Chapter 11 - The Muscular System Flashcards
What is Movement?
Skeletal muscles produce movements by exerting force on tendons
Tendons attach to and pull on bones
Movement occurs
Point of Insertion moves
Not the Origin (Source) of the movement
What are Origin and Insertion?
Most muscles cross at least one joint and are attached at the articulating bones
When a muscle contracts, it draws one articulating bone towards the other
What is Origin?
Origin:
The attachment to the stationary bone
What is Insertion?
Insertion:
The attachment to the moveable bone
What is a Lever System and Leverage?
Levers: bones
Fulcrums: joints
The lever is acted on by:
Resistance
Effort
What is a First Class Lever?
Fulcrum between Effort and Resistance
What is a Second Class Lever?
Resistance between Fulcrum and Effort
What is a Third Class Lever?
Effort between Fulcrum and Resistance
What are the Effects of Fascicle Arrangements?
Muscle fibers are arranged in parallel bundles within fascicles but the arrangement of fasciculi in relation to the tendon can vary
Fascicular arrangement is correlated with:
Amount of power a muscle can produce
Range of motion a muscle can produce
(more fascicles = more power and ROM)
What are the different Arrangements of Fascicles?
Parallel
Fusiform
Circular
Triangular
Pennate
Unipennate
Bipennate
Multipennate
What is Parallel Arrangement of Fascicles?
Fascicles parallel to longitudinal axis of muscle
Terminate at either end in flat tendons
ex- Sternohyoid muscle
What is Fusiform Arrangement of Fascicles?
Fascicles nearly parallel to longitudinal axis of muscle
Terminate in flat tendons
Muscle tapers towards tendons, where diameter is less than at belly
ex- Digastric muscle
What is Circular Arrangement of Fascicles?
Fascicles in concentric circular arrangements from sphincter muscles that enclose an orifice (opening)
ex- Orbicularis Oculi muscle
What is Triangular Arrangement of Fascicles?
Fascicles spread over broad are converge at thick central tendon
Gives muscle a triangular shape
ex- Pectoralis Major muscle
What is Pennate Arrangement of Fascicles?
Short fascicles in relation to total muscle length
Tendon extends nearly the entire length of the muscle
What is Unipennate Arrangement of Fascicles?
Fascicles arranged on only one side of tendon
ex- Extensor Digitorum Longus muscle
What is Bipennate Arrangement of Fascicles?
Fascicles arranged on both sides of centrally positioned tendons
ex- Rectus Femoris muscle
What is Multipennate Arrangement of Fascicles?
Fascicles attach obliquely from many directions to several tendons
ex- Deltoid muscle
How does Coordination within muscle groups work?
Most muscle movements are coordinated by several skeletal muscles acting in groups rather than individually
And most skeletal muscles are arranged in opposing pairs at joints
Agonist/Prime Mover
Antagonist
Synergist
What is Agonist/Prime Mover?
Carry
ex- Biceps
What is Antagonist?
Put back after carry
ex- Triceps
What is Synergist?
Multiple muscles work together at same time
Same purpose, some pull up, some pull forward
Like Inhalation and Expiration Muscles
ex- Chest muscles
How are Muscles named?
Muscles are named based on:
Location
Size
Number of origins
Appearance
Direction of fibers
Origin and insertion
Muscle action
What is Rectus?
Parallel to midline
ex- Rectus Abdominis
What is Transverse?
Perpendicular to midline
ex- transversus Abdominis
What is Oblique?
Diagonal to midline
ex- External Oblique
What is Maximus?
Largest
ex- Gluteus Maximus
What is Minimus?
Smallest
ex- Gluteus Minimus
What is Longus?
Long
ex- Adductor Longus
What is Brevis?
Short
ex- Adductor Brevis
What is Latissimus?
Widest
ex- Latissimus Dorsi
What is Longissimus?
Longest
ex- Longissimus Capitis
What is Magnus?
Large
ex- Adductor Magnus
What is Major?
Larger
ex- Pectoralis Major
What is Minor?
Smaller
ex- Pectoralis Minor
What is Vastus?
Huge
ex- Vastus Lateralis
What is Deltoid?
Triangular
ex- Deltoid
What is Trapezius?
Trapezoid
ex- Trapezius
What is Serratus?
Saw-toothed
ex- Serratus Anterior
What is Rhomboid?
Diamon-shaped
ex- Rhomboid Major
What is Orbicularis?
