A&p Exam 2

A herniated disc refers to a condition where the soft center of a spinal disc pushes through a crack in the tougher exterior, causing pain and discomfort. The vertebral foramen is the opening between the vertebrae through which the spinal cord passes. If a herniated disc extends into the vertebral foramen, it can potentially compress or damage the spinal cord, leading to various neurological symptoms and impairments.

The sternum is a flat bone, as it is a broad and thin bone that provides protection for the organs in the chest. On the other hand, the atlas is an irregular bone, as it does not fit into any other category of bone shape. It is the first cervical vertebra and is responsible for supporting the skull and allowing for the nodding motion of the head.

Both Haversian canals and Volkmann's canals contain blood vessels and nerves. Haversian canals are found in compact bone and contain blood vessels that supply nutrients and oxygen to the osteocytes. Volkmann's canals, on the other hand, are channels that connect the Haversian canals and allow blood vessels and nerves to travel between them. Therefore, both A (blood vessels) and C (nerves) are present in both types of canals.

Keratin is a protein found in hair, skin, and nails, but it is not a component of bone matrix. Bone matrix is primarily composed of collagen, calcium phosphate, and minerals such as fluoride, sodium, potassium, and magnesium. Keratin does not play a role in bone structure or composition.

The sagittal suture is the correct answer because it is the suture that separates the parietal bones. The coronal suture separates the frontal bone from the parietal bones, the lambdoidal suture separates the occipital bone from the parietal bones, and the squamous suture separates the temporal bone from the parietal bones. Therefore, none of the other options are correct in this case.

The occipital bone is a cranial bone that forms the lambdoid suture with the parietal bone. The lambdoid suture is located at the back of the skull and connects the occipital bone with the parietal bones. This suture helps to provide stability and support to the skull. The frontal bone is located at the front of the skull, the sphenoid bone is located in the middle of the skull, the ethmoid bone is located between the eyes, and the mandible is the lower jaw bone. Therefore, the occipital bone is the correct answer as it forms the lambdoid suture with the parietal bone.

The correct answer is humerus because the brachium region refers to the upper arm, and the humerus is the bone located in the upper arm. The radius and ulna are bones in the forearm, while the tibia and femur are bones in the lower leg and thigh respectively.

The superiormost region of the sternum is referred to as the manubrium. The manubrium is the upper part of the sternum that is located near the base of the neck. It is shaped like a trapezoid and articulates with the clavicles and the first pair of ribs. The manubrium plays a crucial role in protecting the organs in the thoracic cavity and providing attachment points for various muscles and ligaments.

The patella, also known as the kneecap, is a good example of a sesamoid bone. Sesamoid bones are small, round bones that are embedded within tendons, where they act to protect the tendon and increase its mechanical advantage. The patella is located within the tendon of the quadriceps muscle and helps to increase the leverage and efficiency of the muscle in extending the leg. Therefore, the patella fits the description of a sesamoid bone.

Intramembranous ossification is the process by which flat bones of the skull are formed from embryonic mesenchyme. This process results in the formation of a sandwich-like structure consisting of compact bone on the outer layers and spongy bone on the inner layers. Therefore, the correct answer is "flat, mesenchyme, compact, spongy."

The endosteum is a thin layer of reticular connective tissue that lines the marrow cavity within bones. It is responsible for providing nutrients to the bone tissue and is involved in the process of bone remodeling.

The vertebral column of an adult consists of 24 separate bones and 9 fused bones. The separate bones, known as vertebrae, are stacked on top of each other and provide flexibility and support to the spine. The fused bones, called sacrum and coccyx, are formed by the fusion of several vertebrae and provide stability to the pelvis. Together, these bones make up the vertebral column, which protects the spinal cord and allows for movement and posture.

Osteocytes are trapped cells that reside in lacunae, which are connected by cannaliculi. This arrangement allows for communication and exchange of nutrients and waste between osteocytes. Osteoblasts are responsible for bone formation and do not reside in lacunae. Osteoclasts are responsible for bone resorption and do not reside in central canals. Osteons are structural units of compact bone and do not contain lacunae. Therefore, the correct answer is osteocytes, lacunae, cannaliculi.

Interstitial growth refers to the growth of bones in length, which occurs at the epiphyseal plate. This type of growth involves the production of new bone tissue in layers called circumferential lamellae, which contribute to the width of the bone. Therefore, the correct answer is "length, epiphyseal plate, width, circumferential lamellae."

The ilium, acetabulum, and obturator foramen are all structures that are associated with the pelvis. The ilium is one of the three bones that make up the hip bone, while the acetabulum is the socket of the hip joint. The obturator foramen is a large hole in the hip bone. On the other hand, the olecranon is a bony prominence of the ulna in the forearm, which is not associated with the pelvis. Therefore, the correct answer is olecranon.

A ball and socket joint allows for a wide range of movement, including abduction and adduction. This type of joint consists of a ball-shaped end of one bone fitting into a socket-shaped cavity of another bone. The rounded head of the bone allows for movement in multiple directions, making it suitable for abduction (movement away from the body) and adduction (movement towards the body).

