Class Notes (1,100,000)
CA (630,000)
UTSC (30,000)
BIOB33H3 (100)
Lecture 7

BIOB33H3 Lecture Notes - Lecture 7: Popliteus Muscle, Hamstring, Gluteus Maximus Muscle


Department
Biological Sciences
Course Code
BIOB33H3
Professor
Connie Potroff
Lecture
7

Page:
of 3
1
Lecture 7
The Muscular System: Appendicular Musculature
(based on Chapter 11)
Appendicular Musculature
Muscles of the Pectoral Girdle and Upper Limbs
Muscles That Move the Forearm and Hand
The elbow joint is the articulation of the distal surface of the humerus with radius and ulna
hinge joint composed of two articulations enclosed in a single joint capsule and another separate joint not part of the
hinge
muscles that move the elbow, flexion (biceps brachii, brachioradialis and brachialis), extension (*anconeus, triceps
brachii), pronation (pronator teres, pronator quadratus), supination (supinator)
**Most of these muscles originate on the humerus and insert upon the forearm and wrist
Exceptions include:
Long head of triceps brachii: originates on the scapula and inserts on the olecranon of ulna
(lateral and medial heads originate on humerus and insert on olacranon)
Short and Long head of biceps brachii: originate on the scapula and insert of the radial
tuberosity of the radius
Biceps brachii: flexes at the elbow and shoulder (see above)
Brachialis: flexes at the elbow (origin: humerus, insertion: forearm and wrist)
Brachioradialis: flexes at the elbow (origin: humerus, insertion: forearm and wrist)
Anconeus: extension at the elbow (origin: humerus, insertion: forearm and wrist)
Triceps brachii: extension at elbow, extension and adduction at elbow (long head) (origin: scapula,
insertion: ulna)
Lateral head: extension at the elbow (origin: scapula, insertion: ulna)
Long head: extension at the elbow and adduction at the shoulder (origin: scapula, insertion: ulna)
Medial head: extension at the elbow (origin: scapula, insertion: ulna)
Pronator quadratus: pronates the forearm (origin: humerus, insertion: forearm and wrist)
Pronator teres: pronates the forearm (origin: humerus, insertion: forearm and wrist)
Supinator: supinates the forearm (origin: humerus, insertion: forearm and wrist)
- muscles of the forearm move the joints of the wrist, hand and fingers
lots of muscles front and back , 2 classes:
muscles that flex the wrist, superficial closer to skin surface
muscles that flex the fingers, deeper
**muscles of wrist that produce flexion come from medial epicondyle (aka common flexor origin)
on radial side - Flexor carpi radialis: flex and abduct the wrist (landmark for locating the radial artery, where the
pulse is usually taken)
On ulnar (medial) side - Flexor carpi ulnaris: flex and adduct the wrist
**Palmaris longus: flexion at the wrist
**wrist and finger (deeper) muscles that produce extension – extensors from lateral epicondyle (on lateral side)
of humerus
Extensor carpi radialis longus: extend and abduct at the wrist
Extensor carpi radialis brevis: extend and abduct at the wrist
Extensor carpi ulnaris: extension and adduction at the wrist
Muscles That Move the Hand and Fingers
© 2012 Pearson Education, Inc.
2
**Extrinsic Muscles of the Hand
Relatively large muscles that perform ** flexion and extension ** at the joints of the fingers
Provide strength and crude control of the hand and fingers
These muscles are found mostly in the lower arm
Flexor digitorum superficialis: flexion at the wrist and some digits
Flexor digitorum profundus: flexion at the wrist and some digits
Flexor pollicis longus: flexion of the thumb
Abductor pollicis longus: abduction of thumb
Extensor digitorum: extension of fingers and wrist
Extensor pollicis brevis: extension of thumb, abducts the wrist
Extensor indicis: extension and adduction of index finger
Extensor digiti minimi: extension of little finger, extension of wrist
**Intrinsic Muscles of the Hand
Smaller muscles that provide fine control of hand
Responsible for flexion and extension, and abduction and adduction of the fingers at the
metacarpophalangeal joints
**Responsible for opposition and reposition of the thumb
**These muscles are found mostly in the palm or the dorsum of the hand
Adductor pollicis: adducts the thumb
Opponens pollicis: opposition of the thumb
Abductor digiti minimi: abducts little finger
Abductor pollicis brevis: abducts the thumb
Flexor pollicis brevis: flex and adduct thumb
Flexor digiti minimi brevis: flex little finger
Opponens digiti minimi: brings digits in opposition with the thumb
**Lumbricals: flexion of the digits
Muscles of the Pelvic Girdle and Lower Limbs
The muscles of the lower limbs are larger and more powerful than those of the upper limbs.
These muscles can be divided into three groups:
Muscles that move the thigh
Muscles that move the leg
Muscles that move the foot and toes
Muscles That Move the Thigh
Originate on the pelvis; many are large and powerful
Four groups
Gluteal group
Lateral rotator group
Adductor group
Iliopsoas group
The Gluteal Group
Gluteus maximus: posterior extension at the hip
Gluteus medius: abducts at the hip
Gluteus minimus: abducts at the hip
*Tensor fasciae latae: abduction at the hip
The Lateral Rotator Group
Obturators: lateral rotation and abduction of hip
© 2012 Pearson Education, Inc.
3
Piriformis: lateral rotation and abduction of hip
Gemelli: lateral rotation and abduction of hip (superior and inferior)
Quadratus femoris: lateral rotation of hip
The Adductor Group
Adductor magnus: adduction at the hip
*Gracilis: flexion and medial rotation at the knee/adduction and medial rotation at the hip
Adductor brevis: adduction at the hip
Adductor longus: adduction and medial rotation at the hip
*Pectineus: flexion and adduction at the hip
The Iliopsoas Group
Iliacus: flexion at the hip
Psoas major: flexion at the hip
Muscles That Move the Leg
*Extensors of the Knee
The three vastus muscles and the rectus femoris muscle are collectively called the Q uadriceps
femoris (Quads)
Vastus intermedius: extends the lower leg
Vastus lateralis: extends the lower leg
Vastus medialis: extends the lower leg
*Rectus femoris: extends the lower leg/flexion at the hip
Flexors of the Knee
The biceps femoris, semimembranosus, and semitendinosus are collectively called the
H amstrings
Biceps femoris: flexes lower leg/extension at the hip
Semimembranosus: flexes lower leg
Semitendinosus: flexes the lower leg
**Sartorius: allows crossing of the lower leg (tailor’s muscle, longest)
**Popliteus: flexes lower leg
**Muscles That Move the Foot and Toes
*Extrinsic Muscles of the Foot and Toes (dorsiflexor)
Muscles that originate on the lower leg but yet move the foot and toes
*Intrinsic Muscles of the Toes (plantarflexor)
Muscles that originate on some aspect of the foot but yet move the toes
Tibialis anterior: dorsiflexion of the foot
Gastrocnemius: plantar flexion of the foot
Fibularis brevis: eversion of the foot
Fibularis longus: eversion of the foot
Plantaris: plantar flexion
Soleus: plantar flexion
Tibialis posterior: inversion of the foot
More Extrinsic and Intrinsic Muscles That Move the Toes we won’t cover these
© 2012 Pearson Education, Inc.