Safrans exams
Contracting the gastrocnemius muscles to elevate the body on the toes involves a ________ lever, which means that the load is __
second-class; located between the applied force and fulcrum
type of bone with a round and flat shape that is part of the knee joint
sesamoid bone
the joint that permits the greatest range of mobility pf any joint in the body is the __ joint, which is a __ joint
shoulder; diarthrotic
Which organ system provides support, protection of soft tissue, mineral storage, and blood formation?
skeletal
The type of muscle fiber that is most resistant to fatigue is the ________ fiber.
slow
which of the following type of muscle fibers are best adapted for prolonged contraction such as standing all day
slow fibers
__ cells are all of the cells of the body except reproductive cells (sperm and oocytes)
somatic
layer of the epidermis that contains non-dividing keratinocytes producing keratin
squamous cell layer
layer of the epidermis located the deepest that contains dividing stem cells and melanocytes
stratum basale
A muscle that assists the muscle that is primarily responsible for a given action is a(n)
synergist
movable joint where the end of long bones are encased in a capsular cavity filled with fluid
synovial
fibroblast-like cells that constitute the predominant cell types found in the internal lining of a diarthroic joint capsule and produce lubricating fluid components
synoviocytes
in the facilitated diffusion of glucose, what determines the direction in which glucose molecules will be transported and the rate at which glucose molecules are transported
the concentration gradient
the sex of an adult human can be determined by bone shape details. the 2 skeletal structures that are particularly helpful at the basic sexual dimorphism are
the skull and pelvis
Which of the following statements is true?
the tension produced by muscle tendons surrounding a joint stabilize the joint
which of the following descriptors is false regarding enzymes
they are consumed during the reaction
which of the following statements about water is false
they are consumed during the reaction
which of the following is not a property of articular cartilage surfaces located in the synovial joint
covered by perichondrium
reflex that results in a motor response on opposite side of the stimulus and complements the response produced on the same side of the stimulus
crossed extensor reflex
Process by which the cytoplasm is divided into two equal parts at the end of a cell division
cytokinesis
Phase that corresponds to a mature cell that stopped dividing and exited the cell cycle
g-phase
The junction type that lets neighboring cells exchange small molecules is the
gap junction
Membranous organelle involved in the modification, storage and packaging of secretory products
golgi apartus
non-movable joint where fibrous connections form a periodontal ligament
gomphosis
a fasicle is
group of muscle fibers that are encased in the perimysium
what structural characteristics distinguish cardiac tissue from skeletal tissue? cardiac muscle cells
have intercalated discs, contract automatically without neural stimulation
according to the national institute of health each of the following is a risk factor for osteoarthritis except
high blood pressure
the acetabulum is the socket of a __, into which the head of the __ fits
hip bone; femur
Glands that secrete their product by the bursting of cells are __ glands
holocrine
The maintenance of a relatively constant internal environment in an organism is termed
homeostasis
the most common type of cartilage is __ cartilage
hyaline
non polar organic molecules are good examples of:
hydrophobic compounds
Hemolysis may occur when a blood cell is placed into a __ solution
hypotonic
the 3 bones that make up a hip bone are
ilium, ischium, pubis
microvilli are found on cells of the inner surface of the small intestine, where they
increase the absorption of nutrients from digested food
which of the following is NOT true regarding the establishment of a resting potential for neurons
ion pumps in the plasma membrane force sodium ions into the cell and eject potassium ion out of the cell
Reflexes that activate muscles on the same side of the body as the stimulus are called
ipsilateral
the end of a muscle that __ when the muscle contraction is called the __
is stationary; origin
in the human muscular-skeletal system, a __ can be compared to a fulcrum, and a __ to a lever
joint; bone
what substance makes nails hard structures
keratin proteins
