Week 4 // Muscular Tissue AND Muscular System Flashcards
What are the 3 types of muscular tissue?
Skeletal muscle
Cardiac muscle
Smooth muscle
What is the function and location of skeletal muscles?
Skeletal, function is to move bones.
What is the function and location of cardiac muscles?
In heart, function is to pump blood.
What is the function and location of visceral (smooth) muscles?
various organs, various functions (ex. paristalsis)
What is the appearance of skeletal, cardiac and smooth muscle tissue?
skeletal: multi-nucleated and striated
cardiac: one nucleus, striated, intercalated disks
What are the functions of muscular tissue?
- Generating heat
- Producing body movements
- Stabilizing body positions
- Storing and mobilizing substances within the body
(In a less known but critically important role, muscle influences energy and protein metabolism throughout the body. Muscle is a primary site for glucose uptake and storage, and it is also a reservoir of amino acids stored as protein.)
Properties of muscular tissue?
- Electrical excitability
- Contractility
- Extensibility
- Elasticity
How are muscles formed?
Myoblasts
How do skeletal muscles produce movements?
Skeletal muscles produce movements by exerting force on tendons
Tendons attach to and pull on bones, and movement occurs
Origin and Insertion
When a muscle contracts, it draws one articulating bone toward the other
Origin – the attachment to the stationary bone
Insertion – the attachment to the moveable bone
Lever Systems and Leverage
Levers are acted upon by ____ and ________
The lever is acted on by:
Load (Resistance)
Effort
Bones serve as levers and joints serve as
________
fulcrums
What is a lever?
Lever is a rigid structure that can move around a fixed point called a fulcrum
First Class Lever
Load and effort on opposite sides of fulcrum.
Second Class Lever
Load and Effort on same sides as fulcrum, the effort is farthest away from fulcrum.
(wheelbarrel)
Third Class Lever
Load and Effort on same sides as fulcrum.
Load is farthest away from fulcrum.
(Picking something up, biceps)
How are most skeletal muscles arranged?
most skeletal muscles are arranged in opposing pairs at joints
Agonist/prime mover
biceps brachii (add from text)
Antagonist
Triceps brachii muscle must relax to allow biceps to move
Synergist
During forearm flexion, for example lifting a cup, a muscle called the biceps brachii is the prime mover. Because it can be assisted by the brachialis, the brachialis is called a synergist in this action
(Smaller muscles that help Agonist and Antagonist muscles to finish movements)
How are muscles named?
A muscle may be named based on:
Location
Size
Number of origins
Appearance
Direction of fibres
Origin and insertion
Muscle action
Rectus
Parallel to midline
Transverse
Perpendicular to midline
Oblique
Diagonal to midline
Meaning of Maximus (Gluteus Maximus)
Maximus = Largest
Meaning of Minimus (Gluteus Minimus)
Minimus = Smallest
Meaning of Longus (Adductor longus)
Longus = Long
Meaning of Brevis (Adductor brevis)
Brevis = Short
Meaning of Latissimus (Latissimus dorsi) and where is it?
