NURS 8022 Exam 5 SG.

Exam 5 Study guide Musculoskeletal Musculoskeletal Physiology Define differences between bone cells Bone Cells About Osteoblasts Bone forming cells. Bone makers. Become osteocytes that are imbedded in bone. Form new bone & synthesize osteoid (un-mineralized portion of bone matrix  mature bone) Osteoclasts Bone resorbing. Bone breakers. They’re attached to integrins by podosomes—which helps bind to bone. Secretes HCl & protease enzyme  resorption of bone (dissolves bone minerals & collagenase). They “rest” when they’re not resorbing. Osteocytes Bone maintaining. These coordinate osteoblast & clast function. They respond to PTH.  Osteoblasts are important in The formation of new bone.  Osteocytes are important in bone maintenance.  Osteoclasts are important in bone resorption. Understand difference between compact and spongy bone  Compact – “cortical bone”. This is the main part of skeleton. Solid & strong. Consists of Haversian system (structural unit). NURS8022 Exam 5 SG.  Spongy – “cancellous bone”. Filled w/ red marrow. No haversian system—Trabeculae: plates or bars instead. (Epiphysis = red marrow)  Diaphysis – contains yellow marrow.  What is the importance of the bone element, ground substance? Diffusion of substances between the bond and blood vessels.  Which part of the bone contains the yellow marrow? Diaphysis. Understand basics of bone remodeling and bone repair  Bone heals itself.  Remodeling – periosteal & endosteal surfaces are remodeled to size/shape of bone before injury. o Phases: activation, resorption, formation of new bone (aka secondary bone) – 3-4 mos.  What is the final step in formation of bone? Mineralization. Describe different joint classifications  1. Movement based: o Synarthrosis – immovable o Amphiarthrosis – slightly movable (Amphi = both) o Diarthrosis – freely movable  Which of the following joint types is classified as an immovable joint? Synarthrosis  2. Structure based: o Fibrous – bone to bone. Ex sutures in skull. Directly connected to bone by dense fibrous connective tissue. o Cartilaginous – connected by fibrocartilage or hyaline cartilage  Symphysis – Ex symphysis pubis & intervertebral disks. Bones are connected by pad/disk of fibrocartilage  Synchondrosis – Ex joints btwn ribs & sternum. Bones are connected by hyaline cartilage (costal cartilage) o Synovial – moveable, complex, diarthrosis (synovial fluid – lubrication/moveable)  Articular cartilage – reduces friction in joint & distributes forces of weight bearing. Has NO blood vessels, lymph vessels, or nerves (insensitive to pain & regenerates slowly after injury)  Which of the following is TRUE regarding the articular cartilage? Has no blood vessels Define muscle fiber differences and types  Each muscle fiber is a single muscle cell surrounded by a membrane that can excite/send an impulse  Myofibrils – functional unit of contraction  White muscle – type II fibers – FAST  Red muscle – type I fibers – sloooooow  Muscle membrane: o Sarcolemma – spreads impulse o Basement membrane – keeps cell’s shape Understand basics of muscle contraction  Ryanodine receptors (RyRs) are the primary ion channels that control Ca2+ release in muscles  Phases: o Excitation – AP travels from nerve terminal  NMJ  initiates electrical impulse (muscle fiber AP). This triggers receptors in t-tubule wall  opening RyR channels & Ca2+ release o Coupling – Ca2+ is released so now actin can bind w/ myosin o Contraction – actin slides toward myosin to form cross-bridge  muscle shortening. “All or nothing”. o Relaxation – cross-bridge detaches. Sarcomere lengthens as Ca2+ pumps back into SR. Understand basics of types of muscle contraction and muscle movement