pengantar kuliah otot sistem muskuloskeletal

1. • Huang Juan
• Department of anatomy
• Chongqing medical university
05 -- Myology

2. The general aspects on the muscles
1.The relations of the muscles to the bone
（1） All of them are attached by at least
one end to some parts of the skeleton
The number of the joints that the muscle
acts on depends on how many joints it covers.
（2） Most of them cover the joints

3. 2. The principles of the nomenclature of the muscles
① Relying on the origin & the insertion:
coracobrachialis M., sternocleidomastoid M.
② Relying on the shape: deltoid M.
③ Relying on the location: external intercostal M.
④ Relying on the function & shape: pronator teres

4. Each muscle is composed of: ★
• Belly: contracts the muscle
Aponeurosis
• Tendon: anchors the bones, cartilage, articular capsule
Tendon
Belly
• Biceps brachii
Tendon

5. The muscles are divided into 4 types:
1. Long M.
2. Short M.
3. Broad M.
4. Orbicular M.
Orbicularis oris
Orbicularis oculi

6. Ⅰ. Muscles of the trunk
Ⅱ. Muscles of the head
Ⅲ. Muscles of the neck
Ⅳ. Muscles of the upper limb
Ⅴ. Muscles of the lower limb

7. Ⅰ）Muscles of the back
Ⅰ. Muscles of the trunk
Ⅱ）Muscles of thorax
Ⅲ）The diaphragm
Ⅳ）Muscles of abdomen

8. Ⅰ） Muscles of the back
1. The superficial group
① Trapezius
② Latissimus dorsi
• skull, vertebrae → scapula
• raises, descends & rotates the scapula
• spinous processes, sacrum & ilium
→ humerus
• extends, adducts, medially rotates humerus

9. 2. The deep group
Erector spinae
• sacrum, ilium → ribs, vertebrae, mastoid process
• acts on one side: bends & rotates the spinal column
• acts on both sides: extends the spinal column
① Erector spinae
② Rhomboid muscle
②

10. Ⅱ）Muscles of thorax
① Pectoralis major
② Pectoralis minor
• clavicle, sternum & costal cartilages
→ humerus
• adducts, flexes & medially rotates
the shoulder joint
• 3rd , 4th, 5th ribs → coracoid process
• draws scapula forward & downwards
1. The extrinsic muscles

11. ③ Serratus anterior
• upper 8 or 9 ribs → scapula
• holds the scapula against the chest wall

12. The intercostal muscles
• The external intercostal M.
• The internal intercostal M.
• The innermost intercostal M.
2. The intrinsic muscles
Inspiration
Expiration

13. Ⅲ）The diaphragm ★
• dome-shaped musclofibrous septum
• separates the thoracic cavity from abdominal cavity
• central tendon + muscular fibers
• is the principal muscle of inspiration
Central tendon

14. Esophageal hiatus
Aortic hiatus
Vena caval foramen
Opening Location / level Transmits
Vena caval
foramen
T8 inferior vena cava
Esophageal
hiatus
T10 esophagus, vagus N.
Aortic hiatus T12
abdominal aorta,
thoracic duct

15. Ⅳ）The muscles of abdomen
1. The anterolateral group
③ Transversus abdominis
① External oblique abdominis
② Internal oblique abdominis
① ② ③
④
Linea alba
④ Rectus abdominis

16. External oblique
• form a strong expandable support to protect the viscera
• maintain & increase the intra-abdominal pressure
• assist in respiration, defecation, micturition, parturition,
coughing and vomiting.

17. 2. The posterior group
Quadratus lumborum

18. Ⅰ） Facial M. / craniofacial M.
Orbicularis oris
Orbicularis oculi
Ⅱ. Muscles of the head
Occipitofrontalis
• skull → skin
• express the emotions

19. Ⅱ）Masticatory muscles
Masseter
Temporalis
• temporal bone → coronoid process
• elevates the mandible, closes the mouth
• zygomatic arch → angle of the mandible
• elevates the mandible, closes the mouth

20. ② Medial pterygoid
① Lateral pterygoid
② elevates the mandible, closes the mouth
① assists in opening the mouth
by pulling forward the mandible
• Sphenoid B. → medial surface of mandible
• Sphenoid B. → neck of the mandible

21. Ⅰ）The superficial group
Platysma
Sternocleidomastoid
• manubrium, clavicle → mastoid process
• acting alone: the head is incline laterally,
and the face is rotated to the opposite side.
• acting together: draw the head forward
Ⅲ. Muscles of the neck