type of bone that consists of a diaphysis and two epiphyses and is found in limbs
long bone
all of the following statements are true about the organic phase of bone except
is the phase that stores large amounts of calcium
the type of contraction in which the muscle fibers do not shorten is called
isometric
which of the following is NOT true about the cerebrum
it derives from the mesencephalon (midbrain)
which of the following is NOT true of acetylcholine
it enters the muscle fiber to release calcium from the sarcoplasmic reticulum
which of the following statements describe PTH action on bone
it increases calcium reabsorption from the kidneys, it increases calcium release from bone
which of the following about hydrogen bonds is false
it is composed of non-polar molecules
the 3 functions of synovial fluid are nutrient distribution, shock absorption, and
lubrication
Why does osteoporosis affect less aging men than aging women
men continue producing sex hormones into old age
Stage of mitosis when all the chromosomes are condensed and arranged at the equator of the dividing cell
metaphase
the portion located between 1 of 2 extremities and the shaft of the long bone is called the
metaphysis
what are 3 different components that make up the cytoskeleton in all body cells
microfilaments, intermediate filaments, microtubles
Membranous organelle with a double membrane which is involved in cellular respiration
mitochondria
the end of a muscle that is attached the point that __ when the muscle contracts is the __
moves; insertion
motor neurons that control skeletal muscles typically have multiple dendrites and a single axon and are classified as
multipolar
protein component of thick filaments
myosin
which of the following is arranged in the correct order from the most complex to the simplest
organism, system, organ, tissue, cellular, molecular
cells that lay down the organic compounds of the bone matrix are called
osteoblasts
type of cells that are multinucleated and dissolve the bone matrix by secreting acids
osteoclasts
type of cells that are mature and trapped within lacunae of the bone matrix
osteocytes
stem cells that divide into cells which, which in turn, will be responsible in the production of the organic bone matrix
osteogenic cells
the structural units of mature compact bone are called __ and have a central canal in which __ are located
osteon; blood vessels
if blood calcium levels get too high which hormone is likely to be activated and what organ is responsible for its production
parathyroid hormone and parathyroid gland
A defense cell engulfing a bacterium illustrates
phagocytosis
The increase in muscle tension that is produced by increasing the number of active motor units is called
recruitment
a patient takes a medication that blocks ACh receptors of skeletal muscle fibers. what is the drug's effect on skeletal muscle contraction
reduces the muscle's ability for contraction
in a series of measurements of resting membrane potentials, the following values were record. which one is likeliest to be an error
+100mV
The region of the sarcomere containing the thick filaments is the
A band
During anaerobic glycolysis
ATP is produced.; pyruvic acid is produced. oxygen is not consumed.; carbohydrate is metabolized
Puffer fish poison blocks voltage-gated sodium channels like a cork. What effect would this neurotoxin have on the function of neurons?
The axon would be unable to generate action potentials.
Mike falls off his skateboard and sprains his ankle. Which of the following most likely occurs with this type of accident?
a ligament is stretched and collagen fibers in the ligament are damaged
in which of the following would the rate of impulse conduction be the greatest
a myelinated fiber of a 10-um diameter
the period during which an excitable membrane cannot respond to any further stimulation is the __ period and is due to inactivation of __
absolute refractory; voltage-gated sodium channels
Triggering of the muscle action potential occurs after
acetylcholine binds to chemically gated channels in the motor end plate membrane.
globular protein that polymerizes to form thin filaments
actin
a process that requires cellular energy to move a substance against its concentration gradient is called
active transport
type of cells that contain a large single droplet
adipocytes
How do lipid-soluble molecules diffuse across the plasma membrane?
diffuse directly through the plasma membrane
How do small water-soluble molecules and ions diffuse across the plasma membrane?
