Chapter 11 Flashcards
Muscular system
Voluntarily controlled muscles of your body
Origin
Attachment site of muscle tendon to stationary bone
Insertion
Attachment site of muscles tendons to moveable bone
Belly
Slushy portion of muscle between the tendons
Actions Of a muscle
Main movements that occur when the muscle contracts
Reverse muscle action (RMA)
When specific movements of the body can be reversed and the positions of the origin and insertion are switched
Lever
A rigid structure that can move around a fixed point called a fulcrum
Fulcrum
The fixed point
Effort
Causes movement
Load
Also known as resistance, opposes movement
Mechanical advantage
When the load is closer to the fulcrum and the effort is farther from the fulcrum it takes a smaller amount of effort to move the load which is called the mechanical advantage
Mechanical disadvantage
When the load is farther from the fulcrum and the effort is closer to the fulcrum it creates a mechanical disadvantage so that you need more effort to move the load
First class levers
Fulcrum is between the effort and the load
produces a mechanical advantage or disadvantage
examples are the head resting on the vertebral column
Second class levers
Load is between the fulcrum and the effort
operate like a wheel barrel
always produce a mechanical advantage
sacrifices speed and range of motion for force
uncommon in the human body example standing up on your toes
Third class levers
Effort between the fulcrum and the load
operate like a pair of forceps
most common levers in the body always produce a mechanical disadvantage
favour speed and range of motion over force
example elbow joint the biceps brachii muscle in the bones of the arm and forearm
Fascicles
Bundles of muscle fibres
What are the five patterns of fascicles in tendons?
- Parallel
- Fusiform
- Circular
- Triangular
- Pinnate
Prime mover
Contracts to cause an action
Antagonist
Stretches and yields to the effects of the prime mover
Parallel fascicles
Parallel to longitudinal axis of muscle terminate at each end in for attendance
Fusiform
Fascicles nearly parallel to longitudinal axis of muscle terminate in flat tendons muscles taper towards tendons were diameter is less than at the belly
Circular fascicles
Classicals in Concentric circular arrangements from sphincter muscles that enclose an orphus
Triangular fascicles
Fascicle spread over broad area coverage at thick Central tendon gives muscle a triangular appearance
Pennate fascicles
Short fascicles in relation to total muscle length tendon extends nearly entire length of muscle
Synergists
Contract and stabilize the intermediate joints
Fixators
Stabilizing the origin of the prime mover so that the prime mover can act more efficiently
Compartment
A group of skeletal muscles in the limbs, there associated blood vessels and associated nerves all of which have a common function
Rectus
Parallel to the midline
Transverse
Perpendicular to the midline
Oblique
Diagonal to the midline
Maximus
Largest
Minimus
Smallest
Longus
Long
Brevis
Short
Latissimus
Widest
Longissimus
Longest
Magnus
Large
Major
Larger
Minor
Smaller
Vastus
Huge
Deltoid
Triangular
Trapezius
Trapezoid
Serratus
Sawtooth
Rhomboid
Diamond shaped
Orbicularis
Circular
Pectinate
Comb like
Piriformis
Pear-shaped
Platys
Flat
Quadratus
Square four sided
Gracilis
Slender
Flexor
Decreases joint angle
Extensor
Increases joint angle
Abductor
Moves bone away from the midline
Adductor
Moves bone closer to midline
Levator
Raises or elevate body part
Depressor
Lowers or depresses body part
Supinator
Turns palm anteriorly
Pronator
Turns palm posteriorly
Sphincter
Decreasing size of an opening
Tensor
Makes body part rigid
Rotator
Rotates bone around longitudinal axis
What are the muscles of the head the produce facial expressions?
- Scalp muscles
- mouth muscles
- orbit and eyebrow muscles
Scalp muscles
Occipitofrontalis
1. Frontal belly
2. occipital belly
Frontal belly
Draw scalp anteriorly raises eyebrows and wrinkles skin of four head horizontally as in look of surprise
Occipital belly
Draws scalp posteriorly
Mouth muscles
- Orbicularis Oris
- zygomaticus major
- Buccinator
Orbicularis Oris
Closes and protrude lips; as in kissing, compresses lips against teeth, and shapes lips during speech
Zygomaticus major
Draws angle of mouth superiorly and laterally as in smiling
Buccinator
Presses cheeks against teeth and lips as in whistling, blowing, and sucking, draws corner of mouth laterally and assist in mastication by keeping food between the teeth
Orbits an eyebrow muscles
Orbicularis oculi
Orbicularis oculi
Closes Eye
What are the muscles that move the mandible at the temporomandibular joint known as?
Muscles of mastication
What are the three muscles of mastication known as the powerful closers?
Masseter, temporalis, medial pterygoid
Which muscles move the mandible side to side to help grind food?
Medial and lateral pterygoid
Masseter
Origin: Maxilla and zygomatic arch
Insertion: Angle and ramus of mandible
Action:  Elevates mandible as in, closing mouth
Temporalis
Origin: Temporal bone
Insertion: Coronoid process and Ramus of mandible
Action: Elevates in retracts mandible
What are the muscles of the neck that move the head?
