PRACTICE E2 Flashcards
The surge of sex hormones that accompanies puberty has a wide range of effects on the body. One of those effects is to enhance the activity of the sebaceous glands, increasing the production of sebum. Which of the following is the most likely to result from the increased sebaceous activity?
Increased cooling of the skin.
Increased oily appearance and more acne.
Decreased vitamin D synthesis.
Increased oily appearance and more acne.
The type of cell that gives rise to a squamous cell carcinoma is in the…
Stratum corneum
Stratum basale
Papillary layer of the dermis
Reticular layer of the dermis
In the epidermis, but in neither the stratum corneum nor stratum basale
In the epidermis, but in neither the stratum corneum nor stratum basale
Water loss through our skin on a very cold, windy day is mostly…
Sensible perspiration
Insensible perspiration
Insensible perspiration
Fluid replacement is critical for individuals suffering extensive 3rd degree burns. This is because…
Burns are hot and stimulate sweat glands to sweat excessively
Insensible perspiration is dramatically increased
Water is lost due to diarrhea
Respiratory water loss increases more than other types of water loss
Vomiting
Insensible perspiration is dramatically increased
In order for melanin to protect against at least two types of skin cancer, the pigment must be passed to…
Epithelial cells
Fibroblasts
Smooth muscle cells
Neurons
Epithelial cells
Many choice: Which of the following are sensory receptors in the skin?
Pacinian corpuscle
Meisner’s corpuscle
Hair follicle receptor
Pacinian corpuscle
Meisner’s corpuscle
Hair follicle receptor
Which of the following is considered the most effective stimulus for bone growth in adults?
Calcium consumption
Vitamin D3 consumption
Weight bearing exercise and bone stress
Meditation
Weight bearing exercise and bone stress
Many choice: Which of the following are effectors in the feedback loop that helps maintain blood calcium homeostasis?
Osteoclasts
The kidney
The parathyroid gland
Osteoclasts
The kidney
Which of the following cell types creates new bone?
Osteoblasts
Osteoclasts
Osteocytes
Chondroblasts
Chondrocytes
Osteoblasts
As a long bone grows,…
Cartilage is replaced by bone tissue
Fibroblasts create more mineral matrix
Osteoclasts lay down bone tissue at increasingly rapid rates
Cartilage is replaced by bone tissue
Many choice: Which of the following are synovial joints?
Knee
Shoulder
Joint between adjacent vertebral bodies
Knee
Shoulder
The primary motor proteins in muscle are found in the…
Sarcoplasmic reticulum
Sarcolemma
Thin filament
Thick filament
Nuclei
Thick filament
In a muscle fiber, motor proteins are located in the…
Thick filament
Thin filament
Z-line
Epimysium
Thick filament
Tubocurarine binds to the nicotinic ACh receptor at the motor end plate and locks it in a closed position. In this case…
No action potentials would be fired
One action potential would be fired, but no subsequent action potentials
Action potentials would be continually fired until the tubocurarine was degraded
No action potentials would be fired
The tissue that surrounds an individual muscle fiber is called the…
Epimysium
Perimysium
Endomysium
Endoneurium
Epineurium
Endomysium
The membrane potential in a muscle fiber treated with tubocurarine would be…
Above threshold
Below threshold
Below threshold
A motor unit refers to…
All fibers in a one muscle
All fibers in one muscle fascicle
All fibers contained in one endomysium
All fibers stimulated by a specific motor neuron
All fibers stimulated by a specific motor neuron
A synergist is a muscle that…
Assists the prime mover for a motion
Assists the antagonist for a motion
Is primarily responsible for a movement
Is primarily responsible for opposing a movement
Assists the prime mover for a motion
Glutamate is a major excitatory neurotransmitter in the brain. From this information, you know that most glutamate receptors…
Depolarize a neuron
Hyperpolarize a neuron
Are voltage-gated
I need more information.
Depolarize a neuron
Tetanus causes sustained skeletal muscle contraction by…
Locking ACh receptors in an open position
Blocking ACh release at the lower motor neuron
Blocking inhibition of the lower motor neuron in the spinal cord
Blocking the activity of the blood-brain barrier
Blocking inhibition of the lower motor neuron in the spinal cord
Myelin…
Insulates dendrites and causes action potentials to travel faster
Insulates dendrites and causes action potentials to travel slower
Insulates cell bodies and causes action potentials to travel faster
Insulates axons and causes action potentials to travel faster
Insulates axons and causes action potentials to travel slower
Insulates axons and causes action potentials to travel faster
Multiple sclerosis is a disease in which myelination of neurons is disrupted. This is a problem because…
Non-myelinated neurons cannot fire action potentials
Non-myelinated neurons immediately die
Action potentials from non-myelinated neurons cannot reach the axon terminal
Action potentials from non-myelinated neurons are not timed correctly
Action potentials from non-myelinated neurons are not timed correctly
Which of the following would relax a neuron?
Sodium moving into a cell
Chloride moving into a cell
Potassium moving into a cell
Chloride moving into a cell
Does oxygen diffuse into the blood through human skin?
Yes
No
Yes
If a motor neuron is firing action potentials at its maximum rate, can force generated by the muscle organ increase?
Yes
No
No
If the stratum corneum allowed no light to pass, bones would become more…
Brittle
Flexible
There would be no effect on bone tissue
Flexible
Even if it sounds confusing, low extracellular calcium increases neuron excitability. The mechanism involves a change in sodium moving across the cell’s plasma membrane. If low calcium increases neuron excitability, extracellular calcium must…
Increase sodium moving into a cell
Decrease sodium moving into a cell
Decrease sodium moving into a cell
When typing, flexion of fingers depends on muscles on the _____________ side of the body.
