#7: the Muscular system

Question 1

Distinguish between the different types of joints in the body

Answer 1

1) The structural classification
- based on the types of tissue between the bones
- fibrous, cartilaginous, bony, synovial

2) The functional classification (main focus in the labs)
- based on the amount of movement allowed by the joint
- synarthrosis, amphiarthrosis, diarthrosis

Question 2

What’s the structural classification of the joint

Answer 2

: based on the types of tissue between the bones

• fibrous: bones are linked by their fibrous connective tissue
• cartilaginous: bones are linked by cartilage
• bony: bones are connected by either cartilage or fibrous connective tissue that has been ossified (replaced with bone)
• synovial: bones are connected by a fluid-filled capsule and supported by other additional structures

Question 3

What’s functional classification of joints?

Answer 3

: based on the amount of movement allowed by the joint
- synarthrosis: no movement
- amphiarthrosis: a small amount of movement
- diarthrosis: free movement (all diarthrosis joints are also synovial joints)

Question 4

Describe the structural features of the knee including the bones and ligaments involved

Answer 4

Knee joint:
- a hinge joint involving the femur, tibia, fibula and patella
- the lateral and medial condyles of the femur articulate with those of the tibia and these connections are cushioned by the lateral and medial menisci
- On either side of the knee are the collateral ligaments: the tibial or medial collateral ligament / lateral collateral ligament (connected the femur and fibula)
- the femur and tibia are also connected by two cruciate ligaments: anterior and posterior cruciate ligaments

Question 5

Describe the structural features
of hip joints, including the bones and ligaments involved

Answer 5

• a ball and socket joint
• hip bone forms from the fusion of three bones (superior ilium, the inferior and anterior pubis and the inferior and posterior ischium = acetabulum)
• the head of the femur fits into the acetabulum of the hip joint

5 ligaments
1) iliofemoral
2) ischiofemoral
3) pubofemoral ligaments
= link their respective regions of the hip bone to the femur
4) transverse acetabular ligament
= wraps around the inferior border of the acetabulum and the acetabular notch to help hold the head of the femur in place
5) ligament of the femoral head
= connects the transverse acetabular ligament to the head of the femur

*like most other joints, additional support is provided by the muscles surrounding the joint

Question 6

Describe the structural features
of shoulder joints, including the bones and ligaments involved

Answer 6

The shoulder joint:
- is ball and socket joint between the scapula and the humerus and additionally stabilized by the clavicle
- the head of the humerus fits against the glenoid cavity of the scapula and is held in place by many skeletal muscles
- the acromioclavicular ligament: connects the posterior lateral projection of the scapula, the acromion, to the clavicle
- the coracoclavicular ligament: connects the anterior lateral projection of the scapula, the coracoid process, to the clavicle
- the coraco-acromial ligament: bridges the space between the coracoid process and acromion of the scapula
- the coracohumeral ligament: connects the coracoid process to the humerus
- the glenohumeral ligament: connects the glenoid cavity of the scapula to the humerus

Question 7

Identify selected muscles and their insertions, origins, and actions: Deltoid

Answer 7

origins: clavicle, scapula
insertions: humerus
actions: abducts and rotates humerus

Question 8

Identify selected muscles and their insertions, origins, and actions: Trapezius

Answer 8

origins: occipital bone, vertebrae c7-t12
insertions: clavicle, acromion, and spine of scapula
actions: adducts, elevates and depresses scapula

Question 9

Identify selected muscles and their insertions, origins, and actions: Pectoralis major

Answer 9

origins: Clavicle, sternum, cartilages of ribs 1-6
insertions: humerus
actions: flexes, adducts and medially rotates humerus

Question 10

Identify selected muscles and their insertions, origins, and actions: biceps branchii

Answer 10

origins: scapula
insertions: radial tuberosity (radius)
actions: flexes radius (forearm) at elbow and humerus at shoulder

Question 11

Identify selected muscles and their insertions, origins, and actions: tricepts branchii

Answer 11

origins: scapula, humerus
insertions: olecranon process of ulna
actions: extends ulna (forearm) at elbow and hymerus at shoulder

Question 12

Identify selected muscles and their insertions, origins, and actions: latissimus dorsi

Answer 12

origins: lumbar fascia, ribs 9-12, iliac crest (ilium)
insertions: humerus
actions: extends, adducts and medially rotates humerus

