Kin 270 Exam 2 Lecture
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
Smooth muscle appears smooth because
Smooth muscle cells do not have sarcomeres
The type of cell that gives rise to a basal cell carcinoma is in the
Stratum basale
Why might a humid day with a temperature of 70 F feel hotter than a dry day with a temperature of 80 F?
Sweat doesn't evaporate. If sweat doesn't evaporate, it can't cool a person
When frightened by a lion, which branch of the nervous system is increases heart rate?
Sympathetic
Many choice: Joints between adjacent vertebra include
Synovial joints and Fibrocartilaginous joints
The threshold voltage in a muscle fiber is
The voltage at which voltage-gated sodium channels open
Which of the following is the *cause* of the absolute refractory period?
Voltage gated sodium channels cannot open
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
Organophosphates block the action of acetylcholinesterase. In this case, muscle fibers would spend more time
Above threshold
The membrane potential in a muscle fiber treated for a long time with with succinylcholine would be
Above threshold
Injecting potassium into the blood stream stops the heart. In this case, cardiac muscle cells would be stuck in the
Absolute refractory period
Many choice: Which of the following proteins is a component of the thin filament?
Actin, Tropomyosin and Troponin
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
Which of the following is considered the most effective stimulus for bone growth in adults?
Weight bearing exercise and bone stress
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
Which of the following joint types is most stable?
An immoveable joint
Many choice: In which of the following places would you find fibrocartilage?
An intervertebral joint, The knee and The joint at the pubic symphysis
The brachialis flexes the elbow when it shortens. In order to extend the elbow,
Antagonists to elbow flexion must contract
Identify #8 below
Anterior cruciate ligament
please identify #20
Articular capsule
Identify #15 below
Articular cartilage
Identify #18
Articular cartilage
Many choice: Which of the following is a component of a synovial joint
Articular cartilage, Synovial fluid and Synovial membrane
A synergist is a muscle that
Assists the prime mover for a motion
Which of the following cells control the activity of smooth muscle in the gut?
Autonomic motor neurons
When a muscle contracts
Z-lines move closer together
Moving the arm away from a mid-sagittal plane is called
abduction
Raising the arm sideways (within a frontal plane) represents
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
Which of the following types of bone contains osteons?
compact bone
As demonstrated in the skin, blood vessels travel through what tissue type?
connective
If a burn is very painful, it is likely third degree (full thickness).
false
Plantarflexion of the foot brings the big toe (hallux) _______________ the tibial tuberosity.
farther away from
When supinated, the thumb is ______________ the thigh
farther away from
Please identify #4 below:
fibula
When the splenius capitis contracts to elevate the mandible, it is acting as a
first class lever
If we blocked release of acetylcholine at the neuromuscular junction, a person would experience
flaccid paralysis
Tendons are connected to bone by
Collagen fibers from connective tissue in the muscle interweaving with collagen fibers from the periosteum and bone tissue
Blood vessels supplying the epidermis run through
Connective tissue in the dermis
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
If the stratum corneum allowed no light to pass, bones would become more
flexible
Bending our elbow 90 degrees from anatomical position is called
flexion
Bringing the knee to the chest represents ________________ of the hip
flexion
Which of the following predominate in a neuron's dendrites?
graded potentials
Chicken bones that are dissolved in vinegar for a week become flexible. This is due to elimination of ____________ from the bone.
ground substance
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 the cell
Many choice: Which of the following are synovial joints?
knee and shoulder
Ion channels that predominate in the dendrites of neurons are
ligand gated channels
identify #7 below
medial collateral ligament
Which of the following types of skin cancer is most dangerous?
melanoma
Of the choices below, when does a muscle fiber generate the most force?
During an isometric contraction
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
Which of the following joint types is least stable?
A synovial joint
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
If a muscle fiber fired a single action potential but never repolarized, the fiber would
Generate force for a short period of time and relax (a twitch)
If a muscle fiber fired repeated action potentials at a rapid rate, it would
Generate force until ATP is depleted
Which of the following would relax a neuron?
Graded hyperpolarization
Many choice: Which of the following are sensory receptors in the skin?
Hair follicle receptor ,Pacinian corpuscle and Meisner's corpuscle
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
As a patient is developing osteoporosis,
Osteoclast activity is greater than osteoblast activity
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
Chronically elevated levels of which hormone would result in osteoporosis?
Parathyroid hormone
Which of the following hormones increases when blood calcium drops?