diffuse through membrane channels
the auricle, or outer ear, contains
elastic cartilage
The sum of the electrical and chemical forces acting on an ion is known as its
electrochemical gradient
The delicate connective tissue that surrounds the skeletal muscle fibers and ties adjacent muscle fibers together is the
endomysium
all of the following contain blood vessels except the
epidermis
area between the dura mater and the vertebral wall, containing fat and small blood vessels
epidural space
injections of analgesics that alleviate severe back pain such as pain experienced during child laber is usually administered in the __ of the lower spinal segments
epidural space
the dense layer of connective tissue that surrounds an entire skeletal muscle is the
epimysium
synaptic vesicles contain neurotransmitters that are released by __ when the action potential arrives
exocytosis
an adult skull suture is an example of syndesmotic joint
false
Large-diameter, densely packed myofibrils, large glycogen reserves, and few mitochondria are characteristics of
fast fibers
type of bone that consists of thin parallel surfaces that provides protection to underlying soft tissues
flat bone
layer of the dermis located the deepest and that is the closest to the subcutaneous layer
hypodermis
How would the loss of acetylcholinesterase from the motor end plate affect skeletal muscle?
it would cause spastic paralysis
Axons cross from one side of the spinal cord to the other through the
lateral white column
the main components (ingredients) of the Moderna COVID-19 mRNA vaccine are
lipid nano particles, large carbohydrates
which of the following labels best matches osteocyte
mechanosensor, mature bone cell
which of the following is NOT true of melanin
melanin is released by exocytosis into the extracellular environment
When acetylcholine binds to receptors at the motor end plate, the end plate membrane becomes
more permeable to sodium ions.
the anterior root of the spinal cord contains
motor neurons
a single motor neuron together with all the muscle fibers it innervates is called a
motor unit
In an isotonic contraction
muscle tension exceeds the load and the muscle lifts the load.
The white matter of the spinal cord is mainly
myelinated axons
When body temperature rises, a center in the brain initiates physiological changes to decrease the body temperature. This is an example of
negative feedback
which of the following neurotransmitters is a dissolved gas which has an indirect effect on ion channels
nitric oxide
which of the following types of bone fracture is likely to repair the best with careful treatment
nondisplaced epiphyseal
molecules that store and process genetic info are the
nucleic acids
the myelin sheath that covers many CNS axons is formed by
oligodendrocytes
the highest concentration of eccrine (merocrine) sweat glands that secrete watery fluid onto the surface is found
on the palms of the hands
innermost protective layer of the CNS that is in direct contact with either the spinal cord or brain tissue
pia mater
the tracts that connect the cerebellum to the brain stem are located in the
pons
This feedback exaggerates variations from normal
positive feedback
the following is the list of steps involved in the process of secretion by the Golgi apparatus
products from RER are packaged into transport vesicles, vesicles arrive at the forming face, enzymes modify arriving proteins and glycoproteins, cisternae move from the forming face toward the maturing face, secretory vesicles are formed at the maturing face, exocytosis
interaction between individual polypeptide chains to form a protein complex is __ structure
quaternary
sensory function of the hand is by the 3 following peripheral nerves
radial, ulnar, and median
the articulation that provides strength and stability to the elbow is the __ joint. the 2 bones that interlock at this joint are the __
radial; humerus and radius
the layer of skin that contains bundles of collagen and elastic fibers responsible for the strength of the skin is the __ layer
reticular
Non-membranous organelle involved in protein synthesis
ribosomes
After death, muscle fibers run out of ATP and calcium begins to leak from the sarcoplasmic reticulum into the sarcoplasm. This results in a condition known as
rigor mortis
Phase of the interphase during which a cell duplicates its chromosomes by replicating its DNA
s-phase
Glands that discharge an oily secretion into hair follicles are ________ glands.
sebaceous
in the condition called __, a virus that is dormant in anterior horns of the spinal cord reactivated and attack neurons in the posterior roots, causing a painful skin rash as seen in the dermatome supplied by the affected spinal nerve
shingles
type of bone with boxy shape that can be found in wrist or ankle
short bone
cardiac muscle cells are
striated due to the arrangements of intracellular protein complexes
Samples of CSF for diagnostic purposes are normally obtained by placing the tip of a needle in the
subarachnoid space
what are the body's 2 sources of vitamin D3
sunlight and food
The narrow space between the synaptic terminal and the muscle fiber is the
synaptic cleft
non-movable joint where bones are connected by rigid cartilaginous structures
synchondrosis
When a second EPSP arrives at a single synapse before the effects of the first have disappeared, what occurs?
