TEAS 7 - Science (Muscular System) Flashcards
One of three major muscle types, this muscle is found only in the heart.
cardiac muscle
___ are very fine contractile fibers, groups of which extend in parallel columns along the length of striated muscle fibers.
Myofibrils
The ___ is the fundamental unit of contraction and is defined as the region between two Z-lines.
sarcomere
___ are thin filaments of protein that form (together with myosin) the contractile filaments of muscle cells, and are also involved in motion in other types of cells.
Actin
___ are thick filaments of fibrous protein that form (together with actin) the contractile filaments of muscle cells and are also involved in motion in other types of cells.
Myosin
Muscles move bones by ___ and ___.
contracting
relaxing
There are 3 types of muscles. What are they?
- skeletal muscle
- cardiac muscle
- smooth muscle
___ muscle moves bones and generates heat.
Skeletal muscle
Skeletal muscle moves ___ and generates heat.
bones
The cells in skeletal muscle are called ___ and they contain a reddish pigment called ___. These cells have ___ nuclei.
myocytes
myoglobin
multiple
If you looked at skeletal muscle under a microscope, you would see that it has tiny lines called ___.
striations
The striations of skeletal muscle mark the contractile units called ___. In other words, between each set of striations is a sarcomere.
sarcomeres
What is between each set of striations?
a sarcomere
The myocytes also contain ___ nuclei.
multiple
___ muscle looks a lot like skeletal muscle since it is also striated.
Cardiac muscle
Why do cardiac muscle and skeletal muscle look alike?
they both have striations
The cells of cardiac muscles are called ___. These cells have ___ nucleus
cardiomyocytes
1
Cardiac muscle contains special cell junctions called ___ ___.
intercalated discs
___ muscle contains special cell junctions called intercalated discs which help the cells contract ___ which is important in moving blood through the ___.
Cardiac muscle
together
heart
Smooth muscle has a ___ organized structure than skeletal or cardiac muscle.
less
Smooth muscle contains cells with only ___ nucleus and there are __ striations.
1
no
What is the only type of muscle without striations?
smooth muscle
What is the only type of muscle with intercalated discs?
cardiac muscle
What is the only muscle cell with multiple nuceli?
myocytes (skeletal muscle)
What are the two muscle types with striations?
skeletal muscle
cardiac muscle
Where is smooth muscle found?
the digestive, reproductive, and urinary systems and in blood vessels
Skeletal muscle is arranged in ___ within bundles. The most outer layer contains connective tissue called ___. Deep to the fascia there is a layer called the ___ and deep to this layer we have smaller bundles called ___.
bundles
fascia
epimysium
fascicles
The most outer layer of skeletal muscle contains connective tissue called ___ which continues along the length of the muscle and becomes the ___ that attach muscle to bone.
fascia
tendons
What is the most outer layer of skeletal muscle?
fascia
What is the layer deep to the fascia called?
epimysium
What is the layer deep to the epimysium called?
fascicles
Each fascicle contains an outer layer called the ___ and inside each fascicle there are bundles of muscle fibers. The ___ surrounds each muscle fiber, and the muscle fibers contain smaller protein filaments surrounded by a membrane known as the ___.
perimysium
endomysium
sarcolemma
What layer surrounds each fascicle?
perimysium
What layer surrounds each muscle fiber?
endomysium
What surrounds the smaller protein filaments of the muscle fibers?
sarcolemma
Cardiac muscle can contract on its ___ because it contains areas of special tissue called nodes. The nodes control large areas of muscle in order to produce synchronous ___ of the heart.
own
contractions
Why can cardiac muscle contract on its own?
because it contains areas of special tissue called nodes
Smooth muscle is under ___ control and can sustain contractions for ___ period of time.
involuntary
long
Is smooth muscle under voluntary or involuntary control?
involuntary
Smooth muscle can also produce a wave like contraction called ___. For example, food moves through the digestive tract by way of ___.
peristalsis
peristalsis
When we describe the ___ of skeletal muscles, we use the terms origin and insertion.
location
The ___ of a muscle is the less mobile end of a joint. The ___ is the more mobile end of a joint.
