Human Biology Chapter 13 (Muscular) – Flashcards

Unlock all answers in this set

Unlock answers
question
What do smooth, cardiac, and skeletal muscle all have in common? They are all uninucleated. They are all striated. They are all found in the walls of blood vessels. The cells of these muscles are all called muscle fibers. They all interlock at intercalated disks.
answer
The cells of these muscles are all called muscle fibers. *The cells of all three types of muscle tissues are called muscle fibers. (section 13.01)
question
Of the three types of muscle tissue, which has multinucleated fibers? smooth muscle cardiac muscle skeletal muscle both smooth and skeletal muscles both cardiac and smooth muscles
answer
skeletal muscle *Only skeletal muscle has multinucleated fibers. (section 13.01)
question
Of the three types of muscle tissue, which is voluntary? smooth muscle cardiac muscle skeletal muscle both smooth and skeletal both cardiac and skeletal
answer
skeletal muscle *Skeletal muscle is voluntary. (section 13.01)
question
Of the three types of muscle tissue, which is not striated? smooth muscle cardiac muscle skeletal muscle skeletal and smooth lack striations cardiac and smooth lack striations
answer
smooth muscle *Smooth muscle is not striated. (section 13.01)
question
Skeletal muscle contractions play a role in returning the venous blood to the heart. True False
answer
true *True, the skeletal muscle contractions play a role in returning the venous blood to the heart. (section 13.05)
question
What is found within the intercalated disks of cardiac muscle? sarcoplasmic reticulum gap junctions dense connective tissue bone myoglobin
answer
gap juctions *Gap junctions are found at intercalated disks to permit contracts to spread quickly. (section 13.01)
question
Because the heart beats continuously, cardiac fibers never relax completely. True False
answer
false *Cardiac fibers relax completely between contractions, which prevents fatigue. (section 13.01)
question
Which of the following is not a function of skeletal muscles? pumping of blood throughout the body support movement of bones maintenance of body temperature protection of internal organs
answer
pumping of blood throughout the body *Cardiac muscle makes up the heart that pumps blood throughout the body. (section 13.01)
question
From the outside of a muscle coming in, the first thing encountered would be fascia. fascicle. dense connective tissue. muscle fiber. myofibril.
answer
fascia *Muscles are covered with fascia, a type of connective tissue. (section 13.01)
question
What structure attaches a muscle to a bone? ligaments tendons bursae sarcolemma sarcoplasm
answer
tendons *Tendons connect muscles to bone. Bursae act as a cushion in the connection. Sarcolemma are the plasma membranes of a muscle fiber. Sarcoplasm is the cytoplasm of a muscle cell. (section 13.01)
question
What muscle works in a pair with the biceps brachii? the triceps brachii the trapezius the masseter the pectoralis major the sartorius
answer
the triceps brachii *The biceps brachii and triceps brachii are a pair of antagonistic muscles. (section 13.01)
question
Muscles can only pull; they cannot push. True False
answer
true *Muscles can only contract and pull on the bone they are attached to. (section 13.01)
question
The origin of a muscle is on a stationary bone. True False
answer
true *The origin is on the stationary bone while the insertion is on the bone that moves. (section 13.01)
question
Which of the following is not a term that refers to how muscles work? prime mover synergists antagonist synergism origin
answer
synergism *Synergism is not a term that refers to muscle movement. (section 13.01)
question
What is the deltoid muscle shaped like? a long thin line a square a triangle a circle a trapezoid
answer
a triangle *The Greek letter delta looks like a triangle and the deltoid is shaped like a triangle. (section 13.01)
question
What does the word brevis mean when referring to a muscle? large small huge long short
answer
short *Brevis means short and is used to indicate the size of a muscle. (section 13.01)
question
What is the name of the muscle that is responsible for blinking and winking? latissimus dorsi trapezius pectoralis major orbicularis oculi extensor digitorum
answer
orbicularis oculi *The orbicularis oculi is around the eye and is responsible for blinking and winking. (section 13.01)