temporal summation
At each end of the muscle, the collagen fibers of the epimysium, and each perimysium and endomysium, come together to form a
tendon
incoming sensory information is processed and relayed to the cerebrum by the
thalamus
which of the following statements about the potential is FALSE
the rapid depolarization phase is caused by the entry of potassium ions into the cell
each of the following is a direct function of the skeletal system except
thermoregualtion
which of the following become connected by myosin cross-bridges during muscle contraction
thin and thick filaments
which of the following best describes the term Z line
thin filaments are anchored here
elastic protein that extends from the Z line to the ends of thick filaments
titin
sensory neurons of the PNS that display a single elongated process with a cell body that lies off to the side are classified as
unipolar
The passageway between the lateral ventricles and the third ventricle is the
2 interventricular foramens
the type of burn that is the lease painful but requires skin grafting is a
3rd degree
Thin skin contains ________ epidermal layers
4
thick skin contains ________ layers.
5
the amount of time it takes for a cell to progress from stratum basale to stratum corneum is
7-10 days
method used by clinicians that test for CNS damage and which results in the bending back of toes following stimulation at the lateral sole of an adult foot
Babinski reflex
what is the correct order of occurrence for the steps of protein synthesis
DNA uncoils for transcription, mRNA is produced in nucleus, mRNA moves to ribosome, ribosome moves along mRNA, tRNA brings amino acids to ribosome, polypeptide is produced.
cutaneous plexus
Deep network of arteries along the reticular layer
The region of the sarcomere that always contains thin filaments is the
I band
the center of a sarcomere where the thick filaments are linked together and stablized by accessory proteins is called the
M line
Epithelium is connected to underlying connective tissue by
a basement membrane
the following are the main steps in the generation of an action potential
a graded depolarization brings an area of an excitable membrane to threshold, voltage-gated sodium channel activation occurs, sodium ions enter the cell and depolarization occurs, voltage-gated sodium channels are inactivated, voltage gated potassium channels open and potassium moves out of the cell, initiating repolarization, voltage gated sodium channels regain their normal resting properties, a temporary hyper-polarization occurs
Compared to the extracellular fluid, cytosol contains
a lower concentration of sodium ions
slightly movable joints where bones are connected by a ligament
amphiarthroses
the following steps involved in transmission at a cholinergic synapse
an action potential depolarizes the synaptic terminal at the presynaptic membrane, calcium ions enter the synaptic terminal, acetylcholine is released from storage vesicles by exocytosis acetylcholine binds to receptors on the postsynaptic membrane, chemically-gated sodium channels on the postsynaptic membrane are activated, acetylcholinesterase hydrolyzes acetylcholine, the pre-synaptic terminal reabsorbs choline.
type of muscle whose action opposes that of another muscle is called an
antagonist
all of the following are true of muscle spindles EXCEPT they
are found in tendons
Arthritis always involves damage to the ________ cartilages, but the specific cause can vary.
articular
Mary is in an automobile accident and suffers a spinal cord injury. She has lost feeling in her lower body. Her doctor tells her that swelling is compressing a portion of her spinal cord. Which part of her cord is likely to be compressed?