Question 13

Identify selected muscles and their insertions, origins, and actions: external oblique

Answer 13

origins: ribs 5-12
insertions: linea alba, iliac crest (ilium), pubic tubercle and crest (pubis)
actions: lateral flexion of vertebral column (one); compress of abdomen and flex vertebral column (both)

Question 14

Identify selected muscles and their insertions, origins, and actions: internal oblique

Answer 14

origins: lumbar fascia, iliac crest (Ilium)
insertions: linea alba, pubic crest (pubis), ribs 9-12
actions: lateral flexion of vertebral column (one); compress of abdomen and flex vertebral column (both) = same as external

Question 15

Identify selected muscles and their insertions, origins, and actions: Rectus abdominis

Answer 15

origins: pubic crest (pubis)
insertions: Xiphoid process, cartilage of ribs 5-7
actions: flexes and rotates lumbar region of vertebral column

Question 16

Identify selected muscles and their insertions, origins, and actions: diaphragm

Answer 16

origins: lumbar vertebrae, inferior margin of rib cage
insertions: central tendon of diaphragm
actions: pulls central tendon down increasing volume of thoracic cavity

Question 17

Identify selected muscles and their insertions, origins, and actions: Gastrocnemius

Answer 17

origins: lateral and medial condyles of the femur
insertions: calcaneus
actions: plantar flexion of foot; flexion of tibia (leg) at knee

Question 18

Identify selected muscles and their insertions, origins, and actions: Gluteus maximus

Answer 18

origins: dorsal ilium, sacrum, and coccyx
insertions: gluteal tuberosity (femur)
actions: extension, abduction and lateral rotation of femur (thigh) at hip

Question 19

Identify selected muscles and their insertions, origins, and actions (quadriceps femoris group): Rectus femoris

Answer 19

origins: anterior spine of ilium
insertions: patella and tibial tuberosity (tibia)
actions: flexion of femur (thigh) at hip; extension of leg at knee

Question 20

Identify selected muscles and their insertions, origins, and actions (quadriceps femoris group): Vastus lateralis

Answer 20

origins: lateral surface of femur
insertions: patella and tibial tuberosity (tibia) = same as other parts of quadriceps femoris group
actions: extension of tibia (leg) at knee

Question 21

Identify selected muscles and their insertions, origins, and actions (quadriceps femoris group): vastus medialis

Answer 21

origins: medial surface of femur
insertions: patella and tibial tuberosity (tibia) = same as other parts of quadriceps femoris group
actions: extension of tibia (leg) at knee = same as vastus lateralis

Question 22

Identify selected muscles and their insertions, origins, and actions (quadriceps femoris group): vastus intermedius

Answer 22

origins: upper anterior surface of femur
insertions: patella and tibial tuberosity (tibia) = same as other parts of quadriceps femoris group
actions: extension of tibia (leg) at knee = same as vastus lateralis

Question 23

Identify selected muscles and their insertions, origins, and actions (hamstring group): Biceps femoris

Answer 23

origins: Ishial tuberosity (ischium) and femur
insertions: Fibula and lateral epicondyle of tibia
actions: extension of femur (thigh) at hip; flexion of tibia (leg) at knee

Question 24

Identify selected muscles and their insertions, origins, and actions (hamstring group): Semitendinosus

Answer 24

origins: Ishial tuberosity (ischium) and femur = same as biceps femoris
insertions: medial condyle of tibia
actions: extension of femur (thigh) at hip; flexion of tibia (leg) at knee = same as biceps femoris

Question 25

Identify selected muscles and their insertions, origins, and actions (hamstring group): Semi-membranosus

Answer 25

origins: Ischium
insertions: medial condyle of tibia
actions: extension of femur (thigh) at hip; flexion of tibia (leg) at knee = same as biceps femoris

Question 26

Distinguish between the three (3) types of muscle tissues using slides

Answer 26

1) Skeletal muscle
: voluntary and striated
2) Smooth muscle
: involuntary and non-striated
3) Cardiac muscle
: involuntary and striated

Question 27

what is skeletal muscle?