Latissimus = Widest
Meanings of muscle names
(naming muscles by size)
Magnus, Major, Minor, Vastus
Magnus= Large
(ex. Adductor magnus)
Major = Larger
(Pectoralis major)
Minor = Smaller
(Pectoralis minor)
Vastus = Huge
(Vastus lateralis)
Meaning of Muscie names
(naming muscles by action)
Flexor, Extensor, Abductor, Adductor, Levator, Depressor, Supinator, Pronator, Sphincter, Tensor, Rotator
Flexor = Decreases joint angle
(Flexor carpi radialis)
Extensor = Increases joint angle
(Extensor carpi ulnaris)
Abductor = Moves bone away from midline
(Abductor pollicis longus)
Adductor = Moves bone closer to midline
(Adductor longus)
Levator = Raises or elevates body part
(Levator scapulae)
Depressor = Lowers or depresses body part
(Depressor labii inferioris)
Supinator = Turns palm anteriorly
(Supinator)
Pronator = Turns palm posteriorly
(Pronator teres)
Sphincter = Decreases size of an opening
(External anal sphincter)
Tensor = Makes body part rigid
(Tensor fasciae latae)
Rotator = Rotates bone around longitudinal axis
(Rotatore)
Meaning of Muscie names
(naming muscles by shape)
Deltoid, Trapezoid, Serratus, Rhomboid, Orbicularis, Pectinate, Piriformis, Platys, Quadratus, Gracilis
deltoid = triangle, trapezoid = trapezius, Serratus = Saw-toothed, Rhomboid = Diamond-shaped, Orbicularis = Circular, Pectinate = Comb-like, Piriformis= Pear-shaped,
Platys, Flat, Quadratus= Square, four-sided, Gracilis=
Slender
Muscles of facial expression lie within this layer
the subcutaneous layer, originating on the fascia or bones of the skull and inserting into the skin
Occipalfrontalis *
Front of forehead - wrinkles forehead, raises eyebrows
Consists of two parts:
- *Frontal belly** (frontalis) at forehead
- Origin: Epicranial aponeurosis.*
- Insertion: Skin of eyebrow, muscles of forehead*
Occipital belly (near occiptal bone)
Origin: Occipital bone and mastoid process of temporal bone.
Insertion:Epicranial aponeurosis.
When muscles of facial expression contract, they move this instead of a joint
they move the skin rather than a joint
Frontal belly
Origin: Epicranial aponeurosis.
Insertion: Skin superior to supraorbital margin.
Zygomaticus major
origin: zygomatic bone.
insertion: sides of mouth
Draws angle of mouth superiorly and laterally, as in smiling.
Zygomaticus minor
origin= zygomatic bone. Raises upper lip, shows teeth
Levator labii superioris
Raises upper lip.
Temporalis *
Elevates and retracts mandible.
Original temporal bone, insert, coronoid process and ramus of mandible
Platysma *
Large muscle front of neck,
origin: Fascia over deltoid and pectoralis major muscles.
Draws outer part of lower lip inferiorly and posteriorly as in pouting; depresses mandible
Masseter *
Elevates mandible, as in closing mouth.
Medial pterygoid *
Elevates and protracts (protrudes) mandible and moves mandible from side to side.
Origin: Medial surface of lateral portion of pterygoid process of sphenoid bone; maxilla.
Insertion: Angle and ramus of mandible.
Medial pterygoid *
Protracts mandible, depresses mandible as in opening mouth, and moves mandible from side to side.
Origin: Greater wing and lateral surface of lateral portion of pterygoid process of sphenoid bone.
Insertion: Condyle of mandible; temporomandibular joint (TMJ).
Sternocleidomastoid *
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 and 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.
Origin: Sternal head: manubrium of sternum; clavicular head: medial third of clavicle.
Insertion: Mastoid process of temporal bone and lateral half of superior nuchal line of occipital bone.
The anterolateral abdominal wall is composed skin, fascia, and four pairs of muscles: (4 names)
rectus abdominus, external abdominal oblique, internal abdominal oblique, transverse abdominus
Linea Alba
white line in centre of abdomen separating muscles
Rectus Abdominus
Flexes vertebral column, especially lumbar portion, and compresses abdomen to aid in defecation, urination, forced exhalation, and childbirth. RMA: Flexes pelvis on the vertebral column.
Origin: Pubic crest and pubic symphysis.
Insertion: Cartilage of ribs 5–7 and xiphoid process.
Rectus Abdominus*
Flexes vertebral column, especially lumbar portion, and compresses abdomen to aid in defecation, urination, forced exhalation, and childbirth. RMA: Flexes pelvis on the vertebral column.
Origin: Pubic crest and pubic symphysis.
Insertion: Cartilage of ribs 5–7 and xiphoid process. (crunches abdomen and flexes pelvis) normally, insertion portion moves. In this case * insertion area does no move, and the origin portion moves! * REVERSED
Rectus Abdominus*
Flexes vertebral column, especially lumbar portion, and compresses abdomen to aid in defecation, urination, forced exhalation, and childbirth. RMA: Flexes pelvis on the vertebral column.
