A Case on Bone Tissue Structure and Repair

Lab 8 Assignment Clinical Case Study: Look out Below: A Case on Bone Tissue Structure and Repair Mrs. Debbie Morgan is a 45-year-old female who works as a stocking clerk for a local home improvement store. While she was at work today a large box of metal rivets fell from a 20-ft.-high overhead shelf, striking her outstretched arm and knocking her to the ground. The ambulance personnel reported that she had lost quite a bit of blood at the accident scene and was unconscious when they arrived. To minimize further hemorrhage, the paramedics applied a pressure bandage to her arm. You meet the paramedics as they bring Mrs. Morgan into the emergency room and begin to assess her for injuries. She is awake and alert, but complaining of severe left arm and back pain, plus she has a "killer headache." To fully examine her injuries you remove four blood-soaked bandages from her arm. You notice a large open wound on her arm with what appears to be bone tissue sticking out of the skin. She also has bruises covering her left shoulder, left wrist, and lower back. To determine the extent of her injuries Mrs. Morgan undergoes several x-rays, which reveal the following: 1) fracture of the left humerus at the proximal diaphysis, 2) depressed fracture of the occipital bone, 3) fracture of the 3rd lumbar vertebral body. Part A 12/2/21, 12:01 AM Lab 8 Assignment Mrs. Morgan has an occipital bone fracture. Select the correct classification for this bone. Hint 1. Recall that this bone helps to form the cranial vault. ANSWER: flat long irregular short Correct Flat bones are broad and thin. Part B One of Mrs. Morgan's fractures is described as being located on the proximal diaphysis. Which of these phrases best describes the anatomical location of this fracture? Hint 1. Review your directional terminology. ANSWER: shaft of the bone closest to the shoulder joint expanded end closest to the shoulder joint fractured shaft of the bone closest to the elbow joint expanded end closest to the elbow joint fractured Correct Proximal describes a point of attachment of a limb closest to the trunk; the diaphysis is the shaft of a long bone. Part C Mrs. Morgan's fracture is described as having "bone tissue sticking out of the skin." This could make her susceptible to which of the following complications? Hint 1. The intact skin provides us with a physical barrier against environmental pathogens. ANSWER: osteomyelitis osteoporosis osteosarcoma osteomalacia Correct Osteomyelitis is the medical term for an infection in a bone; it can occur if an injury exposes the bone to germs. Part D Mrs. Morgan's fracture has not developed a soft callus. Which type of cartilage is her body having trouble forming? Hint 1. 23/63 12/2/21, 12:01 AM Lab 8 Assignment During fracture repair the bone ends must stay aligned to ensure ossification. ANSWER: hyaline cartilage compact cartilage fibrocartilage elastic cartilage Correct Fibrocartilage forms the soft callus, which appears just a few days after the fracture occurs. Part E A depressed fracture is _______. Hint 1. Fractures can be classified based on their location, shape, or degree of displacement. ANSWER: one in which broken bone fragments are displaced inward one due to weakening of the bone structure by pathologic processes such as cancer, osteomalacia, or osteomyelitis a term used to describe a fracture site that lacks ossification one in which the bone has been twisted apart Correct Part F Define the following terms, used in the case and also in associated questions. a. hemorrhage b. fracture c. proximal d. diaphysis Hint 1. Use your textbook or other resource to look up the definitions. ANSWER: 3513 Character(s) remaining Hemorrhage: bleeding or the abnormal flow of blood. Can be external like in this case or internal. Fracture: Breaks in the continuity of a bones' structure. Proximal: Point of attachment of a limb closest to the truck. Diaphysis: Narrow elongated center portion of a long bone: the shaft Credit granted by instructor; correct answer displayed Part G One way bones are classified is by their shape. How would you classify the bones fractured by Mrs. Morgan? Hint 1. Think about the general shapes of bones within the skeleton. 