Musculoskeletal High-Yield Biomedical Sciences Flashcards

Biomedical Flashcards

What are the two main parts of the skeleton?

Axial skeleton and Appendicular skeleton.

From which embryonic layer are bones primarily derived?

Mesoderm.

Name the process through which most bones develop.

Endochondral ossification.

Which bones undergo intramembranous ossification?

Clavicles and flat bones such as parietal and mandible.

What is the neurocranium?

The part of skull that encases the brain, consisting of membranous and cartilaginous components.

At what age do the skull sutures typically close?

By 18 months.

What structure connects the ribs to the sternum?

Costal cartilage.

What encompasses the embryological development of the spine?

Vertebrae development from somites, which undergo sclerotome resegmentation.

What happens during the sclerotome resegmentation of vertebrae?

Cephalic portion fuses with the caudal portion of neighboring somites.

What are the components of the primary spinal curves?

Thoracic and sacral kyphosis.

What are dermatomes?

Segments of skin innervated by specific spinal nerves.

What are the three muscle types and their embryonic origins?

Skeletal muscle from paraxial mesoderm, cardiac muscle from visceral mesoderm, and smooth muscle from both visceral mesoderm and ectoderm.

How do muscle fibers (myofibrils) form?

Myoblasts fuse to form multinucleated myotubes that aggregate into muscle fibers.

What is the function of the Apical Ectodermal Ridge (AER)?

It induces mesenchyme to remain undifferentiated for limb development.

At what week do limb buds become visible?

At the end of week 4.

What is the composition of hyaline cartilage during bone development?

It serves as a model for bone formation.

What type of joints are classified as synarthrosis?

Fibrous joints.

What categorizes synovial joints?

Joint capsule connecting bones, filled with synovial fluid.

What type of bone is primarily found in the axial skeleton?

Red marrow.

What are osteons?

Structural units of compact bone containing Haversian canals.

What happens to trapped osteoblasts in bone matrix?

They mature into osteocytes.

What structures form joint ligaments?

Dense connective tissue.

What are the two growth patterns experienced by articular cartilage?

Appositional and interstitial growth.

What does Wolff’s Law state?

Bones remodel in response to the weight they bear.

What is the role of proteoglycans in cartilage?

To provide the cartilage with structural integrity and hold water.

How do skeletal and smooth muscle contractions differ?

Skeletal muscle contractions are voluntary while smooth muscle contractions are involuntary.

What does the term 'myogenic' refer to?

The ability of muscle cells to contract independently.

What muscle forms the anatomical connection between the arm and shoulder?

Deltoid.

What are the major muscles responsible for shoulder abduction?

Supraspinatus and deltoid.

Which nerve innervates the biceps muscle?

Musculocutaneous nerve.

What is included in the brachial plexus?

Spinal nerves C5-T1 which innervate the upper limb.

What is the significant function of the iliopsoas muscle?

Hip flexion.

What structure connects the biceps femoris to the tibia?

The fibula.

What attaches muscles to bones?

Tendons.

What covers the ends of long bones at a synovial joint?

Articular cartilage.

What type of cartilage is most commonly found in joints?

Hyaline cartilage.

What is the primary function of osteoclasts?

To break down bone matrix.

Name the major types of fiber present in connective tissues.

Collagen and elastin.

What nerve is responsible for shoulder elevation?

Accessory nerve (CN XI).

Identify the tensile strength of different types of cartilage.

Fibrocartilage has the greatest tensile strength.

What are the types of synovial joints based on movement?

Hinge, pivot, plane, ball and socket, condyloid, and saddle joints.

What are the primary actions of the leg muscles?

Flexion, extension, rotation.

What is the role of the lateral pectoral nerve?

Innervates pectoralis major and minor.

What shape are skeletal muscle fibers compared to smooth muscle fibers?

Skeletal muscle fibers are long and cylindrical, smooth muscle fibers are fusiform.

What is a helpful hint for muscle origin and insertion?

Muscles are generally named by the places they connect to.

What is the embryological origin of skeletal muscle?

Skeletal muscle originates from paraxial mesoderm which forms somites.

What is myogenesis?

Myogenesis is the process of muscle formation.

What are myoblasts?

Myoblasts are mononucleated cells that undergo division and fuse to form multinucleated myotubes.

What is the role of osteoblasts?

Osteoblasts build bone by forming bone tissue and secreting collagen.

What is the process of endochondral ossification?

Endochondral ossification involves the conversion of a cartilaginous model of the bone into bone tissue, primarily in long bones.

What is membranous ossification?

Membranous ossification is the direct formation of bone from mesenchyme without a cartilage model, seen in facial bones and the clavicle.

What markers indicate osteoblast activity?

Bone alkaline phosphatase (ALP), osteocalcin, and pro-peptides of type 1 collagen.

What is the function of osteoclasts?

Osteoclasts break down bone tissue by secreting acids and enzymes.

How does parathyroid hormone (PTH) affect bone?

PTH increases calcium levels in the serum by stimulating osteoclast activity and promoting calcium reabsorption in the kidneys.

What is the effect of estrogen on bone metabolism?

Estrogen inhibits apoptosis in osteoblasts and promotes apoptosis in osteoclasts, thus maintaining bone density.

What type of muscle is characterized as striated and voluntary?

Skeletal muscle is characterized as striated and voluntary.

How are skeletal muscle fibers organized?

Skeletal muscle fibers are organized into bundles called fascicles, surrounded by connective tissue layers.

