Anatomy and Physiology Exam 3 Learning Objectives

Muscles and The Nervous System

Origin

The point of attachment of a muscle to the stationary bone

Insertion

The point of attachment of a muscle to the bone that moves during contraction

Parallel Muscle Fascicle Arrangement

A type of muscle fiber arrangement where fascicles are aligned parallel to the long axis of the muscle, allowing for greater shortening and range of motion

Circular Muscle Fascicle Arrangement

A type of muscle fiber arrangement where fascicles are arranged in concentric rings, allowing for the muscle to tighten around an opening when contractedand is commonly found in sphincter muscles

Fusiform Muscle Fascicle Arrangement

A type of muscle fiber arrangement where fascicles are tapered at both ends, allowing for a larger muscle belly and moderate shortening capability

Triangular Muscle Fascicle Arrangement

Muscle fascicles spread over broad area converge at thick central tendon; gives muscle a triangular appearance multi directional movement moderate force and range of motion

Unipennate Muscle Fascicle Arrangement

muscle fascicles arranged on only one side of the tendon greater force but reduced range of motion

Bipennate Muscle Fascicle Arrangement

muscle fascicles arranged on both sides of the centrally positioned tendons high force and moderate range

Multipennate Muscle Fascicle Arrangement

muscle fascicles attached obliquely from many directions to several tendons maximum force and least range of motion

First-Class Lever

the fulcrum is between the effort, and the load scissors and seesaws are examples can produce either a mechanical advantage or disadvantage based on whether the effort or load is closer to the fulcrum example of this adult and child on seesaw example in the body is head nodding

Second-Class Lever

the load is between the fulcrum and effort operate like wheelbarrow always produce mechanical advantage because the load is always closer to the fulcrum than the effort uncommon in the body and example is standing on your toes

Third-Class Lever

operate like a pair of forceps and the most common always produce a mechanical disadvantage because the effort is always closer to the fulcrum than the load speed and range of motion over force the elbow joint, the biceps brachii and the bones of the arm and forearm are an example

Prime Mover

the muscle directly responsible for producing desired movement also know as agonist

Antagonist

the muscle that has an action opposite of the prime mover(agonist) and yields to the movement of the prime mover stretches and yields to the effects of the prime mover

Synergists

assists the prime mover by reducing undesired action or unnecessary movement by contracting and stabilizing the intermediate joints

Skeletal Muscle Naming ( Direction)

Orientation of muscle fascicles relative to the body’s midline

Rectus: Parallel to midline Transverse: Perpendicular to midline

Oblique: Diagonal to midline

Skeletal Muscle Naming (Size)

Maximus: Largest

Minimus: Smallest

Longus: Long

Brevis: Short

Latissimus: Widest

Longismiss: Long

Magnus: Large

Major: Larger

Minor: Smaller

Vastus: Huge

Skeletal Muscle Naming (Action)

Flexor: decreases joint angle

Extensor: increases joint angle

Abductor: moves bone away from midline

Adductor: moves bone closer to midline

Levator: raises or elevates body part

Depressor: lowers or depresses body part

Supinator: turns palm anteriorly

Pronator: turns palm posteriorly

Sphincter: decreases size of an opening

Tensor: makes body part rigid

Rotator: rotates bone around longitudinal axis

Skeletal Muscle Naming (number of origins)

number of tendons of origin (biceps 2 triceps 3 quadriceps 4)

Skeletal Muscle Naming (location)

structure near which a muscle is found

Skeletal Muscle Naming (origin and insertion)

sites where muscle originates and inserts

Occipitofrontalis (origin, insertion, action, and innervation)

Origin: Frontal Belly (upper anterior aspect of skull)

Occipital Belly: lateral 2/3 of superior nuchal line of occipital bone; mastoid process

Insertion: Epicranial Aponeurosis (tough layer of tissue that covers the upper part of skull in humans)

Action: elevates eyebrows, wrinkles forehead, occipital belly retracts scalp

Innervation: Facial Nerve (VII)

Orbicularis Oris (origin, insertion, action, and innervation)

Origin: muscle fibers surrounding the opening of the mouth

Insertion: skin at corner of mouth

Action: kissing, talking, helps move mouth in different ways

Innervation: Facial Nerve (VII)

Orbicularis Oculi

Origin: medial wall of orbit

Insertion: circular path around orbit

Action: closes eye

Innervation: facial nerve (VII)

Platysma (origin, insertion, action, and innervation)

Origin: fascia over deltoid and pectoralis major muscles

Insertion: mandible and skin of lower face

Action: Frowning

Innervation: Facial Nerve (VII)