Circular
ex- Orbicularis Oculi
What is Pectinate?
Comblike
ex- Pectineus
What is Piriformis?
Pear-shaped
ex- Piriformis
What is Platys?
Flat
ex- Platysma
What is Quadratus?
Square, 4-sided
ex- Quadratus Femoris
What is Gracilis?
Slender
ex- Gracilis
What is Flexor?
Decrease joint angle
ex- Flexor Carpi Radialis
What is Extensor?
Increase joint angle
ex- Extensor Carpi Ulnaris
What is Abductor?
Moves bone away from midline
ex- Abductor Pollicis Longus
What is Adductor?
Moves bone closer to midline
ex- Adductor Longus
What is Levator?
Raise or elevate body part
ex- Levator Scapulae
What is Depressor?
Lower or depress body part
ex- Depressor Labii Inferioris
What is Supinator?
Turns palm anteriorly
ex- Supinator
What is Pronator?
Turn palm posteriorly
ex- Pronator Teres
What is Sphincter?
Decrease size of an opening
ex- External Anal Sphincter
What is Tensor?
Make body part rigid
ex- Tensor Fasciae Latae
What is Rotator?
Rotate bone around longitudinal axis
ex- Rotatore
What is Biceps?
2 origins
ex- Biceps Brachii
What is Triceps?
3 origins
ex- Triceps Brachii
What is Quadriceps?
4 origins
ex- Quadriceps Femoris
What is Temporalis?
Muscle near Temporal Bone
What is Sternocleidomastoid?
Originating on sternum and clavicle
Inserting on mastoid process of temporal bone
What are the Muscles of Facial Expression?
Muscles of facial expression lie within subcutaneous layer
Originating on the fascia of bones of the skull and inserting into the skin
When these muscles contract, they move the skin rather than a joint
Supplied by Facial Nerve 7 (VII)
What is Occipitofrontalis?
Scalp muscle
Has Frontal belly and Occipital belly
What is Frontal Belly of Occipitofrontalis?
Origin:
Epicranial aponeurosis
Insertion:
Skin superior to Supraorbital Margin
Action:
Draws scalp anteriorly
Raises eyebrows
Wrinkles skin of forehead horizontally as in surprise
Innervation:
Facial Nerve 7 (VII)
What is Occipital Belly of Occipitofrontalis?
Origin:
Occipital bone
Mastoid process of temporal bone
Insertion:
Epicranial aponeurosis
Action:
Draws scalp posteriorly
Innervation:
Facial Nerve 7 (VII)
What is Orbicularis Oris?
Mouth muscle
Origin:
Muscle fibers surrounding opening of mouth
Insertion:
Skin at corner of mouth
Action:
Closes and protrudes lips as in kissing
Compresses lips against teeth
Shapes lips during speech
Innervation:
Facial Nerve 7 (VII)
What is Zygomaticus Major?
Mouth muscle
Origin:
Zygomatic bone
Insertion:
Skin at angle of mouth and Orbicularis Oris
Action:
Draws angle of mouth superiorly and laterally as in smiling
Innervation:
Facial Nerve 7 (VII)
What is Zygomaticus Minor?
Mouth muscle
Origin:
Zygomatic bone
Insertion:
Upper lip
Action:
Raise (elevate) upper lip exposing maxillary teeth
Innervation:
Facial Nerve 7 (VII)
What is Levator Labii Superioris?
Mouth muscle
Origin:
Superior to infraorbital foramen of maxilla
Insertion:
Skin at angle of mouth and Orbicularis Oris
Action:
Raise upper lip
Innervation:
Facial Nerve 7 (VII)
What is Depressor Labii Inferioris?
Mouth muscle
Origin:
Mandible
Insertion:
Skin of lower lip
Action:
Depress (lowers) lower lip
Innervation:
Facial Nerve 7 (VII)
What is Depressor Anguli Oris?
Mouth muscle
Origin:
Mandible
Insertion:
Angle of mouth
Action:
Draws angle of mouth laterally and inferiorly as in open mouth
Innervation:
Facial Nerve 7 (VII)
What is Levator Anguli Oris?
Mouth muscle
Origin:
Inferior to infraorbital foramen
Insertion:
Skin of lower lip and Orbicularis Oris
Action:
Draws angle of mouth laterally and superiorly
Innervation:
Facial Nerve 7 (VII)
What is Buccinator?