What is the functional unit of a muscle fiber?

The sarcomere is the functional unit of a muscle fiber.

What defines the H-zone in a sarcomere?

The H-zone is the part of the myosin filament that does not overlap with actin.

What type of muscle fiber is most resistant to fatigue?

Type IIA muscle fibers are resistant to fatigue due to their high oxidative capacity.

What characterizes compact bone?

Compact bone is composed of densely packed osteons, and it forms the outer layer of bones.

What is spongy bone?

Spongy bone is lighter and less dense, consisting of trabeculae arranged to provide strength.

What are synovial joints?

Synovial joints are joints that contain a joint cavity filled with synovial fluid and permit free movement.

What are the two main types of movements allowed by synovial joints?

Synovial joints allow for uniaxial (one plane) and multiaxial (multiple planes) movements.

What is Hilton's Law?

Hilton's Law states that the nerves supplying a joint also supply the muscles moving the joint and the skin covering their distal attachments.

What comprises the shoulder girdle?

The shoulder girdle includes the scapula and clavicle.

What is the role of the rotator cuff muscles?

The rotator cuff muscles stabilize the shoulder joint and allow for various movements.

What is the main function of the hip joint?

The hip joint allows for flexion, extension, adduction, abduction, and rotation.

What ligaments stabilize the knee joint?

The knee joint is stabilized by the anterior cruciate ligament (ACL), posterior cruciate ligament (PCL), and collateral ligaments.

What is the primary muscle group responsible for knee extension?

The quadriceps muscle group, including the rectus femoris and vastus muscles.

What is osteoarthritis?

Osteoarthritis is a degenerative joint disease characterized by mechanical wear and tear of cartilage.

What defines rheumatoid arthritis?

Rheumatoid arthritis is an autoimmune condition that causes inflammation and erosion of joints.

What is the typical presentation of gout?

Gout presents as acute inflammatory arthritis caused by the deposition of urate crystals in joints.

What is the significance of the lumbar spine's curvature?

The lumbar spine's lordotic curvature aids in weight distribution and mobility.

What are the common injuries related to the brachial plexus?

Common injuries include Erb's Palsy and Klumpke Palsy due to traction or nerve damage.

What are the symptoms of carpal tunnel syndrome?

Symptoms include numbness, tingling, and pain in the median nerve distribution in the hand.

What are the differences between the types of muscle contraction?

Skeletal muscle contraction involves troponin and tropomyosin; smooth muscle contraction is mediated by MLCK and calmodulin; cardiac muscle contraction has a different mechanism involving calcium entry.

What are common causes of septic arthritis?

Common causes include Staphylococcus aureus and Neisseria gonorrhoeae.

What is the effect of immobilization on bones?

Immobilization leads to bone loss due to decreased mechanical loading and reduced osteoblast activity.

What is Paget's disease?

Paget's disease is a localized disorder of bone remodeling characterized by increased osteoclast and osteoblast activity.

What factors contribute to the development of osteoporosis?

Factors include aging, hormonal changes, low physical activity, and nutritional deficiencies.

What is the most common type of fracture in children?

Greenstick fractures are the most common type in children.

What happens during a muscle fiber contraction?

During contraction, cross-bridges form between actin and myosin, leading to muscle shortening.

What is the purpose of calcium in muscle contraction?

Calcium binds to troponin, causing a conformational change that allows myosin to bind to actin.

What are the roles of the different types of muscle fibers?

Type I fibers are slow-twitch and fatigue-resistant, while Type II fibers are fast-twitch with rapid fatigue.

What markers indicate muscle damage?

Increased creatine kinase (CK) and aldolase levels indicate muscle damage.

What are the common risk factors for musculoskeletal diseases?

Common risk factors include age, obesity, genetics, and physical inactivity.

How can vitamin D deficiency affect the musculoskeletal system?

Vitamin D deficiency can lead to osteomalacia in adults and rickets in children, affecting bone mineralization.

What is myositis?

Myositis is inflammation of muscle tissue that leads to muscle weakness.

What are the common findings in a muscle biopsy for polymyositis?

A muscle biopsy for polymyositis typically shows endomysial inflammation with CD8+ T cells.

What role does estrogen play in bone health?

Estrogen helps maintain bone density by inhibiting osteoclast activity and promoting osteoblast survival.

What is significant about the acetabulum?

The acetabulum is the deep socket of the hip joint that articulates with the head of the femur.

What does a positive Tinel's sign indicate?

A positive Tinel's sign may indicate carpal tunnel syndrome or other nerve compression conditions.

What anatomical structures support the stability of the shoulder joint?

The shoulder joint is stabilized by a fibrous capsule, ligaments, and rotator cuff muscles.

What functional roles do the menisci play in the knee joint?

The menisci improve the congruence of the femur and tibia, cushioning the joint during movement.

What is the anatomical position of the phalanges in relation to the metacarpals?

The phalanges are distal to the metacarpals, forming the fingers at the carpometacarpal joints.

What is the common mechanism of injury for the anterior cruciate ligament (ACL)?

The ACL is commonly injured during sports activities involving sudden stops, changes in direction, or landing.

What is the common presentation of a knee meniscus tear?

Common presentations include joint pain, swelling, and difficulty with movement, particularly rotation.

What promotes muscle fiber regeneration?

Satellite cells play a crucial role in regulating muscle fiber regeneration following injury.

What are the structural components of a sarcomere?

The sarcomere comprises actin filaments, myosin filaments, Z lines, and M lines.