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