Musculatory System Flashcards
Bundles are long with multinucleated cells and cross-striations, contraction is quick, forceful and voluntary.
Attached to the bone.
Skeletal Muscle
End that remains fixed during contraction, proximal to the insertion in the limb
Origin
End that moves during contraction
insertion
Benign tumor of skeletal muscle
Rhabdomyoma
Malignant tumor of skeletal muscle, most common soft tissue sarcoma found in children, usually affects the head and neck region: orbit, nasal cavity and nasopharynx
Rhabdomyosarcoma
External sheath of dense irregular connective tissue that surrounds the entire muscle. Carries nerves, blood vessels and lymphatics of the muscle.
Epimysium
Thin connective tissue that surrounds a bundle of muscle fibers. Middle layer; covers fascicle. Makes up functional unit of muscle.
Perimysium
Thin delicate layer of reticular fibers and scattered fibroblasts. Surrounds individual muscle fiber myofibril. capillaries form a rich network bringing oxygen into muscle.
Innermost; covers muscle cells or muscle fiber.
Endomysium
Functional/contractile unit of muscle; extends from z disc to another z disc
Sarcomere
Birefringent in polarized light “Anisotropic”, also known as “Dark Band”
A Bands
do not alter polarized light “Isortropic”, also known as “Light band”
I Band
Separates cone sarcomere to another; attachment site for thin filaments
Z Discs
Contains thick filaments but no thin filaments
H zone
Cell membrane or plasma membrane of the muscle, myofibril
Sarcolemma
Invaginations or infoldings on the sarcolemma. Perpendicular sarcolemma
Transverse tubules or T Tubules
Membranous smooth endoplasmic reticulum of skeletal muscle; Storage for calcium ions.
Sarcoplasmic Reticulum
Dilated end sacks of SR: Terminal Cisternae
Space between the Ach and the nicotinic receptorm forms a
Synaptic Cleft or Neruromuscular Junction
Smallest skeletal muscle
Stapedium
Smallest muscle
Arrector Pili
Skeletal muscles in the human body
650
autoimmune condition that antibodies block the nicotinic receptor preventing depolarization, affects extraocular muscles and eyelids first.
Myasthenia Gravis
Loss of power or movement, inability to contract. Damage to motor neural pathwats or inherent disease
Paralysis
Damage to the upper motor neuron, exaggerated tendon jerks
Spastic Paralysis
Damage to the lower motor neuron, affects NMJ, loss of tendon jerks.
Flaccid Paralysis
Decreased angle between two body segments, movement to the coronal plane
Flexion
Increased angle between two body segments, movement away from the coronal plane
Extension
Movement away from the midline, sagittal plane
Abduction
Movement towards the midline, sagittal plane.
Adduction
Turns the bone outward
Lateral rotation
Turns the bone inward
Medial rotation
Combination of flexion, abduction, extension and adduction. Movement at the end of the bone in a circular motion
Circumduction
Raised to more superior level
Elevation
Pulling to a more inferior position
Depression
Allows a forward movement
Protraction
Allows a backward movement
Retraction
Acts to draw the eyebrows together, creating vertical wrinkles on the bridge of the nose
Corrugator Supercili
Contraction of this muscle pulls the eyebrows downward to produce transverse wrinkles over the nose
Procerus
pulls the cheek inwards against the teeth, preventing accumulation of food in that area.
Buccinator
Muscle of facial expressions are developed from the __ pharyngeal arch.
2nd
Muscle of facial expressions are supplied by the ____ nerve
Facial
muscle for whistling
Buccinator
Muscle that closes the eye
Orbicularis Oculi
muscle that elevates the upper lip
levator labi superioris
Origin of masseter
Zygomatic arch
Origin of temporalis
Temporal Fossa
Tensor veli palatini is innervated by
Trigeminal Nerve
Levator veli palatini, Palatoglossus, Palatopharyngeus, uvula is innvervated by
Vagus and accessory nerve
Raises soft palate
Levator veli palatini
Shuts off nasopharynx during second stage of swallowing
Palatopharyngeus
Raises back of tongue during the first stage of swallowing
Palatoglossus
Stylopharyngeus is innervated by
Glossopharyngeal Nerve
Platysma is innervated by
CN VII
Wrinkles the skin of the neck. Superficial fascia, only muscle innervated by the cervical branch of the facial nerve
Platysma
Turns the head to the opposite side, flexes neck to the same side.
Sternocleidomastoid
“Shrugs Shoulders”
Elevated scapula, extension of the head and neck.
Trapezius
Elevates the 1st and 2nd rib
Scalene Muscles
helps in shrugs muscles
Levator Scapulae
Infrahyoid muscles is innervated by
Cervical Plexus “Ansa Cervicalis”
C1-C3
Only infrahyoid muscle that innervates by C1 via hypoglossal nerve.