question
What information does the word rectus give you about a muscle? the size of the muscle fibers the attachment of the muscle fibers the action of the muscle fibers the shape of the muscle fibers the direction of muscle fibers
answer
the direction of muscle fibers *Rectus means straight and gives information about the direction of the muscle fibers. (section 13.01)
question
Which of the following does not attach to the sternocleidomastoid muscle? rib clavicle sternum mastoid process skull
answer
rib *The sternocleidomastoid does not attach to a rib. (section 13.01)
question
Which way does the adductor longus move the thigh? away from the midline toward the midline in a circle in a cone towards the back
answer
toward the midline *The adductor longus adducts the thigh, or moves it toward the midline. It also raises the thigh. (section 13.01)
question
What is the biggest muscle (in terms of mass) in the body? gluteus maximus sartorius stapedius quadriceps femoris latissimus dorsi
answer
gluteus maximus *The gluteus maximus which makes up the buttocks is the largest muscle in the body. (section 13.01)
question
What does the word sarco mean? large short muscle tubule smooth
answer
muscle *The word sarco means muscle. (section 13.02)
question
Several of the structures in the muscle cell are given special names. For example, the cytoplasm of a muscle fiber is called the sarcoplasm. Which of the following is truly a unique structure to muscle cells (not just a renamed one)? cytoplasm nucleus endoplasmic reticulum transverse (T) system plasma membrane
answer
transverse (T) system *The T system is not found in other types of cells. (section 13.02)
question
A muscle fiber is made up of many muscle cells. T tubules. myofibrils. fascicles. bursa.
answer
myofibrils. *A muscle fiber is made up of many myofibrils divided into sarcomeres. (section 13.02)
question
One sarcomere extends from Z line to Z line. is composed of many myofibrils. contains only actin fibers. is composed of many muscle fibers. surrounds each muscle in the body.
answer
extends from Z line to Z line. *A sarcomere extends between two dark vertical lines called Z lines. (section 13.02)
question
What ion is responsible for initiating muscle contraction? Mg^2+ Ca^2+ H+ Cl- Na+
answer
Ca^2+ *Calcium ions are released from the sarcoplasmic reticulum to initiate muscle contraction. (section 13.02)
question
When a muscle contracts, the H zone almost disappears. True False
answer
true *The H zone is the area in the center of the sarcomere that almost disappears when the muscle contracts. (section 13.02)
question
What happens to the actin and myosin filaments when a muscle contracts? both of them shorten both of them lengthen both stay the same length actin shortens while myosin lengthens myosin shortens while actin lengthens
answer
both stay the same length *The actin and myosin filaments stay the same length when a muscle contracts. They just slide past each other. (section 13.02)
question
What supplies the energy for muscle contraction? actin myosin tropomyosin ATP Ca^2+
answer
ATP *ATP supplies the energy necessary for muscle contraction. (section 13.02)
question
Each actin molecule is shaped like a golf club, with a straight portion ending in a globular head. True False
answer
false *Each myosin molecule is shaped like a golf club. (section 13.02)
question
What does troponin bind to and what happens when it binds? Ca^2+, tropomyosin shifts tropomyosin, the sarcomere relaxes acetylcholine, the sarcome shortens ATP, tropomyosin returns to normal position T tubules, the sarcomere shortens
answer
Ca^2+, tropomyosin shifts *Troponin binds to Ca^2+ and this results in a shift of the tropomyosin threads, exposing myosin-binding sites. (section 13.02)
question
What is the name of the small gap that separates the axon terminal of a nerve from the sarcolemma? T tubule sliding filament synaptic cleft synaptic vesicle sarcoplasmic reticulum
answer
synaptic cleft *The small gap is called a synaptic cleft. The entire region is called a neuromuscular junction. (section 13.02)
question
When the nerve signal reaches the axon terminal what happens next? The muscle contracts. The synaptic vesicles release neurotransmitter. An electrical signal is formed that jumps the synaptic cleft. H+ is pumped into the synaptic cleft. Myosin is released from the axon terminal.