Mouth muscle
Origin:
Alveolar processes of maxilla and mandible and pterygomandibular raphe
(fibrous band extending from pterygoid process of sphenoid bone to mandible)
Insertion:
Orbicularis Oris
Action:
Press cheeks against teeth and lips as in whistling
Draw corner of mouth laterally
Assist in mastication by keeping food between teeth and not between cheeks and teeth
Innervation:
Facial Nerve 7 (VII)
What is Risorius?
Mouth muscle
Origin:
Fascia over Parotid (salivary) gland
Insertion:
Skin at angle of mouth
Action:
Draw angle of mouth laterally as in grimacing
Innervation:
Facial Nerve 7 (VII)
What is Mentalis?
Mouth muscle
Origin:
Mandible
Insertion:
Skin of chin
Action:
Elevate and protrude lower lip
Pulls skin of chin up as in pouting
Innervation:
Facial Nerve 7 (VII)
What are the Muscles of the Eyeballs?
Extrinsic Eye Muscles:
The muscles that move the Eyeballs
They originate in the orbit
Insert on Sclera
3 Pairs of Extrinsic Eye Muscles:
1- Superior and Inferior Recti
2- Lateral and Medial Recti
3- Superior and Inferior Obliques
What are the Muscles of the Upper Eyelids?
The tendon of the Levator Palpebrae Superioris passes the eyeball and inserts into the upper eyelid
This point of insertion allows it to raise the eyelid
What is Superior Rectus?
Muscle of the Eyeball
Origin:
Common Tendinous Ring
(Attached to orbit around Optic Foramen)
Insertion:
Superior and central part of eyeball
Action:
Moves eyeball superiorly (elevation)
Moves eyeball medially (adduction)
Rotates eyeball medially
Innervation:
Oculomotor Nerve 3 (III)
What is Inferior Rectus?
Muscle of the Eyeball
Origin:
Common Tendinous Ring
(Attached to orbit around Optic Foramen)
Insertion:
Inferior and central part of eyeball
Action:
Moves eyeball inferiorly (depression)
Moves eyeball medially (adduction)
Rotates eyeball laterally
Innervation:
Oculomotor Nerve 3 (III)
What is Lateral Rectus?
Muscle of the Eyeball
Origin:
Common Tendinous Ring
(Attached to orbit around Optic Foramen)
Insertion:
Lateral side of eyeball
Action:
Moves eyeball laterally (abduction)
Innervation:
Abducens Nerve 6 (VI)
What is Medial Rectus?
Muscle of the Eyeball
Origin:
Common Tendinous Ring
(Attaches to orbit around Optic Foramen)
Insertion:
Medial side of eyeball
Action:
Moves eyeball medially (adduction)
Innervation:
Oculomotor Nerve 3 (III)
What is Levator Palpebrae Superioris?
Muscle of the Upper Lid
Origin:
Roof of orbit
(Lesser wing of Sphenoid bone)
Insertion:
Skin and Tarsal Plate of Upper Lid
Action:
Elevate upper eyelid (opens eye)
Innervation:
Oculomotor Nerve 3 (III)
What is Superior Oblique?
Muscle of the Eyeball
Origin:
Sphenoid bone
Superior and medial to Common Tendinous Ring in orbit
Insertion:
Eyeball between Superior and Lateral Recti
Muscle inserts into superior and lateral surfaces of eyeball via tendon that passes through Trochlea
Action:
Moves eyeball inferiorly (depression)
Moves eyeball laterally (abduction)
Rotates eyeball medially
Innervation:
Trochlear Nerve 4 (IV)
What is Inferior Oblique?
Muscle of the Eyeball
Origin:
Maxilla in floor of orbit
Insertion:
Eyeball between Inferior and Lateral Recti
Action:
Moves eyeball superiorly (elevation)
Moves eyeball laterally (abduction)
Rotates eyeball laterally
Innervation:
Oculomotor Nerve 3 (III)
What is the Innervation of the Muscles of the Eye and Upper Eyelids?
(All cranial nerve 3, LR6, SO4)
1- Oculomotor Nerve 3 (III):
Superior Rectus
Inferior Rectus
Medial Rectus
Inferior Oblique
Levator Palpebrae Superioris
2- Abducens Nerve 6 (VI):
Lateral Rectus
3- Trochlear Nerve 4 (IV):
Superior Oblique
What are the Muscles of Mastication?