Origin: Pubic crest and pubic symphysis.
Insertion: Cartilage of ribs 5–7 and xiphoid process. (crunches abdomen and flexes pelvis) normally, insertion portion moves. In this case * insertion area does no move, and the origin portion moves! * REVERSED
Internal abdominal oblique *
Acting together, compress abdomen and flex vertebral column; acting singly, laterally flex vertebral column, especially lumbar portion, and rotate vertebral column.
Origin:: Iliac crest, inguinal ligament, and linea alba.
Insertion: Cartilage of ribs 7–10 and thoracolumbar fascia.
Transversus abdominis*
Compresses abdomen.
Origin: Iliac crest, inguinal ligament, lumbar fascia, and cartilages of ribs 5–10.
Insertion: Xiphoid process, linea alba, and pubis.
Quadratus lumborum
Acting together, pull 12th ribs inferiorly during forced exhalation, fix 12th ribs to prevent their elevation during deep inhalation, and help extend lumbar portion of vertebral column; acting singly, laterally flex vertebral column, especially lumbar portion. RMA: Elevates hip bone, commonly on one side.
Origin: Iliac crest and iliolumbar ligament.
Insertion: Inferior border of rib 12 and L1–L4.
The muscles of which area allow breathing?
The muscles of the thorax alter the size of the thoracic cavity so that breathing can occur
What are the muscles of the thorax?
Diaphragm, Internal intercostals, External intercostals
Diaphragm
Action: Contraction of diaphragm causes it to flatten and increases vertical dimension of thoracic cavity, resulting in inhalation; relaxation of diaphragm causes it to move superiorly and decreases vertical dimension of thoracic cavity, resulting in exhalation. (Major muscle to assist breathing)
Origin: Xiphoid process of sternum, costal cartilages and adjacent portions of ribs 7–12, lumbar vertebrae and their intervertebral discs. Insertion: Central tendon.
External intercostals
Action: Contraction elevates ribs and increases anteroposterior and lateral dimensions of thoracic cavity, resulting in inhalation; relaxation depresses ribs and decreases anteroposterior and lateral dimensions of thoracic cavity, resulting in exhalation.
Origin: Inferior border of rib above.
Superior: Superior border of rib below.
*OPPOSITE TO INTERNAL INTERCOSTAL*
Internal intercostals *
Action: Contraction draws adjacent ribs together to further decrease anteroposterior and lateral dimensions of thoracic cavity during forced exhalation. *OPPOSITE to EXTERNAL INTERCOSTAL*
Origin: Superior border of rib below.
Insertion: Inferior border of rib above.
(Origin of internal is the insertion of the external, and vice versa. They work together.)
How are the internal / external intercostal muscles opposite? *
The insertion of one is the origin of the other and vice versa
Muscles of the Thorax that move the pectoral girdle
Anterior: Subclavicus, Pectoralis minor
Serratus anterior
Posterior: Levator scapulae, trapezius, Rhomboid major , Rhomboid minor
,
Muscles of the Thorax and Shoulder that Move the Humerus
AXIAL:
Pectoralis major, Latissimus dorsi
SCAPULAR: Deltoid, Subscapularis , Supraspinatus, Infraspinatus, Teres major, Coracobrachialis,
Triceps Bracchii* What are the heads?
Has three heads:
Long head
Lateral head
Medial Head
Biceps Bracchi* What are the heads?
