Complete Test 1 Review Flashcards
Homeostasis is defined as:
The condition in which the body’s internal environment remains relatively constant within limits.
Which cation is most abundant in the extracellular fluid?
Sodium, Na+
Which cation is most abundant in the intracellular fluid?
Potassium, K+
Which anion is most abundant in the extracellular fluid?
Cloride, Cl-
Gain is defined as:
The effectiveness with which a control system maintains constant conditions.
Gain=correction/error
Uncontrolled system: 100 to 175
Controlled system: 100 to 125
correction is -50, error is 25
Gain=-2
Which of the following would have to be a transmembrane protein?
A. A receptor protein
B. A protein binding to the cytoskeleton
C. A channel protein
D. A phosphorylase
C. A channel protein
Which organelle(s) is/are associated with intracellular trafficking?
ER and Golgi
Which organelle is associated with most ATP production?
mitochondria
Which of the following processes does not require the presence of mitochondria?
A. Oxidative phosphorylation
B. Production of carbon dioxide and water
C. Breakdown of glucose to pyruvic acid
D. Electron transfer between cytochromes
E. Utilization of oxygen as a final electron acceptor
C. Breakdown of glucose to pyruvic acid
Proteins bound for the cytoplasm, nucleus, mitochondria, or to other cell membranes are synthesized where?
on free ribosomes
Proteins bound for lysosomes or for secretion are synthesized where?
on Rough ER
Which organelle forms lysosomes?
Golgi apparatus
Where does glycolysis occur?
the cytoplasm
does not require oxygen
Which of the following transport mechanisms requires energy other than kinetic energy?
A. Osmosis
B. Diffusion
C. Active transport
D. Facilitated diffusion
C. Active transport
Of the following ions, which is most concentrated in the extracellular environment?
A. Sodium
B. Potassium
C. Chloride
D. Calcium
A. Sodium
The sodium-potassium pump is an example of which of the following kinds of transport?
A. Diffusion
B. Primary active transport
C. Secondary active transport
D. Facilitated diffusion
B. Primary active transport
The sodium-glucose pump is an example of which of the following kinds of transport?
A. Diffusion
B. Primary active transport
C. Secondary active transport
D. Facilitated diffusion
C. Secondary active transport
The sodium-calcium pump is an example of which of the following kinds of transport?
A. Diffusion
B. Primary active transport
C. Secondary active transport
D. Facilitated diffusion
C. Secondary active transport
Glucose transporters (GLUT transporters) employ which of the following kinds of transport?
A. Diffusion
B. Primary active transport
C. Secondary active transport
D. Facilitated diffusion
D. Facilitated diffusion
Define Osmosis:
movement of a solvent from a region of high concentration to a region of low concentration across a semi-permeable membrane.
Explain Osmotic Pressure
When water moves across a cell membrane because of the concentration differences, water will accumulate on one side of the membrane. This will usually create a higher pressure on one side of the membrane than the other. This increase in pressure is the osmotic pressure.
the energy for diffusion comes from:
random kinetic energy of particles.
Which of the following factors effect the rate of diffusion?
A. Concentration difference across membrane
B. Membrane electric potential
C. Pressure difference
D. ATP available
A, B, C - figure 4-9
Vmax refers to:
When transporters are saturated and cannot increase the rate of transfer. Effect easily seen when looking at facilitated diffusion vs. diffusion
Which of the following types of neurons would transmit an action potential the fastest?
A. Small diameter, non-myelinated
B. Small diameter, myelinated
C. Large diameter, mylinated
D. Large diameter, non-myelinated
C. Large diameter, mylinated
Saltatory conduction is characteristic of which part of a typical neuron?
A. Dendrite
B. Nerve cell body
C. Axon hillock
D. Axon
D. Axon
A selectivity filter with carbonyl oxygens is associated with which of the following kinds of ion channels?
A. Gated sodium
B. Non-gated sodium
C. Potassium
D. Chloride
C. Potassium
The resting potential for a typical neuron, such as a motor neuron, is best represented by which of the following potentials?
A. 74 mV
B. -84 mV
C. 90 mV
D. -90 mV
D. -90 mV
True or False: The cell body characteristically has voltage-gated ion channels
False
True or false: The cell body is characterized by action potentials
False, local potentials are characteristic.
True or false: dendrites are characterized by the presence of ligand-gated ion channels
True
Do dendrites conduct local potentials or action potentials?
Local potentials
The membrane surrounding the axon is called:
the axolemma, characterized by the presence of voltage gated ion channels.
The principle of electrical neutrality states:
The sum of cations= sum of anions in any compartment
The following describe what type of potential?
All-or-none
Self-propagating
Non-decremental
action potential
The inactivation gate for the sodium channel is open or closed at -90 mV?
Open
How many gates does a sodium voltage gated channel have?
2, Activation gate and an inactivation gate
Activation gate closed at -90
Inactivation gate open at -90
Both gates open between -90 and +35
+35 inactivation gate closes (to allow cell to get back to resting potential)
Voltage Gated Potassium Channels how many gates?
1
closed at resting potential -90
slow activation opens the gate from +35 to -90 (more on the inside of the cell, helps being cell back to resting potential, as positive ions flow out of cell through channel)
What is the purpose of myelin?
increase the membrane resistance (creates a capacitor like effect - serves as the insulator)
The threshold of an action potential is:
A. -90
B. -30
C. +30
D. -65
D. -65
Define:
Orthodromic direction
Antidromic direction
Orthodromic - toward the distal end of axon (normal)
Antidromic - toward the cell body
Why do action potentials typically travel in orthodromic directions?
only voltage gated channels going down the axon, and starts at axon hillock. doesn’y travel back because of the refractroy period!