origin
insertion
Think of how the body is structured. Joints need to be ___ on one end and more mobile on the other. Generally, there is more mobility at the distal ends of joints.
anchored
distal
How bones connect to bones?
ligaments
How do muscles connect to bones?
tendons
Muscles connect to bones through dense connective tissue structures called ___.
tendons
Sometimes the tendons are broad and flattened. These are called ___.
aponeuroses
An example of an aponeurosis is a ___ ___ on the lateral aspect of the thigh known as the iliotibial band.
flat tendon
What is an example of an aponeurosis?
flat tendon on the lateral aspect of the thigh known as the iliotibial band
Think of how muscles move joints. In order to ___ a joint in one direction you have to have at least one muscle on that side of the joint. To bring the joint back to its ___ position you need to have at least one muscle on the opposite side of the joint.
move
original
When the first muscle contracts the other muscle ___. The first muscle that produced the movement is called the ___. The second muscle on the opposite side of the joint that opposes the movement is called the ___.
relaxes
agonist
antagonist
The ___ muscle that produced the movement is called the agonist.
first muscle
The ___ muscle on the opposite side of the joint that opposes the movement is called the antagonist.
second muscle
Let’s look at an example to illustrate this:
The elbow can move into flexion or extension. The elbow has a muscle on the anterior side called the ___. It also has a muscle on the posterior side called the ___. Elbow flexion (bending the elbow) is caused by contraction of the biceps muscle. In this case, we can say that the biceps muscle is the ___. Since the triceps muscle opposes this movement it is called the ___.
biceps
triceps
agonist
antagonist
Identify the epicranial aponeurosis.
Point to the structure.
Identify the occipitiofrontalis muscle.
Point to the structure.
Identify the orbicularis oris.
Point to the structure.
Identify the buccinator.
Point to the structure.
Identify the sternocleidomastoid.
Point to the structure.
Identify the trapezius.
Point to the structure.
Identify the levator scapulae.
Point to the structure.
Identify the scalenes.
Point to the structures.
Identify the pectoralis major muscle.
Point to the structure.
Identify the serratus anterior muscle.
Point to the structure.
Identify the abdominal muscles.
Point to the structures.
Identify the external oblique muscles.
Point to the structures.
Identify the rectus sheath.
Point to the structure.
Identify the linea alba.
Point to the structure.
Identify the internal obliques.
Point to the structures.
Identify the transverse abdominus.
Point to the structure.
Identify the trapezius.
Point to the structure.
Identify the rhomboids.
Point to the structures.
Identify the deltoid muscle.
Point to the structure.
Identify the latissimus dorsi muscle.
Point to the structure.
Identify the erector spinae group.
Point to the structure.
Identify the longissiumus capitis muscle.
Point to the structure.
Identify the semispinalis capitis muscle.
Point to the structure.
Identify the cervicis muscles.
Point to the structures.
Identify the thoracis muscles.
Point to the structures.
Identify the lumborum muscles.
Point to the structures.
The words longissimus means ___ fibers and spinalis means attaching to the ___. The name iliocostalis tells you that the muscle attaches to the ___ and ___.
long
spine
ilium
ribs
The ___ muscles are short muscle attaching directly to the spine and the ___ are even smaller muscles attaching to the spine that help to rotate the spine.
multifidus
rotators
Identify the supraspinatus muscle.
Point to the structure.
Identify the infraspinatus muscle.
Point to the structure.
Identify the teres minor muscles.
Point to the structures.
Identify the rotator cuff muscles.
Point to the structures.
Identify the subscapularis muscle.
Point to the structure.
Identify the triceps brachii.
Point to the structures.
Identify the biceps brachii.
Point to the structures.
Identify the brachialis.
Point to the structure.
All of the muscles on the front of the forearm can be called ___ and all of the muscles on the back of the forearm can be called ___.
flexors
extensors
Identify the brachiradialis muscle.
Point to the structure.
Muscles of the hand also include names that help identify their ___. The word pollicis means ___, brevis means ___, and the muscles are named for the movement they produce.
