Unit 4 Part 2 Notes

Unit 4 Part 2 -- Muscles

"The Governator!"

 

  • Anatomy and Physiology of Muscles
    • Location and Action of muscles in the human body
    • Location, origin, insertion and function of major muscles in the cat

 

  • Smiling Vs. Frowning

  • When you smile, you use around 17 muscles.

  • When you frown, you use around 40 muscles.

 

I.  Skeletal Muscle Groups

  • Head
    • Frontalis – Raises eyebrows and skin of forehead.
    • Orbicularis oris – Puckers lips. "Kissing muscle"
    • Orbicularis oculi – Closes eye. "Winking muscle"
    • Zygomaticus – Elevates corners of mouth. "Smiling muscle"
    • Depressor anguli oris – Lowers corner of lips (muscle for frowning)
    • Levator Labii – raises lips
    • Depressor Labii – Lowers lip

 Facial Muscle Diagram

  • Muscles of Mastication (Chewing)
    • Temporalis – Elevates mandible.
    • Masseter – Closes jaw.
    • Mentalis – Raises Chin

 

 

  • Neck

  • Sternocleidomastoid – Behind ears to neck.

    • Together they flex head on chest

    • Separately it tilts the head to the side.

  • Chest
    • Pectoralis major
      • Located on chest.
      • Flexor of upper arm.
    • Pectoralis minor
      • Small triangular muscle located deep (beneath) the Pectoralis Major
      • Downward rotation and stabilization of the scapula.

 

 File:Pectoralis major.pngFile:Pectoralis minor.png

 

  • Back Muscles
  • Trapezius – Back of head to neck.

    • Elevates shoulders and extends head

    • "Shrugging and Gargling muscle"

  • Latissimus dorsi
  • Located on lower back.
  • Extensor of upper arm.

 

 

  • Shoulder
    • Deltoid – Located on shoulder.
      • Abductor of upper arm.
 
 
 

  

  • Upper Arm
    • Biceps brachii
      • Flexor of lower arm.
    • Triceps brachii
      • Extensor of lower arm.

         

  • Lower Arm
    • Wrist Flexors
      • Flex wrist
    • Wrist Extensors
      • Extend wrist

 

  • Trunk
    • External oblique – Outermost layer of abdominal wall.
    • Internal oblique – Middle layer.
    • Transversus abdominus – Innermost layer.
      • Together the three abdominal wall muscles are antagonists to the diaphragm and assist in defecation, urination, vomiting, and childbirth.
    • Rectus abdominus – Middle of abdomen and flexes the trunk.

 

  • Respiratory Muscles
    • Intercostals – Between the ribs (Internal for exhaling/expiration and external for inhaling/inspiration)

    • Diaphragm – Between thorax and abdomen

 

  • Thigh

 

  • Iliopsoas – Flexor of thigh and trunk (if thigh is still)
    • Postural muscle of trunk (Keeps trunk from falling backwards).

 

  • Gluteus maximus – Buttocks
    • Extensor of thighs.

 

  • Adductor muscles / Groin muscles(magnus, brevis, and longus)
    • Adduct thighs.

                                                                                                   

                Magnus                                  Brevis                                    Longus                                     All 3 Together

 

  • Hamstrings – Semimembranosus, Semitendinosus, and Biceps femoris.
    • Flexes lower leg (calf to thigh)

 

  • Quadriceps femoris – Rectus femoris and Vastus muscles (lateralis, medialis, and intermedialis)
    • Extend lower leg.

 

  • Sartorius – Longest muscle in body.
    • Flexes calf on thigh and thigh on pelvis and rotates leg.

 

  • Lower Leg

 

  • Tibialis anterior – Shin muscle
    • Dorsiflexes foot
    • Responsible for shinsplints

 

  • Gastrocnemius – Calf
    • Plantar flexes and inverts the foot

 

  • Peroneus (fibula) Group – longus, tertius,brevis
    • Plantar flexion and eversion of foot.