2 heads:
Long head
Short head
Muscles of the Arm That Move the Radius and Ulna
FOREARM FLEXORS
Biceps brachii, Brachialis, Brachioradialis,
FOREARM EXTENSORS
Triceps brachii , Anconeus
FOREARM PRONATORS
Pronator teres, Pronator quadratus
FOREARM SUPINATOR
Supinator,
Muscles of the Forearm That Move the Wrist, Hand, Thumb, and Digits
SUPERFICIAL ANTERIOR (FLEXOR) COMPARTMENT OF THE FOREARM: Flexor carpi radialis, Palmaris longus, Flexor carpi ulnaris, Flexor digitorum superficialis,
DEEP ANTERIOR (FLEXOR) Flexor pollicis longus (flex thumb) Flexor digitorum profundus (from top forearm 4 tendons that insert into the ends of the 4 fingers)
SUPERFICIAL POSTERIOR (EXTENSOR) COMPARTMENT OF THE FOREARM
Extensor carpi radialis longus
Extensor carpi radialis brevis
Extensor digitorum (from top of forearm to back of hand insert into joints of 4 fingers)
Extensor digiti minimi
Extensor carpi ulnaris
Abductor pollicis longus
Extensor pollicis brevis
Extensor pollicis longus
Extensor indicis
Where is the Adductor Longus muscle ?
Where is the adductor brevis?
Where is the vatus lateralis?
Quadriceps
Origin : Greater trochanter.
Insertion: Quadriceps tendon to base of patella and onto tibial tuberosity via the patellar ligament.
Occipital Belly*
Insertion: Occipital bone and mastoid process of temporal bone.
Origin: Epicranial aponeurosis.
Part of Occipitalfrontalis
Levator labii superioris
levator = raises or elevates; labii = lip; superioris = upper)
(Raises upper lip)
Origin: Superior to infraorbital foramen of maxilla.
Insertion: Skin at angle of mouth and orbicularis oris.
Depressor labii inferioris
Depresses (lowers) lower lip.
Origin: Mandible.
Insertion: Skin of lower lip.
Depressor anguli oris
Draws angle of mouth laterally and inferiorly, as in opening mouth.
- Origin: Mandible.*
- Insertion: Angle of mouth.*
Which muscle goes around the mouth and closes and protrudes lips, and shapes mouth for speech, kissing, etc.?
orbicularis oris
2 mouth muscles connected to the cheek bone?
Zygomaticus major
Origin: Zygomatic bone.
Insertion: Skin at angle of mouth and orbicularis oris.
Draws angle of mouth superiorly and laterally, as in smiling.
Zygomaticus minor
Origin: Zygomatic bone.
Insertion: Upper lip.
Raises (elevates) upper lip, exposing maxillary (upper) teeth.
Which muscle raises lip?
Levator labii superioris
(le-VĀ-tor LĀ-bē-ī sooper′-ē-OR-is; levator = raises or elevates; labii = lip; superioris = upper)
Buccinator
Presses cheeks against teeth and lips, as in whistling, blowing, and sucking; draws corner of mouth laterally; and assists in mastication (chewing) by keeping food between the teeth (and not between teeth and cheeks).
Origin: Alveolar processes of maxilla and mandible and pterygomandibular raphe (fibrous band extending from pterygoid process of sphenoid bone to mandible)Insertion: Orbicularis oris.
Risorius
Origin: Fascia over parotid (salivary) gland.
Insertion: Skin at angle of mouth.
Mentalis
Origin: Mandible.
Insertion: Skin of chin.
Elevates and protrudes lower lip and pulls skin of chin up, as in pouting.
Where is the Platysma and what does the muscle name mean?
In the neck, muscle is “flat” which is the meaning of platys
Platysma
Origin: Fascia over deltoid and pectoralis major muscles.
Insertion: Mandible, blends with muscles around angle of mouth, and skin of lower face.
Draws outer part of lower lip inferiorly and posteriorly as in pouting; depresses mandible.
Masseter
Masseter
Origin: Maxilla and zygomatic arch.
Insertion: Angle and ramus of mandible.
Elevates mandible, as in closing mouth.
Temporalis
Origin:Temporal bone.
Insertion: Coronoid process and ramus of mandible.
Elevates and retracts mandible.
What are the two pterygoid muscles?
Lateral and Medial
Help with chewing
Medial pterygoid vs Lateral pterygoid
Medial pterygoid
Origin: Medial surface of lateral portion of pterygoid process of sphenoid bone; maxilla.
Insertion: Angle and ramus of mandible.
Elevates and protracts (protrudes) mandible and moves mandible from side to side.
Lateral pterygoid
Origin: Greater wing and lateral surface of lateral portion of pterygoid process of sphenoid bone.