The foramen magnum is not part of the temporal bone. The temporal bone consists of several components including the zygomatic process, external auditory meatus, mastoid process, and styloid process. However, the foramen magnum is located at the base of the skull and is part of the occipital bone, not the temporal bone. It is the large opening through which the spinal cord passes.

The correct answer is primary ossification center. During endochondral ossification, the process by which bones develop from cartilage, chondrocytes in the middle of the bone model start to enlarge. This area is known as the primary ossification center, where bone tissue begins to replace the cartilage. It is the first site of bone formation in the developing bone. The secondary ossification center refers to the additional areas where bone formation occurs later in the development of the bone. Epiphysis refers to the end of a long bone, trabeculae are the thin, branching structures that make up spongy bone, and metaphysis is the region of a long bone between the epiphysis and the diaphysis.

Osteoblasts are primarily responsible for bone/mineral deposition. They are bone-forming cells that synthesize and secrete the organic components of the bone matrix. Osteoblasts play a crucial role in bone growth and remodeling by depositing minerals such as calcium and phosphate, which contribute to the strength and structure of the bone. Osteoclasts, on the other hand, are responsible for bone resorption, breaking down and removing old or damaged bone tissue. Chondrocytes and chondroblasts are cells found in cartilage, not bone. Therefore, the correct answer is osteoblast.

The coracoid process is a bony projection on the scapula (shoulder blade) and is not involved in the creation of the temporomandibular joint. The temporomandibular joint is formed by the mandibular condyle (part of the lower jaw bone) articulating with the mandibular fossa (part of the temporal bone). The sphenomandibular ligament and stylomandibular ligament are also involved in the stability and movement of the temporomandibular joint. Therefore, the coracoid process is the structure that does not help create the temporomandibular joint.

The first rib attachment is a type of synchondrosis, which is a type of joint where the connecting material between the bones is hyaline cartilage.

The correct answer is both C and D. This means that both the fibrous joint being the temporomandibular joint and the synovial joint being the gomphoses are matched incorrectly. This suggests that the temporomandibular joint is not a fibrous joint, and the gomphoses is not a synovial joint.

The skeletal system performs several functions, including blood formation, protection, movement, and electrolyte balance. Therefore, the correct answer is "none of the above" as all of the mentioned functions are indeed performed by the skeletal system.

The zygomatic bone is the only bone listed that does not contain sinuses. The frontal bone, sphenoid bone, maxilla, and ethmoid bone all have sinuses. Sinuses are air-filled cavities within the bones that help reduce the weight of the skull and provide resonance to the voice. However, the zygomatic bone, also known as the cheekbone, does not have sinuses. It is a facial bone that forms part of the eye socket and cheek region.

The calcaneus is the largest tarsal bone and forms the heel of the foot.

Kyphosis is an abnormal curvature of the vertebral column that causes a rounded or hunched back. It is commonly seen in osteoporosis, a bone disease characterized by severe loss of bone density. Osteoporosis weakens the bones, making them more prone to fractures and deformities such as kyphosis. Therefore, the correct answer is kyphosis, osteoporosis.

The trochanters and tuberosities of the femur are bony prominences that serve as attachment points for various muscles. These muscle attachments are important for the movement and stability of the hip joint. Therefore, it is likely that the trochanters and tuberosities of the femur play a role in muscle attachment.

Calcitonin is the correct answer because it reduces osteoclast activity, which in turn leads to less bone resorption. Osteoclasts are cells responsible for breaking down bone tissue, and when their activity is reduced, less bone is broken down and resorbed. Calcitonin helps to regulate calcium levels in the body by inhibiting osteoclasts and promoting bone formation, ultimately leading to a decrease in bone resorption.

Parathyroid hormone (PTH) plays a crucial role in regulating calcium levels in the body. It stimulates osteoclasts, which are responsible for breaking down bone tissue and releasing calcium into the bloodstream. However, the given answer states that reduced osteoclast activity does not result from PTH secretion. This means that PTH does not inhibit or decrease the activity of osteoclasts. Instead, it promotes their activity to release more calcium into the bloodstream. Therefore, the correct answer suggests that reduced osteoclast activity is not a result of PTH secretion.

The maxilla is the correct answer because it is a bone that forms parts of both the orbital (eye) and oral cavities. It is a paired bone located in the upper jaw and forms the upper portion of the mouth, including the roof of the mouth (hard palate) and the floor of the eye socket (orbital floor). The maxilla also houses the upper teeth and plays a role in facial structure and support.

Hypocalcemia is the result of decreased blood calcium and causes excitation of muscles leading to spasms or cramps. When there is a decrease in blood calcium levels, it disrupts the normal balance of calcium ions in the body. This imbalance can lead to increased excitability of muscles, causing them to contract and spasm. Therefore, the correct answer is "decreased, excitation".

