Module 15- Musculoskeletal Patho Flashcards
The musculoskeletal system gives what to the body?
- The body its shape and allows for movement
- It performs many important functions within the body
Functions of the musculoskeletal system- Support
- Support: bones provide a framework, giving the body its shape and allowing it to stand upright
Functions of the musculoskeletal system- Movement
Movement: is generated because muscles are attached to bones via tendons; contraction generates a force, causing motion across a joint
Functions of the musculoskeletal system- Protection
Protection: provides protection to the more fragile organs and structures beneath them. Bones deflect and absorb energy. The skull protects the brain, the rib cages protects the heart, and lungs, and the spinal column protects the spinal cord.
Functions of the musculoskeletal system- Hematopiesis
Hematopoiesis: the process of generating blood cells. Occurs in the bone marrow of the sternum, ribs, vertebral bodies, pelvis, and the proximal portions of the femur and humerus
How bones is the skeleton composed of?
206
What is the skeleton divided into?
- Axial skeleton
- Appendicular skeleton
What bones is the axial skeleton composed of?
- Skull
- Vertebral column
- Ribs
- Sternum
Skull
- Cranium
- Basilar skull
- Face
- Inner ear
- refer to diagram
Vertebral column
33 vertebrae
- 7 cervical
- 12 thoracic
- 5 lumbar
- 5 sacral
- 4 coccygeal
Thorax
- Sternum
- 12 pairs of ribs
- True ribs attach to the sternum
- False ribs indirectly attach to the sternum
- Floating ribs have no anterior attachment
What bones is the appendicular skeleton composed of?
- Pectoral girdle
- Pelvic girdle
- Upper extremities
- Lower extremities
Pectoral (“shoulder”) girdle
- 2 scapulae
- 2 clavicles
Scapulae (“shoulder blade”)
- Flat, triangular bone
- Held to rib cage by powerful muscles that buffer it agaisnt injury
Clavicle (“collar bone”)
- Slender, s- shaped
- Connects scapula to the sternum
- Acts as a strut to keep the shoulder propped up and as scaffolding on which other muscles of the thoracic cavity pull
- Because it is slender, and very exposed it is vulnerable to injury (bleeding risk- clavicle artery)
Upper Extremity
- Joins shoulder at glenohumeral joint
- Proximal portion contains humerus
- Distal portion contains radius and ulna
- This forms the hinged elbow joint
Radius
- Larger of two forearm bones
- Lies on thumb side of forearm
Ulna
- Narrow
- Serves as a pivot around which the radius turns
What 3 bones does the hand contain?
- Carpals (wrist bone)
- Metacarpals (hand bone)
- Phalanges (finger bones)
What 3 separate bones does the pelvic girdle cotain?
- Ischium
- Ilium
- Pubis: fused together to form the hip. These joints allow very little motion, so the pelvic ring is strong & stable
Femur
- Long, powerful bone
- Head of femur articulates proximally with ball and socket joint of the pelvis
- Distally with the hinge joint of the knee
- The head of the femur is the ball shaped part that fits into the acetabulum of the pelvis
- It connects with the shaft or long tubular portion of the femur, by the femoral neck
- Most hip #’s are femur #’s
Tibia
-Shin bone
- Superficial
- Exposed to force:
- Vulnerable to direct blows
Fibula
- Makes up lateral portion of lower leg, lateral knob if the ankle joint (lateral malleolus)
What 3 bones does the foot contain?
- Tarsal (Ankle)
- Metatarsals (foot)
- Phalanges (toes)
What is the largest tarsal bone?
- Calcaneus
- Subject to injury when a person jumps from a height and lands on their feet
What are the 5 bone shapes?
- Long
- Short
- Flat
- Irregular
- Round
Long Bone
- Longer than wide
- Femur, humerus, tibia, fibula
- Radius and ulna
Short
- Nearly as wide as long
- Phalanges, metacarpals and metatarsals
Flat
- Thin, broad
- Sternum, ribs, scapulae, and skull
Irregular
- Nonspecific shape
- Designed for a specific function
- Vertebral column, mandible
Round
- Proximal to a joint and help with movement
- Patella
Physis (growth plate)
Once a person reaches adulthood, the growth plate closes and the mature adult bone is complete.
