Muscles

Items to note:

• Quiz #2 opens today and is available until Monday 4/23

Markus Hartel · New York street photography

Leonardo Di Vinci

1. Name the 3 layers of connective tissue that wrap around skeletal muscles.

2. Which one(s) is (are) continuous with a tendon?

3. Botox (botulinum toxin) works by blocking the release of ACh at the neuromuscular junction. How does this help with:

• crossed eyes• uncontrolled blinking • pesky forehead wrinkles

To do today and Wednesday

• how muscles work – in general• muscles that move the mandible• abdominal wall muscles

• anterior and posterior• inferior and superior• inguinal hernia’s

• muscles that move the humerus and scapula• rotator cuff tears, impingement syndrome

• muscles that move the femur• sprains, strains and “Charley horse”

• muscles that move the foot• shin splints, anterior compartment syndrome• Achilles tendon injuries

Extending your knee

• Extend your knee a few times

• Where are the muscles located that extend your knee?

• What is their fiber direction?

• Which joint do they cross?

• When you extend you knee, where are the antagonist muscles located?

How muscles work in general

Quadriceps = agonists Hamstrings = antagonists

Mandibular fossa

1. Depress & elevate2. Medial & lateral excursion3. Protraction & retraction

Moving the mandible

Temporalis

Masseter

• attachments• actions

Muscles that move the mandible

Medial pterygoid Lateral pterygoid

• attachments• actions

Depress mandible• gravity• digastric muscle• geniohyoid muscle

• when hyoid is fixed

Rectus abdominus

External oblique

Those flashy “core” muscles

OverdevelopedPectoralis major

Rectus abdominis

External oblique

Internal oblique

Transversus abdominis

• Attachments• Actions

Muscles that move (and protect) the abdomen

AB

C

D Rectus sheath(aponeurosis)

Linea alba

Abdominal wall

• abdominal muscles• back muscles• diaphragm• pelvic diaphragm

• “holes” in the wall

Spermatic cord

Inguinal canal – men & womenintestines

Parietal peritoneum

scrotum

1.Location of shoulder muscles2.Which joints do these muscles cross?

Muscle that move the humerus and scapula

3. What is the fiber direction of these muscles?4. What movements do these muscle perform?

• attachments• actions

Deltoid

• attachments• actions

subscapularis

supraspinatus

infraspinatus

Teres minor

4 Rotator cuff muscles

• attachments• actions

• attachments• actions

Scapula movers

Levator scapulae

rhomboids

trapezius

Impingement syndrome

Rotator cuff tears

1. Location of hip and thigh muscles2. Which joints do these muscles cross?

Muscles that move the femur

3. What is the fiber direction of these muscles?4. What kind of movements do these muscle perform?

iliopsoas

adductors

• attachments• actions

TensorFasciaeLatae (TFL)

Rectus femoris

Vastus lateralisvastus intermediusVastus medialis

• attachments• actions• Charley horse

Patellar tendon

Iliotibial Band (IT band)

G. MaximusTensor Fasciae Latae

• attachments• actions

G. minimus

piriformis

G. Medius

G. Maximus

• attachments• actions

• attachments• actions

Anterior

Posterior

Achilles tendon

calcaneus

gastrocnemius

Attachments of the gastrocnemiusAttachments of the soleus

Actions of the gastrocnemius1. Flex the knee2. Plantarflex the foot

Actions of the soleus1. Plantarflex the foot

Ruptured Achilles tendonPulled calf muscle

Tibialis Anterior

Tibialis anterior Attachments

Actions1. Dorsiflex ankle2. Invert foot3. Support arch

Shin splints

Anterior compartment syndrome

TA