CH11 Flashcards
The moveable end of the muscle that attaches to the bone being pulled is called what?
Insertion: The moveable end of the muscle
The end of the muscle attached to a fixed bone is called what?
Origin: the end of the muscle attached to a fixed (stabilized) bone
Fulcrum
the fixed point when a force is applied, joints
Load
any resistance to a movement (e.g. bones, tissue, resistance to movement, etc.)
Effort
force applied by the contracting muscle at its insertion. Motion occurs when the effort exceeds the load
First-class lever
uncommon; the load and force sit on either side of the fulcrum in the same way as a seesaw.
EX: head resting on the vertebral column which acts as the fulcrum, the contraction of the posterior neck muscles provides the effort, the anterior portion of the skull (load) is lifted
Second-class lever
uncommon; the load is between the fulcrum and the effort.
EX: is raising yourself on your toes. The fulcrum is based at the front of the foot, the load is the weight of the body, and the force is applied through the Achilles tendon in the heel. This creates a mechanical advantage because the load is closer to the fulcrum than the effort as in a wheelbarrow
Third-class lever
common; the force is applied between the load and the fulcrum.
EX: biceps brachii. When flexing the elbow, the elbow is the fulcrum and the force applied by the contracting biceps brachii muscle is the effort. The weight of the forearm and any object a person is carrying in their hand is the load
Which lever is most common in the human body?
Third class lever
Compartment Syndrome
- ainful condition when pressure within the muscles builds to dangerous levels.
- Decreases blood flow and prevent nourishment and oxygen to nerve and muscle cells
- Cause: overuse, trauma, car accident
What are the sign/symptoms of compartment Syndrome?
- pain, pallor (pale skin tone)
- paresthesia (numbness feeling)
- pulselessness (faint pulse)
- paralysis (weakness with movements)
compartment Syndrome most commonly found where?
anterior compartment of the leg
extensor muscles of the toes, tibialis anterior, deep peroneal nerve, and the tibial artery
Orbicularis Oris is what type of fascicle arrangement?
Circular (or sphincter) muscles: arranged in concentric rings around an opening or recess
Prime mover or agonist:
principal muscle involved
Antagonist
muscle with opposite action of agonist; relaxes or stretches when prime mover contracts to produce movement
Synergist
- muscle(s) producing similar motion to or in conjunction with agonist
- May add extra force or reduce unwanted force generated by agonist
- May act as fixation to bone or origin so agonist can work more efficiently
What are the two types of parallel muscles?
- Fusiform: spindle shaped, muscles tapers at each end. (Example: biceps brachii)
- Non Fusiform: more rectangular shaped (Example: Sartorius)
The rectus femoris is an example of what type of muscle arrangement?
Bipennate
Pennate (penna = feathers) muscles
attaches to the central tendon; the tendon runs through the length of the muscle
Unipennate
Extensor digitorum (in the forearm)
What is an example of a multipennate muscle?
deltoid
The word “rectus” means what?
straight
Muscles of face
Occipitofrontalis muscle
moves up the scalp and eyebrows. The frontalis is on the forehead and occipitalis is on the back of head
Muscles of the face
Orbicularis Oris
circles the mouth. Moves lips (kissing muscles!)
Muscles of the face
Orbicularis oculi
blinking muscle
Muscles of the face
Zygomaticus major and minor
are the muscles that elevate the mouth laterally when we “smile”
Muscles of the face
Buccinator
whistle, blow, and suck; drinking out of straw
Muscles of the face
Platysma
tenses the skin of our neck and depresses the lower lip
Muscles of the face
Corrugator supercilii
lowers the eyebrows
Where do the facial muscles originate and insert at?
- Insert: connective tissue and dermis of skin
- Origin: on the skull
Bellʻs Palsy
- paralysis of the nerves of facial expression; facial nerve (CN VII).
- There is an inflammation of the nerve within the stylomastoid foramen, where the nerves travel through
- This condition can be caused by infection with the virus for herpes simplex type 1
How many extrinsic eye muscles are there?
6
1. Superior Rectus: elevates eye (look up)
2. Inferior rectus: Depresses eye (look down)
3. Latera rectus: moves eye laterally
4. Medial rectus: moves eye medially
5. Superior Oblique: Depresses eye and moves eye laterally
6. Inferior Oblique: Elevates eye and moves eye laterally
What is the origin and insertion of the eye muscles?
Origin: sphenoid bone
Insertion: outer surface of sclera
What is the main muscle responsible for chewing?
Masseter
Suprahyoid vs infrahyoid muscles
- Suprahyoid muscles (superior to hyoid) elevate hyoid, floor of mouth, and larynx
- digastric
- stylohyoid
- mylohyoid
- Geniohyoid
- Infrahyoid muscles: (inferior to hyoid) depresses hyoid
- omohyoid
- sternohyoid
- thyrohyoid
Assist with deglutition (swallowing) and speech controlled by the positions of the larynx and the hyoid bone
Neck muscles
Sternocleidomastoid (SCM)
lateral flexion to same side, rotation to the opposite side, or flexion when both sides contract
Neck muscles
Scalenes
flexion when both sides contract
Neck muscles
Splenius (capitis and cervicis)
inserts into head, originates from midline/spine, extends/laterally flex, and rotates head
Which neck muscles inserts into the head and originates from the midline of the spine?