Parathyroid hormone
Which of the following hormones primarily elevates blood calcium
Parathyroid hormone (PTH)
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
The layer of connective tissue surrounding a bone is the
Periosteum
identify #5 below
Posterior cruciate ligament
Which of the following could prevent skeletal muscle from contracting?
Preventing calcium from surrounding myofibrils, Preventing sodium from entering a cell and Allowing constant entry of sodium into a cell
The function of melanin is to
Protect cell nuclei from damaging UV radiation
please identify #12 below:
Quadriceps tendon
Many choice: Which of the following cells are involved in bone remodeling
osteoclasts and osteoblasts
Many choice: Which of the following cells are involved in bone remodeling?
osteoclasts and osteoblasts
Many choice: Which of the following cells live in lacunae?
osteocytes and chondrocytes
The organizational unit of compact bone is called a(n)
osteon
Please identify #11 below:
patella
identify #10 below
patellar ligament
identify #17 below
posterior cruciate ligament
Which of the following gives bone some flexibility and resists stretching?
protein fibers
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
red bone marrow
As a person becomes hot, they become
redder
A muscle fiber treated for a long time with succinylcholine would be
relaxed
A muscle fiber treated with tubocurarine would be
relaxed
The triceps surae (gastrocnemius and soleus) act as a
second class lever
Afferent neurons carry
sensory signals
Many choice: Effector tissue in the somatic nervous system consists of
skeletal muscle
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
Many choice: Effector tissue in the autonomic nervous system consists of
smooth muscle and glands
Red bone marrow is found primarily in
spongy bone
Where are blood cells synthesized?
spongy bone
The deepest layer of the epidermis is the
stratum basale
Which of the following is an effector that is activated in a feedback loop that responds to increased body temperature?
sweat gland
In the negative feedback loop that restores body temperature when we get hot, the effector consists of
sweat glands
Does oxygen diffuse into the blood through human skin?
yes
Which of the following would result in brittle bones?
Mutations in the gene encoding collagen
Which of the following would transmit signals the fastest?
Myelinated large diameter fibers
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
The cells that myelinate axons in the central nervous system are
Oligodendrocytes
Sebaceous glands normally secrete contents
Onto the skin surface through hair follicles
Which of the following cell types creates new bone?
Osteoblasts
Cartilage has a rich blood supply
false
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
Why does someone suffering a heart attack turn blue?
Blood becomes deoxygenated and deoxygenated blood looks blue through skin
Many choice: Which of the following affect skin color?
Blood flow and the amount of melanin
If we get insufficient sunlight, which of the following would be the most likely change to bone tissue?
Bones would become more flexible
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
During the absolute refractory period, a neuron
Cannot fire another action potential
As a long bone grows,
Cartilage is replaced by bone tissue
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.
Which of the following would relax a neuron?
Chloride moving into a cell
Flexion usually refers to
Decreasing the angle between two bones
Injecting potassium into the blood stream stops the heart. In this case, voltage gated sodium channels in cardiac muscle would be
Inactivated
The tissue that surrounds an individual muscle fiber is called the
Endomysium
The tissue that surrounds an entire muscle (the organ) is called the
Epimysium
Growth of a long bone occurs at the
Epiphysis
In a long bone, red bone marrow is located in the
Epiphysis
In order for melanin to protect against at least two types of skin cancer, the pigment must be passed to
Epithelial cells
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
In high humidity, what happens to the feedback loop that helps maintain body temperature?
Everything works normally, but the environment diminishes the effectiveness of the feedback loop.
When the pectoralis major contracts while throwing a ball, the hand moves
Faster than the insertion of the muscle
An intervertebral disc contains
Fibrocartilage
The meniscus in the knee consists of
Fibrocartilage
Which of the following stabilize joints?
Fibrous connective tissue, Cartilage, Muscles and tendons and Ligaments
A muscle that originates on the ischial tuberosity and inserts on the head of the fibula would
Flex the knee and extend the hip.
