KIN muscle tissue and system
Many choice: The central nervous system includes
- the brain -the spinal cord
The equilibrium potential for potassium is about -90 mV. If potassium channels remained open and all other ion channels were closed, the voltage inside a neuron would be
-90 mV
Imagine that the middle head of the deltoid were the only muscle supporting the outstretched arm below. If the deltoid contracted so that the hand moved at a speed of 1 meter per second, the insertion of the deltoid would move
Slower than one meter per second
Smooth muscle appears smooth because
Smooth muscle cells do not have sarcomeres
The threshold voltage in a muscle fiber is
The voltage at which voltage-gated sodium channels open
Moving the arm away from a mid-sagittal plane is called
Abduction
The equilibrium potential for sodium is about +66 mV. If only sodium channels were open in a cell's plasma membrane, the membrane potential would be
About +66 mV
The membrane potential in a muscle fiber treated for a long time with with succinylcholine would be
Above threshold
Multiple sclerosis is a disease in which myelination of neurons is disrupted. This is a problem because
Action potentials from non-myelinated neurons are not timed correctly
An action potential that begins at the axon hillock travels only towards the axon terminal. This is because
After depolarizing, each portion of the axon enters the absolute refractory period so can't transmit a signal either backwards or forwards.
A motor unit refers to
All fibers stimulated by a specific motor neuron
If we shock an axon in the middle, bringing the voltage inside the middle of the axon above threshold,
An action potential will be generated and will travel in both directions
Many choice: Lidocaine would block sensory signals while allowing muscle contraction if
Answer: it blocked voltage gated sodium channels in sensory neurons
The brachialis flexes the elbow when it shortens. In order to extend the elbow,
Antagonists to elbow flexion must contract
A synergist is a muscle that
Assists the prime mover for a motion
Many choice: When a muscle contracts
Z-lines move closer together
Which of the following joint types is least stable?
a synovial joint
Raising the arm sideways (within a frontal plane) represents
abduction
Organophosphates block the action of acetylcholinesterase. In this case, muscle fibers would spend more time
above threshold
Which of the following types of bone contains osteons?
compact bone
Which of the following would result in lowest bone mass over two weeks?
consuming high levels of calcium while physically inactive
Muscle is a motor because it
converts chemical energy to mechanical energy
When the pectoralis major contracts while throwing a ball, the hand moves
faster than the insertion of the muscle
An intervertebral disc contains
fibrocartilage
When the splenius capitis contracts to elevate the mandible, it is acting as a
first class lever
A muscle that originates on the ischial tuberosity and inserts on the head of the fibula would
flex the knee and extend the hip
tendons are connected to bone by
Collagen fibers from connective tissue in the muscle interweaving with collagen fibers from the periosteum and bone tissue
A muscle that originates on the coracoid process of the scapula and inserts on radial tuberosity would (you may assume the muscle is located on the anterior side of the arm)
flex the shoulder and flex the elbow
if a muscle fiber fired a single action potential but never depolarized, the fiber would
generate force for a short period of time and relax(a twitch)
Which of the following would relax a neuron?
graded hyper polarization
Chicken bones that are dissolved in vinegar for a week become flexible. This is due to elimination of ____________ from the bone.
ground substance
The cartilage the covers the lateral condyle of the femur consists of
hyaline cartilage
Which of the following makes up articular cartilage that reduces friction in joints?
hyaline cartilage
In an adult, the joint between two parietal bones in the skull is
immoveable
Where would you look for osteocytes in a slide of bone tissue?
in lacunae
During the absolute refractory period, voltage gated sodium channels are
inactivated
The equilibrium potential for chloride is about -65 mV. If a neuron's membrane potential is stuck at -63 mV and chloride channels open, chloride would travel
into cell
Ion channels that predominate in the dendrites of neurons are
ligand gated channels
Imagine you were locked in a room for a year without exposure to sunlight. Your diet was healthy, but included no supplements. Which of the following would be of most concern?
Flexible bones
Many choice: Effector tissue in the autonomic nervous system consists of
-glands -smooth muscle
Many choice: Which of the following cells are involved in bone remodeling?
