9. 10.+joints+and+muscle+systemb
TRANSCRIPT
Chapter 9: Joints; and 10, muscular system
Figure 9.2
Figure 9.4
Cartilaginous joints
Figure 9.5
Anatomy of a synovial joint
Learn joint disorders: Table 9.1
Tendon Sheaths and Bursae
• Bursa: saclike extension of joint capsule that extends between nearby structures, allowing them to slide more easily past each other
• Tendon sheaths: elongated cylinders of connective tissue lined with synovial membrane & wrapped around a tendon
The Functions of Muscles
• Movement of body parts and organ contents
• Maintain posture and prevent movement
• Communication - speech, expression & writing
• Control of openings and passageways
• Body heat production
Figure 10.1
The arrangement of fascicles affects power and range of motion that a muscle can produce.
Range of motion:
-muscle fibers contract to about 70% of their resting length.
-therefore, the longer the muscle fibers, the greater the range of motion.
Power: -depends on the number of fibers
Structures of Muscles
Figure 10.2
• Origin– attachment at stationary
end of muscle
• Belly– thicker, middle region of
muscle
• Insertion– attachment at mobile end
of muscle
Muscles act in groups• Agonist: prime mover.
– The muscle that produces the most force during a particular joint action.
• Antagonist: A muscle that opposes the prime mover.
– Antagonistic pairs: produce opposite effects such as flexion and extension.
• Synergist: A muscle that aids the prime mover.
• Fixator: prevents a bone from moving.
Muscle Actions during Elbow Flexion
• Prime mover (agonist) = brachialis m.
• Synergist = biceps brachii m.
• Antagonist = triceps brachii m.
• Fixator = muscle that holds scapula firmly in place such as rhomboideus m.
Figure 9.9a
Joints as lever systems
Figure 9.9b
Figure 9.8b
Figure 9.9c
Fig. 8-21a, p.335
The elbow and biceps brachii: mechanical model
Figure 9.8a
Types of synovial joints
Figure 10.7a
Figure 10.7b
The muscles of chewing and swallowing
The muscles of chewing and swallowing
Figure 10.10a
Figure 10.10b
Figure 10.17
The muscles of respiration• Primary muscles:
– Diaphragm– External intercostals– Internal intercostals
Figure 10.13
The muscles of the anterior abdomen wall
External abdominal obliqueInternal abdominal obliqueTransverse abdominalRectus abdominus
Tendons are aponeurosesRectus sheath
The muscles of the anterior abdomen
Figure 10.14
The muscles of the back 1.
Trapezius and latissimus dorsi:Primarily act on upper limb.
The muscles of the back 2.
• Erector spinae: runs from cranium to sacrum.
– Ascends and forms 3 parallel columns
– (lateral to medial)
• Iliocostalis
• Longissimus
• Spinalis
• Quadratus lumborum
The muscles of the back cont.
• Semispinalis thoracis
• Multifidus: a series of tiny muscles connecting adjacent vertebrae to each other.
The erector spinae and quadratus lumborum are enclosed in the thoracolumbar fascia, which is the origin for some abdominal and lumbar muscles.
The muscles of the pectoral girdle• Muscles acting on the pectoral girdle originate on the
axial skeleton and insert on the clavicle and scapula.
• Muscles acting on the scapula:
• Anterior group:– Pectoralis minor– Serratus anterior
Muscles acting on the scapula:• Posterior group:
– Levator scapulae– Rhomboideus minor– Rhomboideus major– Trapezius
Figure 10.21
The muscles acting on the humerus• Axial muscles: originate primarily on the axial
skeleton.– Pectoralis major– Latissimus dorsi• These are the prime movers of the shoulder joint.
• Scapular muscles: 7 muscles originate on the scapula. Tendons of 4 of these form the rotator cuff.