Superior Rectus (origin, insertion, action, and innervation)

Origin: common tendinous ring attached to orbit around optic foramen

Insertion: superior and central parts of eyeballs

Action: moves eyeballs superiorly (elevation) and rotates them medially (adduction)

Innervation: oculomotor (III) nerve

Inferior Rectus (origin, insertion, action, and innervation)

Origin: common tendinous ring attached to orbit around optic foramen

Insertion: inferior and central part of eyeballs

Action: moves eyeballs inferiorly (depression) and medially (adduction), and rotates them laterally

Innervation: oculomotor (III) nerve

Lateral Rectus (origin, insertion, action, and innervation)

Origin: common tendinous ring attached to orbit around optic foramen

Insertion: lateral side of eyeballs

Action: moves eyeballs laterally (abduction)

Innervation: abducens (VI) nerve

Medial Rectus (origin, insertion, action, and innervation)

Origin: common tendinous ring attached to orbit around optic foramen

Insertion: medial side of eyeballs

Action: moves eyeballs medially (adduction)

Innervation: Oculomotor (III) nerve

Superior Oblique (origin, insertion, action, and innervation)

Origin: sphenoid bone

Insertion: eyeball between superior and lateral recti

Action: moves eyeballs inferiorly (elevation) and laterally (adduction), and rotates them medially

Innervation: trochlear (IV) nerve

Inferior Oblique (origin, insertion, action, and innervation)

Origin: maxilla

Insertion: eyeball between inferior and lateral recti

Action: move eyeballs superiorly (elevation) and laterally (abduction), and rotates them laterally

Innervation: oculomotor (III) nerve

Masseter (origin, insertion, action, and innervation)

Origin: maxilla and zygomatic arch

Insertion: angle and ramus of mandible

Action: elevates mandible like closing your mouth

Innervation: mandibular division of trigeminal (V) nerve

Temporalis (origin, insertion, action, and innervation)

Origin: temporal bone

Insertion: coronoid process and ramus of mandible

Action: elevates and retracts mandible opens and closes mouth

Innervation: mandibular division of the trigeminal (V) nerve

Sternocleidomastoid (origin, insertion, action, and innervation)

Origin: sternal head, manubrium of sternum, clavicular head medial third of clavicle

Insertion: mastoid process of temporal bone and lateral half of occipital bone

Action: help move the head by using neck muscles

Innervation: accessory (XI) nerve, c2, and c3

Rectus Abdominus (origin, insertion, action, and innervation)

Origin: pubic crest and pubic symphysis

Insertion: cartilage of ribs 5-7 and xiphoid process

Action: flexes vertebral column especially lumbar portion compress abdomen to aid in bodily excretion flexes pelvis and vertebral column

Innervation: thoracic spinal nerves t7-t12

External Abdominal Oblique (origin, insertion, action, and innervation)

Origin: ribs 5-12

Insertion: iliac crest and Linea alba

Action: compress abdomen and flex vertebral column

Innervation: thoracic spinal nerves t7-t12 and the iliohypogastric nerve

Internal Abdominal Oblique (origin, insertion, action, and innervation)

Origin: iliac crest, inguinal ligament, and linea alba

Insertion: cartilage of ribs 7–10 and thoracolumbar fascia

Action: compress abdomen and flex vertebral column

Innervation: thoracic spinal nerves T8–T12, the iliohypogastric nerve, and ilioinguinal nerve

Transversus Abdominus (origin, insertion, action, and innervation)

Origin: iliac crest, inguinal ligament, lumbar fascia, and cartilages of ribs 5–10

Insertion: xiphoid process, linea alba, and pubis

Action: compresses abdomen

Innervation: thoracic spinal nerves T8–T12, iliohypogastric nerve, and ilioinguinal nerve

Diaphragm (origin, insertion, action, and innervation)

Origin: xiphoid process of sternum, costal cartilages and adjacent portions of ribs 7–12, lumbar vertebrae and their intervertebral discs

Insertion: central tendon

Action: breathing

Innervation: phrenic nerve, which contains axons from cervical spinal nerves (C3–C5)

External Intercostals (origin, insertion, action, and innervation)

Origin: inferior border of rib above

Insertion: superior border of rib below

Action: allows ribcage to expand allowing inhalation

Innervation: thoracic spinal nerves t2-t12

Internal Intercostals (origin, insertion, action, and innervation)

Origin: superior border of rib below

Insertion: inferior border of rib above

Action: allows ribcage to go together in order to exhale

Innervation: thoracic spinal nerves t2-t12