BIO 168 Chapter 10: Muscular System Gross Anatomy

Tongue Movements

Important in speech: changes shape Swallowing -Moves food around in mouth -Holds food in place during grinding -Pushes food up to palate and back toward pharynx Intrinsic: entirely within the tongue and allow change in shape Extrinsic: insert in tongue and allow change in shape and movement

class I lever

-Fulcrum between force and weight -Seesaw -Head movement at the atlantooccipital joint

which best describes the general roles of the larynx, pharynx, and soft palate muscles?

-directing food passage -speech production -swallowing

name the extensors of the wrist:

-extensor carpi radialis longus -extensor carpi radialis -extensor carpi ulnaris

name the flexors of the wrist:

-flexor carpi ulnaris -flexor carpi radialis

which of the following are characteristics used in the naming of individual muscles?

-function -number of heads -bone attachment sites **location, size, shape, orientation of fascicles, origin and insertion, number of heads, and function.

which two statements describe mastication?

-grinding the food between the teeth -forceful closing of the mouth

which of the following are important functions of the tongue?

-moves food around in the mouth -holds food in place for grinding -helps produce speech -initiates swallowing

which of the following muscles are considered the "kissing" muscles?

-orbicularis oris -buccinator

class III lever

-pull located between fulcrum and weight -person using a shovel -most common: biceps brachii with elbow as fulcrum

class II lever

-weight is between fulcrum and pull -wheelbarrow -standing on toes; metatarsophalangeal joint

muscle types

1. PENNATE MUSCLE unipennate muscle bipennate muscle multipennate muscle 2. PARALLEL MUSCLE 3. CIRCULAR MUSCLE 4. CONVERGENT MUSCLE

put the three layers of the lateral abdominal wall in order from deep to superficial.

1. transversus abdominus 2. internal oblique 3. external oblique

Extrinsic Muscles of the Foot

12 muscles 4 well defined compartments

Swallowing and the Larynx

Hyoid muscles: infra- and suprahyoid groups -Suprahyoid muscles fix the hyoid, then thyrohyoid can elevate larynx -When infrahyoid group fixes hyoid, suprahyoid muscles can help depress the mandible Swallowing: Elevation of pharynx and larynx Constriction of the pharynx from superior to inferior Salpingopharyngeus opens auditory tubes to equalize pressure between middle ear and atmosphere

Muscles of Mastication and Hyoid

Mastication: chewing. Involves elevation/depression of the mandible and excursion to grind the teeth together Act with the muscles of hyoid in movement of the mandible Muscles of the cheek and tongue aid mastication by pushing the food under the teeth Examples: masseter, temporalis, pterygoids, digastrics

the muscles located outside of the tongue which change the shape of the tongue and move the tongue around are called ____.

extrinsic muscles

true or false: most of the muscles that evert the foot will be found in the anterior compartment of the leg.

false

true or false: muscles of the soft palate, pharynx and larynx play an important role in mastication

false

the extrinsic eye muscles are individually named for their:

fascicle orientation

most of the anterior forearm muscles have what action on the wrist and fingers?

flexion

match each neck muscle group with its major function

flexion - anterior neck muscles extension - posterior neck muscles lateral flexion - lateral neck muscles

the extrinsic hand muscles are located in the _____.

forearm

the movement accomplished by contraction of a muscle is referred to as the muscle's ____.

action

the muscle that produces most of the force during a particular movement is called a(n) ____.

agonist

the muscle that produces most of the force for a particular movement is called a(n):

agonist

the intrinsic hand muscles are located in the

hand.

extrinsic muscles cause an action in a particular region but ____.

have their origin in another region

when a muscle has multiple origins, each origin is referred to as a(n) ____.

head

the overall function of the extrinsic eye muscles is:

moving the eye around in the orbit

the site of muscle attachment that does not more during contraction is its ____.

origin

Muscles that Move the Leg

originate on the pelvis and femur, and insert on the tibia and/or fibula

Forearm Movement

Movements at the elbow Extension: triceps brachii and anconeus Flexion: biceps brachii, brachioradialis, and brachialis Supination and pronation: -Supination: supinator and biceps brachii -Pronation: pronator quadratus and pronator teres