Muscles of Mastication:
The muscles that move the Mandible
What is Masseter?
Muscle of Mastication
Origin:
Maxilla
Zygomatic Arch
Insertion:
Angle of Ramus of Mandible
Action:
Elevate Mandible, as in closing mouth
Innervation:
Mandibular division of Trigeminal Nerve 5 (V)
What is Temporalis?
Muscle of Mastication
Origin:
Temporal bone
Insertion:
Coronoid Process and Ramus of Mandible
Action:
Elevate and retracts Mandible
Innervation:
Mandibular division of Trigeminal Nerve 5 (V)
What is Medial Pterygoid?
Muscle of Mastication
Origin:
Medial surface of lateral portion of Pterygoid Process of Sphenoid bone
Maxilla
Insertion:
Angle and Ramus of Mandible
Action:
Elevate and protract Mandible
Moves Mandible from side to side
Innervation:
Mandibular division of Trigeminal Nerve 5 (V)
What is Lateral Pterygoid?
Muscle of Mastication
Origin:
Greater Wing and lateral surface of lateral portion of Pterygoid Process of Sphenoid bone
Insertion:
Condyle of Mandible
TMJ
Action:
Protract Mandible
Depress Mandible, as in open mouth
Move Mandible from side to side
Innervation:
Mandibular division of Trigeminal Nerve 5 (V)
What are the Muscles of the Tongue?
Tongue is highly mobile structure that plays a critical role in mastication, taste, and swallowing
Tongue is attached to Mandible, Styloid Process of Temporal Bone, and Hyoid Bone
(Taste buds on distal third of tongue)
What is Genioglossus?
Muscle of the Tongue
Origin:
Mandible
Insertion:
Undersurface of Tongue and Hyoid Bone
Action:
Depress tongue
Thrust tongue anteriorly (protraction)
Innervation:
Hypoglossal Nerve 12 (XII)
What is Styloglossus?
Muscle of the Tongue
Origin:
Styloid Process of Temporal bone
Insertion:
Side of undersurface of tongue
Action:
Elevate tongue
Draws tongue posteriorly (retraction)
Innervation:
Hypoglossal Nerve 12 (XII)
What is Hyoglossus?
Muscle of the Tongue
Origin:
Greater Horn and Body of Hyoid Bone
Insertion:
Side of tongue
Action:
Depress tongue
Draws tongue down its side
Innervation:
Hypoglossal Nerve 12 (XII)
What is Palatoglossus?
Muscle of the Tongue
Origin:
Anterior surface of Soft Palate
Insertion:
Side of tongue
Action:
Elevate posterior portion of tongue
Draws Soft Palate down on tongue
Innervation:
Pharyngeal Plexus
Which contains axons from Vagus Nerve 10 (X)
What are the Muscles of the Neck?
1- Suprahyoid muscles:
Elevate Hyoid bone
Elevate floor of oral cavity
Elevate Tongue
While swallowing
2- Infrahyoid Muscles:
Most depress Hyoid Bone
Some move Larynx
What is Digastric?
Muscle of Neck
Suprahyoid Muscle
Origin:
Anterior Belly from inner side of Inferior Border of Mandible
Posterior Belly from Temporal bone
Insertion:
Body of Hyoid bone via Intermediate Tendon
Action:
Elevate Hyoid bone
Depress Mandible, as in open mouth
Innervation:
Anterior Belly - Mandibular division of Trigeminal Nerve 5 (V)
Posterior Belly - Facial Nerve 7 (VII)
What is Stylohyoid?
Muscle of Neck
Suprahyoid Muscle
Origin:
Styloid Process of Temporal bone
Insertion:
Body of Hyoid bone
Action:
Elevate Hyoid bone
Draws Hyoid bone posteriorly
Innervation:
Facial Nerve 7 (VII)
What is Mylohyoid?
Muscle of Neck
Suprahyoid Muscle
Origin:
Inner surface of Mandible
Insertion:
Body of Hyoid bone
Action:
Elevate Hyoid bone and floor of mouth
Depress Mandible
Innervation:
Mandibular division of Trigeminal Nerve 5 (V)
What is Geniohyoid?
Muscle of Neck
Suprahyoid Muscle
Origin:
Inner surface of Mandible
Insertion:
Body of Hyoid bone
Action:
Elevate Hyoid bone
Draws Hyoid bone and tongue anteriorly
Depress Mandible
Innervation:
First Cervical Spinal Nerve (C1)
What is Omohyoid?