24/63 12/2/21, 12:01 AM Lab 8 Assignment ANSWER: 3612 Character(s) remaining Flat, long, short, and irregular are the classifications of bones based on their shape. Mrs. Morgan's humerus is a long bone, the occipital bone is flat and vertebrae is an irregular bone. Credit granted by instructor; correct answer displayed Part H The body of Mrs. Morgan's vertebra is fractured. What type of bone tissue makes up the majority of the vertebral body? Describe the structure and function of this type of bone. Hint 1. Review the two major types of bone in your textbook. ANSWER: 3526 Character(s) remaining Most of the vertebral body is made up of spongy bone. Spongy bone is made up of trabeculae (small bean) and have an open arrangement of osseous tissue which helps decrease the weight of bone. Additionally spongy bone trabeculae align along stress lines to prevent breakage. Credit granted by instructor; correct answer displayed Part I The diaphysis of Mrs. Morgan's humerus is fractured. What type of bone makes up the majority of the diaphysis of long bones like the humerus? Describe the layers of bone tissue found here. Hint 1. The diaphysis is the shaft of a long bone. ANSWER: 3408 Character(s) remaining The diaphysis of a long bone is made up almost entirely by compact bone. Compact bone is made up of lamella (layers) that are named according to their shape or position within compact bone - *concentric lamellae* - circular shape; form the osteon *interstitial lamellae* - located in between the osteons *circumferential lamellae* - located at the outer /inner surfaces of compact bone. Credit granted by instructor; correct answer displayed Part J Most connective tissue, including bone, is highly vascular. Which anatomical structures in Mrs. Morgan's compact bone house blood vessels? What sign or symptom in Mrs. Morgan's case is directly related to disruption of these structures by her bone fractures? How is the sign or symptom related to these anatomical structures? 25/63 12/2/21, 12:01 AM Lab 8 Assignment Hint 1. When a fracture occurs, the normal anatomy of a bone is disrupted. ANSWER: 3414 Character(s) remaining The perforating and central canals house arteries and veins plus nerves in compact bone. Mrs. Morgan is hemorrhaging as a result of her bones breaking. When bones break the jagged ends of the bones can pierce the blood vessels within the bone causing uncontrolled bleeding. additionally, the soft tissue (muscle skin) surrounding the bone can be damaged resulting in further blood loss Credit granted by instructor; correct answer displayed Part K Within days after a fracture, a "soft callus" of fibrocartilage forms. What fibers are found in this type of cartilage? Identify the cells required for fibrocartilaginous callus formation and list their functions. Hint 1. The prefix chondro- is used to denote cartilage. ANSWER: 3598 Character(s) remaining collagen fibers are found in high abundance in the fibrocartilage tissue matrix. Fibroblasts = produce collagen fibers that bridge the gaps between fracture ends Chondroblasts= secrete cartilage matrix Credit granted by instructor; correct answer displayed Part L As a fracture is repaired, new bone is added to the injury site. What term is used to describe the addition of new bone tissue? Identify which bone cell is responsible for this process and explain how it occurs. Hint 1. The combining word osteo is used to denote bone. ANSWER: 3398 Character(s) remaining Bone deposition, mineral deposition or ossification are terms used to describe the process of adding new bones tissue to an injured or weak area. the cells that function in this process is the osteoblast. This bone secretes both type I collagen fibers and osteoid ground substances via exocytosis. the osteoid ground substance will become hardened (ossified) with the addition of calcium and phosphorus Credit granted by instructor; correct answer displayed 26/63 12/2/21, 12:01 AM Lab 8 Assignment Part M In the final stage of bone repair, some of the osseous tissue must be broken down and removed. What term is used to define the breaking down of osseous tissue? Which bone cell would be best suited for this task? Hint 1. The suffix -clast means "something that breaks." ANSWER: 3620 Character(s) remaining Bone or mineral resorption is the term used to describe dissolving away osseous tissue. the osteoclast (bone breaker) secrets substances by exocytosis that dissolve the bone matrix Credit granted by instructor; correct answer displayed Part N The extracellular matrix (ECM) of bone is considered to be a composite material made up of organic and inorganic matter. What makes up the organic and inorganic portions of the matrix? Describe the cellular mechanism involved in breaking down this matrix; include the bone cell required for the process. Hint 1. A composite material is one that is made up of at least two parts. ANSWER: 3197 Character(s) remaining Collagen fibers, glycosaminoglycans and glycoproteins are organic while hydroxyapatite (crystallized calcium and phosphate ) makes up the most of the inorganic portion - Acid phosphates secreted by osteoclast target collagen fibers for destruction. The osteoclasts has hydrogen pumps present in high numbers on the ruffled border. As hydrogen ions are pumped out they combine with chloride ions forming hydrochloric acid (HCL) the acid acts directly on hydroxyapatite to liberate calcium. Additionally HCl increases the solubility of calcium so it can be transferred back into the blood for others Credit granted by instructor; correct answer displayed 27/63