unit1.5 intro to musculoskelatal

Question 1

the skeletal system is divided into two parts

Bones articulate through joints. Part of what tissue, subtype, is also included in the skeletal system?

Answer 1

two parts

1. axial
   
   1. head, neck, trunk, skull hyoid, vertebrae, ribs and sternum
2. appendicular
   
   1. limbs, including pectoral and pelvic girdle

Bones articulate at joints, which contain different types of connective tissue:cartilage, Dense regular/irregular CT…much more

Question 2

What are the two types of bone development

Answer 2

It takes 20 years to for ossification to copmlete. bones are derived from the embryonic CT (mesenchyme)

1. intramembranous ossification-mesenchyme ossifies
2. endochondrial ossificaion-> cartilage model forms mesenchyme and then ossifies following invasion by capillaries

Question 3

describr morphology of long bone

Answer 3

Question 4

Explain the difference between cancellous and compact bone

Answer 4

1. compact
   
   1. bone exterior
   2. strong, dense, tightly packed w. matirx
2. cancellous
   
   1. spongy latticework of interconnecting bony bars = trabeculae

Question 5

Two compartments of the skeletal system house important material for components of blood.

Answer 5

1. diaphysis-main shaft
   
   1. yellow marrow
2. epiphisis
   
   1. spongy bone
   2. red marrow

Question 6

Describe what is happening in this photo. what can be found on this bone in the joint?

Answer 6

1. epiphyseal plates
   
   1. generated as a growth plate at the end product of maturity.
   2. the photo shows the growth plate size difference in maturing vs fully grown adult.
2. articular artilage
   
   1. form the joint surfaces as .hyaline cartilage

Question 7

label and give function of bone organization. What are they arranged into?

Answer 7

1. periosteum-fibrous CT that conver the entire bone except at joint surfaces
   
   1. function
      
      1. anchors ligaments and tendons to the bone
      2. involved in bone formation and repair.
      3. degenerate with age=harder to heal broken bones
2. endosteum
   
   1. thin CT that lines the medullary cavity and functions in bone growth and remodeling

Question 8

describe general blood and nerve vessel layout and structures in bone

Answer 8

1. vessels
   
   1. compact bone
      
      1. nutrient via foramina
      2. periosteal artieris
   2. spongy bone
      
      1. nutrients enter via shaft
   3. periarticular arterial plexus
      
      1. ​for end bones
   4. lymphatics vessels are abundant in the periosteum
2. nerves
   
   1. accompany blood vessels
   2. periosteal nerves-carry pain
      
      1. ​GSA
   3. vasomotor nerves-regulate blood flow through bone marrow
      
      1. ​GSE, seympathetic

Question 9

define two ways to categorize joints and provide subcategories

Answer 9

1. structual-joints oddered by tissue type that binds together at articulation
   
   1. fibrous
      
      1. held by tight dense fibrous CT
   2. cartilaginous
      
      1. held by hyaline or fibrocartilage
   3. synovial
      
      1. complex, fluid filled
2. functional-according to movement
   
   1. synarthrosis
      
      1. immovable joint
   2. amphiarthrosis
      
      1. allows slight movement, but lacks articular cavity or synovial joint
   3. diarthrosis
      
      1. freely moveable joint

Question 10

what are the following types of joints.

Answer 10

1. fibrous joints
   
   1. suture
      
      1. flat bones of the skull, held by DENSE CT- sutural ligaments
      2. synarthrotic (no movement)
   2. gomphosis
      
      1. teeth
      2. synarthrotic (no movement)
   3. syndesmosis
      
      1. bones bound by fibrous CT which form an interosseous ligament
      2. amphiarthrotic (some movement)
      3. radius-ulna and distal tibia-fibia

Question 11

what are these joints examples of? classify, name and describe what is in pic

Answer 11

structural classification

1. cartilagionous joints
   
   1. synchondrosis
      
      1. temporary
      2. synarthrotic
      3. ex
         
         1. metaphysis
         2. 1st sternocostal joint xiphisternal joint
   2. symphysis
      
      1. permanent
      2. amphiarthrotic
      3. bones connected by a pad of fibrocartilage
      4. example
         
         1. pubic symphysis
         2. intervertebral discs
         3. manubriosternal joint

Question 12

what class and movement type is this joint? list the cartilage and explain layers around.

Answer 12

synovial joints

1. diarthrotic-
2. 2 or more articular surfaces covered with hyaline cartilage (articular cartilage)
3. the articular capsule
   
   1. outer layer:tough fibrous capsule
   2. inner layer: synovial membrane
      
      1. ​provide serous fluid to the joint
         
         1. lubricates, nutrient pass and removes debris
4. fortified by ligaments outside the joint
5. the most common and most complex joint

Question 13

what are the accessory structures offered in some synovial joints, outside of the capsule?

Answer 13

1. accessory ligament-reinforce joint
   
   1. synovial sheaths
      
      1. affected by carpal tunnel
2. meniscus/labum-both made of fibrocartilage
   
   1. cartilagenous protection
3. bursa-fluid filled sac that acts as a cushion
   
   1. type of fascia.
   2. between joint and skin, found outside of the joint

Question 14

list the classification of synovial joints via shape

Answer 14

1. hinge-flexion and extension
   
   1. elbow
2. pivot-rotation around central axis
   
   1. atlantoaxial
3. gliding(plane)-horizontal movement
   
   1. acromiclavicular
4. saddle-adduction/adbuction and flexion/extension
   
   1. carpometacarpal joint of thumb
5. condyloid-adduction/abduction and flexion/extension
   
   1. knuckle joints
6. ball and socket 3d movement
   
   1. hip

Question 15

after 20yrs of professional baseball jim was diagnosed with arthritis in his knees. What happened to his joints? why can’t it heal like the bone?

