MSK Flashcards
What is the role of the RANKL-OPG system in bone development?
Regulates bone remodeling and maintenance
RANKL (Receptor Activator of Nuclear Factor Kappa-B Ligand) promotes osteoclast formation, while OPG (Osteoprotegerin) acts as a decoy receptor.
What hormone is important for stimulating bone growth?
Growth hormone
Promotes growth of bone and cartilage.
Which hormones are classified as sex hormones that influence bone health?
Estrogen and testosterone
They play a crucial role in bone density and maintenance.
What is the function of parathyroid hormone in bone physiology?
Regulates calcium levels in the blood by increasing osteoclast activity
It helps to release calcium from bones into the bloodstream.
What is the role of calcitonin in bone health?
Lowers blood calcium levels by inhibiting osteoclast activity
It helps to reduce bone resorption.
What is the active form of vitamin D that is crucial for bone health?
Calcitriol
It enhances calcium absorption in the intestines.
What are the stages of skeletal muscle contraction?
Excitation, contraction, and relaxation
Each stage involves specific biochemical and mechanical processes.
What are myofibrils?
Contractile units within muscle fibers
They contain actin and myosin filaments.
Name three key neurotransmitters necessary for skeletal muscle function.
Acetylcholine, norepinephrine, and serotonin
They play roles in muscle contraction and relaxation.
What is the purpose of calcium in skeletal muscle function?
Facilitates muscle contraction
Calcium binds to troponin, allowing actin-myosin interaction.
What are the effects of calcium imbalance in skeletal muscle?
Muscle weakness, cramps, and spasms
Both hypocalcemia and hypercalcemia can disrupt normal muscle function.
Differentiate between trabecular and cortical bones.
Trabecular bones are spongy and found at the ends of long bones; cortical bones are dense and form the outer layer
Trabecular bone is more metabolically active.
What is the difference between red and yellow bone marrow?
Red bone marrow produces blood cells; yellow bone marrow stores fat
Red marrow is found in flat bones and the ends of long bones, while yellow marrow is found in the medullary cavity.
What is the main function of tendons?
Connect muscles to bones
Tendons transmit the force generated by muscles to facilitate movement.
What is the primary function of ligaments?
Connect bones to other bones
They provide stability to joints.
What is osteoporosis?
A condition characterized by weak and brittle bones
It increases the risk of fractures.
What are rickets/osteomalacia?
Diseases caused by vitamin D deficiency leading to soft and weak bones
Rickets occurs in children, while osteomalacia occurs in adults.
