Human Anatomy and Physiology : Skeletal and Articular Physiology

Study concepts, example questions & explanations for Human Anatomy and Physiology

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Example Questions

Example Question #1 : Help With General Bone And Joint Structures

What type of bone cells secrete osteoid and synthesize bone?

Possible Answers:

Hydroxyapatite

Osteocytes

Osteoblasts

Osteoclasts

Correct answer:

Osteoblasts

Explanation:

Osteoblasts are differentiated non-dividing cells that secrete osteoid, an organic matrix material, that becomes mineralized forming bone. These are the cells primarily responsible for building bone.

Osteocytes are osteoblasts that become trapped in lacunae by bony matrix. These cells still maintain the bone environment, but do not actively build or modify bone a significant amount.

Osteoclasts resorb bone by breaking down the crystalline matrix.

Deposition of the calcium phosphate salt hydroxyapatite leads to mineralization of the bony matrix. 

Example Question #1 : Skeletal And Articular Physiology

Which of the following is NOT an example of a synarthrosis? 

Possible Answers:

Symphysis

Diarthrosis

Synostosis

Syndesmosis

Correct answer:

Diarthrosis

Explanation:

A synarthrosis is a type of joint that permits little or no movement. Syndesmoses, synostoses, and symphyses are all examples of synarthroses. Syndesmoses are joined by an interosseous ligament. Joints between carpals and tarsals are mostly syndesmoses. Synostoses is a joint formed from the fusion of two bones, generally in an atypical fashion. Symphyses can be synarthroses or amphiarthorses and are characterized by a fibrocartilage band between bones, such as in the pubic symphysis.

A diarthrosis, also known as a synovial joint, is the most common joint type in humans and allows free bone movement. The knee and elbow are examples of a diarthroses or synovial joints.

Example Question #1 : Bone And Articular Physiology

Which of the following cannot be used to describe a joint?

Possible Answers:

Saddle

Syndesmoses

Swinging

Synovial

Correct answer:

Swinging

Explanation:

The joints, or articulations, of the body can be classified according to several different criteria. They can be named for their structure, type of motion, or range of motion.

Synovial joints are determined by the joint structure. All synovial joints are housed within a joint capsule and contain synovial fluid. Joints between long bones are almost always synovial joints.

Syndesmoses are defined by their range of motion, and have very small, if any, motility. Syndesmoses are joined by interosseous ligaments, such as those between the carpals of the wrist.

Saddle joints are defined the type of motion allowed at the joint. Saddle joints are biaxial, allowing flexion, extension, adduction, and abduction, but no axial rotation. The pollical (thumb) joint is a saddle joint. While a "swinging joint" would seem to indicate a joint defined by its type of motion, no such joint exists in anatomical terms.

Example Question #2 : Skeletal And Articular Physiology

What is the name of the concentric rings formed by osteoblasts in bone tissue?

Possible Answers:

Lamellae

Trabeculae

Canaliculi

Lacunae

Epiphyses

Correct answer:

Lamellae

Explanation:

Osteoblasts will lay down bone matrix around previously formed bone tissue. This forms concentric rings of bone tissue referred to as lamellae.

Lacunae are small gaps in the hydroxyapatite matrix that house the osteocytes. Trabeculae are thin bony structures that span and branch within the region of spongy bone. Canaliculi are small channels between lacunae that allow for cellular nourishment and communication. The epiphyses are the ends of the bone (as opposed to the diaphysis, or bone shaft).

Example Question #74 : Musculoskeletal Physiology

What is the medullary cavity?

Possible Answers:

The end of a long bone

Dense outer layer of bone

Shaft of a long bone

The marrow cavity

Correct answer:

The marrow cavity

Explanation:

The medullary cavity is the bone marrow cavity contains red and/or yellow bone marrow; red bone marrow is the site of hematopoiesis. The end of a long bone is known as the epiphysis. Compact bone (cortical bone) is the dense outer layer of bone. The diaphysis is the shaft of a long bone.

Example Question #5 : Help With General Bone And Joint Structures

In long bones, which of the following areas has the greatest metabolic activity during growth?

