anatomy,muscles, joints, Dr.sabreen mahmoud

1. Cartilage & muscles
& joints
Dr. Sabreen Mahmoud
Lecturer of human anatomy

2. O B J E C T I V E S
This lecture introduces some of the basic
structures that compose the body, such as
cartilage, fascia, muscles, ligaments and joints.

3. Cartilage
1) hard connective tissue.
2) devoid of nerves & B.V & lymphatics.
3) It consists of = chondrocytes + matrix.

4. 4) resists pressure and friction.
5) high capacity of growth.
6) Hyaline cartilage is covered by →
perichondrium.

5. Nutrition of cartilage:
 cartilage is avascular
 gets its nutrients by → diffusion from →
perichondrium.

6. Types of cartilage:
1) Hyaline cartilage:
 translucent & glossy.
 present in the articular cartilage, costal
cartilages, trachea, bronchi.
 replaced by bone in old age, except the articular
cartilage.
 It is incapable of repair when injured.

7. 1) Hyaline cartilage:

8. 2) White fibrocartilage:
 rich in collagenous bundles → tough.
present in :
1 - Intervertebral discs .
2- Symphysis pubis.
3 - Articular discs → in synovial Joints
 no ossification in old age.

10. 3) Yellow elastic fibrocartilage:
 rich in elastic fibres → yellow colour.
 never replaced by bone in old age
 present in the auricle of the ear, auditory
tube.

12. JOINTS
 DEFINITION: the meeting place of 2 or
more bones.
 The study of joints = “arthrology”

13. Fibrous joints
the articulating bones are separated by fibrous
tissue.
no or very limited movement.
Examples:
1) Sutures of the cap of the skull.
2) Inferior tibio-fibular joint
3) Gomphosis : it is a joint where a peg is fixed
into a socket.

15. Cartilaginous joints
a disc of cartilage between the articulating
bone. 2 types :
1) Primary cartilaginous joint.
2) Secondary cartilaginous joint.

16. 1) Primary cartilaginous joint.
 a temporary plate of hyaline cartilage which
disappears in adulthood.
 represented by the epiphyslal plate of cartilage.
 called synchondrosls
 does not allow any movement

18. 2) secondary cartilaginous joint:
 a disc of white fibrocartilage between the
articulating bones.
 The opposed bony surfaces → hyaline cartilage.
 lie in the median plane of the body.
 e.g. intervertebral discs & symphysis pubis.

20. characteristics:
a - no fibrous capsule.
b - ligaments.
c - limited movement.

21. Synovial joints
1) a cavity → synovial fluid.
2) a fibrous capsule
3) a synovial membrane → does not cover
the articular surfaces, discs or menisci.
4) synovial fluid.

23. The synovial fluid
 pale yellow, viscous fluid
 resembles egg albumin.
 contains lymphocytes, macrophages and
free synovial cells.
 for lubrication & nutrition of articular
cartilage.

24.  The articular surfaces → hyaline cartilage.
 The articular cartilage is not visible in X-
ray films.

25. Structures inside some joints:
1) Articular disc
2) Menisci.
3) Tendons.
4) Ligaments.

27. N.B.: Any structure inside a joint cavity =
intracapsular and extrasynovial.

28. TYPES OF SYNOVIAL JOINTS:
According to number of bones:
1) Simple joint: = 2 bones (shoulder joint).
2) Compound joint = more than 2 bones (elbow
joint).
3) Complex joint: → menisci (knee joint)

30. According to number of axes of movement:
1) Uni-axial joint: elbow joint.
2) Bi-axial joint: the metacarpo-phalangeal
joint
3) MultI-axial joint: shoulder joint.

31. According to shape of articulating surfaces:
1) Plane joint: surfaces are flat, and the
movements → sliding,
e.g. intercarpal and intertarsat joints.

33. 2) Pivot joint:
central bony pivot surrounded by a ring
partly bony & partly ligamentous,
e.g. superior radio-ulnar joint.

35. 3) Bicondylar joint :
2 convex condyles & 2 concave surfaces,
e.g. knee joint.

37. 4) Ellipsoid joint:
a convex surface & concave surface,
e g. radiocarpal (wrist).

39. 5) Saddle joint:
concavoconvex, i.e. the surface is concave
in one direction and convex in a direction at
right angle to the former direction;
e.g. carpo-meacarpal joint of the thumb.

41. 6) Hinge joint:
As the hinge of the door,
e.g. elbow joint.

