Muscular System Flashcards
Function of the Muscular System?
MMSPRCC
Movement
Maintain Posture
Stabilize Joints
Production of body heat
Respiration and heartbeat
Communication
Contraction of organs and vessels
Properties of Muscle
Contractibility
Excitability
Extensibility
Elasticity
Ability of muscle to shorten forcefully, or contract
Contractibility
Capacity of Muscle to respond to a stimulus
Excitability
Ability to be stretched beyond it normal resting length and still be able to contract
Extensibility
Ability of the muscle to recoil to its original resting length after it has been stretched
Elasticity
Types of Muscles
Skeletal
Cardiac
Smooth
Attached to Bone
Striated
Voluntarily controlled
Skeletal
Located in the heart
Striated
Involuntarily Controlled
Cardiac
Located in the blood vessels, hollow organs
Non-striated visceral
Involuntarily controlled
Smooth
Also known as Striated Muscle
Skeletal Muscle
It can be seen in the muscle under microscope
Transverse Band or Striation
Example of Skeletal Muscle that are complete organ
Biceps Brachii
Each Skeletal M. is surrounded by a connective tissue sheath
Epimysium
Group of Muscle cells
Fascicles
Connective Tissue covering of Fascicles
Perimysium
Muscle fiber/cell is surrounded by a connective tissue covering
Endomysium
Single cylindrical cells with several nuclei located at its periphery
Muscle Fiber
Sarcolemma has many tubelike inward folds
T-tubules/ Transverse Tubules
T-tubules connect the sarcolemma to the terminal cisternae to form
Muscle Triad
Cytoplasm of muscle fiber
Sarcoplasm
Bundles of protein filaments
Myofibrils
Kinds of Myofibrils
Myofilament
Actin
Myosin
Thick/Thin Filament
Dark/ Light Band
Thick- myosin molecules- Dark Band/ A band
Thin-actin molecules- Light band/ I band
Basic structural and functional unit of a skeletal
muscle because it is the smallest portion of a skeletal muscle capable of
contracting.
Sarcomere
3 Components of Actin Myofilament
Actin
Troponin
Tropomyosin
Resemble bundles of tiny golf clubs
Myosin Filament
What does myosin head have
ATP binding site
The electrical charge difference across the cell membrane of an
unstimulated cell
Resting Membrane Potential
The resting membrane potential is due to the inside of the membrane being?
Negatively Charged
Due to the membranes having gated channels
Action Potential
The resting membrane potential exist because of
Concentration of K being higher on the inside of the cell membrane
Concentration of Na being higher on the outside
The presence of negatively charged molecules such as protein causes RMP exists?
True
The presence of leak protein channels that are more permeable to K than Na
True
How to initiate a muscle contraction
RMP must be changed to an action potential when gated cell membrane channels open
The entry of NA causes the inside of the cell membrane to become more positive than when RMB
T
Increase in positive charge
Depolarization
How AP is triggered
If the depolarization changes the membrane potential to a value of treshold
Rapid change in charge across the cell membrane
Action Potential
What happened when the gated K channels are open
Repolarization
Repolarization is due to the exit of K from the cell
T
Outward diffusion of K turns the cell to its resting membrane condition
T
Action Potential results in
Muscle Contraction
A nerve cell stimulates muscle cells
Motor Neuron
Fiber of a nerve
connects with a muscle fiber
Neuromuscular junction
Cell-to-cell junction between a nerve cell to a nerve cell
Synapse
End of neuron cell axon fiber
Presynaptic terminal
Space between presynaptic terminal
Synaptic Cleft
Muscle fiber membrane
Postsynaptic Membrane
Vesicles in the presynaptic
Synaptic Vesicles
Chemicals stimulate or inhibits postsynaptic cells
Neurotransmitter
Neurotransmitter that stimulates skeletal muscle
Acetylcholine
Two types of muscle contractions
Isometric and Isotonic.
Increase in muscle tension, but no change in length
Isometric contraction
Change in muscle length with no change in tension.
Isotonic contraction
Isotonic contractions in which muscle tension increases as
the muscle shortens
Concentric contractions
Isotonic contractions in which tension is maintained in a
muscle, but the opposing resistance causes the muscle to lengthen
Eccentric contractions
Constant tension produced by body muscles over long
periods of time.
Muscle tone
-non-striated small, spindle-shaped muscle cells, usually with one nucleus per cell.
-The myofilaments are not organized into sarcomeres.
-The controlled involuntarily
-Neurotransmitter substances, hormones, and other substances can
stimulate smooth muscle
Smooth Muscle
-long, striated, and branching, with usually only one nucleus per cell.
