Human Anatomy Muscles Quiz

Muscles of the Human Body

• The study of muscles is called myology
• Embalming and restorative art are technical skills
• Located and identify selected skeletal muscles is the lecture objective
• Muscles attach to and move bones
• Posture is maintained via tonic contraction
• Muscles produce heat through chemical energy into mechanical energy
• Muscles are necessary for body functions, such as digestion, breathing, speaking and pumping blood
• Muscles are classified as smooth, skeletal, and cardiac

Types of Muscle

• Smooth muscles are involuntary, not under conscious control, and are widely distributed throughout the body. They are also called visceral muscle and are non-striated.
• Skeletal muscles are voluntary, under conscious control, and are striated.
• Cardiac muscle is found only in the heart, it is striated and involuntary.

Associated Structures

• Tendons anchor muscles to bones
• Bursae provide protection for bones and joints
• Fascia surrounds and secures structures
• Aponeuroses connect bone to flat muscles

Other Classifications of Muscles

• Sphincters are circular muscles that constrict an orifice (opening)
• Muscles related to the front of the chest are called pectoral muscles, with an example being the pectoralis major

Muscle Structure

• The belly of a muscle is its widest/largest portion
• The origin is the muscle attachment to the stationary bone during movement
• The insertion is the muscle attachment to the moving bone during a movement

Muscle Naming Basis (Examples)

• Muscle shape and location: temporalis, trapezius
• Muscle divisions and attachments: zygomaticus major, intercostals, omohyoid
• Muscle fiber direction: transversus abdominis
• Muscle superficiality and depth: flexor digitorum superficialis, internal oblique
• Muscle size: adductor longus, gluteus maximus
• Muscle action: levator palpebrae superioris

Movement

• Flexion decreases the angle between two bones at a joint
• Extension increases the angle between two bones at a joint
• Abduction is movement away from the body's midline
• Adduction is movement towards the body's midline
• Rotation is movement around a longitudinal axis
• Supination is when the palms of the hands face anteriorly (forward)
• Pronation is when the palms of the hands face posteriorly (backward)
• Inversion is when the sole of the foot faces medially (inward)
• Eversion is when the sole of the foot faces laterally (outward)
• Constriction narrows a vessel
• Dilation widens a vessel
• Elevation moves something superiorly (upward)
• Depression moves something inferiorly (downward)

Myofibrils and Muscle Movement

• Myofibrils are threads that combine to form muscle fibers, which are skeletal muscle cells.
• Muscle fibers combine into fascicles, which combine to form muscles.
• Muscle contraction occurs when sarcomeres shorten, caused by actin and myosin filaments attaching to each other.

Sliding Filament Model

• At rest, actin and myosin filaments are not touching.
• A signal (action potential) is sent by the brain.
• Calcium is released, binding to troponin.
• Tropomyosin is released by actin.
• Myosin binds with ATP.
• ATP changes to ADP.
• Myosin binds with actin.
• The sarcomere shrinks, and the muscle contracts.
• ADP unbinds.
• ATP binds with myosin again.
• Myosin releases actin.
• Muscle relaxes.

Muscles of the Face

• Chewing muscles: temporalis, masseter, buccinator
• Eyebrow muscles: occipitofrontalis (epicranius), orbicularis oculi, corrugator, procerus, levator palpebrae superioris
• "False" smiling muscles: levator labii superioris, levator anguli oris, risorius
• "Real" smiling muscles: zygomaticus major, zygomaticus minor
• Other mouth muscles: orbicularis oris, quadratus labii superioris, levator labii superioris alaeque nasi, depressor anguli oris, depressor labii inferioris, mentalis

Muscles of the Neck

• Platysma
• Sternocleidomastoid
• Omohyoid
• Digastricus

Muscles of the Back

• Trapezius
• Latissimus dorsi
• Teres major

Muscles of the Chest

• Pectoralis major
• Pectoralis minor
• Subscapularis

Breathing Muscles

• Serratus anterior
• Intercostals
• Diaphragm

Muscles of the Abdomen

• External oblique
• Internal oblique
• Transversus abdominis
• Rectus abdominis
• Psoas major

Muscles of the Upper Extremities

• Upper arm: Deltoid, Coracobrachialis, Brachialis
• Forearm (Anterior): Flexor carpi radialis, Flexor carpi ulnaris, Flexor digitorum superficialis, Pronator teres, Flexor digitorum profundus, Palmaris longus
• Forearm (Posterior): Brachioradialis, Supinator

Muscles of the Lower Extremities

• Anterior thigh: Sartorius, Quadriceps femoris, Iliopsoas, Pectineus
• Posterior Thigh: Gluteus maximus, Biceps femoris, Semitendinosus, Semimembranosus
• Medial Thigh: Adductor longus, Adductor magnus
• Popliteal Muscles: Popliteus, Oblique popliteal ligament

Lower Leg Muscles

• (Anterior): Tibialis anterior , Extensor hallucis longus
• (Posterior): Gastrocnemius, Soleus, Calcaneal tendon (Achilles heel)

Review and Vocabulary

• The lecture provides a review of the learned concepts
• The Vocabulary check provides words associated with the muscles and their names.