Answer 15

1. trauma or abnormal wear leads to structural disruption of matrix
2. loses elasticity therefore increases stiffness
3. limited capacity to regenerate or repait
4. why?
   
   1. restricted access to nutrient blood

Question 16

I warm up by stretching. Why am I stretching? what happens to these structures if I don’t exercise at all

Answer 16

tendons and ligaments

1. these become stronger with exercise
   
   1. number and quality of collagen cross-links increases
2. if no exercise
   
   1. weaker and less stiff
      
      1. loss of collagen
      2. lower deformation
   2. “use it or lose it”

Question 17

define and reson the following

1. sprains
2. bursitis
3. arthritis

Answer 17

1. sprains
   
   1. damage to CT, ligaments, of a joint.
   2. usually from trauma
2. bursitis
   
   1. painful inflammation of bursa
   2. from over use of a muscle
   3. “rubbing, rubbing, rubbing”
3. arthritis-cartilage destruction
   
   1. osteoarthritis
      
      1. cartilage broken down by abrasion, aging, high-use
   2. traumatic arthritis -
      
      1. injury w/ avascular necrosis of cartilage, like OA
   3. inflammatory arthritis
      
      1. autoimmune attack on synovial membrane cause destruction of joint/bilateral small joinst/ankylosis (bones fuse)
      2. can have deformed hands/feet
      3. diagnosed bilaterally

Question 18

how do skeletal muscles grow?

Answer 18

hypertrophy of existing muscle fiber, don’t grow more cells. they just get bigger.

Question 19

Define the layers of the muscle, start with actin/myosin.

Answer 19

the CT component of the muscle=fascia of the body

1. muscle cell
2. muscle fiber
3. fasciculi
   
   1. surrounded by perimysium
4. many fasciculi
   
   1. surrounded by epimysium
      
      1. connects to tendon or aponeurosis

Question 20

describe fascia layers involved in muscle. use image to assist.

Answer 20

1. superficial fascia
   
   1. Skin
      
      1. loose CT, adipose
      2. varies on thickness
      3. contains
         
         1. nerves and vessels
2. deep fascia
   
   1. dense CT
   2. contains
      
      1. no adipose
   3. names
      
      1. investing layer
      2. intermuscular septa
      3. retinaculum-thickening near joint
         
         1. not a tendon.
         2. just provide a bit more support to the joint. knee =example

Question 21

what is a commonality between innervation and comparments of muscle? What are three motor fibers?

Answer 21

muscles of common fascial compartment share innervation from same nerve

1. motor fibers
   
   1. voluntary/reflexive
   2. motor nerve
   3. sensory nerve

Question 22

classify the muscle shape

Answer 22

the shape of a muscle combined with the joint structure will determine the strength and movement potential of that muscle at a particular articulation

Question 23

muscle can be distinguished by its shape.

discuss the contraction type, apperance and provision of the two categories of muscle shown.

Answer 23

1. parallel
   
   1. apperance
      
      1. long and slender
   2. provide
      
      1. good range of motion but relatively weak contractions
2. pennate
   
   1. apperance
      
      1. short and thick with fibers anled toward one or more internal tendinous bands
   2. provide
      
      1. shorter range but stronger contractions

Question 24

Muscles can be named according to 6 features

Answer 24

1. attachment
   
   1. sternocleidomastoid
2. action
   
   1. levator scapulae
3. shape
   
   1. trapezius, deltoid
4. numbers of different parts
   
   1. quadriceps femoris
5. size
   
   1. maximus/minimus
6. location
   
   1. flexor digitorum superficialis and flexor digitorum profundus

Question 25

fill in and define the two term.

When a muscle contracts its ______ is pulled toward its _______.

Answer 25

“when a muscle contracts its insertion is pulled toward its origin.”

this is based on how the movement will happen.

origin-the immovable anchor that one end of a muscle is attached to.

insertion-the moveable structure on the other side of the joint from the origin.

Question 26

Describe the types of muscle contraction

Answer 26

1. isometric contraction
   
   1. the muscle is changing in force BUT does not change in length
2. isotonic contractions
   
   1. concentric contraction
      
      1. muscle shortening
   2. eccentric contraction
      
      1. muscle lengthening
      2. often overlooked, but are clinically significant

Question 27

describe the four individual muscle roles.

Answer 27

1. prime mover
   
   1. the muscle that does the moving
2. synergists
   
   1. not the most important muscle in the movement but assist
3. reserve muscle
   
   1. little helper
   2. most of the time it does nothing, but in certain movements it is asked to contribute
4. antagonist
   
   1. resist the action of the prime mover.
   2. example
      
      1. flex the arm
         
         1. bicep contracts
         2. tricep resists
      2. extend arm
         
         1. bicep resists
         2. tricep contracts

Question 28

describe the muscle limiting movements shown in the picture.

Answer 28

1. active insufficiency
   
   1. the muscles cannot do two jobs at the same time.
   2. muscle acts on both joints.
   3. example
      
      1. flex and extend leg. you cannot devot 100% of each muscle to perform action
2. passive insufficiency
   
   1. non contracting muscle cannot stretch enough
   2. stretches the antagonist
   3. example
      
      1. stretching the back of your leg for a run, stretching hands before drums.

Question 29

Not only do muscles provide for movement at a joint but stabalize the joint too.

Describe the two types of stabilization with respect to muscles

Answer 29

1. dynamic stabilization
   
   1. muscles contract across joints, instead of moving them
   2. example
      
      1. rotator cuff
2. static stabilization
   
   1. stabilize the joint with out contracting
   2. exmple
      
      1. ligaments, retinaculums.. and other structures