answer
The synaptic vesicles release neurotransmitter. *The synaptic vesicles release acetylcholine, a neurotransmitter, into the synaptic cleft. (section 13.02)
question
One motor neuron activates one muscle fiber. True False
answer
false *One motor neuron can stimulate from a few to several muscle fibers of a muscle because each axon has several branches. (section 13.02)
question
One motor unit obeys a principle called the all-or-none law True False
answer
true *All the muscle fibers in a motor unit are stimulated at once. They all either contract or do not contract. (section 13.03)
question
Why is the innervation ratio in the ocular muscles one motor axon per 23 muscle fibers, whereas in the gastrocnemius muscle it is one motor axon per 1000 muscle fibers? There are more nerves in the upper body than in the lower extremities. The ocular muscles require finer control than moving the legs. The innervation ratio has to do with the overall size of the muscle--the bigger the muscle, the fewer the muscle fibers per motor axon. The gastrocnemius muscle contracts much harder than the ocular muscles do. There are fewer muscle fibers in the gastrocnemius muscle than in the ocular muscles.
answer
The ocular muscles require finer control than moving the legs. *The ocular muscles require much finer control than moving the legs. (section 13.03)
question
Which of the following is not a phase of a single muscle twitch? stimulation period latent period contraction period relaxation period none of these are phases of a muscle twitch
answer
stimulation period *A stimulation period is not a phase of a muscle twitch. (section 13.03)
question
What is happening during the latent period of a muscle twitch? The muscle relaxes and returns to its former length. Fresh ATP binds to the myosin causing it to return to its resting position. ADP and phosphate are released, and the power stroke of the contraction occurs. The myosin-actin cross-bridges are broken and the sarcomere shortens. The neurotransmitter is diffusing across the synaptic cleft causing an electrical signal in the muscle cell.
answer
The neurotransmitter is diffusing across the synaptic cleft causing an electrical signal in the muscle cell. *All of the activities that begin a contraction are occurring. (section 13.03)
question
Which of the following does not occur when a muscle fatigues? Its energy reserves are depleted. Stimulation continues. Tetanus is achieved. Acetylcholine is crossing the synaptic cleft. The muscle relaxes.
answer
Tetanus is achieved. *Tetanus is maximal sustained contraction and does not occur during muscle fatigue. (section 13.03)
question
In good muscle tone, how many motor units are contracted? none some all 5 -10% of the motor units 10 - 15% of the motor units
answer
some *In good muscle tone, some motor units are always contracted, but not enough to cause movement. (section 13.03)
question
Contraction of a muscle requires all the motor units to be undergoing tetanic contraction. True False
answer
false *Some motor units are contracting maximally while others are resting, allowing sustained contractions to occur. (section 13.03)
question
Which of the following is not an energy source for muscle contraction? glycogen triglycerides glucose fatty acids starch
answer
starch *Muscles store glycogen and triglycerides for use as energy and acquire glucose and fatty acids from the blood. (section 13.03)
question
Which of the following is not a source of ATP for muscle contraction? ATP in the blood ATP stored in the cell the creatine phosphate pathway fermentation aerobic respiration
answer
ATP in the blood *Muscles do not get ATP from the blood. (section 13.03)
question
Of the three pathways for obtaining ATP for muscle contraction, which one requires oxygen? only the creatine phosphate pathway only fermentation only respiration fermentation and respiration the creatine phosphate pathway and fermentation
answer
only respiration *Aerobic respiration requires a supply of oxygen. The creatine phosphate pathway and fermentation pathway do not require oxygen. (section 13.03)
question
Of the three pathways for supplying ATP to the muscle, which pathway(s) do slow-twitch fibers prefer? the creatine phosphate pathway fermentation aerobic respiration the creatine phosphate pathway or fermentation the creatine phosphate pathway or aerobic respiration
answer
aerobic respiration *Slow-twitch fibers prefer to use aerobic respiration for their ATP source since it produces a large supply of ATP. (section 13.03)
question
Jillian is a top level cross country runner due to her having predominantly slow-twitch muscle fibers. True False
answer
true *Slow-twitch muscle fibers are aerobic, have steady power, and have endurance--all required for cross country running. (section 13.03)
question
Why are slow-twitch muscles dark? They have many more myofibrils per motor unit than fast-twitch fibers. They are designed for strength and explosions of energy. They need less blood than fast-twitch fibers. They contain myoglobin. They have fewer mitochondria.