For example, the flexor pollicis brevis is a short muscle that flexes the thumb.
locations
thumb
short
Identify the sartorius or Tailor’s muscle.
Point to the structure.
Identify the quadriceps muscles.
Point to the structure.
Identify the rectus femoris muscle.
Point to the structure.
Identify the vastus medialis muscle.
Point to the structure.
Identify the vastus lateralis muscle.
Point to the structure.
Identify the vastus intermedius muscle.
Point to the structure.
Identify the psoas major muscle.
Point to the structure.
Identify the iliopsoas muscle.
Point to the structure.
What are the 3 gluteal muscles? Identify them by pointing to their strucures.
gluteus maximus muscle
gluteus medial muscle
gluteus minimus muscle
Identify the piriformis muscle.
Point to the structure.
Identify the gemellus muscles (superior and inferior).
Point to the structures.
Identify the adductor groups of muscles.
Point to the structures.
Identify the gracilis muscle.
Point to the structure.
Identify the biceps femoris muscle.
Point to the structure.
identify the semimembranosus muscle.
Point to the structure.
Identify the semitendinosus muscle.
Point to the structure.
Identify the tibialis anterior.
Point to the structure.
Identify the extensor digitorum.
Point to the structure.
Identify the fibularis muscles.
Point to the structures.
Identify the extensor hallucis longus.
Point to the structure.
Identify the gastrocnemius muscle.
Point to the structure.
Identify the soleus muscle.
Point to the structure.
Identify the achilles or calcaneal tendon.
Point to the structure.
Identify the plantaris muscle.
Point to the structure.
Identify the popliteus muscle.
Point to the structure.
Identify the tibialis posterior muscle.
Point to the structure.
Identify the flexor muscles of the ankle.
Point to the structures.
The words digitorum would mean digits or ___ and hallucis means ___ ___.
For example the abductor hallucis moves the big toe into abduction and the flexor digitorum brevis is a short muscle that flexes the toes.
toes
big toe
So how does a muscle contract?
Here is an example of picking up a coffee cup:
Let’s say that I am sitting here writing and want to pick up a cup of coffee. In order to do so I must send a command to the muscles in my arm. The command comes from a thought generated in my nervous system. The command travels from my brain to my spinal cord to a nerve that attaches to a muscle in my arm. The command tells my muscle to contract and my arm dutifully responds by moving closer to the coffee.
What are muscles made of?
protein
If we were to examine a skeletal muscle under a microscope we would see that it is composed of tiny protein fibers or ___.
filaments
When a muscle receives a command from the nervous system to contract the protein filaments ___ past each other. In fact one of the filaments ___ to the other and drags it along.
slide
connects
The command to contract a muscle must somehow get from the ___ of the muscle to the inside.
outside
Tiny messengers called ___ bring the message from the nerve to the muscle.
neurotransmitters
Muscles need ___ to contract. Muscles must have some sort of power source in order to power the sliding filaments. The energy comes from ___.
energy
ATP
Where does a motor neuron connect to a skeletal muscle?
motor end plate
A ___ neuron connects to a skeletal muscle at a special area called the motor end plate.
motor
There is a gap (or ___ ___) between the axon terminal of the axon and the motor end plate on the muscle.
synaptic cleft
An action potential (1) in the motor neuron will cause the influx of ___ into the axon terminal (2) which promotes the release of the neurotransmitter ___ from the axon terminal (3). Acetylcholine moves across the synaptic cleft to the motor end plate (4) and promotes the opening of ___ channels causing sodium to rush into the skeletal muscle cell (5).
At rest, skeletal muscle is polarized and the movement of sodium causes it to ___.
This has an effect on the sarcoplasmic reticulum (6).
calcium
acetylcholine
sodium
depolarize
The sarcolemma surrounding the muscle cell contains tube-like structures called ___.
