division is separated further into a somatic motor division and a(n) AUTONOMIC motor division. 5.) Autonomic refers to the controls we are not aware of, like SMOOTH muscle, cardiac muscles, and glands.
Arrange the following in the proper order in which they occur at the postsynaptic side of a neuromuscular junction. 1.) Action potential is propagated over the muscle cell membrane. 2.) Depolarization of the postsynaptic membrane occurs. 3.) Sodium ions move into muscle cell.
3.) Sodium ions move into muscle cell 2.) Depolarization of the post-synaptic membrane 1.) Action potential is propagated over the muscle cell membrane
The area of the muscle fiber where the actin and myosin myofilaments overlap is the...
A band
All the muscle fibers under the control of a single motor axon are referred to as...
A motor unit.
Fill in the blanks with the terms provided. Not all terms will be used.
A synapse is the specific location where A NEURON is functionally connected to either another neuron or AN EFFECTOR. There are two types of synapses in the human body: chemical synapses and electrical synapses. Most synapses within the nervous system are CHEMICAL synapses.
Which of the following events does not occur during skeletal muscle relaxation?
ACh binds its receptor on the motor end plate.
Energy is released when...
ATP is broken down into ADP and phosphate.
The primary neurotransmitter at the neuromuscular junction is...
Acetylcholine
The bond between the actin and myosin head is broken when...
An ATP molecule binds to the myosin head.
Which connective tissue wrapping separates individual muscle fibers?
Endomysium
A skeletal muscle fiber (cell) contains a single nucleus.
False.
Cardiac muscle tissue contains fewer mitochondria than are found in skeletal muscle tissue.
False.
Receptors that bind the neurotransmitter at the postsynaptic cell membrane are voltage-gated.
False.
A bundle of muscle fibers is known as a...
Fascicle
Which of the following best describes the role of Ca2+ in muscle contraction?
It binds to troponin, moving tropomyosin, so that myosin heads can bind to actin.
Classify the given items with the appropriate group.
Multipolar - Most common, has many dendrites and a single axon. Bipolar - Has one axon and one dendrite. Unipolar - Has central and peripheral processes. Anaxonic - No axons present, only produce local potentials.
The muscle cell membrane is called the...
Sarcolemma.
The distance from one Z disk to the next Z disk is called a...
Sarcomere
An action potential causes calcium ions to diffuse from the ________ into the ________.
Sarcoplasmic Reticulum; Sarcoplasm
Place these neurons into the proper classification group.
Structural - Unipolar neuron, bipolar neuron and multipolar neuron. Functional - Sensory neuron, motor neuron, interneuron, afferent neuron, efferent neuron and association neuron.
Which part of a neuron contains calcium pumps and channels?
Synaptic bulbs.
A typical synapse in the CNS consists of a presynaptic neuron and a postsynaptic neuron, separated by a narrow space called the...
Synaptic cleft.
Which of the following connects muscle to bone?
Tendons.
The component of a muscle fiber that quickly transports a muscle impulse from the sarcolemma throughout the entire muscle fiber is called the...
Transverse tubule (T-tubule).
During contraction of a muscle, calcium ions bind to the...
Troponin molecule
All of the following are filamentous proteins except...
Troponin.