Muscle of Neck
Infrahyoid Muscle
Origin:
Superior Border of Scapula
Superior Transverse Ligament
Insertion:
Body of Hyoid bone
Action:
Depress Hyoid bone
Innervation:
Branches of Spinal Nerves C1-C3
What is Sternohyoid?
Muscle of Neck
Infrahyoid Muscle
Origin:
Medial end of Clavicle
Manubrium of Sternum
Insertion:
Body of Hyoid bone
Action:
Depress Hyoid bone
Innervation:
Branches of Spinal Nerves C1-C3
What is Sternothyroid?
Muscle of Neck
Infrahyoid Muscle
Origin:
Manubrium of Sternum
Insertion:
Thyroid Cartilage of Larynx
Action:
Depress Thyroid Cartilage of Larynx
Innervation:
Branches of Spinal Nerves C1-C3
What is Thyrohyoid?
Muscle of Neck
Infrahyoid Muscle
Origin:
Thyroid Cartilage of Larynx
Insertion:
Greater Horn of Hyoid bone
Action:
Depress Hyoid bone
RMA- Elevate Thyroid Cartilage
Innervation:
Branches of Spinal Nerves C1-C2
Descending Hypoglossal Nerve 12 (XII)
What is Sternocleidomastoid?
Muscle of the Neck that move the Head
Origin:
Sternal Head of Manubrium of Sternum
Clavicular Head - medial third of Clavicle
Insertion:
Mastoid Process of Temporal bone
Lateral half of Superior Nuchal Line of Occipital bone
Action:
Acting together (bilaterally):
Flex cervical portion of vertebral column
Extend head at Atlanto-occipital joints
Acting Singly (unilaterally):
Laterally flex neck and head to same side
Rotate head to side opposite contracting muscle
Laterally rotate and flex head to opposite side of contracting muscle
Posterior fibers of muscle can assist in extension of head
RMA- Elevate Sternum during forced inhalation
Innervation:
Accessory Nerve 11 (XI)
Spinal Nerve C2 and C3
What is Semispinalis Capitis?
Muscle of the Neck that move the Head
Origin:
Articular processes of C4-C6
Transverse processes of C7-T7
Insertion:
Occipital bone between Superior and Inferior Nuchal Lines
Action:
Acting together:
Extend head and vertebral column
Acting singly:
Rotate head to side opposite contracting muscle
Innervation:
Cervical Spinal Nerves
What is Splenius Capitis?
Muscle of the Neck that move the Head
Origin:
Ligamentum Nuchae
Spinous process of C7-T4
Insertion:
Occipital bone
Mastoid process of Temporal bone
Action:
Extend head
Acting together:
Muscle of each region (cervical and thoracic) extend vertebral column of their respective regions
Innervation:
Cervical Spinal Nerves
What is Longissimus Capitis?
Muscle of the Neck that move the Head
Origin:
Articular process of T1-T4
Insertion:
Mastoid process of Temporal bone
Action:
Acting together:
extend head and vertebral column
Acting singly:
Laterally flex and rotate head to same side as contracting muscle
Innervation:
Cervical Spinal Nerves
What is Spinalis Capitis?
Muscle of the Neck that move the Head
Origin:
Often absent or very small
Arises with Semispinalis Capitis
Insertion:
Occipital bone
Action:
Extends head and vertebral column
Innervation:
Cervical Spinal Nerves
What are the Muscles of the Abdomen?
The anterolateral abdominal wall is composed of skin, fascia, and 4 pairs of muscles
They help in Respiration
What is Rectus Abdominis?
Muscle of the Abdomen
Origin:
Pubic Crest
Pubic Symphysis
Insertion:
Cartilage of Ribs 5-7
Xiphoid Process
Action:
Flex vertebral column especially lumbar portion
Compress abdomen to aid in defecation, urination, forced exhalation, and child birth
RMA- Flex Pelvis on vertebral column
Innervation:
Thoracis Spinal Nerves T7-T12
What is External Oblique?
Muscle of the Abdomen
Origin:
Ribs 5-12
Insertion:
Iliac Crest
Linea Alba
Action:
Acting together (bilaterally):
Compress abdomen
Flex vertebral column
Acting singly (unilaterally):
Flex vertebral column especially lumbar portion
Rotate vertebral column
Innervation:
Thoracic Spinal Nerves T7-T12
Iliohypogastric Nerve
What is Internal Oblique?