Insertion: Condyle of mandible; temporomandibular joint (TMJ).
Protracts mandible, depresses mandible as in opening mouth, and moves mandible from side to side.
Sternocleidomastoid *
Origin: Sternal head: manubrium of sternum; clavicular head: medial third of clavicle.
Insertion: Mastoid process of temporal bone and lateral half of superior nuchal line of occipital bone.
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 and 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.
Longissimus capitis
Origin Articular processes of T1–T4.
Insertion Mastoid process of temporal bone.
Acting together, extend head and vertebral column; acting singly, laterally flex and rotate head to same side as contracting muscle.
Spinalis capitis
Often absent or very small; arises with semispinalis capitis.
origin: Occipital bone.
insert: Extends head and vertebral column.
The anterolateral abdominal wall is composed skin,
fascia, and these four pairs of muscles
Internal Obliques
External Obliques
Transverse Abdominus
Rectus Abdominus
Which abdominal muscles travel up and down parallel to the midline?
rectus abdominus
Rectus abdominis
Origin : Pubic crest and pubic symphysis.
Insertion: Cartilage of ribs 5–7 and xiphoid process.
Flexes vertebral column, especially lumbar portion, and compresses abdomen to aid in defecation, urination, forced exhalation, and childbirth. RMA: Flexes pelvis on the vertebral column.
External abdominal oblique
Origin: Ribs 5–12.
Insertion: Iliac crest and linea alba.
Acting together (bilaterally), compress abdomen and flex vertebral column; acting singly (unilaterally), laterally flex vertebral column, especially lumbar portion, and rotate vertebral column.
Internal abdominal oblique
(internal = farther from surface)
Origin: Iliac crest, inguinal ligament, and linea alba.
Insertion: Cartilage of ribs 7–10 and thoracolumbar fascia.
Acting together, compress abdomen and flex vertebral column; acting singly, laterally flex vertebral column, especially lumbar portion, and rotate vertebral column.
Transversus abdominis
Origin: Iliac crest, inguinal ligament, lumbar fascia, and cartilages of ribs 5–10.
Insertion: Xiphoid process, linea alba, and pubis.
Compresses abdomen.
Muscles for breathing
Diaphragm
Origin: Xiphoid process of sternum, costal cartilages and adjacent portions of ribs 7–12, lumbar vertebrae and their intervertebral discs.
Insertion Central tendon.
Contraction of diaphragm causes it to flatten and increases vertical dimension of thoracic cavity, resulting in inhalation; relaxation of diaphragm causes it to move superiorly and decreases vertical dimension of thoracic cavity, resulting in exhalation.
External intercostals
The external intercostals are small muscles located in between each rib
Origin: Inferior border of rib above.
Insertion: Superior border of rib below.
Contraction elevates ribs and increases anteroposterior and lateral dimensions of thoracic cavity, resulting in inhalation; relaxation depresses ribs and decreases anteroposterior and lateral dimensions of thoracic cavity, resulting in exhalation.
Intrnal intercostals
(internal = farther from surface)
Origin : Superior border of rib below.
Insertion: Inferior border of rib above.
Contraction draws adjacent ribs together to further decrease anteroposterior and lateral dimensions of thoracic cavity during forced exhalation.
What are the Muscles of the Thorax That Move the Pectoral Girdle?
(4)
Levator Scapulae, Trapezius, Serratus Anterior, Pectoralis Minor
3 more deep muscles that go around the scapula that Move the Pectoral Girdle
Supraspinatus, Infraspinatus, Teres Minor
Serratus anterior
Origin : Ribs 1–8 or 1–9.
Insertion: Vertebral border and inferior angle of scapula.
Abducts scapula and rotates it upward. RMA: Elevates ribs when scapula is stabilized. Known as “boxer’s muscle” because it is important in horizontal arm movements such as punching and pushing.
Trapezius
Origin: Superior nuchal line of occipital bone, ligamentum nuchae, and spines of C7–T12.
Insertion: Clavicle and acromion and spine of scapula.