A suntan is caused by
Increased UV radiation activating melanocytes, resulting in a darkening of the skin
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
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
The type of cell that gives rise to a squamous cell carcinoma is in the
In the epidermis, but in neither the stratum corneum nor stratum basale
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 oily appearance and more acne
Whether or not you think it makes sense, 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
Increases sodium moving into a cell
Extension usually refers to
Increasing the angle between two bone's
Water loss from a third degree burn would be classified as
Insensible perspiration
Water loss through our skin on a very cold, windy day is mostly
Insensible perspiration
Fluid replacement is critical for individuals suffering extensive 3rd degree burns. This is because
Insensible perspiration is dramatically increased
myelin
Insulates axons and causes action potentials to travel faster
Many choice: Lidocaine would block sensory signals while allowing muscle contraction if
It blocked voltage gated sodium channels in sensory neurons
Identify #1 below
Lateral collateral ligament
Please identify #2 below
Lateral condyle of femur
Please identify #3 below
Lateral meniscus
identify #19
Lateral meniscus
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
Ligand gated potassium channel
The most superficial layer of the epidermis is made up of
Many layers of dead keratinocytes
Please identify # 6 below
Medial condyle of femur
Identify #16
Medial meniscus
please identify #9 below
Medial meniscus
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.
As a muscle exerts more force, which of the following is always true?
More cross bridges form
A motor neuron and the muscle fibers it innervates is a
Motor unit
Abduction refers to
Moving a limb away from the body's midline
Adduction refers to
Moving a limb towards the body's midline
The epithelial tissue of the skin is particularly well suited to its function because
Multiple layers of cells protect against entry of harmful substances and loss of vital substances
A group of muscle fibers surrounded by perimysium is a
Muscle fascicle
The origin of a muscle refers to
The "fixed" attachment
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
Which of the following prevents most insensible perspiration?
The epidermis
Many choice: Which of the following is a synovial joint?
The facet joint between vertebra
A herniated disc involves damage to
The fibrocartilage between adjacent vertebral bodies
Voltage gated sodium channels open when (reminder: choose the best answer)
The membrane potential reaches a threshold voltage
The primary sensors in the feedback loop that helps maintain blood calcium are
The parathyroid glands
Many choice: fibers from which of the following connective tissues help form a connection with bone?
The perimysium, The periosteum, The epimysium and The tendon
Skeletal muscle fibers generate maximal force when
They are at intermediate length
In a muscle fiber, motor proteins are located in the
Thick filament
The primary motor proteins in muscle are found in the
Thick filament
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
In skeletal muscle, an action potential is most directly caused by opening of
Voltage gated sodium channels
Identify #14 below
anterior cruciate ligament
Responsible for goose bumps:
arrector pili muscle
Which of the following cells maintain the blood-brain barrier?
astrocytes
Dorsiflexion of the foot brings the big toe (hallux) _______________ the tibial tuberosity.
closer to
Laterally (externally) rotating the arm brings the hand ________________ a mid-saggital plane
closer to
Medially (internally) rotating the arm brings the hand ________________ a mid-saggital plane
closer to
When pronated, the thumb is ______________ the thigh
closer to
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?
bone density
If the gene for collagen were damaged such that the collagen in bone became non-functional, the bone tissue would be
brittle
Imagine you had a mutation that disrupted the gene encoding collagen. Which of the following would be of most concern?
brittle bones
Which of the following has the smallest blood supply?
cartilage
Many choice: Similarities between bone and hyaline cartilage include
cells residing in lacunae
During the relative refractory period, voltage gated sodium channels are
closed
If melanocytes were so active that all cells in the body contained enormous levels of melanin, the individual would appear
dark brown or black
Glutamate is a major excitatory neurotransmitter in the brain. From this information, you know that most glutamate receptors
depolarize a neuron
In order for melanin to protect against at least two types of skin cancer, the pigment must be passed to
epithelial tissue
Please identify #21:
synovial cavity
Many choice: The central nervous system includes
the brain and spinal cord
Many choice: Which of the following is a layer of the true skin?
the epidermis and the dermis
Many choice: Which of the following are effectors in the feedback loop that helps maintain blood calcium homeostasis?
the kidney and the osteoclasts
Many choice: Which of the following articulate with the humerus in the shoulder joint?
the scapula
The least stabile joint in our body is the
the shoulder
The most mobile joint in the body is the
the shoulder
Many choice: Which of the following bones articulate with the femur at the knee?
the tibia
Many choice: Which of the following bones articulate with the humerus in the elbow?
the ulna and radius
When the pectoralis major contracts while throwing a ball, it acts on the arm as a
third class lever
identify #13 below
tibia
Bone has a rich blood supply
true
Estrogen helps maintain bone mass
true
Weight bearing exercise maintains bone mass
true
The dermis has
two layers
