BIO 240 NCSU Exam 1 EXAM ELABORATIONS LATEST UPDATED VERSION 100% GUARANTEED (GRADED A+)

Yellow bone marrow - Answer️Fat storage. Osteoprogenitor cells - Answer️Bone stem cells. Osteoblasts - Answer️Build bone. Osteocytes - Answer️Maintain bone. Osteoclasts - Answer️Break down bone. Osteon - Answer️Structural unit of compact bone. Central canal - Answer️Contains blood vessels and nerves. Lamellae - Answer️Rings of bone matrix. Canaliculi - Answer️Tiny channels connecting bone cells. Interstitial growth - Answer️Length growth from inside cartilage. Appositional growth - Answer️Width growth from surface. Intramembranous ossification - Answer️Bone forms directly from mesenchyme. Endochondral ossification - Answer️Bone forms from cartilage template. Five zones of epiphyseal plate - Answer️Resting, proliferating, hypertrophic, calcified, ossification. Zone where length growth occurs - Answer️Proliferating and hypertrophic zones. Growth plate becomes - Answer️Epiphyseal line. Bone remodeling - Answer️Continuous breakdown and rebuilding of bone. Effect of exercise on bone - Answer️Increases bone density. Growth hormone role - Answer️Stimulates cartilage growth. Sex hormones effect - Answer️Close growth plates. PTH effect - Answer️Raises blood calcium. Calcitriol effect - Answer️Increases calcium absorption. How does facilitated diffusion differ from active transport? - Answer️Facilitated diffusion uses membrane proteins but no ATP and moves substances down their concentration gradient, while active transport requires energy to move substances against a gradient. Why does increased mechanical stress increase bone density? - Answer️Mechanical stress stimulates osteoblast activity, leading to increased bone formation through remodeling. Why do graded potentials not travel long distances? - Answer️They decrease in strength over distance and vary in magnitude, unlike action potentials which are all-or-none. Why does myelination increase the speed of nerve conduction? - Answer️Myelination allows saltatory conduction, where action potentials jump between nodes of Ranvier, increasing speed. What determines whether a neurotransmitter is excitatory or inhibitory? - Answer️The type of receptor it binds to on the postsynaptic cell determines its effect. Why are action potentials considered all-or-none? - Answer️Once threshold is reached, the action potential occurs at full strength and does not vary in magnitude. Why is calcium important at the synapse? - Answer️Calcium entry into the presynaptic terminal triggers neurotransmitter release. What is an organ system? - Answer️A group of organs working together to perform a major function. How many organ systems are in the human body? - Answer️11 Function of the integumentary system - Answer️Protection and temperature regulation. Function of the skeletal system - Answer️Support, protection, mineral storage, blood cell production. Function of the muscular system - Answer️Movement and heat production. Function of the nervous system - Answer️Fast control and communication. Function of the endocrine system - Answer️Slow, long-lasting control via hormones. Function of the cardiovascular system - Answer️Transport of oxygen, nutrients, and wastes. Function of the lymphatic/immune system - Answer️Defense and fluid return. Function of the respiratory system - Answer️Oxygen intake and carbon dioxide removal. Function of the urinary system - Answer️Waste removal and water/salt balance. Function of the digestive system - Answer️Break down food and absorb nutrients. Function of the reproductive system - Answer️Produce offspring. What is homeostasis? - Answer️Maintaining stable internal conditions despite external changes. Why is homeostasis important? - Answer️Cells only function properly within narrow ranges. Three parts of a homeostatic system - Answer️Receptor, control center, effector. What does a receptor do? - Answer️Detects changes (stimuli). What does the control center do? - Answer️Compares to set point and decides response. What does an effector do? - Answer️Produces the response to restore balance. Negative feedback definition - Answer️Response reverses the original stimulus. Example of negative feedback - Answer️Sweating when hot. Positive feedback definition - Answer️Response amplifies the stimulus until completion.