Introduction to muscular system Flashcards
What are the four functions of the skeletal muscle?
Movement
posture
protection
thermogenesis
What type of skeletal muscle is this?
_________-contraction pulls on insertions where a tendon attaches to a bone or
other tissue.
Movement
What type of skeletal muscle is this?
_________-producing muscle tone with continuous contractions to stabilize
joints.
Posture
What type of skeletal muscle is this?
_________-muscles support the walls of the abdominopelvic cavity and protect
the visceral organs ex: rectus abdominis and transverse abdominis protect the intestines.
Protection
What type of skeletal muscle is this?
_________-Metabolism can be regulated to produce heat and warm the body
temperature.
Thermogenesis
What are the two general functional properties of muscle tissue?
Excitability and
contractility
What type of general functional property of muscle tissue is this?
_______- muscles respond to stimuli. In the case of skeletal muscles, we will
see that the stimulus comes from a motor neuron.
Excitability
What type of general functional property of muscle tissue is this?
_______-muscles can shorten when stimulated.
Contractility
Structure/Location Cardiac Muscle: Found in the muscular wall of the heart (myocardium).
Branching striated cells called 7)______ have a central round nucleus and form cell
junctions called 8)___________ disks that contain desmosomes and gap junctions.
9)_____________- alternating light and dark bands (stripes)
7) cardiomyocytes
8) Intercalated discs
9) Striations
Functional Properties of Cardiac Muscle:
• Contraction is 10) _______
o Stimulated by an internal pacemaker of the heart.
o Regulated by the autonomic nervous system and endocrine system.
10) involuntary
Structure/Location of Smooth Muscle: Spindle shaped (fusiform) cells with a central nucleus
and no striations. Found in the walls of hollow organs.
Functional Properties of Smooth Muscle:
• 11) ______
o Regulated by the autonomic nervous system and endocrine system.
11) involuntary
Structure/Location of Skeletal Muscle: Long, striated cells called 12)_________ that
contain multiple nuclei.
12) fibers
13)_________- a bundle of skeletal muscle fibers
The Skeletal Muscle Organs are connected to bones through tendons (dense regular CT)
• Aponeurosis- tendon that forms a thick flattened sheet.
Fascicle
14)_________- location where a tendon attaches to a bone that remains stationary during
the action produced by contraction of that skeletal muscle.
Origin
15)________- attachment that moves during the action produced by contraction.
Insertion
Connective Tissue layers of skeletal muscle.
*In order
Epimysium perimysium endomysium sarcolemma myofibril Sarcoplasmic Transverse (T) Tubules Terminal citernae.
What connective tissue layer of skeletal muscle is this?
16)_________- superficial covering of fibrous CT that encloses the skeletal muscle
organ and connects to the tendons
Epimysium
What connective tissue layer of skeletal muscle is this?
______-fibrous CT covering bundles of muscle fibers called fascicles
Perimysium
What connective tissue layer of skeletal muscle is this?
______-areolar CT covering individual fibers within a fascicle.
Endomysium
What connective tissue layer of skeletal muscle is this?
_______-plasma membrane of a muscle fiber
Sarcolemma
What connective tissue layer of skeletal muscle is this?
_______-non-membranous organelles within muscle fibers made of repeating
structural and functional units called Sarcomeres containing overlapping myofilaments.
Myofibril
What connective tissue layer of skeletal muscle is this?
______-membranous organelles similar to the smooth endoplasmic
reticulum surrounding myofibrils its primary function is storage and release of calcium.
Sarcoplasmic Reticulum
What connective tissue layer of skeletal muscle is this?
______-deep indentations in the sarcolemmal surface forming a
network of narrow spaces filled with extracellular fluid. The sarcolemma here contains channels
that allow facilitated diffusion of sodium ion from the extracellular fluid into the cytoplasm
surrounding the sarcoplasmic reticulum
Transverse (T) tubules
What connective tissue layer of skeletal muscle is this?
_____-expanded chambers of sarcoplasmic reticulum adjacent to
T-tubules.
Terminal cisternae
________: structural and functional unit of skeletal muscle cells contains
overlapping thick and thin myofilaments
Structure of Sarcomere
What type of Structure of Sarcomere is this:
24)_______: fibrous proteins within myofibrils that produce contraction
o Thick filaments contain the motor protein called 25)________ ATPase
o Thin filaments contain actin, tropomyosin, and troponin
§ ____- cytoskeletal protein supports shape of the cell and contains
binding sites for myosin.