- Sternocleidomastoid
Sternocleidomastoid
Origin: Sternal head: manubrium of sternum, clavicular head: medial third of clavicle
Insertion: Mastoid process of temporal bone in lateral half of superior nuchal line of occipital bone
Action: Acting together, flex cervical portion of vertebral column, extend head at Atlanto-occipital joint. Elevate sternum during forced inhalationad.
RMA: Elevate sternum during forced inhalation
Muscles of the abdomen that protect abdominal viscera and move the vertebral column
- Rectus abdominous
- external oblique
- internal oblique
- transversus abdominis
Rectus abdominous
Origin: Pubic crest and pubic symphysis
Insertion: Cartilage of ribs 5 to and xiphoid process
Action: 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 oblique
Acting together, compress abdomen and flex vertebral column. acting single, laterally flex vertebral column especially lumbar portion and rotate vertebral column
Internal oblique
Acting together, compress abdomen and flex vertebral column; acting singly, laterally flex vertebral column, especially lumber portion, and rotate vertebral column
Transversus abdominis
Insertion: Xiphoid process linea alba and pubis
Action: Compresses abdomen
What form the rectus sheaths?
The Aponeurosis of the external oblique, internal oblique and transversus abdominis muscle’s
The rectus sheath meet at the midline to form what?
Linea alba
Linea alba
A tough fibrous band that extends from the xiphoid process of the sternum to the pubic symphysis
Central tendon
A strong aponeurosis located near the centre of the muscle
Diaphragm
The most important muscle that powers breathing and separates the thoracic and abdominal cavities
Muscles of the thorax that assistant breathing?
- Diaphragm
- external intercostals
- internal intercostals
Diaphragm
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 decreases vertical dimension of thoracic cavity; resulting in exhalation
External intercostals
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
Internal intercostals
Contraction draws adjacent ribs together to further decrease anteroposterior and lateral dimensions of thoracic cavity during forced exhalation
Muscles of the thorax that move the pectoral girdle
- Anterior thoracic muscles
- Pectoralis minor
- Serratus anterior - Posterior thoracic muscles
- Trapezius
- levator scapulae
- Rhomboid major
Pectoralis minor
Abduct scapula and rotates it downwards
RMA: elevates ribs 3 to 5 during forced inhalation when scapula is fixed
Serratus anterior
Origin: Ribs 1 to 8 or 1 to 9
Insertion: Vertebral border and inferior angle of scapula
Action: Abduct scapular and rotated upward
RMA: elevates ribs when scapulas stabilized known as “boxers muscle”because it is important in horizontal arm movement such as punching and pushing
Trapezius
Origin: Superior nuchal line of occipital bone, ligamentum nuchae, and spines of C7 to T 12
Insertion: Clavicle and acromion and spine of scapula
Action: Superior fibres upward rotate scapula; middle fibres adduct scapula; inferior fibres depressed and upward rotate scapula; superior and inferior fibres together rotates scapula upward; stabilizes scapula
RMA: superior fibres can help extend head
Levator scapulae
Origin: Transverse processes of C1 to C4
Insertion: Superior vertebral border of scapula
Action: Elevates scapula and rotates it downward
Rhomboid major
Elevates and adducts scapula and rotated downward; stabilizes scapula
Muscles of the thorax and shoulder that move the humerus
- Axial muscles that move the humerus
- Pectoralis major
- Latissimus dorsi - scapular muscles that move the humerus
- Deltoid
- Subscapularis
- Infraspinatus
- Teres major
- Teres minor
Pectoralis major
Origin: Clavicle sternum and costal cartilages of ribs 2 to 6 and sometimes ribs 1 to 7
Insertion: Greater tubercle and lateral lip of intertubercular sulcus of humerus
Action: As a whole, adducts and medially rotates arm and shoulder joint; clavicular head flexes arm, and sternocostal head extends flexed arm to side of trunk
Latissimus dorsi
Extends adducts and mediately rotates arm at shoulder joint; draws arm inferiorly and posteriorly, RMA: elevates vertebral column and torso
Deltoid
Origin: Acromial extremity of clavicle, acromion of scapula, and spine of scapula
Insertion: Deltoid tuberosity of humorous
Action: Lateral fibres abduct arm at shoulder joint; anterior fibres flex and medially rotate arm at shoulder joint; posterior fibres extend and laterally rotate arm at shoulder joint
Subscapularis
Medially rotates arm and shoulder joint
Supraspinatous
Origin: Supraspinatous fossa of scapula
Insertion: Greater tubercle of the humerus
Action: Assist deltoid muscle in abducting arm at shoulder joint
Infraspinatus
Laterally rotates arm at shoulder joint
Teres major
Extends arm and shoulder joint an assistant adduction and medial rotation of arm and shoulder joint
Teres minor
Laterally rotates and extends arm at shoulder joint
Muscles of the arm that move the radius and ulna
- Forearm flexors
- Biceps brachii
- Brachialis
- Brachioradialis
