Skeletal and Muscular Systems Quiz

Human Skeletal System

• The axial skeleton forms the central axis of the body, providing structural support and protection for the brain, spine, and thoracic organs.
• The femur is the longest and largest bone in the human body, crucial for weight-bearing and locomotion.
• An adult human skeletal system typically consists of 206 bones, varying in number during development and age.
• Cortical bone, also known as compact bone, forms the hard, outer shell of bones, providing strength and stability.

Functions and Structure of the Skeleton

• The skeleton serves multiple functions including support, protection of vital organs, movement facilitation, mineral storage, and hematopoiesis (blood cell production).
• The atlas (C1 vertebra) is responsible for the pivot joint in the neck, allowing for head rotation.

Bone Cells and Remodeling

• Osteoclasts are specialized cells that break down bone tissue through the process of bone resorption, helping to regulate calcium levels in the body.
• Osteoblasts are the cells that regenerate bone tissue via bone deposition, essential for growth and repair.
• Bone remodeling's main function is to maintain bone strength and mineral homeostasis, adapting to mechanical stresses and repairing micro-damages.

Gender Differences in Skeleton

• Common skeletal differences observed between men and women include variations in pelvic structure, bone density, and overall size, usually attributed to hormonal influences and evolutionary factors.
• The Q angle refers to the angle formed between the quadriceps muscle and the patellar tendon, significant for assessing knee function and potential injury risk.

Muscle Interaction with Bones

• Skeletal muscle interacts with bones to produce voluntary body movements, under conscious control and influenced by the nervous system.
• In muscle contraction, the power stroke occurs when myosin changes shape and pulls actin filaments toward the center of the sarcomere, leading to muscle shortening.

Neuro-muscular Function and ATP Role

• When an action potential travels down a motor neuron, it triggers a release of neurotransmitters at the muscle cell membrane, leading to muscle contraction initiation.
• ATP is essential in muscle contraction for providing the energy required for myosin heads to detach from actin and reset for the next contraction cycle.

Hormones and Muscle Mass

• Testosterone is the hormone responsible for the differences in muscle mass between men and women, influencing muscle size and strength characteristics.
• The main symptom of muscular dystrophy is progressive muscle weakness and degeneration, leading to mobility issues and complications.

Myosin and Actin Interaction

• When a myosin head binds to an actin molecule during muscle contraction, it forms a cross-bridge, allowing contraction to occur as part of the sliding filament theory.
• Muscle cell and tissue death in muscular dystrophy are often caused by genetic mutations that disrupt the production of proteins needed for muscle integrity, leading to muscle degeneration.

Test your knowledge of the skeletal and muscular systems with this quiz! Explore topics such as the axial and appendicular skeletons, bones, cartilage, and more.