22. Ⅱ）The hyoid muscles
① Suprahyoid M.
② Infrahyoid M.
• pull the hyoid upward, backward
& forward in swallowing & speaking
• depress, retract & steady the hyoid bone
and the larynx in swallowing & phonation

23. ③ Scalenus posterior
① Scalenus anterior
② Scalenus medius
Ⅲ）Deep cervical muscles
①
②
• Flex & rotate the neck

24. Deltoid
Ⅰ）Muscles of shoulder
Ⅳ. Muscles of the upper limb
• clavicle, acromion & scapula →
humerus
• abducts the shoulder joint

25. Ⅱ）Muscles of upper arm
• Anterior: biceps brachii ① --- flexes the elbow joint
• Posterior: triceps brachii② --- extends the elbow joint
① ②
• Anterior view • Posterior view

26. Ⅲ）Muscles of forearm
2. The posterior group: 2 layers, 10 muscles
--- extend the joints of the hand
1. The anterior group: 4 layers, 9 muscles
--- flex the joints of the hand
• Anterior view • Posterior view

27. Ⅳ）Muscles of hand
1.Lateral group: thenar
3.Intermediate group: lumbricals & interosseous muscles
2.Medial group: hypothenar
①
③
②

28. Ⅰ）Muscles of the hip
1. Anterior group
② Tensor fasciae latae
① Iliopsoas
Ⅴ. Muscles of the lower limb
①
②
• Flex the hip joint

29. 2. Posterior group
Gluteus maximus
• Ilium, sacrum & coccyx → femur
• extends thigh
Gluteus medius
Gluteus minimus
Piriformis

30. Ⅱ）Muscles of thigh
1. Anterior group
① rectus femoris
② vastus medialis
③ vastus lateralis
④ vastus intermedius
Quadriceps femoris
• femur → tibia
• Flexes the hip joint &
extends the knee joint
Patellar lig.
①
③
②
Sartorius

31. 2. Medial group
① Pectineus
② Adductor longus
③ Gracilis
④ Adductor brevis
⑤ Adductor magnus
• Pubis, ischium → femur, tibia
• adduct, flex & laterally rotate the thigh
①
④
③
⑤
②

32. 3. Posterior group
③ Biceps femoris
① Semitendinosus
② Semimembranosus
①
②
③ • Ischium, femur → tibia, fibula
• Extend the thigh & flex the leg

33. Ⅲ）Muscles of leg
1. Anterior group
2. Lateral group
• evert foot, plantarflex ankle joint
• tibia, fibula → metatarsal bones &
phalanges of toes
• invert foot, dorsiflex ankle joint
① Tibialis anterior
② Extensor digitorum longus
③ Extensor hallucis longus
①
②

34. 3. Posterior group
Triceps surae:
Tendo calcaneus
• femur, tibia & fibula → bones of foot
• inverse foot, plantarflex ankle joint
① Gastrocnemius
② Soleus ①
②
Calcaneus

35. Ⅳ）Muscles of foot

36. Summary
⑴ Orbicularis oculi: (innervated by facial N.)
• actions: close the eyelids.
• If the VII. N is injured, the eyelids can’t closed.
Facial muscles:
⑵ Orbicularis oris (innervated by bilateral facial N.)
actions: close mouth.
• Normally, muscles in bilateral sides contract, the mouth is right in
the middle.
• If VII. N is injured, the face looks asymmetrical. When a smile is
attempted, the angle of mouth is wry toward the unaffected side.

37. ⑴ Inspiratory:
a. external intercostal M. contract to make ribs lift, the diameter
from anterior to posterior is increasing, which result in increasing
of the volume of thoracic cavity.
b. the diaphragm contracts to make the top of dome lower,
subsequently the volume of thoracic cavity is increasing.
⑵ Expiratory
a. internal intercostal M. contract to make ribs lower,
which results in the decreasing of thoracic cavity.
b. the diaphragm is relax to make the top of dome lift.
subsequently the volume of thoracic cavity is decreasing.
when deep respiration is performed, the muscles of abdomen,
even some of muscles of neck will take part in the action.
Movement of respiratory：

38. The muscles of leg:
• lateral & anterior group ------ innervated by common peroneal N.
• when common peroneal N. is injured, the muscles of lateral and
anterior groups are paralysis, the foot is inversion in position,
the ankle joint is plantarflex in position;
• posterior group------ innervated by tibial N.
• when tibial N. is injured, the foot is eversion in position,
the ankle joint is joint is dorsiflex in position.

39. ★ Key points
• The diagram.

40. Next class
• Introduction of splanchnology
• Alimentary system