Axial muscles:Latissimus dorsiPectoralis major
Table 10.10b
Scapular muscles acting on the humerus– 1. Deltoid– 2. Teres major– 3. Coracobrachialis
• Rotator cuff muscles:– 4. Supraspinatus– 5. Infraspinatus– 6. Teres minor– 7. Subscapularis
Figure 10.22a
Deltoid
Figure 10.22d
Subscapularis
Coracobrachialis
Figure 10.22b
Supraspinatus
Infraspinatus
Teres minor
Teres major
Figure 9.10
Movements of the shoulder joint.
Prime movers of shoulder• Flexion: anterior deltoid, pectoralis major
• Extension: posterior deltoid, latissimus dorsi
• Abduction: lateral deltoid
• Adduction: pectoralis major, latissimus dorsi
• Medial rotation: subscapularis
• Lateral rotation: infraspinatus
Figure 9.23b
Figure 9.23c
Figure 10.22c
Figure 10.24
• Rotator cuff muscles:
– 4. Supraspinatus
– 5. Infraspinatus
– 6. Teres minor
– 7. Subscapularis
Figure 9.23d
Muscles acting on the forearm
• Muscles with bellies in the arm (brachium)– Biceps brachii– Brachialis– Triceps brachii
• Muscles with bellies in the forearm (antebrachium):– Brachioradialis– Anconeus– Pronator quadratus– Pronator Teres– Supinator
Figure 10.22a
Figure 10.22b
The elbow• Hinge (humeroulnar), Pivot (radioulnar).
• Prime movers of elbow:
• Flexors: primarily Brachialis, to a lesser extent Biceps brachii, Brachioradialis
• Extension: primarily Triceps brachii
• Pronation: primarily Pronator quadratus, assisted by Pronator teres
• Supination: Biceps brachii, Supinator
Figure 9.24a
Figure 9.24b
Figure 9.24c
Figure 9.24d
Prime movers of the elbow:
• Flexors: primarily Brachialis, to a lesser extent Biceps brachii, Brachioradialis
• Extension: primarily Triceps brachii
• Pronation: primarily Pronator quadratus, assisted by Pronator teres
• Supination: Biceps brachii, Supinator
Figure 10.22c
Figure 10.22d
Figure 10.22b
Figure 10.25
The wrist
• Intrinsic and extrinsic muscles acting on the hand.
• Flexors
• Extensors
• Carpel tunnel
Figure 9.6
Extrinsic vs intrinsicmuscles
Figure 10.27
Figure 10.28
Figure 10.29a
Figure 9.6
Figure 10.30b
Figure 10.30a
Figure 10.29d
The Hip joint
• Ball and socket
Figure 9.25b
Figure 9.25c
Figure 9.25d
The muscles acting on the hip and femur• Main anterior muscles
(flexors):
– Iliacus– Psoas
– Together form the Iliopsoas
The muscles acting on the hip and femur
• Lateral and posterior muscles (adduction and extension)– Tensor fasciae latae (not
shown)– Gluteus maximus– Gluteus medius– Gluteus minimus (not
shown)
The muscles acting on the hip and femur
• Lateral and posterior muscles– Gluteus minimus
The muscles acting on the hip and femur
• Lateral and posterior muscles– Tensor fasciae latae
The muscles acting on the hip and femur• Lateral rotators:
The muscles acting on the hip and femur
• Medial (adductor) compartment of the thigh:– Pectineus– Adductor brevis– Adductor longus– Adductor magnus– Gracilis
The muscles acting on the knee
• Anterior (extensor) compartment:
• Quadriceps femoris.– Rectus femoris– Vastus lateralis– Vastus medialis– Vastus intermedius
• Sartorius
The muscles acting on the hip and femur
• Posterior (Flexor) compartment of the thigh: the hamstring group.
• Semimembranous
• Semitendinosus
• Biceps femoris
Figure 9.28a
Figure 9.28b
Figure 9.28c
Figure 9.28d
Figure 10.37
Anterior compartment: extensors
Figure 10.38
Posterior compartment, superficial
Figure 10.39
Posterior and lateral compartments, deep.