T-tubules
The T-tubules reach into the muscle fiber and encircle the ___.
sarcomere
Between T-tubules lies a specialized type of endoplasmic reticulum called the ___ ___.
sarcoplasmic reticulum
The sarcoplasmic reticulum is a network of membranous channels called ___. Cisternae near the T-tubules are wider and called ___ ___. A tubule and the two adjacent terminal cisternae are called a ___.
cisternae
terminal cisternae
triad
The sarcoplasmic reticulum actively transports calcium so it contains a high concentration of ___.
calcium
The concentration of calcium inside the sarcoplasmic reticulum is 2000 times greater than inside the muscle cell, so a significant ___ ___ exists between the sarcoplasmic reticulum and the inside of the muscle cell.
calcium gradient
What is excitation-contraction coupling?
The sarcoplasmic reticulum responds to the depolarization of the muscle cell by opening calcium channels in the terminal. When these channels open calcium rushes into the the muscle cell.
The sarcoplasmic reticulum responds to the ___ of the muscle cell by opening calcium channels in the terminal. When these channels open calcium rushes into the the muscle cell. This process is called ___-___ coupling.
depolarization
excitation-contraction coupling
The ___ ___ is a network of tubules that wraps around the muscle cell. Think of a loosely knit winter sweater.
sarcoplasmic reticulum
The sarcoplasmic reticulum will take ___ from the blood and store it until the muscle cell depolarizes. Once it does, the sarcoplasmic reticulum releases calcium into the ___ cell.
calcium
muscle cell
What are the 2 important contractile proteins in muscle cells?
Actin (thin filament)
Myosin (thick filament)
Actin is a contractile protein in muscle cells. It is a ___ filament and is a ___-___ protein.
thin
double-helix
Myosin is a contractile protein in muscle cells. It is a ___ filament and has large ___ protein heads.
thick
globular
The actin and myosin are arranged in an overlapping arrangement with ___ on the outside of myosin.
actin
There is another double helix protein complex wrapped around actin called the ___-___ complex.
troponin-tropomyosin complex
In the middle of this structure, there is only myosin which is called the ___ line and at the ends there are the ___ lines
m
z
The entire contractile unit between the Z lines is called a ___.
sarcomere
The goal is to get actin and myosin to connect and slide past each other so the sarcomere ___.
contracts
How do sarcomeres contract?
actin and myosin connect and slide past each other
Sarcomeres are the entire contractile unit between ___ lines.
Z
Once calcium is released by the ___ ___, calcium rushes into the sarcoplasm of the muscle cell and attaches to the ___ on the troponin-tropomyosin complex wrapped around the actin.
sarcoplasmic reticulum
troponin
When calcium attaches to the troponin on the troponin-tropomyosin complex, this causes a ___ in the position of the troponin that exposes the ___-___ site on the actin. The myosin can now bind with actin forming what is known as a ___-___.
change
myosin-binding
cross-bridge
When myosin binds with actin to form the cross-bridge, myosin can now move at its hinge region and subsequently move the actin along. This results in actin and myosin ___ past each other.
sliding
At the end of a cycle of movement, the ___ must release from actin and return to its ___ position. It can now repeat the cycle and bind with another site on the actin.
myosin
original
The cycle consists of cross-bridge formation, movement, release, and myosin’s return to its original position. This cycle is called ___-___ ___.
cross-bridge cycling
The energy needed for one cross-bridge cycle is provided by one ___ molecule.
ATP
ATP binds to the ___ head.
myosin
The ATP decomposes into ___ and a ___.
ADP
phosphate
Movement of the myosin head while it is attached to actin is called the ___ ___.
power stroke
Movement of the myosin head back to its original position is called the ___ ___.
recovery stroke.
Resting muscles store energy from ATP in the ___ heads while they wait for another contraction.
myosin
The description below illustrates the process of ___ ___.
- First we see the uncontracted sarcomere. Myosin can’t attach to actin.
- Calcium is released by the sarcoplasmic reticulum.
- Calcium attaches to troponin.
- Troponin-tropomyosin move to expose the myosin binding site.
- Myosin binds to actin powered by ATP.
- Myosin pulls the actin along causing the sarcomere to shorten.
sarcomere contraction
When a muscle contraction occurs, does the sarcomere elongate or shorten?
it shortens
Which of the following types of muscles are involuntary?
Cardiac and Visceral