The capitulum articulates with the radius, while the trochlea articulates with the ulna.

The fibula is a non-weight bearing bone found in the crural region that helps stabilize the ankle.

The correct answer is "dens, transverse ligament." The dens is a peg-shaped bone structure located on the axis bone, and it acts as a pivot for the atlantoaxial joint. It is held in place by the transverse ligament, which helps to stabilize the joint and prevent excessive movement.

The interosseus membrane is a syndesmosis and unites the radius and ulna in the antebrachium region.

All of the ligaments mentioned in the options support the glenohumeral joint. Therefore, none of these ligaments do not support the glenohumeral joint.

A severe knee injury can affect various ligaments in the knee, including the tibial collateral ligament, anterior cruciate ligament, and posterior cruciate ligament. However, the anular ligament is not located in the knee joint. It is a ligament found in the elbow joint, and therefore, it would not be affected by a severe knee injury.

Osteoblasts are responsible for bone formation and the secretion of osteocalcin. Osteoblasts are specialized cells that synthesize and deposit new bone tissue, which helps in the growth and repair of bones. Osteocalcin is a protein hormone that is produced by osteoblasts and plays a role in regulating bone formation and mineralization. It helps in the binding of calcium ions to the bone matrix, which is essential for maintaining bone strength and density.

The correct answer is syndesmoses. Synostoses, synarthroses, amphiarthroses, and diarthroses are all major categories of joints. Synostoses are immovable joints where bones fuse together, synarthroses are slightly movable joints, amphiarthroses are freely movable joints, and diarthroses are freely movable joints with a synovial cavity. Syndesmoses, on the other hand, are a type of fibrous joint where bones are connected by ligaments, allowing for limited movement.

Synovial fluid is not considered an accessory structure of diarthroses because it is not a physical structure that is directly associated with the joint. Instead, synovial fluid is a lubricating substance that is found within the joint cavity. It helps to reduce friction between the articulating surfaces of the bones and nourishes the cartilage. While tendons, bursae, ligaments, and tendon sheaths are all accessory structures that support and protect the joint, synovial fluid serves a different function in facilitating smooth joint movement.

Calcitriol acts as a hormone that raises blood calcium concentration by increasing calcium resorption from the skeleton, increasing calcium absorption from the small intestine, and promoting kidney reabsorption of calcium ions. However, it does not inhibit osteoclast activity. Osteoclasts are responsible for breaking down bone tissue, and inhibiting their activity would actually decrease calcium resorption from the skeleton. Therefore, the correct answer is inhibiting osteoclast activity.

The middle cranial fossa is the correct answer because it is the structure that holds or supports the temporal lobes of the brain. The cranial fossae are depressions in the base of the skull that provide protection and support for various parts of the brain. The middle cranial fossa specifically accommodates the temporal lobes, which are responsible for functions such as memory, language, and emotion.

The clavicle articulates with the manubrium and scapula. The clavicle, also known as the collarbone, is a long bone that connects the sternum (specifically the manubrium) to the scapula. It forms a joint with the manubrium at the sternoclavicular joint, and with the scapula at the acromioclavicular joint. This allows for movement and stability of the shoulder complex.

When the palm faces rearward or downward, the arm is said to be pronated. This occurs when the radius and ulna are crossed.

The correct answer is resistance-effort-fulcrum; humeroulnar. In a third class lever, the resistance is located between the effort and the fulcrum. The humeroulnar joint system in the body is an example of a third class lever, where the resistance is the weight of the forearm, the effort is applied by the biceps muscle, and the fulcrum is the elbow joint.

The humeroulnar joint is a hinge joint that allows movement in only one plane, making it monoaxial. This type of joint allows for flexion and extension movements, similar to the opening and closing of a door.

The malleoli are bony processes of the tibia and fibula that overhang the talus, preventing side-side/lateral movement.

Red marrow does not play a role in the process of mineral resorption. Mineral resorption is a process carried out by osteoclasts, which are responsible for breaking down and absorbing minerals from bone. Acid and the ruffled border are also involved in this process. Red marrow, on the other hand, is responsible for the production of red blood cells and is not directly involved in mineral resorption.

The ulnar collateral ligament is often damaged in baseball pitchers requiring Tommy John reconstruction surgery to correct. This ligament is located on the inside of the elbow and is responsible for stabilizing the joint during throwing motions. Over time, the repetitive stress and strain placed on the ligament can lead to tears or complete ruptures. Tommy John surgery involves replacing the damaged ulnar collateral ligament with a tendon from another part of the body to restore stability and function to the elbow joint.

The mechanical advantage of a joint is calculated by dividing the length of the effort arm by the length of the resistance arm. In this case, the effort arm is 50 mm and the resistance arm is 400 mm. Therefore, the mechanical advantage is 50/400 = 0.125. A mechanical advantage of 0.125 means that the joint provides a speed advantage, as the effort arm is shorter than the resistance arm. This means that for every unit of force applied, the joint can move the load at a faster speed.