Splenius
What are the four pairs of abdomen muscles? Which abdomen muscle is the deepest? Which is the most superficial?
Helps maintain body posture and protect internal organs
* External obliques: most superficial
* Internal obliques
* Transversus abdominis: deepest
* Rectus abdominis
What is Diastasis recti?
splitting of the linea alba; common during pregnancy
Diaphragm
- most important muscle for breathing
- changes thoracic and abdominal cavity pressures
- Flattens on contraction (letting air in); inhale
- Relaxes (pushes air out); exhale
Intercostal muscles
changes dimensions of rib cage
External intercostal
Inhalation causes rib elevation, thoracic cavity expansion during contraction
Internal intercostal
Exhalation causes rib depression and thoracic cavity constriction during contraction
Innermost intercostal
synergist to internal intercostals
What are the three erector spinae muscles?
Helps maintain body posture
1. Spinalis
1. Longissimus
1. Iliocostalis
Which muscles make up the pelvic floor?
Levator ani (large muscles made of 2 muscles)
1. Pubococcygeus
2. Iliococcygeus
What muscles stabilize the scapula anteriorly?
Anterior: pectoralis minor and serratus anterior (protraction)
What muscles stabilize the scapula posteriorly?
Posterior: trapezius, rhomboid major, rhomboid minor (retraction)
What movement is the serratus anterior responsible for?
Protraction; extension
What are the Rotator Cuff Muscles?
tendons of the subscapularis, supraspinatus, infraspinatus, and teres minor muscles
Which rotator cuff is most common torn?
Supraspinatus
Which muscles move the humerus?
- Pectoralis major: fan-shaped muscle that covers most of the superior portion of the anterior thorax
- Lattisimus dorsi: broad and triangular shaped
located on the inferior part of the back
produces many of the movements required for swimming
What is the primary muscle working for Elbow Flexion? Elbow Extension?
- Elbow Flexion: Biceps brachii, brachialis, and brachioradialis
- Elbow Extension: Triceps brachii
What muscles move the radius & ulna?
Forearm Pronation: Pronator teres
Forearm Supination: Supinator and biceps brachii
Which muscles attach to the medial epicondyle of humerus?
- Flexor carpi radialis
- palmaris longus
- flexor carpi ulnaris
- flexor digitorum superficialis
- pronator teres
Golfer’s Elbow
caused by repetitive strain of the flexor muscles (especially the flexor carpi radialis) from swinging a golf club
Which structure holds the tendons in place as they cross the wrist?
Flexor retinaculum
What muscles are found in the anterior compartment of the forearm?
- flexor carpi radialis
- palmaris longus
- flexor carpi ulnaris
- flexor digitorum superficialis
- flexor pollicis longus
- flexor digitorum profundus
What motion is the gluteus maximus responsible for?
Hip extension
What muscles make up the hamstrings? What is the bony origin of the hamstrings?
- biceps femoris
- semitendinosus
- semimembranosus
* These muscles are responsible for hip extension and knee flexion.
* Common origin: ischial tuberosity
What muscles make up the quadriceps?
- Rectus femoris
- Vastus lateralis
- Vastus medialis
- Vastus intermedius
Where is the quadriceps muscle insertion at?
Insertion: quadriceps tendon > patellar ligament inserting into the > tibial tuberosity
What action does the sartorius do?
- allows you to cross one leg on top of the other
- hip flexion, abduction, and lateral rotation at the hip in addition to flexion at the knee
What movement is the Anterior Tibialis responsible for?
lateral surface of the tibia and produces dorsiflexion and inversion
What movement is the Medial compartment of thigh responsible for?
Hip adduction
What muscle/s are in the posterior compartment of the lower leg?
responsible for hip extension and knee flexion. iv-viii : responsible for hip adduction
1. biceps femoris
2. semitendinosus
3. Semimembranosus
What muscle/s are in the posterior compartment of the lower leg? 2
responsible for hip adduction
1. adductor longus
2. adductor brevis
3. adductor magnus
4. pectineus
5. Gracilis
What muscle/s are in the anterior compartment of the lower leg?
knee extension and stabilization
* Rectus femoris
* Vastus lateralis
* Vastus medialis
* Vastus intermedius
* Sartorius muscle
What muscle/s are in the lateral compartment of the lower leg?
plantarflexion and evert the ankle
fibularis longus (peroneus longus)
fibularis brevis (peroneus brevis)
Lateral ankle sprain
common injury that results from excessive inversion of the foot and ankle
- rolled ankle
Avulsion
fibularis brevis tendon can avulse (tear away) from its attachment on the base of the fifth metatarsal
Plantar fasciitis (inflammation)
produces pain in the heel at the origin of the plantar fascia
Overstretched plantar fascia; causing pain & inflammation
What lower leg muscle allows dorsiflexion and extension of the big toe?
extensor hallucis longus
The plantar fascia supports which arch?
longitudinal arch
bottom of the foot from the calcaneus to the toes