Superior fibers upward rotate scapula; middle fibers adduct scapula; inferior fibers depress and upward rotate scapula; superior and inferior fibers together rotate scapula upward; stabilizes scapula. RMA: Superior fibers can help extend head.
Subclavius
Origin: Rib 1.
Insertion: Clavicle.
Depresses and moves clavicle anteriorly and helps stabilize pectoral girdle.
Pectoralis minor
Origin: Ribs 2–5, 3–5, or 2–4.
Insertion: Coracoid process of scapula.
Abducts scapula and rotates it downward. RMA: Elevates ribs 3–5 during forced inhalation when scapula is fixed.
Levator scapulae
Origin: Transverse processes of C1–C4.
Insertion: Superior vertebral border of scapula.
Elevates scapula and rotates it downward; laterally flexes neck to same side.
Rhomboid major
Origin: Spines of T2–T5.
Insertion: Vertebral border of scapula inferior to spine.
Adducts scapula and rotates it downward; stabilizes scapula.
Rhomboid Minor
Origin: Spines of C7–T1.
Insertion: Vertebral border of scapula superior to spine.
Adducts scapula and rotates it downward; stabilizes scapula.
Muscles of the Thorax and Shoulder that move the humerus
Latissimus dorsi
Origin: Spines of T7–L5, lumbar vertebrae, crests of sacrum and ilium, ribs 9–12 via thoracolumbar fascia.
Insertion: Intertubercular sulcus of humerus.
Extends, adducts, and medially rotates arm at shoulder joint; draws arm inferiorly and posteriorly. RMA: Elevates vertebral column and torso.
Deltoid *
Origin: Acromial extremity of clavicle (anterior fibers), acromion of scapula (lateral fibers), and spine of scapula (posterior fibers).
Insertion: Deltoid tuberosity of humerus.
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.
Triceps Brachii and Biceps Brachii *
Heads?
Triceps (posterior) Brachii have three heads:
Long head, lateral head and medial head.
Biceps (anterior) have two heads:
Long head and short head
(* Long head “L” is more “L”ateral)
Supraspinatus
O: Supraspinous fossa of scapula.
I: Greater tubercle of humerus.
Assists deltoid muscle in abducting arm at shoulder joint.
Lifts arm.
(SUPRAspinatus goes to great tubercle of the humerus and SUBscapularis goes to lesser tubercle of the humerus.)
Subscapularis
Origin: Subscapular fossa of scapula.
Insertion: Lesser tubercle of humerus.
Medially rotates arm at shoulder joint. (It is part of the four rotator cuff muscles, the other three are the supraspinatus, infraspinatus and teres minor muscles. The subscapularis is the largest and strongest muscle of the rotator cuff.)
Supraspinatus
Origin: Supraspinous fossa of scapula.
Insertion: Greater tubercle of humerus.
Assists deltoid muscle in abducting arm at shoulder joint.
Infraspinatus
The infraspinatus is one of four muscles that make up the rotator cuff, which helps your arm and shoulder move and stay stable. Your infraspinatus is in the back of your shoulder. It attaches the top of your humerus (the top bone in your arm) to your shoulder, and it helps you rotate your arm to the side. Infraspinatus is the main external rotator of the shoulder joint. It assists in producing shoulder extension. With the arm fixed, it abducts the inferior angle of the scapula.
Origin: Infraspinous fossa of scapula.
Insertion: Greater tubercle of humerus.
Laterally rotates arm at shoulder joint.
Teres major
Teres major is a small muscle that runs along the lateral border of the scapula. It forms the inferior border of both the triangular space and quadrangular space. It’s sometimes called “lat’s little helper” because of its synergistic action with the latissimus dorsi.
O: Inferior angle of scapula.
I: Medial lip of intertubercular sulcus of humerus.
Extends arm at shoulder joint and assists in adduction and medial rotation of arm at shoulder joint.
Teres minor
Teres minor
O: Infraspinous fossa of scapula.
I: Greater tubercle of humerus.
Laterally rotates and extends arm at shoulder joint.
