Cells
What organelle produces ATP?
Mitochondria
Name the four basic tissue types.
Epithelial, connective, muscle, nervous
What is the central structural unit of compact bone that contains lamellae and a central canal?
Osteon (Haversian system)
Name the neurotransmitter released at the neuromuscular junction that binds to receptors on the motor end plate
Acetylcholine
Name the membrane process that moves water across a semipermeable membrane.
Osmosis
What tissue type is blood classified as and why?
Connective tissue — cells suspended in an extracellular matrix (plasma) that transports and connects body systems
Name the two major divisions of the skeleton.
Axial and appendicular
What muscle filament is primarily responsible for the power stroke during contraction?
Myosin (thick filament)
Provide the main stages of mitosis
Prophase, Metaphase, Anaphase, Telophase
Compare hyaline cartilage and fibrocartilage by typical location and primary function in two short phrases.
Hyaline: fetal skeleton/trachea — smooth support and growth Fibrocartilage: intervertebral discs/menisci — tensile strength and shock absorption
Which part of a long bone is formed first during primary ossification, and which part develops later during secondary ossification?
Diaphysis — Epiphysis
Briefly explain the sliding filament theory including roles for Ca2+ and ATP in two sentences.
Calcium from the sarcoplasmic reticulum binds troponin, moving tropomyosin to expose binding sites on actin. Myosin heads use ATP to bind, perform power strokes, and detach, resulting in sarcomere shortening.
Which condition — often resulting from defective ciliary motility — causes a mirror-image reversal of internal organs?
Situs Inversus
Which cell builds bone, which resorbs bone, and how do they work together for remodeling?
Osteoblasts build bone by depositing matrix; osteoclasts resorb bone by breaking down matrix; coordinated activity maintains bone homeostasis
List risk factors or causes of osteoporosis and why older adults commonly sustain hip fractures.
Risk factors: aging, estrogen deficiency, low calcium/vitamin D, sedentary lifestyle, long-term corticosteroids; older adults have decreased bone density and higher fall risk, making the proximal femur susceptible to fracture
Name the repeating contractile unit within a myofibril and identify the protein bands that define its boundaries.
Sarcomere
Which organelle contains hydrolytic enzymes, and helps the cell rid waste products?
Explain how loss of collagen affects skin structure and healing in two brief sentences.
Loss of collagen weakens the extracellular matrix, reducing tensile strength and elasticity. Wound healing is impaired because collagen provides the scaffold and strength needed for tissue repair.
What rare disorder causes heterotopic ossification (Second skeleton? following minor injuries due to a mutated BMP receptor
Fibrodysplasia ossificans progressiva (FOP)
Describe the hierarchical organization of a skeletal muscle from the whole muscle down to the myofilament, listing each structural level in order.
Muscle → fascicle → muscle fiber (myocyte) → myofibril → sarcomere → myofilaments (actin and myosin)