-osteoblasts -osteoclasts
Many choice: Which of the following is a component of a synovial joint
-synovial fluid -synovial membrane -articular cartilage -joint capsule
Many choice: Joints between adjacent vertebra include
-synovial joints -fibrocartilaginous joints
Many choice: In which of the following places would you find fibrocartilage?
-the joint at the pubic symphysis -the knee -an intervertebral joint
Many choice: Which of the following proteins is a component of the thin filament?
-troponin -tropomyosin -Actin
As a patient is developing osteoporosis,
.Osteoclast activity is greater than osteoblast activity
If a muscle fiber fired repeated action potentials at a rapid rate, it would
Generate force until ATP depleted
Which of the following predominate in a neuron's dendrites?
Graded potentials
Which of the following gives bone the ability to resist compression?
Ground substance
Chronically elevated levels of which hormone would result in osteoporosis?
Parathyroid hormone
Which of the following hormones primarily elevates blood calcium
Parathyroid hormone (PTH)
A motor neuron and the muscle fibers it innervates is a
motor unit
A group of muscle fibers surrounded by perimysium is a
muscle fascicle
Which of the following would result in brittle bones?
mutations in the gene encoding collagen
Presume 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
Tendons are connected to bone by
not answer: Nerves from the periosteum stimulating specific muscle fibers
Which of the following joint types is most stable?
not answer: a synovial joint
Bending our elbow 90 degrees from anatomical position is called
not answer: adduction abduction
Bringing the knee to the chest represents ________________ of the hip
not answer: extension
In a muscle fiber, motor proteins are located in the
not answer: thin filament
A neuron has
one nucleus
During the relative refractory period, voltage-gated potassium channels are
open
The tissue that surrounds a muscle fascicle is called the
Perimysium
Which of the following cell types creates new bone?
osteoblasts
A muscle fiber treated with tubocurarine would be
Relaxed
Dissolving bone with vinegar is similar to the activity of which of the following cell types?
osteoclasts
Which of the following cell types dissolves bone tissue?
osteoclasts
Many choice: Which of the following cells live in lacunae?
osteocytes -something else
The organizational unit of compact bone is called a(n)
osteon
Which of the following hormones increases when blood calcium drops?
parathyroid hormone
The layer of connective tissue surrounding a bone is the
periosteum
Which of the following gives bone some flexibility and resists stretching?
protein fibers
A muscle fiber treated for a long time with succinylcholine would be
relaxed
The triceps surae (gastrocnemius and soleus) act as a
second class lever
Afferent neurons carry
sensory signals
The least stabile joint in our body is the
shoulder
The most mobile joint in the body is the
shoulder
Many choice: Which of the following are synovial joints?
shoulder knee
Effector tissue in the somatic nervous system consists of
skeletal muscle
Red bone marrow is found primarily in
spongy bone
Where are blood cells synthesized?
spongy bone
When frightened by a lion, which branch of the nervous system is increases heart rate?
sympathetic
Which of the following would transmit signals the fastest?
Myelinated large diameter fibers
In a long bone, red bone marrow is located in the
Not answer: diaphysis
Even without having studied a feedback loop that restores red blood cells mass after we bleed, you know that effector tissue in the feedback loop must be located in
Not answer: kidney
If a muscle fiber fired a single action potential but never repolarized, the fiber would
Not answer: not generate force
The primary motor proteins in muscle are found in the
Not answer: nuclei or sarcoplasmic reticulum
The cells that myelinate axons in the central nervous system are
Not answer: oligodendrocytes or ependymal cells
Many choice: Which of the following is a synovial joint?
Not answer: the joint between the teeth and the mandible
Many choice: Which of the following are effectors in the feedback loop that helps maintain blood calcium homeostasis?
Not answer: the parathyroid gland
Skeletal muscle fibers generate maximal force when
Not answer: they are longest
The primary sensors in the feedback loop that helps maintain blood calcium are
the parathyroid glands
When acetylcholine binds its receptor at the motor end plate,
A graded depolarization occurs
The membrane potential in a muscle fiber treated with tubocurarine would be
Below threshold
Imagine you had a mutation that disrupted the gene encoding collagen. Which of the following would be of most concern?