What is the principle lipid found in myelin sheaths?
Spingomyelin
Differentiate between the relative and absolute refractory periods
Absolute - no second action potential no matter how strong a stimulus
Relative - stronger than normal stimulus can cause an action potential
Which of the following refers to a chain of sarcomeres?
A. Muscle
B. Myofiber
C. Myofibril
D. Myofilament
C. Myofibril
Which of the following sarcomeric bands does not undergo a change in length during the contraction of a skeletal muscle?
A. A band
B. H band
C. I band
D. J band
A. A band
DHP channels are part of which of the following structures?
A. Sarcoplasmic reticulum
B. Plasmalemma
C. T tubules
D. Z discs
C. T tubules
Ryanodine-sensitive clacium ion release channels are part of which of the following structures?
A. Sarcoplasmic reticulum
B. Plasmalemma
C. T-tubules
D. Z discs
A. Sarcoplasmic reticulum
Which of the following events occurs first during the transmission of a signal from an alpha motor neuron to a skeletal muscle fiber?
A. End plate depolarization (EPP)
B. Calcium Ion Influx into Axon Terminal
C. Exocytosis of synaptic vescicles
D. Sarcolemma Action Potential
B. Calcium Ion Influx into Axon Terminal
Which of the following represents the factor by which the concentration of calcium ion increases in the cytosol after release from the sarcoplasmic reticulum?
A. 10
B. 50
C. 100
D. 1000
C. 100
Which of the following maintains an optimum calcium concentration gradient to facilitate return of calcium to the SR
A. Calsequestrin
B. SERCA
B. DHP
D. Ryanodine
A. Calsequestrin
Fast twitch fibers have which of the following characteristics?
A.They are reddish in color comparted to slow twitch fibers
B. They have more mitochondria than slow twitch fibers
C. They have more myoglobin than slow twitch fibers
D. They are more fatigable than slow twitch fibers
D. They are more fatigable than slow twitch fibers
Which of the following represents an example of an eccentric contraction?
A. The triceps musce during the throwing of a ball
B. The triceps muscle while raising the body from the floor during a push up
C. The triceps muscle while lowering the body to the floor during a push up
D. The biceps muscle while raising the body during a pull up
C. The triceps muscle while lowering the body to the floor during a push up
What is connective tissues surrounding the entire muscle?
Epimysium
What is made up of multiple fascicles?
Muscle
What is connective tissue surrounding individual fascicle?
Perimysium
What is a bundle of myofibers?
Fascicle
What is delicate connective tissue around each myofiber?
Edomysium
What is the cell membrane of each muscle fiber called?
Sarcolemma (=plasmalemma)
What is an individual multinucleated muscle cell called?
Myofiber
What is a chain of sarcomeres within a myofiber?
Myofibril
What is actin and myosin filaments that make up a sarcomere called?
Myofilament
What anchor actin filaments and are located at the end of a sarcomere?
Z discs (Z lines)
What are composed entirely of actin and change their width during contraction?
I bands
What are composed of actin and myosin and do not change their width during contraction?
A bands
What are composed entirely of myosin and change their widths during contraction?
H bands
What are responsible for the banding pattern characteristic of striated muscle?
Sarcomeres alignment
Describe the sequences LEADING UP TO the sliding filament mechanism.
1) Action potential arrives2) Voltage gated calcium channels open3) Ach released into synaptic cleft4) Opening of ligand gated sodium channels5) Action potential occurs6) Voltage gated T-tubules interact with ryanodine receptors on SR membrane7) Opening of Ryanodine-sensitive calcium ion release channels8) Ca2+ increases in cytosol9) activation of sliding filament mechanism
Describe the sequences after Calcium has been released in the cytosol to muscle contraction.
1) Calcium ions bind to troponin2) Tropomyosin uncovers myosin binding sites on actin.3) ATPase heads of myosin molecules split ATP and bind to actin.4) Stored energy in myosin head causes deformation such that thick and thin filaments slide past one another.5) A second ATP binds to myosin and causes it to release actin6) process is repeated7) contraction stops when ATP-dependent calcium pump sequesters calcium ions into SR.
What causes conformational changes in the ryanodine receptors and are located on the sacrolemma T-tubules?
Dihydropyridine receptors (DHP)
What open in response to conformational changes in the DHP receptors and allow calcium to flow into the cytosol from the SR?
Ryanodine receptors (RyRs or Ca2+ release channels)
How many heads does each myosin molecule contain?
2
Where is ATP required for muscle contraction? (3)
1) sliding filament mechanism (most)2) pumping calcium from sarcoplasm back into SR3) pumping sodium and potassium ions through the sarcolemma to reestablish resting potential.
What type of contraction occurs when there is an increase in tension but not in length?
Isometric
What type of contraction occurs when there is a change in muscle length? (2)
Isotonic contraction. Eccentric - lengthens, Concentric - shortens.
What type of muscle has fewer mitochondria, primarily uses anaerobic respiration, and has a larger concentration of ATPase?
Fast(white), contract rapidly but have less endurance. Example: gastrocnemius
What type of muscle has more mitochondria, primarily uses aerobic respiration, has more myoglobin, and smaller concentration of ATPase?
Slow(red), slow twitch fibers contract more slowly but have more endurance. Example: soleus