Coracobrachialis
(kor′-a-kō-brā-kē-Ā -lis; coraco- = coracoid process [of the scapula]; -brachi- = arm)
Coracoid process of scapula.
Middle of medial surface of shaft of humerus.
Flexes and adducts arm at shoulder joint. The coracobrachialis is a long and slender muscle of the anterior compartment of the arm. As its name suggests, it extends from the coracoid process of scapula to the shaft of the humerus. The main function of the coracobrachialis muscle is to produce flexion and adduction of the arm at the shoulder joint.
Deltoid muscle
How many types of fibers and where? *
Deltoid muscle appears to be made up of three distinct sets of muscle fibers.
- 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.
Deltoid Origin and Insertion?
Insertion :Deltoid tuberosity of humerus.
Origin depends on which fibers.
Anterior Fibers: Acromial extremity of clavicle
Lateral Fibers: Acromion of scapula
Posterior Fibers: Spine of scapula
Teres minor and Teres major.
Which one adducts laterally and which one medially?
Teres Minor is lateral
Teres Major is medial
Biceps brachii
(O & I?)
O: Long head originates from tubercle above glenoid cavity of scapula (supraglenoid tubercle).
Short head originates from coracoid process of scapula.
I: Radial tuberosity of radius and bicipital aponeurosis.
Flexes forearm at elbow joint, supinates forearm at radioulnar joints, and flexes arm at shoulder joint.
What are the DEEP muscles that move that radius and the ulna?
(Deeper than the biceps and triceps)
Brachialis (flexor)
Brachioradialus (flexor)
Aconeus (extendor)
Supinator (supinator / palm or forearm up)
Pronator teres (pronator / palm down)
What are the 4 major muscles that move the radius and ulna? *
Biceps, Triceps, Brachilis and Aconeus
Anterior Forearm
Flexor carpi radialis
O: Medial epicondyle of humerus.
I: Metacarpals 2 and 3.
Flexes and abducts hand (radial deviation) at wrist joint.
Palmaris longus
O: Medial epicondyle of humerus.
I: Flexor retinaculum and palmar aponeurosis (fascia in center of palm).
Weakly flexes hand at wrist joint. (Put baby finger and thumb together to see this on anterior/ inside of wrist. Absent in about 14% of population!)
Flexor carpi ulnaris
O: Medial epicondyle of humerus and superior posterior border of ulna.
I: Pisiform, hamate, and base of metacarpal 5.
Flexes and adducts hand (ulnar deviation) at wrist joint.
Flexor digitorum superficialis
O: Medial epicondyle of humerus, coronoid process of ulna, and ridge along lateral margin or anterior surface (anterior oblique line) of radius.
I: Middle phalanx of each finger.
Flexes middle phalanx of each finger at proximal interphalangeal joint, proximal phalanx of each finger at metacarpophalangeal joint, and hand at wrist joint.
Flexor pollicis longus
(Pollex = thumb)
O:Anterior surface of radius and interosseous membrane (sheet of fibrous tissue that holds shafts of ulna and radius together).
I: Base of distal phalanx of thumb.
Flexes distal phalanx of thumb at interphalangeal joint.
Flexor digitorum profundus
O: Anterior surface of body of ulna and ulnar side of interosseous membrane.
I: Base of distal phalanx of each finger.
Flexes distal and middle phalanges of each finger at interphalangeal joints, proximal phalanx of each finger at metacarpophalangeal joint, and hand at wrist joint.
Which flexors in the hand go to the middle phalanx of each finger?
Flexor digitorum superficialis
Which flexors go to the base of the distal phalanx of each finger?
Flexor digitorum profundus
Which flexor moves the distal phalanx of thumb?
Flexor pollicis longus
Which flexors move the hand at wrist joint? (2)
Flexor carpi ulnaris (weakly) and Palmaris longus
These make the anatomincal snuffbox of thumb
(WIll need in future)
Extensor pollicis brevis and Extensor pollicis longus
Abductor pollicis longus
O: Posterior surface of middle of radius and ulna and interosseous membrane.
I: Metacarpal 1.
