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Example Questions
Example Question #291 : Systems Biology And Tissue Types
After a bone fracture, what cells function to repair the damage of the injury?
Osteodentins
Osteons
Osteoblasts
Osteocytes
Osteoclasts
Osteoblasts
After a fracture, osteoblasts—bone forming cells—start to produce new bone through the process of osteogenesis. They produce compact bone and fuse the bone segments together.
An osteocyte is a mature bone cell. Osteoclasts are cells that dissolve the bony matrix. An osteon is a unit of hard bone with embedded osteocytes that surround a central (Haversian) canal containing a capillary. Osteodentin is calcification resembling bone that forms very rapidly in response to trauma, such that cells and blood vessels are incorporated.
Example Question #307 : Biology
What structure serves to connect different Haversian canals and provides a means for communication and nutrient transport?
Volkmann canals
Canaliculi
Lymph vessels
Trabeculae
Osteoarterials
Volkmann canals
Volkmann canals connect different Haversian systems, allowing the osteocytes within their lacuna to communicate via chemical and cellular signalling.
Canaliculi form a "spiderweb" of tiny channels to facilitate communication between osteocytes within a single Haversian system, but do not permit communication between different osteons.
Example Question #308 : Biology
An individual with long cancer is advised to undergo radiation therapy. The radiation therapy destroys all of his bone marrow. Which of the following will be deficient in this individual?
Myogenesis
Neurogenesis
Osteogenesis
Erythropoiesis
Epithelial tissue synthesis
Erythropoiesis
The primary function of red bone marrow is to make red blood cells in the process known as erythropoiesis. If all bone marrow is destroyed, then an individual will lose the ability to make red blood cells.
Myogenesis is performed by muscle fibers and satellite cells. Osteogenesis is performed by osteoblasts. Neurogenesis primarily occurs during early development and is performed by neural stem cells.
Example Question #21 : Bone
What is the main function of red bone marrow?
It creates osteoblasts
It carries out erythropoesis
It stores fat cells
It helps with immunity
It breaks down worn out red blood cells
It carries out erythropoesis
Red bone marrow is primarily located in flat bones (such as the sternum and pelvis) and in the epiphyses of long bones. It is responsible for producing red blood cells, a process known as erythropoiesis. At birth, all bones of the human skeleton carry out erythropoesis, but many bones stop this function as the newborn ages.
It is important to note that yellow bone marrow is found in the medullary cavity within the diaphyses of long bones and assists in fat storage.
Example Question #331 : Mcat Biological Sciences
Hematopoietic stem cells are the cells that are targeted in bone marrow transplants. These stem cells are found in the red marrow of the bone. Which part of a long bone would be targeted in order to extract hematopoietic stem cells for a transplant?
The medullary cavity
The epiphysis
The periosteum
The diaphysis
The epiphysis
Red bone marrow is filled with hematopoietic stem cells. Red bone marrow is found in the heads, or epiphyses, of long bones. Yellow marrow fills the medullary cavity and consists mostly of fats. The diaphysis contains the medullary cavity and therefore contains no red marrow. The periosteum has no marrow in it at all.
Example Question #21 : Bone
Hypoxia would result in which of the following?
Yellow bone marrow being converted to red bone marrow for increased red blood cell production
The ratio of spongy bone to compact bone being increased to accommodate storage of red blood cells
Blood vessel density being increased through the spongy bone for increased oxygen delivery
Red bone marrow being converted to adipocytes for increased energy storage
Yellow bone marrow being converted to red bone marrow for increased red blood cell production
Since red bone marrow is a site of red blood cell and platelet production, hypoxia (low oxygen) would result in an increase in red marrow and therefore RBC concentration. Yellow bone marrow (typcially adipocyte-filled) can be converted into red bone marrow under conditions of low oxygen or blood loss.
Example Question #1 : Other Bone Concepts
Which of the following is not a component of a typical long bone?
I. A periosteal and soft tissue envelope
II. Nutrient artery foramina
III. A metaphysis
IV. Articular cartilage
V. All of these are normal components of a long bone
IV
II
III
I
V
V
Bone is living tissue and it therefore requires a blood supply, which is brought to the bone itself by the vital soft tissue envelope around it. Articular cartilage routinely caps the epiphysis (end) of a long bone. The region adjacent to the epiphysis is termed the metaphysis, whereas the shaft of a long bone is the diaphysis.
Example Question #1 : Other Bone Concepts
Which of the following is false regarding compact bone and spongy bone?
I. Compact bone is also called cancellous bone
II. Spongy bone has a haversian system
III. Compact bone is the site of red blood cell development
III only
II and III
I and III
I, II, and III
I, II, and III
There are two main types of structural configurations that form bone tissue: compact bone (or cortical bone) and spongy bone (or cancellous bone). Compact bones function to maintain the structure of the body and release chemical elements, such as calcium. Compact bones are characterized by their specialized haversian system, or osteon structure. It is the fundamental unit of compact bone structure and consists of a haversian canal (a tunnel that is created by osteoclast activity to remove bone tissue) and lamellae (layers of compact bone tissue organized in concentric circles). Spongy bones do not contain these haversian systems.
Spongy bone is relatively flexible bone tissue that is found at the end of long bones (the epiphyses). One of their main functions is to develop red blood cells, as they house the red bone marrow responsible for erythropoiesis and erythrocyte maturation. Compact bones, on the other hand, contain yellow bone marrow that functions to store fat and adipose tissue.
Example Question #2 : Other Bone Concepts
Osteocytes exchange nutrients through which structures in bone tissue?
Haversian canals
Canaliculi
Lacunae
Lamellae
Canaliculi
Osteocytes are differentiated osteoblasts that have become imbedded in hydroxyapatite bone matrix. The osteocytes are found in small gaps in bone matrix called lacunae and exchange nutrients with the blood using small canals called canaliculi. Lamellae are the concentric regions of osteocytes that are arranged around the central Haversian canal. The canal houses blood vessels and nerves to nourish and stimulate the osteocytes via the canaliculi.
Example Question #112 : Musculoskeletal System And Muscle Tissue
Which of the following is not a function of the skeletal system?
Fat storage
Red blood cell formation
Mineral homeostasis
B-cell and T-cell development
B-cell and T-cell development
The skeletal system is responsible for a variety of functions in the body. Long bones contain both red and yellow bone marrow, which are the sites for fat storage and hematopoeisis respectively. Bones are also responsible for the storage of calcium and phosphate, which can be released in order to maintain normal levels in the blood.
White blood cells are derived from stem cells in the bone marrow. B-cells continue to develop in the bone marrow, but T-cells develop in the thymus.
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