ascending tracts
which one of the follow is NOT one of the 4 main tissue categories
bone tissue
spinal nerves conduct
both afferent and efferent signals, both sensory and motor info
what is released from sarcoplasmic reticulum terminal cisternae upon arrival of an action potential
calcium
all of the following statements are true about the prolonged effect of UV radiations striking the unprotected skin except
can decrease the production of vitamin D
an example of function of the PNS is
carrying motor commands to skeletal, smooth, and cardiac muscles, bringing sensory input to the CNS
endochondral ossification begins with the formation of a
cartilage scaffold
the posterior root ganglia mainly contain
cell bodies of sensory neurons
the glial cells that wrap the __ of a typical motor neuron are called Schwann Cells
cell body
which main region of your brain coordinates complex somatic motor pattern that involved voluntary movements such as posture and balance and can fail when intoxicated with alcohol
cerebellum
a postsynaptic neuron will develop an EPSP when
chemically regulated sodium channels open and sodium is diffusing into the cell
types of cells that are mature and trapped within lacunae of the cartilage mix
chondrocytes
the dominant type of extracellular protein fiber in dense connective tissue is
collagen
what type of muscle contraction occurs when the stimuli are so high that the relaxation phase is suppressed and the highest tension possible is maintained over a plateau period
complete tetanus
what physiological process occurs along the membrane of a T-tubule invagination
conduction of the action potential into the cell interior
Blood is what type of tissue?
connective
the tough superficial layer of the epidermis is known as the stratum
corneum
Long-term deficiency of vitamin D results in
decrease in circulating levels of calcitriol, rickets
a threshold stimulus is the
depolarization necessary to cause an action potential
area of the skin that a single nerve innervates
dermatome
place the following events in the correct order starting where the CSF is mad an ENDING at the site where the CSF is absorbed into the general circualtion
ependymal cell layers which are modified epithelia with tight junctions produces CSF at the choroid plexus, the CSF moves from the choroid plexus into the ventricles and fills the spinal cord central canal, the CSF enters the subarachnoid space through small apertures located by the 4th ventricle, the CSF flows around the entire periphery of the brain and of the spinal cord providing cushioning against physical trauma, the CSF is absorbed into the venous sinuses at the arachnoid villi and eventually regains the general circulation through the jugular veins
Put the following structures in order from superficial to deep: 1. muscle fiber 2. perimysium 3. myofibril 4. fascicle 5. endomysium 6. epimysium
epimysium, perimysium, fascicle, endomysium, muscle fiber, myofibril
dense layer of connective tissue composed of collage fibers that surrounds the exterior of peripheral nerves
epineurium
the severe acute respiratory disease called COVID-19 is caused by a DNA virus that uses all the steps of the central dogma (transcription and translation) to replicate into new particles
false
type of cells that are always found in connective tissues proper and produce large amount of proteins that assemble in fibers
fibroblasts
non-movable joint where 2 bones are completely fused
fibrous joint
the purpose of the blood brain barrier is
to isolate neural tissue in the CNS from the general circulation, to protect the brain from toxins or pathogens that circulate in the blood
at rest, active sites on the actin are blocked by
tropomyosin molecules
When calcium ion binds to troponin,
tropomyosin rolls away from the active site on actin
an action potential develops if simultaneous stimuli produce postsynaptic graded potentials as follows: 3 EPSPs that each corresponds to +10mV and 1 IPSP that corresponds to -10mV? To answer this question consider a resting potential of -70mV and a threshold potential of -60mV
true
hair follicles are usually not affected in a second degree burn. this is because basal cells in the hair matrix are responisble for hair regrowth are located in the deeper portion of the dermis
true
at the brachial plexus, the anterior rami of several spinal nerves converge into large bundles of axons that are termed
trunks
put the following events of the neuromuscular junction in the order in which they occur
vesicles full of acetylcholine are stored at the axon terminal, action potential arrives at the neuromuscular joint, acetylcholine is released into the synaptic cleft, acetylcholine binds to ligand gated sodium channels, action potential is propagated in the sarcolemma
In hydrolysis reactions, compounds react with
water, causing decomposition
in a sarcomere, cross-bridge attachement occurs specifically in the
zone of overlap
When a skeletal muscle fiber contracts,
zones of overlap get larger