Brittle bones
In the nervous system, most information processing occurs in the
CNS
Many choice: Imagine that the voltage of a muscle fiber were held constant at -70 mV even when ions are injected. Injection of which of the following ions would cause muscle contraction?
Calcium
Skeletal muscle relaxes because
Calcium pumps are always removing calcium from the sarcoplasm
which of the following has the smallest blood supply?
Cartilage
Glutamate is a major excitatory neurotransmitter in the brain. From this information, you know that most glutamate receptors
Depolarize a neuron
The tissue that surrounds an entire muscle (the organ) is called the
Epimysium
If a person has been dead for a day, calcium concentration in the fluid surrounding the myofibrils would be
Equal to the calcium concentration in the sarcoplasmic reticulum
The meniscus in the knee consists of
Fibrocartilage
If we blocked release of acetylcholine at the neuromuscular junction, a person would experience
Flaccid paralysis
If a neuron's resting membrane potential is -70 mV and there were consistent graded membrane potentials, you would expect the voltage inside the cell to become
I need more information
Myelin
Insulates axons and causes action potentials to travel faster
If the immune system destroyed all ACh receptors on a skeletal muscle fiber,
Membrane potential would remain negative, voltage-gated sodium channels would be closed, and the muscle fiber would not generate force.
Imagine that the middle head of the deltoid were the only muscle supporting the outstretched arm below. The muscle must support the weight of the arm plus a five pound weight. If we measured the force generated by the muscle is would be
More than five pounds
When we throw a ball, the muscles moving our arm exert force on a third class lever. In this case,
The distal part of the arm moves faster than the insertion of the brachialis
Voltage gated sodium channels open when (reminder: choose the best answer)
The membrane potential reaches a threshold voltage
When the pectoralis major contracts while throwing a ball, it acts on the arm as a
Third class lever
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
To provide stress on bone so that astronauts do not experience osteoporosis before returning to earth
The structural units of spongy bone are
Trabeculae
In skeletal muscle, the protein that covers myosin binding sites when the muscle is at rest is
Tropomyosin
In skeletal muscle, the protein that binds calcium in order to initiate contraction is
Troponin
Bone has a rich blood supply
True
Estrogen helps maintain bone mass
True
Weight bearing exercise maintains bone mass
True
estrogen helps maintain bone mass
True
In skeletal muscle, an action potential is most directly caused by opening of
Voltage gated sodium channels
Many choice: Which of the following articulate with the humerus in the shoulder joint?
answer: scapula not answer: clavicle
Which of the following cells maintain the blood-brain barrier?
astrocytes
Which of the following cells control the activity of smooth muscle in the gut?
autonomic motor neurons
If we get insufficient sunlight, which of the following would be the most likely change to bone tissue?
bones would become more flexible
If the gene for collagen were damaged such that the collagen in bone became non-functional, the bone tissue would be
brittle
During the absolute refractory period, a neuron
cannot fire another action potential
As a long bone grows,
cartilage is replaced by bone tissue
Many choice: Similarities between bone and hyaline cartilage include
cells residing in lacunae
Which of the following would relax a neuron?
chloride moving into a cell
During the relative refractory period, voltage gated sodium channels are
closed
Cartilage has a rich blood supply
false
Of the choices below, when does a muscle fiber generate the most force?
during an isometric contraction
The tissue that surrounds an individual muscle fiber is called the
end-myosin
Growth of a long bone occurs at the
epiphysis
The origin of a muscle refers to
the "fixed" attachment
A herniated disc involves damage to
the fibrocartilage between adjacent vertebral bodies
Many choice: Which of the following bones articulate with the femur at the knee?
the tibia
skeletal muscle fibers generate maximal force when
they are at intermediate length
Many choice: Which of the following bones articulate with the humerus in the elbow?
ulna radius
Which of the following is considered the most effective stimulus for bone growth in adults?
weight bearing exercise and bone stress