-contraction is autorhythmic.
-Cells are connected to one another by specialized structures
that include desmosomes and gap junctions called intercalated disks.
Cardiac Muscle
Connects Skeletal muscle to bone
Tendon
Broad, sheetlike tendons
Aponeuroses
Bands of connective tissue that holds down the tendon at each wrist and ankle
Retinaculum
Attachment at the least mobile location
Origin
End of the muscles attached to the bone undergoing the greatest movement
Insertion
Between the origin and insertion
Belly
Group of muscles working together
Agonist
Group of muscles oppose muscle actions
Antagonist
Muscles of Mastication
Temporalis
Masseter
Pterygoids (Medial and Lateral)
Buccinator
Prime Mover of jaw closure (Trigeminal Nerve)
Masseter
Closes Jaw (Trigeminal Nerve)
Temporalis
Acts with lateral Pterygoid muscle to protract the mandible and promote side-to-side grinding movement (Trigeminal Nerve)
Medial Pterygoid
Provide side to side grinding movement and protracts mandible (Trigeminal Nerve)
Lateral Pterygoid
Compresses the cheek– keeps food between (Facial Nerve)
Buccinator
Smile Facial Expression
Zygomaticus Major
Pucker
Orbicularis Oris
Pout
Mentalis
Raised Eyebrow/ Wrinkled Forehead
Frontal Belly of Epicranius
Angry Eyebrows
Corrugator Supercilii
Blink
Orbicularis Oculi
Tense Neck
Platysma
Tongue and Swallowing Muscles
Suprahyoid Muscles
Infrahyoid Muscles
Pharyngeal Constrictor Muscles
Suprahyoid Muscles
Digastric
Stylohyoid
Mylohyoid
Geniohyoid
Open mouth and depress mandible
Digastric
Elevates and retracts hyoid
Stylohyoid
Elevates hyoid bone and floor of mouth
Mylohyoid
Elevates and protracts hyoid
Geniohyoid
Infrahyoid Muscles
Sternohyoid
Sternothyroid
Omohyoid
Thyrohyoid
Depress larynx and hyoid bone if mandible is fixed
Sternohyoid
Depress larynx and hyoid bone
Sternothyroid
Depresses and retracts hyoid bone
Omohyoid
Depresses hyoid bones or elevates larynx
Thyrohyoid
Pharyngeal Constrictor Muscles
Superior, Middle and Inferior Pharyngeal constrictor Muscle
Constrict pharynx during swallowing
^^
Anterolateral Neck Muscles
Sternocleidomastoid
Scalenes
Flexes and laterally rotates the head
Sternocleidomastoid
Elevates first two ribs
Scalenes
Intrinsic Muscles of the Back
Splenius
Extend or hyperextend heads
Splenius
Prime mover of back extension
Erector Spinae
3 Erector Spinae
Iliocostalis
Longissimus
Spinalis
Thoracis Muscle
External Intercostals
Internal Intercostals
Diaphragm
Elevates ribs for inspiration
External Intercostals
Depress ribs during forced expiration
Internal Intercostals
Move during quiet breathing
Prime mover of inspiration
Diaphragm
Abdominal Wall Muscles
Rectus Abdominis
External Abdominal Oblique
Internal Abdominal Oblique
Transverse Abdominis
Center of Abdomen
Compresses Abdomen
Rectus Abdominis
Side of abdomen
External Abdominal Oblique
Prime mover of arm abduction
Deltoid
Prime mover of arm extension
Latissimus dorsi
Rotate arm medially
Subscapularis
Powerful forearm extensor
Triceps brachii
Prime mover of forearm pronation
Pronator Quadratus
Prime mover of finger extension
Extensor digitorum
Prime mover for flexing thigh
Iliacus (Iliopsoas)
Thumbs Muscle
Abductor Pollicis brevis (Abducts thumb)
Flexor Pollicis Brevis (Flexes Thumb)
Opponens Pollicis (Opposition)
Adductor Pollicis (Adducts thumb)
Little Finger Muscle
Abductor digiti minimi (Abducts)
Flexor digiti minimi (Flexes)
Oppones digiti minimi (Opposition)
Major extensor of thigh
Gluteus Maximus
Abducts and medially rotates thigh
Gluteus Medius
Fleshy muscle of posterior thigh
Hamstring
Prime mover of dorsiflexion
Tibialis anterior
Prime mover of toe extension
Extensor Digitorum longus
Prime mover of feet
Tibialis Posterior