2.forearm extensors
- Triceps brachii
- Anconeus - forearm pronators
- pronator Teres - forearm supinator
- Supinator
Biceps brachii
Origin: Long head originate from to Berkel above Glenoid cavity of scapula
Insertion: Radial tuberosity of radius and bicipital aponeuroses
Action: Flexes forearm at elbow joint, supinates forearm at radioulnar joints, and flexes arm at shoulder joint
Brachialis
Flexes forearm at elbow joint
Brachioradialis
Flexes forearm at elbow joint; supinates and pronates forearm at radioulnar joints to neutral position
Triceps brachii
Origin: Long head originates from infraglenoid tubercle a projection inferior to glenoid cavity of scapula
lateral head originates from lateral and posterior surface of humerus
medial head originates from entire posterior surface of humerus inferior to a groove for the radial nerve
Insertion: Olecranon of ulna
Action: Extends forearm at elbow joint and extends arm and shoulder joint
Anconeus
Origin: Lateral epicondyle of the humerus
Insertion: Olecranon and superior portion of shaft of Ulna
Action: Extends forearm at elbow joint
Innervation: Radial nerve
Pronator teres
Pronates forearm at radioulnar joint and weekly flexes forearm at elbow joint
Supinator
Supinates forearm at radioulnar joints
Muscles of a 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 - Superficial posterior (extensor) compartment of the forearm
- Extensor carpi radialis longus
- Extensor digitorum
- Extensor carpi ulnaris
Flexor carpi radialis
Origin: Medial epicondyle of the humerus
Insertion: Metacarpals two and three
Action: Flexes and abducts hand at wrist joint
Palmaris longus
Weakly flexes hand at risk joint
Flexor carpi ulnaris
Origin: Medial epicondyle of the humerus and superior posterior border of ulna
Insertion: Pisiform, Hamate, and base of metacarpal five
Action: Flexes and Adducts hand at wrist joint
Flexor digitorum superficialis
Origin: Medial epicondyle of the humerus coronoid process of Onna and ridge along lateral margin or anterior surface of radius
Insertion: Middle phalanx of each finger
Action: Flexes middle phalanx of each finger at proximal inter-phalangeal joint; proximal phalanx of each finger at metacarpal phalangeal joint; and hand at wrist joint
Extensor carpi radialis longus
Extends and abduct hand at wrist joint
Extensor digitorum
Origin: Lateral epicondyle of the humerus
Insertion: Distal and middle phalanges of each finger
Action: Extends distal and middle phalanges of each finger at interphalangeal joints, proximal phalanx of each finger at metacarpal phalangeal joint, and hand at wrist joint
Extensor carpi ulnaris
Origin: Lateral epicondyle of the humerus and posterior border of Ulna
Insertion: Metacarpal five
Action: Extends and adducts hand at wrist joint
Muscles of the neck and back that move the vertebral column
- Arrector spinae consists of iliocostalis muscles (lateral), longissimus muscles (intermediate), and spinalis muscles (medial), ilio costalis group (lateral)
- Iliocostalis cervicis
- Iliocostalis thoracis
- Iliocostalis lumborum - Scalenes
- Anterior scalene
- Middle scalene
- Posterior scalene
Iliocostalis cera sis, iliocostalis thoracis ,iliocostalis lumborum
Acting together muscles of each region extend any maintain erect posture of vertebral column of their respective regions acting singly laterally flex vertebral column of their respective regions to same side as contracting muscle
Anterior scalene
Acting together right and left anterior scaling and middle scalene muscles elevate first ribs during deep inhalation
Middle scalene
RMA: flex cervical vertebrae. acting singly, laterally flex and slightly rotate cervical vertebrae
Posterior scalene
Acting together right and left posterior scaling elevate second ribs during deep inhalation
RMA: Flex cervical vertebrae acting singly laterally flex and slightly rotate cervical vertebrae
Psoas major
Origin: Transverse processes and bodies of lumbar vertebrae
Insertion: With iliacus into lesser trochanter femur
Action: psoas major and iliacus Muscles acting together flex thigh at hip joint rotate bilaterally and flexed trunk on hip as in sitting up from supine position
Gluteus maximus
Origin: Iliac crest sacrum and coccyx and aponeurosis of sacrospinalis
Insertion: Iliotibial tract of fascia Lata and superior lateral part of linea aspera under greater trochanter of femur
Action: Extends the at hip joint in laterally rotates the helps lock me in extension RMA extends torso
Gluteus medius
Abduct thigh at hip joint medially rotates thigh
Adductor longus
Addicts and flexes thigh at hip joint and rotates the RMA extended thigh
Adductor Magnus
Adducts thigh at hip joint and rotates thigh, anterior part flexes thigh at hip joint, and posterior part extends that hip joint
Flexor digitorum longus
Plantar flexes foot ankle joint flex is distal middle phalanges of toes 2 to 5 at interphalangeal joints and proximal phalanx of toes 2 to 5 at metatarsophalangeal joint
Soleus
Plantar flexes foot ankle joint
Gastrocnemius
Plantar flexes foot at ankle joint and flexes leg at knee joint