What three regions is the long bone divided into?
- Epiphysis
- Diaphysis
- Metaphysis
Periosteum
- Portion of the bone not covered by cartilage
- Dense, fibrous membrane
- Contains capillaries and cells that are important for bone repair and maintenance
Endosteum
- Lines the hollow inner portion of the shaft
- Similar to periosteum, but on the inside
- Contains yellow, fatty marrow in adults
Medullary Canal
- Hollow inner portion of the shaft
- Entrance for nutrient artery
Joints
- When 2 bones come together, they articulate with one another to form a joint
- Some are fused, allowing no motion (skull)
- Other permit motion, typically within a plane that is defined by the structure of the bone
Flexion
Elbow joint when the hand is brought near the shoulder
Extension
Straightening your arm or bending your head back
Abduction
Movement away from the midline of the body
Adduction
Movement towards the midline of the body
Rotation
Revolves around a single long axis. Moving head side to side
Circumduction
To move a limb in a circular motion
Pronation
Rotation of the forearm turning the palm inwards towards the body
Supination
Turning the palm outwards so it faces away
What are the type of joints?
- Fibrous
- Cartilaginous
- Synovial
Fibrous Joints
- Fused joints
- Contain dense, fibrous tissue
- Do not allow for motion
- Skull
- Distal tibiofibular joint
Cartilaginous Joints
- “Amphiarthrosis”
- Allow for minimal motion between bones
- Pubic symphysis
- Joint connecting the ribs-sternum
Synovial Joints
- “Diarthroses”
- Most mobile joints of the body
- Surrounded by joint capsule
- Extension of periosteum
- Bones that form them are heal in place by strong ligaments
- Contain articular cartilage and synovial membrane
- Synovial membrane secretes synovial fluid into the joint cavity for lubrication
Must remember that with the flexibility of the synovial joint comes a measure of instability that results in damage to ligament and disarticulations of bones
Bursa
Cavity located within connective tissue
- Usually close to a joint
- Usually lined with synovial membrane and lubricant to reduce friction between tendon and bone or tendon and ligament
- Bursitis is an inflammation of the bursa
- Found in elbow, shoulder, and knee
Tendons
- Connect muscles to bones
- Flat, cordlike bands of connective tissue
- Have a glistening, white appearance
Ligaments
- Have similar structure to tendons
- Connect bone to bone
- Help maintain stability of joints
- Determine degree of joint motion
Cartilage
- Consists of fibers of collagen embedded in gelatinous substance
- Provides smooth surface over bones ends where they articulate
- Cushions (eg, vertebrae)
- Provides structure (eg, nose, larynx and trachea)
- Serves as model for formation in skeleton of children
- Limited neurovascular supply
Does not heal well when injured due to limited blood supply
Muscles
Muscles are composed of specialized cells that contract (shorten) when stimulated to exert a force on a part of the body.
What are the 3 type of muscles?
- Smooth
- Cardiac
- Skeletal
Skeletal Muscle
- Includes all muscles attached to the skeleton
Muscle Innervation
Skeletal muscle innervated by somatic motor neurons
- Transmit electrical signal, causing contraction
- When motor unit receives a signal to contract is does so forcefully or does not contract at all
- All-or-nothing for each motor unit
- To generate a more forceful contraction, more neurons need to signal more muscle cells to contract, a process called recruitment
Plexuses (Innervation of the upper extremities arises from the:)
- Brachial plexus
- Network of nerves that originates from the spinal cord at the C5-T1 levels and provides nerves for upper extremities
Plexuses (Innervation of the lower extremities is provided by the:)
- Lumbar and lumbosacral plexuses
- Originating from L1-S4
- Leads to formation of distinct nerve such as sciatic nerve
Musculoskeletal Blood Supply
- The upper extremity’s blood supply originates from the subclavian artery.
- Called the axillary artery when it reaches the axilla
- Becomes the brachial artery after it leaves the axilla
- Divides into the radial artery and ulnar artery after if passes through the elbow
- Branches into digital arteries at the fingers