Muscle of the Abdomen
Origin:
Iliac Crest
Inguinal Ligament
Thoracolumbar Fascia
Insertion:
Cartilage of Ribs 7-10
Linea Alba
Action:
Acting together:
Compress abdomen
Flex vertebral column
Acting singly:
Laterally flex vertebral column, especially lumbar portion
Rotate vertebral column
Innervation:
Thoracic Spinal Nerves T8-T12
Iliohypogastric Nerve
Ilioinguinal Nerve
What is Transversus Abdominis?
Muscle of the Abdomen
Origin:
Iliac Crest
Inguinal Ligament
Lumbar Fascia
Cartilages of Ribs 5-10
Insertion:
Xiphoid process
Linea Alba
Pubis
Action:
Compress abdomen
Innervation:
Thoracis Spinal Nerves T8-T12
Iliohypogastric Nerve
Ilioinguinal Nerve
What is Quadratus Lumborum?
Muscle of the Abdomen
Origin:
Iliac Crest
Iliolumbar Ligament
Insertion:
Inferior border of rib 12
L1-L4
Action:
Acting together:
Pull 12th Rib inferiorly during forced exhalation
Fix 12th Ribs to prevent their elevation during deep inhalation
Help extend lumbar portion of vertebral column
Acting singly:
Laterally flex vertebral column, especially lumbar portion
RMA- Elevate Hip bone, commonly on one side
Innervation:
Thoracic Spinal Nerve T12
Lumbar Spinal Nerve L1-L3 or L1-L4
What are the Muscles of the Thorax?
Muscles of the Thorax alter size of the Thoracic Cavity so that breathing can occur
Lungs are elastic
Muscles pull on the walls
Diaphragm contracts (up) then relaxes (down)
What is Diaphragm?
Muscle of the Thorax
Origin:
Xiphoid process
Costal Cartilages and adjacent portions of Ribs 7-12
Lumbar vertebrae and their intervertebral discs
Insertion:
Central Tendon
Action:
Contraction of Diaphragm causes it to flatten and increase vertical dimension of Thoracic Cavity, resulting in Inhalation
Relaxation of Diaphragm causes it to move superiorly and decrease vertical dimension of Thoracic Cavity, resulting in Exhalation
Innervation:
Phrenic Nerve
Which contains axons from Cervical Spinal Nerves C3-C5
What is External Intercostals?
Muscle of the Thorax
Origin:
Inferior border of rib above
Insertion:
Superior border of rib below
Action:
Contraction elevate ribs and increase anteroposterior and lateral dimensions of Thoracic cavity, resulting in Inhalation
Relaxation depress ribs and decrease anteroposterior and lateral dimensions of Thoracic Cavity, resulting in Exhalation
Innervation:
Thoracic Spinal Nerves T2-T12
What is Internal Intercostals?
Muscle of the Thorax
Origin:
Superior border of rib below
Insertion:
Inferior border of rib above
Action:
Contraction draws adjacent ribs together to further decrease anteroposterior and lateral dimensions of Thoracic Cavity during Forced Exhalation
Innervation:
Thoracic Spinal Nerves T2-T12
What are the Muscles of the Pelvic Floor?
Pelvic Diaphragm:
Group of muscles and associated fascia
Stretching from Pubis to the Coccyx
From one lateral wall of the pelvis to the other
What is Levator Ani?
Muscle of the Pelvic Floor
Muscle divisible into 3 parts:
1- Pubococcygeus muscle
2- Puborectalis muscle
3- Iliococcygeus muscle
What is Pubococcygeus?
Muscle of the Pelvic Floor
Origin:
Pubis
Ischial Spine
Insertion:
Coccyx
Urethra
Anal canal
Perineal body of Perineum (wedge-shaped mass of fibrous tissue in center of Perineum)
Anococcygeal Ligament (narrow fibrous band that extends from Anus to Coccyx)
Action:
Support and maintain position of pelvic viscera
Resist increase in intra-abdominal pressure during forced exhalation, coughing, vomiting, urination, and defecation
Constrict Anus, urethra, and vagina
Innervation:
Sacral Spinal Nerves S2-S4
What is Puboractalis?
Muscle of the Pelvic Floor
Origin:
Posterior surface of Pubic bone
Insertion:
Forms a sling posterior to the Anorectal Junction
Action:
Help maintain fecal continence
Assist in defecation
Innervation:
Sacral Spinal Nerves S2-S4
What is Iliococcygeus?
