1. CHAPTER 6 STUDY GUIDE MUSCULAR SYSTEM
Anatomy Test
Prep
CHAPTER 6 STUDY GUIDE MUSCULAR SYSTEM

2. Three Major types of muscle tissue (understand the differences)
Skeletal muscle
-”striated muscle”
-”voluntary muscle”
Cardiac muscle
-”involuntary muscle”
Smooth muscle
-”visceral muscle”
For each, know where it is located, the physical description, and what it does

3. Muscle Types Skeletal muscle: Smooth muscle: Cardiac muscle:
Is in our biceps, triceps, postural muscles, etc
Smooth muscle:
Is found along our digestive tract: used to move food along
Cardiac muscle:
Is found in the heart

4. Structure of Skeletal muscle
Origin
The stationary attachment to bone
Insertion
The more movable attachment site to bone
Tendons
Anchor muscles firmly to bones
Made of dense fibrous connective tissue in the shape of heavy cords
Bursae
Lie in between some tendons and bones beneath them
Synovial membrane
Secretes a slippery lubricating fluid that fills the bursa
Tendon sheaths
Enclose some tendons

5. Microscopic structure of skeletal muscle
Muscle fibers
Specialized contractile cells that are grouped together and arranged in a highly organized way
Thin and thick myofilaments
Thick filaments are composed of myosin
Thin filaments composed of actin
Actin
Thin filaments
Myosin
Thick filaments
Sarcomere
The basic functional or contractile unit of skeletal muscle

6. Muscle stimulus Understand what a motor unit is and how it works
Define:
Neuromuscular junction
Specialized point of contact between a nerve ending and the muscle fiber it innervates
Motor neuron
a specialized nerve that transmits an impulse to a muscle
Know how the process of muscle stimulus works
When does a muscle fiber fire?
Acetylcholine / Ca2+
“All or none” muscle response
Muscles will not partially contract. It will contract or remain the same

7. Types of skeletal muscle contraction
Know the difference between:
A twitch contraction vs. a tetanic contraction
An isotonic contraction vs. an isometric contraction

8. Contractions Twitch contraction Tetanic Is laboratory
Does not play a significant role in normal muscular activity
Tetanic
Are sustained and steady contractions caused by a series of stimuli bombarding the muscle

9. Exercise effects What happens when you don’t exercise?
Know and define:
Disuse atrophy
Atrophy is when the muscle fibers weak due to lack of stimulation
What happens when you do exercise?
Hypertrophy
Hypertrophy is the increased size of a muscle due to increase of cells

10. Exercise What are different types of exercise? Know and define:
Strength training
Exercise involving the contraction of muscle against heavy resistance
Endurance training
Increases a muscles ability to sustain moderate exercise over a long period of time
is also called “Aerobic training”
Allows for more efficient deliver of oxygen to muscles

11. Skeletal muscle groups
Know the muscles of each group and what each muscle does
Muscles of the Head and Neck
Facial muscles
Orbicularis oculi
Orbicularis oris
Zygomaticus
Frontalis
Muscles of Mastication
Masseter
Temporal
Sternocleidomastoid
Trapezius
Buccinator

12. SKELETAL MUSCLE GROUPS
Muscles that move the Upper Extremities
Pectoralis major- flexes upper arm
Latissimus dorsi- extends upper arm
Deltoid- abducts upper arm
Biceps brachii-flexes forearm
Triceps brachii- extends forearm
Muscles of the Trunk
Rectus abdominis
External oblique
Internal oblique
Transversus abdominis
Muscles that move the Lower Extremities
Iliopsoas-flexes hip
Gluteus maximus- extends thigh
Adductors - adducts thighs
Hamstrings- flex lower leg
Quadriceps- extends lower leg
Gastrocnemius
Soleus
Tibialis anteror

13. Movements produced by skeletal muscle contractions
Flexion
Movement that decreases the angle between two bones at their joint: bending
Extension
Movement that increases the angle between two bones
Abduction
Movement of a part away from the midline of the body
Adduction
Movement of a part towards the midline of the body
Rotation
Movement around a longitudinal axis
Supination and pronation
Hand positions that result from rotation of the forearm;
Supination results in palms facing up
Pronation results in palms facing down
Dorsiflexion and plantar flexion
Foot movements;
Dorsiflexion results in elevation of dorsum or top of foot
During plantar flexion- the bottom of the foot is directed downward