Muscle Movements

Muscles and their tendons and bones act together as lever systems to move either parts of the body or the whole body. Muscle contractions are a pull or force by relative positions of -Lever: rigid shaft or bone -Fulcrum: pivot point or joint -Weight or resistance (force of gravity either in the form of the weight of the body parts or the weight of an object being lifted, pulled, or pushed)

Nomenclature

Muscles are named according to: -Location: pectoralis gluteus, brachial -Size: maximus, minimus, longus, brevis -Shape: deltoid, quadratus, teres -Orientation: rectus -Origin and insertion: sternocleidomastoid, brachioradialis -Number of heads: biceps, triceps -Function: abductor, adductor, masseter

Rotator Cuff

Primary muscles holding humerus in the glenoid cavity Form a cuff or cap over the proximal humerus Involved in flexion, extension, abduction, adduction, rotation and circumduction Infraspinatus, subscapularis, supraspinatus, teres minor

Leg Movements

Quadriceps femoris: anterior surface of thigh -Extension of the leg at the knee. -Rectus femoris also flexes the hip. -Insert by common tendon (patellar tendon) on and around the patella -Patellar tendon extends from patella to tibial tuberosity Sartorius: flexes hip and knee, laterally rotates thigh Medial thigh muscles: adduction Posterior thigh muscles: hamstrings. Flexion and rotation of the knee

Extrinsic Muscles of the Eye

Rectus muscles: insert on sclera anterior to center of sphere. Move eyeball and thus pupil laterally, superiorly, inferiorly, and medially Oblique muscles: insert onto the posterolateral margin of the eyeball and both laterally deviate the eyeball. The superior oblique passes through a pulley-like trochlea

Muscles of Facial Expression

Cutaneous; origin and insertion in the superficial fascia. Confined primarily to head and neck. Move the skin; some act as sphincters. Examples: orbicularis oris, orbicularis oculi, platysma.

Intrinsic Muscles of the Foot

Analogous to intrinsics of hand, but serve in support and locomotion Flexion, extension, abduction and adduction of toes Deep fascia forms plantar aponeurosis.

Ankle, Foot, and Toe Movements

Extrinsic foot muscles Three leg compartments -Anterior compartment: extensors involved in dorsiflexion and eversion/inversion of foot; extension of toes. Dorsiflex foot, extend toes. -Lateral compartment: plantar flexion and eversion. -Posterior compartment- --Superficial muscles (plantar flexion) have common tendon of insertion called the calcaneal (Achilles) tendon. Gastrocnemius, plantaris --Deep muscles: plantar flex and invert foot

Abdominal Wall

Flex and rotate vertebral column, decrease volume of abdominal and thoracic cavities Aid in forced expiration, vomiting, defecation, urination, childbirth Crossing pattern of muscles adds strength to abdominal wall to support organs Rectus Abdominis -Linea alba in center -Covered by rectus sheath -Tendinous intersections divided muscle into sections -Flexes vertebral column External abdominal oblique: flexes and rotates abdomen Internal abdominal oblique: flexes and rotates abdomen Transversus abdominis: compresses abdominal wall

Head and Neck Muscles

Flexion: muscles deep within the neck along the anterior margins of the vertebral bodies Extension: posterior neck muscles attached to occipital bone Rotation and abduction: lateral and posterior groups Examples: sternocleidomastoid, trapezius, splenius muscles the figure is pointing to the sternocleidomastoid

Thoracic Muscles

Involved in breathing Four groups associated with rib cage -Scalenes: elevate first two ribs during inspiration -External intercostals: elevate the ribs -Internal intercostals: depress ribs during expiration -Transversus thoracis: depresses ribs during expiration -Diaphragm: major movement of inspiration. Flattens during contraction and increases the volume of the thoracic cavity

Wrist, Hand, and Finger Movements

Muscles on anterior surface of forearm: flexion as well as abduction and adduction of the wrist. Muscles on posterior surface of forearm: extension and abduction. Retinacula- bands of deep fascia which hold tendons of muscles of forearm, blood vessels, and nerves close to wrist. -Flexor retinaculum (transverse carpal ligament): on the flexor surface -Extensor retinaculum (dorsal carpal ligament): on the extensor surface

Arm Movements

Muscles that attach arm to thorax: pectoralis major, latissimus dorsi Deltoid and pectoralis major both act as flexors and extensors of the shoulder Deltoid abducts and medially and laterally rotates arm