Muscle of the Pelvic Floor
Origin:
Ischial spine
Insertion:
Coccyx
Action:
Support and maintain position of pelvic viscera
Resist increase in intra-abdominal pressure during forced exhalation, coughing, vomiting, urination, and defecation
Constrict Anus, urethra, and vagina
Innervation:
Sacral Spinal Nerves S2-S4
What is Ischiococcygeus?
Muscle of the Pelvic Floor
Origin:
Ischial spine
Insertion:
Lower Sacrum
Upper Coccyx
Action:
Support and maintain position of pelvic viscera
Resist increase in intra-abdominal pressure during forced exhalation, coughing, vomiting, urination, and defecation
Pulls Coccyx anteriorly following defecation or child birth
Innervation:
Sacral Spinal Nerves S2-S4
What are the Muscles of the Perineum?
The Perineum is the region of the trunk inferior to the pelvic diaphragm
Diamond-shaped
Extends from the Pubis Symphysis to the Coccyx and Ischial Tuberosities
What is Superficial Transverse Perineal?
Muscle of the Perineum
Origin:
Ischial Tuberosity
Insertion:
Perineal body of Perineum
Action:
Stabilize perineal body of Perineum
Innervation:
Perineal Branch of Pudendal Nerve of Sacral Plexus
What is Bulbospongiosus?
Muscle of the Perineum
Origin:
Perineal body of Perineum
Insertion:
Perineal membrane of deep muscles of Perineum
Corpus Spongiosum of penis
Deep fascia on dorsum of penis in male
Pubic Arch and dorsum of Clitoris in female
Action:
Help expel urine during urination
Help propel semen along Urethra
Assist in erection of penis in male
Constrict Vaginal Orifice and assist in erection of Clitoris in female
Innervation:
Perineal Branch of Pudendal Nerve of Sacral Plexus
What is Ischiocavernosus?
Muscle of the Perineum
Origin:
Ischial tuberosity
Ischial and Pubic Rami
Insertion:
Corpora Cavernosa of penis in male
Clitoris in female
Pubic Symphysis
Action:
Maintain erection of penis in male and clitoris in female by decreasing urine drainage
Innervation:
Perineal Branch of the Pudendal Nerve of Sacral Plexus
What is Subclavius?
Muscle of the Thorax that move Pectoral Girdle
Anterior Thoracic Muscle
Origin:
Rib 1
Insertion:
Clavicle
Action:
Depress and move Clavicle anteriorly
Help stabilize pectoral girdle
Innervation:
Subclavian Nerve
What is Pectoralis Minor?
Muscle of the Thorax that move Pectoral Girdle
Anterior Thoracic Muscle
MUSCLE OF INSPIRATION
Origin:
Ribs 2-5
Or Ribs 3-5
Or Ribs 2-4
Insertion:
Coracoid process of Scapula
Action:
Abduct scapula and rotates it downward
RMA- Elevate ribs 3-5 during forced Inhalation when scapula is fixed
Innervation:
Medial Pectoral Nerve
What is Serratus Anterior?
Muscle of the Thorax that move Pectoral Girdle
Anterior Thoracic Muscle
MUSCLE OF INSPIRATION
Origin:
Ribs 1-8
Or Ribs 1-9
Insertion:
Vertebral border
Inferior Angle of Scapula
Action:
Abduct scapula and rotates it upward
RMA- Elevate ribs when scapula is stabilized
Known as “boxer’s muscle” because it is important in horizontal arm movements such as punching and pushing
Innervation:
Long Thoracic Nerve
(If damaged, scapula protrudes out, becomes winged, and atrophied)
What is Trapezius?
Muscle of the Thorax that move Pectoral Girdle
Posterior Thoracic Muscle
Origin:
Superior Nuchal Line of Occipital bone
Ligamentum Nuchae
Spines of C7-T12
Insertion:
Clavicle
Acromion and spine of scapula
Action:
Superior fibers upward rotate scapula
Middle fibers depress and upward rotate scapula
Superior and Inferior fibers together rotate scapula upward
Stabilize Scapula
RMA- Superior fibers can help extend head
Innervation:
Accessory Nerve 11 (XI)
Cervical Spinal Nerves C3-C5
What is Levator Scapulae?