Anterior
Posterior
Anterior
Imagine you work in a pharmaceutical firm and are asked to develop an ion channel that keeps neurons from firing an action potential. The ion channel you would choose would be a…
Voltage gated sodium channel
Ligand gated sodium channel
Voltage gated potassium channel
Ligand gated potassium channel
Any of the above ion channels would work depending on the situation.
Voltage gated sodium channel
On average, a person in which of the following professions would be most at risk for osteoporosis?
An office worker.
A construction worker.
A dancer.
An office worker.
Imagine a situation in which neurotransmitter vesicles inside a nerve axon terminus remain constant no matter how much neurotransmitter is released. The vesicles are magically replaced so that the neuron never runs out of neurotransmitter. In this case, elevated calcium inside the axon terminus would…
Cause constant release of neurotransmitter.
Cause a one time release of neurotransmitter and then no further release.
Not affect neurotransmitter release.
Prevent neurotransmitter from being released.
Cause constant release of neurotransmitter.
Injecting potassium into the blood stream stops the heart. In this case, cardiac muscle cells would be stuck in the…
Absolute refractory period
Relative refractory period
Resting state
Absolute refractory period
Acetylcholine released at the heart will slow the rate of action potential generation. From this information you know that…
The heart has acetylcholine receptors that cause depolarization
The heart has acetylcholine receptors that inhibit depolarization
The heart does not have acetylcholine receptors
The heart has acetylcholine receptors that inhibit depolarization
A joint stabilized by only muscles and tendons would be ________________ stabile than a joint stabilized by only fibrous connective tissue.
More
Less
Less
If a person had a mutation that disrupted the structure of keratin in skin, they would…
Become dehydrated
Have trouble getting rid of excess fluid
Become dehydrated
Which of the following could prevent skeletal muscle from contracting?
Preventing calcium from surrounding myofibrils.
Maintaining high levels of calcium around myofibrils
Preventing sodium from entering a cell
Allowing constant entry of sodium into a cell
Preventing calcium from surrounding myofibrils.
Preventing sodium from entering a cell
Allowing constant entry of sodium into a cell
Imagine we lived in a perfectly normal environment in space. The environment contains normal oxygen, humidity, light, and everything else. The only difference is the absence of gravity. Which of the following would be most affected?
Sensible perspiration
Insensible perspiration
Bone density
Joint mobility
The structure of dense irregular connective tissue
Bone density
Responsible for goose bumps:
Group of answer choices
Stratified squamous epithelial tissue
Arrector pili muscle
Sweat glands
Hair follicles
Sebaceous glands
Arrector pili muscle
Many choice: Which of the following articulate with the humerus in the shoulder joint?
Group of answer choices
The clavicle
The scapula
The ulna
The radius
The scapula
Astronauts may run on a treadmill with elastic cords that stretch and contract to simulate gravity on earth. The most likely reason for this is…
Group of answer choices
The exercise creates CO2, which is necessary to sustain the life of plants in the space station
To provide stress on bone so that astronauts do not experience osteoporosis before returning to earth
To provide stress on cartilage so that it continues to remodel
To provide stress on the stem cells in skin, which might otherwise stop dividing
To test the oxygen sensors and valves for function
To provide stress on bone so that astronauts do not experience osteoporosis before returning to earth
A herniated disc involves damage to…
Group of answer choices
The fibrocartilage between adjacent vertebral bodies
The synovial membrane surrounding an intervertebral disc
A vertebra
The smooth muscle of an intervertebral disc
The fibrocartilage between adjacent vertebral bodies
Many choice: Which of the following proteins is a component of the thin filament?
Group of answer choices
Tropomyosin
Actin
Myosin
Troponin
Tropomyosin
Actin
Troponin
During the relative refractory period, voltage-gated potassium channels are…
Group of answer choices
Open
Closed
Inactivated
Open
Imagine a motor end plate has acetylcholine receptors that allow chloride to cross the cell membrane but not sodium. Chloride is negatively charged and the electrochemical gradient drives chloride into cells. A motor neuron would then cause…
Muscle contraction
Muscle relaxation
Muscle relaxation
If you were a researcher who wanted to cure osteoporosis, you might search for a drug that…
Group of answer choices
Turns off osteoclasts
Turns off osteoblasts
Turns off osteocytes
Turns off osteoclasts
Injecting potassium into the blood stream stops the heart. In this case, voltage gated sodium channels in cardiac muscle would be…
Group of answer choices
Open
Closed
Inactivated
Inactivated
The fibular collateral ligament (lateral collateral ligament) prevents _________________ of the knee.
Group of answer choices
Adduction
Abduction
Flexion
Extension
Adduction
If we get insufficient sunlight, which of the following would be the most likely change to bone tissue?
Bones would become harder
Bones would become more flexible
Bones would become more brittle
Bones would become more flexible
A muscle fiber that fires repeated action potentials at a rapid rate will…
Not generate force
Generate force for a short period of time and relax (a twitch)
Generate force until ATP is depleted
Generate force until ATP is depleted
When throwing a ball, extension of the elbow is a result of contraction of muscles on the _________________ side of the body.
Anterior
Posterior
Posterior
Imagine that a motor neuron were physically connected with a skeletal muscle fiber via gap junctions that allow all ions to pass the cell membrane. Using electrodes, we hold the voltage of the skeletal muscle fiber at -70 mV. The voltage doesn’t change even when ions enter and leave because we prevent such a change. When the lower motor neuron fires an action potential, the muscle fiber will…
Generate a little force
There will be absolutely no change in force generation
Generate a little force
