– The Muscular System
Anatomy & Physiology
The Muscular System
1. Name the 4 functions of muscle tissue
a) producing/stabilizing body movements
b) regulating organ volumes
c) Movement of substances
d) producing heat
2. Name 4 characteristics of muscle tissue
a) excitability
b) contractility
c) extensibility
d) elasticity
3. What are the 3 types of muscle tissue, and describe?
a) skeletal
b) cardiac
c) smooth
4. Fill in the blanks relating to the properties of muscle tissue.
a) excitability- respond to chemicals released from nerve cells.
b) Contractility - ability to shorten and generate force.
c) Elasticity - ability to return to original shape after being stretched.
d) Conductivity - ability to propagate electrical signals over membranes.
e) Extensibility - ability to be stretched without damaging the tissue.
5. Describe origin and insertion and how they relate to muscle attachment sites.
a) origin- The attachment of a muscle tendon to a staionary bone or the end opposite the insertion
b) insertion- The attachment of a muscle tendon to a movable bone or the end opposite the origin
6. Fill in the blank with the appropriate number.
# / Term / Definition2 / spasm / 1. involuntary twitching of muscles normally under voluntary control ie. eyelid
5 / fasciculation / 2. involuntary contraction of single muscles
4 / tremor / 3. a painful spasm
3 / cramp / 4. rhythmic, involuntary contraction of opposing muscle groups
1 / tic / 5. involuntary, brief twitch of a motor unit visible under the skin
7. Generally describe the actions of the following skeletal muscles:
Muscle / ActionFrontalis (part of the occipitofrontalis) / wrinkles skin of forehead, scrunches eyebrows
Orbicularis oculi / closes eye
Orbicularis oris / shapes lips during speech, closes and protrudes lips; compresses lips against teeth
Buccinator / Anterior to masseter , posterior to orbicularis oris (fibres run transversely)
-keeps food between teeth, presses cheeks against teeth and lips as in whistling and blowing
Zygomaticus / Raises upper lip
Masseter / Elevates the mandible (closes mouth)
Temporalis / Elevates and retracts mandible
Sternocleidomastoid / Together: Flex head and neck. Singly: ipsilaterally flex neck and contralaterally rotates neck,
Pectoralis major / Flexes, adducts, and medially rotates arm
Intercostal muscles / Aids in inspiration and expiration
Rectus abdominus / Flexes vertebral column, compresses abdomen (suck it in)
Transversus abdominus / Compresses abdomen
Internal oblique / Compress abdomen, flex and rotate vertebral column
External oblique / Compress abdomen, flex and rotate vertebral column
Trapezius / Elevates, adducts, depresses, rotates and stabilizes scapula
Latissimus dorsi / Extends, adducts and medially rotates arm
Erector spinae / Extends vertebral column, maintains erect posture and laterally flex vertebral column
Deltoid / Abducts, flexes, extends and rotates arm
Biceps brachii / Flexes arm and shoulders and supinates forearm
Triceps brachii / Extends elbow/shoulder
Iliopsoas (psoas major & iliacus) / Flex thigh at hip and rotate thigh laterally
Gluteus maximus / Extends and rotates thigh laterally
Gluteus medius / Abducts and rotates thigh medially
Gluteus minimus / Abducts thigh and medially rotates thigh.
Adductor magnus / Adducts, flexes, extends and rotates thigh laterally
Adductor longus / Adducts, flexes and rotates thigh laterally
Adductor brevis / Adducts, flexes and rotates thigh medially
Sartorius / Flexes leg at knee joint; flexes, abducts, and laterally rotates thigh.
Hamstring group (3)
biceps femoris
semitendinosus
semimembranosus / Flexes knee and extends thigh at hip joint
Quadriceps group (4)
vastus lateralis
vastus intermedius
vastus medius
rectus femoris / Extends knee and flexes thigh at hip joint
Tibialis anterior / Dorsiflexes and inverts foot
Peroneal muscles / Longus/brev-plantar flex and evert foot. Tertius-Dorsiflex and evert foot
Gastrocnemius / Plantar flexes foot and flexes leg