Skeletal Muscle
The contractile units of skeletal muscle are called____________.
sarcomere
How many nuclei does skeletal muscle cells have?
Multiple
Name 1 synergist of the biceps brachii
Brachialis, brachioradialis
Which part of a neuron receives messages?
Dendrites (usually)
What are neurotransmitters?
Chemical messengers used in nervous system/ between neurons
What is the function of the astrocyte?
Mediates chemical environment in CNS, braces and supports neurons
During muscle contraction, myosin cross bridges attach to which active sites?
Actin
Bundle of muscle cells surrounded by a perimysium is__________
a fascicle
What is the function of the extensor carpi ulnaris?
Extends and adducts the hand
What ions increase in permeability during depolarization?
Sodium ions
What is another name for efferent nerves? Function?
Motor neurons/nerves
Controls an effector organ (muscle, gland)
Name 2 structures found in the cell body of a neuron
Chromatophilic substance, nucleus & nucleolus, Golgi apparatus, mitochondria, ribosomes, cytoskeleton, lysosomes
Name 2 proteins found in the I band?
Actin, troponin-c, tropomyosin, z-disc, titin
What type of muscle fibers would I use if I were running a marathon or taking a long swim?
Slow oxidative fibers
Flexion of the vertebral column (anteriorly or laterally), rotation of the vertebral column, compression of the abdominal cavity; assist in breathing, used in urination, defecation, vomiting, childbirth, etc
What ions increase in permeability during repolarization?
What ions increase in permeability at hyperpolarization?
Potassium ion
Still potassium ion!
Which neurotransmitter inhibits pain? Which drugs mimic it?
Endorphins
Opioids (e.g., morphine, heroin, fentanyl, oxycodone)
What cell myelinates CNS neurons? PNS neurons?
Oligodendrocytes
Schwann Cells
NMJ: What enzyme breaks down Acetylcholine thus ending the contraction?
Acetylcholinesterase
What is the difference between aerobic and anaerobic pathway?
Aerobic- requires O2, produces 32 net ATP, happens in mitochondria
Anaerobic- doesn't require O2, produces 2 net ATP, happens in cytosol
What is the difference between an agonist, antagonist muscles, synergist, and fixator muscle?
Agonist- prime mover
Antagonist- opposes prime mover
Synergist- assists prime mover
Fixator- stabilizes prime mover
How soon can a second action potential be generated in a cell?
~2-4 milliseconds
- absolute refractory period = 1 ms
- relative refractory period = 1-3 ms
What is a ganglia and nuclei? Where do you find them (different place)?
Both are a collection of cell bodies (gray matter)
Ganglia = PNS, nuclei = CNS
Which CNS cells have cilia and move the cerebral spinal fluid?
Ependymal cells
What is the role of tropomyosin in skeletal muscles?
Which pathway involves direct phosphorylation and would most likely happen if it was a quick use of energy?
Oxidative phosphorylation, where creatine kinase adds a phosphate group to ADP, creating ATP
What effect does epinephrine have on skeletal and cardiac muscles? Smooth muscles?
Skeletal- increases glucose and O2 uptake
Cardiac- excitatory, increases heartrate
Smooth- usually inhibitory, decreases gut movement, etc.
Compare graded potential to non-graded.
Non-graded potential = "action potential", all or nothing, above threshold
Graded potential = EPSPs, below threshold, can summate to form an action potential
Where do you find unipolar neurons, bipolar neurons, multipolar neurons?
Unipolar- sensory neurons of PNS
Bipolar- sensory organs (retina, olfactory epithelium, inner ear)
Multipolar- most common, CNS, motor neurons
At what end of the neuron is a message communicated to a neighboring cell?
The axon terminal of the presynaptic neuron