Answer 27

: voluntary and striated
the largest muscle and each end is attached to one or more bones by tendons, allowing for our large, voluntary movements
- origin: the attachment point to the fixed bone
- insertion: the attachment point to the moveable bone
- the action of the muscle: the type of movement generated by the muscle contraction
- fascicles: within skeletal muscles; wrapped with connective tissue and composed of individual muscle fibers, which are separated by endomysium (loose connective tissue)
- myofibrils: are the basic units of muscle fibers, responsible for muscle contraction
» the oval-shaped nuclei are located right beside the plasma membrane (sarcolemma) b/c each fiber is packed with parallel, banded (or striated) myofibril which extend the length of the cell

Question 28

What is Smooth muscle?

Answer 28

: involuntary and non-striated
2 layers
1) circular
- the SM cells appear long and spindle-shaped each w/ a single, central, oval nucleus
2) longitudinal
- the nuclei appear as small round dots surrounded by a circle of cytoplasm

Question 29

What is Cardiac muscle

Answer 29

: involuntary and striated
similar to that of skeletal muscle, but unlike skeletal muscle, the fibers are branched to form a continuous network
- each fiber in a network is separated from the next fiber by a transverse plate and these end-to-end membranes = intercalated discs
- the nuclei are centrally located

Question 30

How to differentiate 3 types of muscle tissues?

Answer 30

Skeletal muscle:
- attached to bones and tendons
- voluntary movement
- striated
Cardiac muscle:
- found in the heart (used to pump blood)
- striated/ rectangular in shape
- involuntary movement
- the nuclei are centrally located
Smooth muscle:
- found in the walls of hollow organs and blood vessels (e.g. duodenum)
- involuntary movement
- spindle-shaped and non-striated
- the nuclei appear as small round dots surrounded by a circle of cytoplasm

Question 31

Explain how the muscular system works with the skeletal system to affect movement of the body

Answer 31

Noramlly skeletal muscles are attached to the joint; when brain signals the joints to contract, it shortens and pull on the bones, causing the movement.
» also skeletal system provides the framework of body & protections

Question 32

Describe the different types of functional movements effected by muscles: abduction-adduction

Answer 32

abduction: raising the arm at the shoulder joint, moving it laterally away from the body
adduction: brings the arm down to the side of the body

Question 33

Describe the different types of functional movements effected by muscles: Flexion-extension-hyperextension

Answer 33

Flexion: Flexion is the action of decreasing the angle between two body parts or bones at a joint.

(moving the thumb back into the palm or against the index finger)
Extension: Extension is the opposite of flexion; it involves increasing the angle between two body parts or bones at a joint.
(moving the thumb away from the palm)

Hyperextension: when a joint is extended past its normal range of motion
» can cause injuries, such as ligament tears in the knee or whiplash in the neck

Question 34

Describe the different types of functional movements effected by muscles: rotation

Answer 34

Lateral (external) rotation: a limb rotates away from the midline of the body
Medial (internal) rotation: a limb rotates toward the midline of the body

Question 35

Describe the different types of functional movements effected by muscles: Elevation-depression

Answer 35

elevation: shrugging your shoulders - the upward movement of your shoulder blades
depression: the downward movement

Question 36

Describe the different types of functional movements effected by muscles: Dorsiflexion-plantar flexion

Answer 36

Dorsiflexion: the top of the foot moves toward the shin, as when you pull your toes up or walk on heels
plantar flexion: the toes point down, as when you press down on the gas pedal or walk on your toes

Question 37

Identify ALL of the different structural classifications of joints.
1. bony
2. synarthrosis
3. fibrous
4. amphiarthrosis
5. cartilaginous
6. diarthrosis
7. synovial

Answer 37

1. bony
2. fibrous
3. cartilaginous
4. synovial

Question 38

Identify ALL of the different functional classifications of joints.
1. fibrous
2. cartilaginous
3. bony
4. amphiarthrosis
5. synovial
6. diarthrosis
7. synarthrosis

Answer 38

4. amphiarthrosis
5. diarthrosis
6. synarthrosis

Question 39

Choose the best match between the type of muscle tissue and the descriptions below.
1. No striations
skeletal/ cardiac/ smooth
2. Under voluntary control
skeletal/ cardiac/ smooth
3. Contains branched
skeletal/ cardiac/ smooth

Answer 39

1. smooth
2. skeletal
3. cardiac

Question 40

Match the following muscle actions with their antagonist actions.
1. elevate
flex/ depress/ adduct
2. extend
flex/ depress/ adduct
3. abduct
flex/ depress/ adduct

Answer 40

1. depress
2. flex
3. adduct