Possible Answers:

Diaphysis

Metaphysis

Apophysis

Periosteum 

Epiphysis 

Correct answer:

Metaphysis

Explanation:

Metaphysis: has the greatest metabolic activity, and contains the epiphyseal plate, which is replaced by the epiphyseal line

Diaphysis: mechanical support, site of bone marrow and muscle attachments

Apophysis: functions as a site for attachments of ligaments and tendons

Epiphysis: at the end of long bones

Periosteum: covers the diaphysis and parts of metaphysis. 

Example Question #1 : Help With Adult Osteogenesis

Which of the following statements about osteogenesis is false?

Possible Answers:

Osteogenic cells in the periosteum surround hyaline cartilage on the epiphyses of long bones

Osteoblasts hollow out the center of the bone

Osteoblasts are responsible for allowing the bone to thicken

Cartilage is replaced with bone tissue in order for long bones to lengthen

Correct answer:

Osteoblasts hollow out the center of the bone

Explanation:

Bone growth has multiple steps that allow growth in both length and width. One thing to remember is the functions of the bone cells during growth and development. Osteoclasts are responsible for "hollowing out" the center of long bones, which makes for larger cavities within the diaphysis. Osteoblasts, on the other hand, are responsible for laying down additional bone matrix on the outsides of the bones.

As bone cells mature, they become further embedded within subsequent layers of the bony matrix. Osteogenic cells, which give rise to osteoblasts, are located in the outer periosteum of the bone. When damage occurs to the bone, osteogenic cells differentiate and begin repairing the bony matrix from the outside.

Example Question #1 : Skeletal And Articular Physiology

What is the piezoelectric effect?

Possible Answers:

Negative potential resulting in bone deposition

Positive potential resulting in bone resorption

Electric potential that is generated in response to mechanical stress

Orthodonture or bone remodeling

Correct answer:

Electric potential that is generated in response to mechanical stress

Explanation:

Bone is a dynamic tissue that remodels under mechanical stress, or orthodonture. Mechanical stress in bone generates electric potential via the piezoelectric effect. Negative potential results in bone deposition (bone is laid down) whereas positive potential results in bone resorption (bone is broken down).

Example Question #2 : Skeletal And Articular Physiology

Which of the following is NOT a zone of the epiphyseal growth plate?

Possible Answers:

Zone of proliferation

Zone of calcification

Zone of cartilage

Zone of maturation

Correct answer:

Zone of cartilage

Explanation:

Histologically, the epiphyseal growth plate is divided into five zones. From epiphysis to diaphysis they are the resting zone, zone of proliferation, zone of maturation, zone of calcification, and zone of ossification. At the growth plate, cartilage is constantly being developed into the bone of the diaphysis. The stages of this process align with the regions of the epiphyseal plate. The resting zone houses quiescent chondrocytes that are not yet active in bone synthesis. The zone proliferation is characterized by chondrocyte mitosis and replication. These cells then develop and grow with in the zone of maturation. Eventually the cells reach their maximum growth and undergo apoptosis to release cell contents in the zone of calcification. This prevents cartilage from infiltrating the bony region of the diaphysis. The chondrin matrix begins to calcify in this zone as well. As calcification progresses and the organic cartilage matrix is replaced by bony hydroxyapatite mineral in the zone of ossification, the epiphyseal plate completely replaces the original chondrocytes with bone.

As more bone is produced, the epiphyseal plate is pushed farther and farther away from the midpoint of the bone. The lengthening of the bone ends when the zones of the epiphyseal plate fuse and further growth becomes impossible.

Example Question #3 : Skeletal And Articular Physiology

Which of the following cell types synthesizes hydroxyapatite?

Possible Answers:

Osteoblasts

Satellite cells

Common lymphoid progenitor cells

Osteoclasts

None of these

Correct answer:

Osteoblasts

Explanation:

There are three primary types of bone cell: osteoblasts, osteocytes, and osteoclasts. Osteoblasts are responsible for creating new bone by sequestering minerals and generating new hydroxyapatite matrix. Osteoclasts break down this matrix, releasing the minerals into the blood. Osteocytes are mature osteoblasts that have become embedded in the matrix of the bone and serve primarily for communication purposes.

Satellite cells are located at the periphery of muscle cells and are capable of dividing and giving rise to new myoblasts. Satellite cells are, essentially, adult muscle stem cells. Common lymphoid progenitor cells are another type of adult stem cell, housed in red bone marrow, and are responsible for regenerating the erythrocyte population of the body, as well as producing lymphocytes.

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