The Muscular System

1
The Muscular System
2

• or Everything you ever wanted to know about
  Muscles, but were afraid to ask !!!

3
Did you know that ?

• more than 50 of body weight is muscle !
• And muscle is made up of proteins and water

4
(No Transcript)
5
The Muscular System

• Muscles are responsible for all movement of the
  body
• There are three basic types of muscle
• Skeletal
• Cardiac
• Smooth

6
Info About Muscles

• Only body tissue able to contract
• create movement by flexing and extending joints
• Body energy converters

7

• Components of Muscle Fiber
• Excitability- irritability, the ability to
  respond to a stimulus
• Contractibility- become short and thick, causing
  movement
• Extensibility- the ability to be stretched
• Elasticity- allows muscle to return to its
  original shape after it has contracted or
  stretched

8
3 Types of Muscles
9
Three types of muscle
10
Classification of Muscle
Skeletal- found in limbs Cardiac- found in heart Smooth- Found in viscera
voluntary involuntary involuntary
11
Shapes of Muscles

• Triangular- shoulder, neck
• Spindle- arms, legs
• Flat- diaphragm, forehead
• Circular- mouth, anus

12
Skeletal Muscle

• Most are attached by tendons to bones
• Voluntary- subject to conscious control
• Tendons are mostly made of collagen fibers
• Found in the limbs
• Produce movement, maintain posture, generate
  heat, stabilize joints

13
Skeletal muscle - Summary

• Voluntary movement of skeletal parts
• Spans joints and attached to skeleton

14
Smooth Muscle

• Involuntary- no conscious control
• Found mainly in the walls of hollow organs

15
Smooth muscle

• Lines walls of viscera
• in the intestine leads to peristalsis

16
Smooth muscle - Summary

• Found in walls of hollow internal organs
• Involuntary movement of internal organs

17
Cardiac Muscle

• Involuntary
• Found only in the heart

18
Cardiac muscle

• Main muscle of heart
• Pumping mass of heart
• Critical in humans
• Heart muscle cells behave as one unit
• Heart always contracts to its full
  extent

19
Cardiac muscle - Summary

• Found in the heart
• Involuntary rhythmic contraction

20
Muscle Control
Skeletal
Skeletal
Cardiac
Smooth
21
Types of Responses

• Twitch-
• A single brief contraction
• Not a normal muscle function
• Tetanus
• One contraction immediately followed by another
• Muscle never completely returns to a relaxed
  state
• Effects are compounded

22
How are Muscles Attached to Bone?

• Origin-attachment to a movable bone
• Insertion- attachment to an immovable bone
• Muscles are always attached to at least 2 points
• Movement is attained due to a muscle moving an
  attached bone

23
Muscle Attachments
24
Flexion
Types of Musculo-Skeletal Movement
25
Extension
26
Hyperextension
27
Abduction, Adduction Circumduction
28
Rotation
29
More Types of Movement

• Inversion- turn sole of foot medially
• Eversion- turn sole of foot laterally
• Pronation- palm facing down
• Supination- palm facing up
• Opposition- thumb touches tips of fingers on the
  same hand

30
The Skeletal MusclesThere are about 650 muscles
in the human body. They enable us to move,
maintain posture and generate heat. In this
section we will only study a sample of the major
muscles.
31
Sternocleidomastoideus

• Flexes and Rotates Head

32
Masseter

• Elevate Mandible

33
Trapezius

• Extend Head, Adduct, Elevate or Depress Scapula

34
Latissimus Dorsi

• Extend, Adduct Rotate Arm Medially

35
Deltoid

• Abduct, Flex Extend Arm

36
Pectoralis Major

• Flexes, adducts rotates arm medially

37
Biceps Brachii

• Flexes Elbow Joint

38
Triceps Brachii

• Extend Elbow Joint

39
Rectus Abdominus

• Flexes Abdomen

40
External Intercostals

• Elevate ribs

41
Internal Intercostals

• Depress ribs

42
Diaphragm

• Inspiration

43
Gluteus Maximus

• Extends Rotates Thigh Laterally

44
Sartorius

• Flexes Thigh, Rotates Thigh Laterally

45
Quadriceps femoris
front of thigh extents leg injection site
46
Biceps Femoris

• Extends Thigh Flexes Lower Leg

47
Gastrocnemius

• Plantar Flexes Foot Flex Lower Leg

48
Tibialis Anterior

• Dorsiflexes and Inverts Foot