Thyrohyoid
Contraction is involuntary, vigorous and rhythmic, possess cross-striations and branched cells.
Cardiac Muscle
Contractions are slow and involuntary, consists of collections of fusiform cells that lack striations
Smooth Muscle
Benign tumor of smooth muscle, most common tumor found in women, usually affects the uterus.
Leiomyoma
the platysma is supplied by a branch of which of the following cranial nerves?
A. V
B. VII
C. IX
D. X
A. V - Muscles of mastication
Answer: B. VII
C. IX - Pharyngeal Muscles
D. X - Muscles of soft palate, except: Tensor veli palatini
In placing a film for a periapical view of mandibular molars, relaxation of which of the following muscles would aid most?
Mylohyoid
Food may lodge in the oral vestibule if _____ muscle is paralyzed
Buccinator
Which of the following muscles is supplied by the facial nerve?
A. Anterior belly of the digastric
B. Mylohyoid
C. Mentalis
D. Hyoglossus
A. Anterior belly of the digastric - V
B. Mylohyoid - V
ANSWER: C. Mentalis
D. Hyoglossus - XII
the infrahyoid muscles receive their motor innervation from
Branches of the cervical plexus:
C1-C3 “Ansa Cervicalis”
The prime muscle in retracting and elevating the mandible is the
TEMPORALIS
Masseter - Only elevation
Digastric - Depressing
Mylohyoid - Depressing
Lateral Pterygoid - Main depressor and protruding.
the mandible pharyngeal constrictor origin to the
Hyoid bone
the muscle whose tendon loops around the pterygoid hamulus is the
Tensor veli palatini
the skeletal muscle, a triad consist of
Terminal Cisternae and a fingerlike invagination of the sarcolemma “T-tubule” (2)
the medial pterygoid muscle (Internal) is attached to the
Medial surface of the lateral pterygoid plate.
Muscle serves as the prime extensor of the forearm
Triceps bronchii
muscle of the soft palate that is not supplied by the pharyngeal plexus
Tensor veli palatini
Peripherally located nuclei are found in types of adult muscle cells?
Skeletal Only
the two muscles which use the pterygomandibular raphe for part of their attachment receive their innervation from the (Buccinator and superior pharyngeal constrictor)
Facial and Vagus nerve
The insertion of the lateral pterygoid muscle is into the
Articular disc of the temporomandibular and mandibular neck
(Articular disc & Condyle)
a muscle that act to protrude the mandible is the
Lateral Pterygoid
The tendon of the tensor veli palatini muscle curve around the
Pterygoid hamulus
The palatine tonsil lies between arched formed by the
Palatoglossus and palatopharyngeus muscles
The mylohyoid muscle functions to
Raise the floor of the mouth
Depress the hyoid bone
Infrahyoid muscle
Prevent food from entering the larynx
Epiglottis
Approximate faucial pillars
Pharyngeal muscles
When a patient attempts protrusion, the mandible deviates markedly to the right. The muscle that is unable to contract is the:
a. Right lateral pterygoid
b. left lateral pterygoid
A. Right lateral pterygoid
Mandibular Movement
1. Protrusion/Depression -> Mandibular deviation -> Weaker side or injured side -> Muscle of the same side.
2. Lateral excursion -> inability to move the mandible to one side. -> muscle of the opposite side.
Left lateral pterygoid - when Lateral excursion, inability to move to the right.
Protrusion of the tip of the tongue beyond the opening of the oral cavity is accomplished primarily by the
Genioglossus muscle
The posterior belly of the digastric muscle is supplied by
Facial nerve
Anterior belly: Trigeminal Nerve
Local autoregulation of blood flow in skeletal muscle is determined chiefly by
Muscle metabolites
should not be administered to a patient with myasthenia gravis
Curare
DOC: Prostigmine
All of the longitudinal muscles of the pharynx are innervated by the vagus nerve via the pharyngeal plexus except?
A. Stylopharyngeus
B. Palatopharyngeus
C. Salpinopharyngeus
Stylopharyngeus - Glossopharyngeal nerve
Functional unit of the skeletal muscle
Sarcomere
Which muscle separates the anterior cervical triangle from the posterior cervical triangle?
a. Trapezius
b. Omohyoid
c. Mylohyoid
d. Sternocleidomastoid
D. Sternocleidomastoid
Which muscle, when penetrated during an IAN injection, may cause jaw pain and inability to open one’s mouth?
Medial Pterygoid
All muscles of mastication are innervated by
Mandibular division or trigeminal nerve
The connective tissue layer surrounding each individual muscle fiber is called the
Endomysium
Involuntary movements of internal organs such as peristalsis are produced by which type of muscle tissue?
Smooth muscle tissue
Name the molecule that lies along the surface of F-actin and physically covers actin binding sites during the resting state
Tropomyosin