answer
They contain myoglobin. *Slow-twitch fibers are dark because they contain myoglobin, the respiratory pigment found in muscles. (section 13.03)
question
What is the name of a sudden and involuntary muscular contraction, often accompanied by pain? bursitis sprain strain tic spasm
answer
spasm *A spasm is a sudden and involuntary muscular contraction, often accompanied by pain. Bursitis is the inflammation of the bursae. A sprain is a twisting of a joint. A strain is the stretching or tearing of a muscle. A tic is a spasm that can be controlled voluntarily. (section 13.04)
question
What is the difference between a tic and a spasm? A tic is a spasm that can be controlled voluntarily. A tic is a strong, and very painful spasm, especially of the leg and foot. A tic is caused by stretching or tearing of a muscle, while a spasm is just an involuntary contraction. A tic is caused by the inflammation of a tendon, while a spasm is just an involuntary contraction. A tic refers to achy muscles, usually due to over exercise, while a spasm is just an involuntary contraction.
answer
A tic is a spasm that can be controlled voluntarily. *A tic is a spasm that can be controlled voluntarily, but only with great effort. (section 13.04)
question
Which of the following injuries is most likely to happen to the ankle? sprain strain convulsion bursitis muscular dystrophy
answer
sprain *A sprain is a twisting of a joint. A strain is the tearing of a muscle. A convulsion is a seizure of the muscles. Bursitis is the inflammation of the bursa. Muscular dystrophy is a progressive degeneration of muscles (section 13.04)
question
Fibromyalgia is a temporary condition of achy muscles, usually due to overuse. True False
answer
false *Fibromyalgia is a chronic condition whose symptoms include achy pain, tenderness, and stiffness of muscles. (section 13.04)
question
Which muscle injury is characterized by a twisting of a joint leading to swelling and injury? sprain strain tendinitis bursitis myalgia
answer
sprain *A sprain is characterized by a twisting of a joint leading to swelling and injury. A strain is the stretching of a muscle. Tendinitis is the inflammation of a tendon. Bursitis is the irritation of the bursa. Myalgia refers to achy muscles. (section 13.04)
question
Which disease is an autoimmune disease characterized by weakness that especially affects the muscles of the eyelids, face, neck, and extremities? myalgia muscular dystrophy myasthenia gravis tendinitis bursitis
answer
myasthenia gravis *These symptoms describe the disease myasthenia gravis (section 13.04)
question
Leiomyomas are a type of smooth muscle cancer that occurs in the uterine wall. True False
answer
true *True, leiomyomas are a type of smooth muscle cancer that occurs in the uterine wall. (section 13.04)
question
What is the reservoir for Ca2+ in the body? muscles bones liver brain blood
answer
bones *The skeleton acts as a reservoir for calcium. (section 13.05)
question
Which of the following does not occur when you are very, very cold? More blood flows to the surface of the body. Smooth muscle contracts inside the blood vessels supplying the skin. The arrector pili muscles contract. Shivering occurs. You get goose bumps.
answer
More blood flows to the surface of the body. *When you are very, very cold, less blood flows to the surface of the body in order to keep the core of the body, where the vital organs are, warm. (section 13.05)
question
What happens when the arrector pili muscles contract? Your head nods "yes." Your leg kicks out. The hairs on your skin stand on end. The blood from your skin is rerouted to your core. You tap your finger.
answer
The hairs on your skin stand on end. *The arrector pili muscles are tiny bundles of smooth muscle attached to the hair follicles that cause the hairs to stand up. (section 13.05)
question
Temperature sensitive neurons in the skin are responsible for initiating shivering. True False
answer
false *These neurons are located in the hypothalamus of the brain. (section 13.05)
question
If you lock your knees while standing you may pass out because of the lack of venous return to the heart. True False
answer
true *The skeletal muscles aid in the process of venous return by pushing blood back toward the heart. If you lock your knees, there is a shortage of blood returning to the heart and you may pass out. (section 13.05)
Get an explanation on any task
Get unstuck with the help of our AI assistant in seconds
New