§ _____- calcium sensor protein
§ _____- fibrous protein covers myosin binding sites of actin
24) Myofilament
25) Myosin ATpase
* Actin
* Troponin
* Tropomyosin
What type of Structure of Sarcomere is this:
______-ends of sarcomere contain proteins that anchor thin filaments in place.
Z-lines
What type of Structure of Sarcomere is this:
____-entire length of the thick filaments
A- band
What type of Structure of Sarcomere is this:
____-only thin filaments with no overlap of thick filaments
I-Band
What type of Structure of Sarcomere is this:
____-central region of thick filaments with no overlap of thin filaments
H-band
What type of Structure of Sarcomere is this:
_____-center of H band
M-line
Functional Properties of Skeletal Muscle: Contraction is under 26) _______control by the somatic nervous system. Somatic motor neurons excite
contraction of muscle fibers.
26) Voluntary
Nueromuscular:
____-end of motor neuron that releases neurotransmitters to excite
muscle fiber
Axon Terminal
Nueromuscular:
_____-sarcolemmal surface adjacent to axon terminal that has
receptors that detect neurotransmitters
Motor end
Nueromuscular:
_____-small space between the axon terminal and motor end plate
Synaptic cleft
Nueromuscular:
____-a motor neuron and all of the muscle fibers it excites
Motor Unit
Mechanism of excitation contraction coupling:
_____-At the NMJ, the axon terminal releases acetylcholine (ACh). The
motor end-plate is the location of the ACh-receptors in the muscle fiber sarcolemma. When Ach
molecules are released, they diffuse across a minute space called the synaptic cleft and bind to
the receptors that stimulate an action potential (brief reversal of the membrane potential)
Excitation
Mechanism of excitation contraction coupling:
_____-An action potential stimulates the release of calcium ions from the
sarcoplasmic reticulum into flood the sarcoplasm. Calcium is the mediator of excitation
contraction coupling that binds to troponin exposing the binding sites on actin to allow crossbridge
formation. A cross-bridge forms between actin and the myosin heads triggering
contraction. As long as Ca++ ions remain in the sarcoplasm to bind to troponin, and as long as
ATP is available, the muscle fiber will continue to shorten.
Contraction
What are fascicle arrangement: there are 5
- Parallel (non fusiform)
- Fusiform
- Convergent
- Circular
- Pennate
What type of fascicle arrangement is this?
_____-fibers run straight from origin to insertion
o Ex: Sartorius
Parallel (non-fusiform)
What type of fascicle arrangement is this?
____-spindle shaped large belly tapers at ends
o Ex: Biceps brachi
Fusiform
What type of fascicle arrangement is this?
____-spread out broadly at the origin but come together to a
narrow tendon for the insertion.
o Ex: Pectoralis major
Convergent
What type of fascicle arrangement is this?
_____-fascicles form concentric rings that surround an opening
o Ex: Orbuclaris oris
Circular
What type of fascicle arrangement is this?
_____-“feather like” fibers arranged at an oblique angle to a tendon. Allows the
muscle to produce a large force at the expense of producing less movement.
* Unipennate
*Bipennate
*Multipennate
Pennate
What are three different from of pennate one of the fascicle arrangement.
Unipennate
Bipennate
Multipennate
What type of pennate is this?
____-all muscle fibers on same side of the tendon.
§ Ex: Extensor digitorum
Unipennate
What type of pennate is this?
_____-fibers on both sides of the tendon.
§ Ex: Rectus femoris
Bipennate
What type of pennate is this?
____-tendon branches within the muscle.
§ Ex: Deltoid
Multipennate
Muscle Nomenclature: 7 criteria commonly used to name muscles
Shape- ex: 40)______________=triangular
Origin/Insertion- ex: 41)_________________= O- manubrium and clavicle I- mastoid
Fiber direction: rectus abdominis, external and internal abdominal oblique
# of origins: 42)______________ (2 heads) brachii, 43)___________ (3 heads) brachii
Location: ex: biceps brachii (arm), biceps femoris (thigh), temporalis (covers temporal bone)
Size: ex: extensor carpi radialis brevis (short) and longus (long), adductor magnus (largest)
Action: ex: extensor carpi radialis, flexor carpi radialis, adductor magnus, supinator, pronator
40) Deltoid 41) stermocleidomastoid 42) Biceps 43) Triceps
What type of Muscle Terminology: Example of Elbow Flexion:
_____-main muscle responsible for the action.
• Ex: Biceps brachii
Prime mover
What type of Muscle Terminology: Example of Elbow Flexion:
____-muscle that stretches and stabilizes in support of the action
of the agonist.
• Ex: Triceps brachii
o O: long head infraglenoid tubercle, lateral head proximal lateral humerus, medial
head posterior humerus
o I: Olecranon process of ulna
o A: Extension as prime mover but as antagonist slows and stabilizes elbow flexion.
Antigonist
What type of Muscle Terminology: Example of Elbow Flexion:
____-muscles assist by adding additional force for movement or
stability.
• Ex: Brachialis and Brachioradialis assist with flexion of the elbow
Synergist
What are the three types of Muscle Terminology: Example of Elbow Flexion?
Prime mover
Antigonist
Synergist