Scapular Movements

Muscles that attach the upper limb to the body and move or stabilize the scapula and clavicle. Originate on the axial skeleton. Trapezius, levator scapulae, rhomboideus, serratus anterior, pectoralis minor

Muscles that Move the Vertebral Column

Muscles that extend, laterally flex, and rotate the vertebral column. Used to produce erect posture Divided into deep and superficial groups Deep group: from vertebra to vertebra Superficial group extend from vertebrae to ribs

Muscle terminology

Origin or head: muscle end attached to more stationary of two bones Insertion: muscle end attached to bone with greatest movement Belly: largest portion of the muscle between origin and insertion Agonist: muscle that, when it contracts, causes an action Antagonist: a muscle working in opposition to agonist Example: the biceps brachii can be used to lift weights and is the agonist, but when you move a bowling ball back to prepare to bowl, the biceps is the antagonist Synergists: muscles that work together to cause a movement Prime mover: plays major role in accomplishing movement Fixators: stabilize joint/s crossed by the prime mover; prevent movement of the origin of the prime mover.

Intrinsic Muscles of the Hand

Originate and insert in hand.

Thigh Movement

Originate on coxa; insert onto femur Anterior, posterolateral, deep -Anterior: flex hip. Iliacus and psoas major often referred to as iliopsoas since they share a tendon of insertion -Posterolateral: gluteals and tensor fasciae latae Extension of thigh -Deep: thigh rotators

Muscles of Pelvic Floor and Perineum

Pelvic diaphragm: Funnel-shaped, supports the pelvic viscera. Pierced by anal canal, urethra and (vagina). Perineum: diamond-shaped area inferior to pelvic diaphragm. Anterior half of diamond is urogenital triangle; posterior half is anal triangle

Tendons

Tendons: attach muscles to bones Aponeurosis: a very broad tendon

belly

The middle part of the muscle is called the _____.

a muscle that acts in opposition to an agonist is a(n) ____.

antagonist

muscles that dorsiflex the foot will be found in the ____ compartment of the leg.

anterior

the ____ forearm muscles are mostly responsible for flexing the wrist and fingers.

anterior

in skeletal muscle, the broad, thicker part of the muscle between the origin and insertion is called the ____.

belly

the temporalis, masseter lateral pterygoid and medial pterygoid are all considered muscles of

chewing

Classes of Levers

class I, class II, class III

what is the main role of the cutaneous skeletal muscles of the face?

communication through facial expressions

the ____ foot muscles are located in the leg.

extrinsic

the sclera is the insertion point for the ____ muscles of the eye.

extrinsic

the ____ is a strong band of connective tissue that holds tendons in place at the wrist.

extensor retinaculum

the end of the biceps brachii that attaches to the radius is called its ____.

insertion

the site of muscle attachment that moves during contraction is called the:

insertion

by definition, skeletal muscles that are located within the actual structure being moved are known as ____ muscles.

intrinsic

hand muscles that are located entirely within the hand are called _____ muscles.

intrinsic

muscles contained entirely within the tongue, that change the shape of the tongue are called ____ muscles.

intrinsic

the ____ foot muscles are located within the foot itself.

intrinsic

match the thigh compartment with its major action on the hip/thigh

medial compartment - adduction of thigh anterior compartment - flexion of the hip posterior compartment - extension of the hip

the calcaneal tendon attaches the ____ leg muscles to the foot.

posterior

the flexors of the knee are found in the ____ compartment of the thigh.

posterior

the muscles responsible for extending the wrist and fingers are mostly found on the ____ of the forearm.

posterior

the triceps brachii is classified as the ____ in the extension of the elbow.

prime mover

name a muscle that acts on the forearm to pronate the hand:

pronator quadratus

the biceps brachii and supinator act on the forearm to ____ the hand.

surpinate **turn up palm

muscles that work together to produce a movement are called ____.

synergists

muscles are attached to bones by a band of dense connective tissue called a(n) ____.

tendon *tendons are composed of dense connective tissue and can be ropelike, broad and sheetlike called aponeuroses

supraspinatus

the rotator cuff muscle that is indicated in the figure... Abducts arm; stabilizes the head of the humerus in glenoid cavity; one of the "rotator cuff" muscles