Abducts and extends thumb at carpometacarpal joint and abducts hand at wrist joint.
Extensor pollicis brevis
O: Posterior surface of middle of radius and interosseous membrane.
I: Base of proximal phalanx of thumb.
Extends proximal phalanx of thumb at metacarpophalangeal joint, first metacarpal of thumb at carpometacarpal joint, and hand at wrist joint.
Extensor pollicis longus
O: Posterior surface of middle of ulna and interosseous membrane.
I: Base of distal phalanx of thumb.
Extends distal phalanx of thumb at interphalangeal joint, extends first metacarpal of thumb at carpometacarpal joint, and abducts hand at wrist joint.
Extensor indicis
O: Posterior surface of ulna and interosseous membrane.
I: Tendon of extensor digitorum of index finger.
Extends distal and middle phalanges of index finger at interphalangeal joints, proximal phalanx of index finger at metacarpophalangeal joint, and hand at wrist joint.
* Which type of muscles are generally on the back of the hand? *
Extensors
posterior proximal leg (back of thigh) main muscles
Iliopsoas / Psoas major
(SŌ-as MĀ-jor; psoa = a muscle of the loin; major = larger)
O: Transverse processes and bodies of lumbar vertebrae.
I: With iliacus into lesser trochanter of femur.
Psoas: each of a pair of large muscles which run from the lumbar spine through the groin on either side and, with the iliacus, flex the hip. Psoas major and iliacus muscles act together to flex thigh at hip joint, rotate thigh laterally, and flex trunk on hip as in sitting up from supine position.
Iliacus
(il′-ē-A-cus; iliac = ilium)
O: Iliac fossa and sacrum.
I: With psoas major into lesser trochanter of femur.
(Moves hip)
Gluteus maximus
O: Iliac crest, sacrum, coccyx, and aponeurosis of sacrospinalis.
I: Iliotibial tract of fascia lata and superior lateral part of linea aspera (gluteal tuberosity) under greater trochanter of femur.
Extends and laterally rotates hip joint.
Gluteus medius
O: Lateral surface of ilium.
I: Greater trochanter of femur.
Abducts and medially rotates hip joint.
Gluteus minimus
O: Lateral surface of ilium.
I: Greater trochanter of femur.
Abducts and medially rotates hip joint.
Tensor fasciae latae
(TEN-sor FA-shē-ē LĀ-tē; tensor = makes tense; fasciae = band; lat = wide)
Lateral surface of anterior iliac crest and anterior superior iliac spine.
Tibia by way of iliotibial tract.
Flexes and abducts hip joint.
Tensor fasciae latae
O: Lateral surface of anterior iliac crest and anterior superior iliac spine.
I: Tibia by way of iliotibial tract.
Flexes and abducts hip joint.
Piriformis
O: Anterior sacrum.
I: Superior border of greater trochanter of femur.
Laterally rotates and abducts hip joint.
Quadratus femoris
(kwod-RĀ-tus FEM-or-is; quad = square, four-sided; femoris = femur)
O: Ischial tuberosity.
I: Elevation superior to mid-portion of intertrochanteric crest (quadrate tubercle) on posterior femur.
Laterally rotates and stabilizes hip joint.
Adductor magnus
O: Inferior ramus of pubis and ischium to ischial tuberosity.
I: Linea aspera of femur.
Adducts thigh at hip joint and rotates thigh; anterior part flexes thigh at hip joint, and posterior part extends thigh at hip joint.
Pectineus
O: Superior ramus of pubis.
I: Pectineal line of femur, between lesser trochanter and linea aspera.
Flexes and adducts thigh at hip joint.
Gracilis
O: Body and inferior ramus of pubis.
I: Medial surface of body of tibia.
Adducts thigh at hip joint, medially rotates thigh, and flexes leg at knee joint.
Rectus femoris
O: Anterior inferior iliac spine.
I: Patella via quadriceps tendon and then tibial tuberosity via patellar ligament.
All four heads extend leg at knee joint; rectus femoris muscle acting alone also flexes thigh at hip joint.