Muscle of the Thorax that move Pectoral Girdle
Posterior Thoracic Muscle
Origin:
Transverse processes of C1-C4
Insertion:
Superior vertebral border of scapula
Action:
Elevate scapula and rotates it downwards
Innervation:
Dorsal Scapular Nerve
Cervical Spinal Nerves C3-C5
What is Rhomboid Major?
Muscle of the Thorax that move Pectoral Girdle
Posterior Thoracic Muscle
Origin:
Spines of T2-T5
Insertion:
Vertebral border of scapula inferior to spine
Action:
Elevate and adducts scapula and rotates it downwards
Stabilize scapula
Innervation:
Dorsal Scapular Nerve
What is Rhomboid Minor?
Muscle of the Thorax that move Pectoral Girdle
Posterior Thoracic Muscle
Origin:
Spines of C7-T1
Insertion:
Vertebral border of scapula superior to spine
Action:
Elevate and adducts scapula and rotates it downwards
Stabilize scapula
Innervation:
Dorsal Scapular Nerve
What is Deltoid?
Scapular muscle that moves the Humerus
Origin:
Acromial extremity of clavicle (anterior fibers)
Acromion of scapula (lateral fibers)
Spine of scapula (posterior fibers)
Insertion:
Deltoid tuberosity of Humerus
Action:
Lateral fibers abduct arm at shoulder joint
Anterior fibers flex and medially rotate arm at shoulder joint
Posterior fibers extend and laterally rotate arm at shoulder joint
Innervation:
Axillary Nerve
(If damaged, bad ROM)
What is Lumbricals?
Intermediate (mid-palmar)
Muscles that move the Digits (Intrinsic Hand Muscles)
Origin:
Lateral sides of tendons and Flexor Digitorum Profundus of each finger
Insertion:
Lateral sides of tendons of Extensor Digitorum on proximal phalanges of each finger
Action:
Flex each finger at metacarpophalangeal joints
Extend each finger at interphalangeal joints
Innervation:
Median Nerve
Ulnar Nerve
What is Iliopsoas and Psoas Major?
Muscle of the Gluteal Region that move Femur
Origin:
Transverse processes and bodies of Lumbar vertebrae
Insertion:
With Iliacus into Lesser Trochanter of Femur
Action:
Psoas Major and Iliacus muscles acting together flex thigh at hip joint
Rotate thigh laterally
Flex trunk on hips as in silting up from supine position
Innervation:
Lumbar Spinal Nerves L2-L3
What is Iliacus?
Muscle of the Gluteal Region that move Femur
Origin:
Iliac Fossa
Sacrum
Insertion:
With Psoas Major into Lesser Trochanter of Femur
Action:
Psoas Major and Iliacus muscles acting together flex thigh at hip joint
Rotate thigh laterally
Flex trunk on hips as in silting up from supine position
Innervation:
Femoral Nerve
What is Dorsal Interossei?
Intrinsic muscles of the Foot that move the Toes
Origin:
Adjacent side of all metatarsals
Insertion:
Proximal phalanges
Both sides of toe 2
Lateral sides of toe 3 and 4
Action:
Abduct and flex toes 2-4 at metatarsophalangeal joints
Extend toes at interphalangeal joints
Innervation:
Lateral Plantar Nerve
Femoral Nerve
What is Plantar Interossei?
Intrinsic muscles of the Foot that move the Toes
Origin:
Metatarsals 3-5
Insertion:
Medial side of proximal phalanges of toes 3-5
Action:
Adduct and flex proximal metatarsophalangeal joints
Extend toes at interphalangeal joints
Innervation:
Lateral Plantar Nerve
What are some Running Injuries?
Most running injuries involve knee
Running injuries are usually related to faulty training techniques
Running injuries can be treated with:
PRICE - Protection, Rest, Ice, Compression, Elevation
NSAIDS or Corticosteroid injections
Rehabilitative exercises
What is Compartment Syndrome?
Pressure constricts the structures within a compartment resulting in damaged blood vessels
If left untreated:
Nerves can suffer damage
Muscles can develop scar tissue and contracture may result (permanent tightening of the muscles, tendons, skin, and nearby tissues that causes the joints to shorten and become very stiff)
What is Plantar Fasciitis?
Painful heel condition that results from chronic irritation of the plantar aponeurosis at its origin on the calcaneus
Treatment includes:
Ice
Heat
Stretching
Weight loss
Prosthetics
Steroid injections
Surgery
