Integumentary
This is the outermost, non-vascular layer of the skin that acts as the body's first line of defense.
Answer: What is the epidermis?
This structural framework division includes the skull, vertebral column, and thoracic cage, protecting the body's vital organs.
Answer: What is the axial skeleton?
This specific type of muscle tissue is striated, multi-nucleated, and under voluntary conscious control.
Answer: What is skeletal muscle?
This type of freely movable joint, found in the shoulder and hip, allows for the widest range of rotational motion.
Answer: What is a ball-and-socket joint?
The integumentary system synthesizes this crucial nutrient when the skin is exposed to sunlight.
Answer: What is Vitamin D?
This dark pigment, produced by cells in the skin, provides protection against harmful ultraviolet radiation.
Answer: What is melanin?
This is the single longest, heaviest, and strongest bone in the human body.
Answer: What is the femur?
These tough bands of fibrous connective tissue connect skeletal muscles directly to bones.
Answer: What are tendons?
These bands of tough elastic tissue connect one bone to another bone to stabilize a joint.
Answer: What are ligaments?
This muscular, involuntary organ contains unique intercalated discs that allow electrical impulses to spread rapidly through its walls.
Answer: What is the heart (or cardiac muscle)?
These specific tactile receptors located in the dermis are highly sensitive to light touch.
Answer: What are Meissner corpuscles?
This specialized, flexible connective tissue acts as a cushion between bones at joints and forms structures like the external ear.
Answer: What is cartilage?
This is the functional, microscopic contracting unit of a skeletal muscle fiber, bounded by Z-lines.
Answer: What is a sarcomere?
This anatomical term describes a movement that decreases the angle between two bones, such as bending the elbow.
Answer: What is flexion?
This condition involves a chronic loss of bone density, making the skeletal system fragile and highly susceptible to fractures.
Answer: What is osteoporosis?
These specialized exocrine glands secrete an oily substance called sebum to keep skin and hair lubricated.
Answer: What are sebaceous glands?
Found within the spongy interior of flat and long bones, this tissue is responsible for the production of red blood cells.
Answer: What is red bone marrow?
According to the sliding filament theory, these two primary protein filaments slide past one another to generate a muscle contraction.
Answer: What are actin and myosin?
This lubricating fluid reduces friction inside freely movable joint cavities during movement.
Answer: What is synovial fluid?
This structural division of the skeleton includes the limbs, shoulder girdle, and pelvic girdle.
Answer: What is the appendicular skeleton?
This is the deepest, thicker layer of the skin composed of dense irregular connective tissue, housing nerves, blood vessels, and hair follicles.
Answer: What is the dermis?
These mature bone cells maintain the mineral concentration of the bone matrix and develop from osteoblasts.
Answer: What are osteocytes?
This type of smooth, non-striated muscle tissue lines the walls of hollow internal organs like the stomach and intestines.
Answer: What is visceral (or smooth) muscle?
This type of uniaxial joint, found in the elbow and knee, allows movement along only one plane, similar to a door
Answer: What is a hinge joint?
This waterproof, fibrous protein is the primary structural component forming the outer layer of skin, hair, and nails.
Answer: What is keratin?