43. 7) BaIl-and-socket joint:
a globular (rounded) head & a cup-shaped
concave surface,
e.g. shoulder and hip joints.
movements in → 3 axes
(flexion-extension, adduction-abduction,
circumduction and rotation).

45. Video

46. FACTORS AFFECTING STABILITY OF JOINTS:
1) Shape of bones.
2) Contraction of muscles.
3) ligaments.

47. Nerve supply of joints:
Hilton’s law:
joints are innervated by nerves which supply
muscles acting on these joints.
The nerves → sensory = articular nerves.
The synovial membrane is devoid of sensory
nerves.

49. Blood supply of joints:
by networks of arteries → anastomoses.

50. MUSCLE
 Myology = the study of muscles.
 contractility = capacity of becoming short.
 2 types of protein → actin and myosin.

51. Muscle is classified into 3 types:
CARDIAC MUSCLE
 in myocardium of the heart.
 transverse striations,
 does not contract under voluntary control.
Innervation : (autonomic) =
sympathetic & parasympathetic fibers

54. Smooth (non-striated) muscle
 in viscera & blood vessels.
 The muscle cells are not striated =
smooth, plain or non-striated.
 Nerve supply : autonomic fibers =
sympathetic & parasympathetic

55. Skeletal (striated) muscle
attached to the skeleton.
transverse (or cross) striations = striated.
contracts under voluntary control.

56. Connective tissue sheaths
muscle fibers are arranged in bundles.

58. These bundles have connective tissue
sheaths as :
1) Endomysium: → individual muscle fiber.
2) Perimysium: → whole bundle.
3) Epimysium : → whole muscle.

59. Innervation
I) Motor fibers
2) Sensory fibers
 to the muscle spindles.
 Cutting the nerve supply → paralysis.

60. Attachments of skeletal muscles
1) Origin: fixed attachment.
2) Insertion: mobile attachment.

62. Form of muscles
 The range of contraction of a muscle
depends on the length of muscle fibers
 The muscle fibers are arranged →
obliquely or parallel with the “line of pull”.

63. The line of pull
 extending between the origin and
insertion.
 Muscles with fibers parallel with the “line
of pull” → better contraction.

64. 1) Muscles with fibres arranged parallel
with “the line of pull”
a - Quadrilateral → thyrohyoid muscle,
b - Strap-like → sartonus muscle.
c - Fusiform → lumbrical muscles.

66. 2) Muscles with pennate fibres arranged
obliquely to the “line of pull”
a - Unipennate: → flexor pollicis longus.
b - Bipennate: → rectus femoris.
c- Circumpennate: → tibialis anterior
d - Multipennate: → deltoid muscle.
N. B:- Pennate = feather-like

68. 3) Muscles with fibres arranged obllquely to
the “line of pull” but are not pennate
a - triangular → temporalis.
b - Spiral → supinator.
c - Cruciate → masseter.

70. 4) A muscle with more than one fleshy belly
a - Biceps.
b - Triceps.
c - Quadriceps.
d - digastric → 2 bellies attached by an
intermediate tendon.

72. Action of muscles
depends on the length of muscle fibers.
1) Prime movers: → initiation of movement
brachialis → flexion of elbow.
triceps → extension of elbow.

74. 2) Antagonist:
 oppose the action of prime movers.
triceps opposes the brachialis.

75. 3) Synergist:
 eliminate the unwanted movement.
Ex : flexion of the fingers by the flexor muscles is
associated with flexion of the wrist.
 To eliminate the unwanted flexion at the
wrist, the extensor muscles of the wrist
contract = synergists.

76. 4) Fixator (stabilizers):
help the prime mover by stabilizing the joint.
Ex: muscles around shoulder (muscle cuff)
→ stabilizers.

78. Video

79. Tendons
 parallel bundles of collagenous fibers.
 cord-like
 expanded sheet = apponurosis (muscles
of the anterior abdominal wall).

81. Synovial sheath of tendons:
in direct contact with bone.
formed of 2 layers + cavity, :
1) Parietal layer = outer layer.
2) Visceral layer = inner layer.
3) Cavity: contains synovial fluid.

83.  Synovial sheaths protect the tendons from
injury → to facilitate movement.
 Vincula = A synovial fold between the
tendon and the bone → blood vessels
pass to tendons.

84. Blood and nerve supply of tendons:
1) supplied by few blood vessels.
2) sensory fibers only.

85. BURSAE
 a closed sac of synovial membrane filled
with synovial fluid.
 where skin or tendons move over bony
surfaces →free movement.

87. types of bursae:
1) Subcutaneous.
2) Subtendinous.
3) Subfascial.
4) Interligamentous.