Ap Biology Chapter 50 Flashcards

5210032901	Skeletal muscle	Characterized by a hierarchy of smaller and smaller units	0
5210045096	Microfibrils	Smaller bundles that are arranged longitudinally to make up muscle fibers	1
5210114407	Myofilaments	2 different filaments that make up myofibrils	2
5210168723	Thin filaments	Consists of two strands of actin and one strand of regulatory protein	3
5210177623	Thick filaments	Staggered arrays of myosin molecules	4
5210184494	Striated muscle	Regular arrangement of myofilaments creates a pattern of light/dark bands (heart/skeletal)	5
5210196742	Sarcomere	The functional unit of a muscle (bordered by Z-lines)	6
5210202779	Sliding filament model	Filaments slide past each other longitudinally, producing more overlap between thin and thick filaments	7
5210218377	Tropomyosin	Blocks myosin-binding sites on the thin filament when a muscle is at rest	8
5210239595	Troponin complex	Occurs when calcium ions bind to a set of regulatory proteins	9
5210313907	Transverse tubules	The path that action potentials use to travel to the interior muscle fiber	10
5210324612	Sarcoplasmic reticulum	Releases Ca² due to the action potential traveling along tubules	11
5210366810	Motor unit	Consists of a single motor neuron and all the muscle fibers it controls	12
5210369936	Recruitment	Leads to stronger contractions by using multiple motor neurons	13
5210380581	Tetanus	A state of smooth and sustained contraction produced when motor neurons deliver a volley of action potentials	14
5210388963	Myoglobin	A protein that binds oxygen more tightly than hemoglobin does	15
5210396867	Slow twitch fibers	Fibers that contract more slowly, but sustain longer contractions (uses oxidative)	16
5210406067	Fast twitch fibers	Fibers that contract more rapidly, but sustain shorter contractions (uses glycolytic or oxidative)	17
5210417592	Cardiac	Striated cells electrically connected by intercalated discs	18
5210422102	Intercalated discs	The way that the striated cells of the heart are electrically connected	19
5210436903	Smooth muscle	Found mainly in walls of hollow organs, contractions are relatively slow and may be initiated by the muscles themselves	20
5210444094	Hydrostatic skeleton	Consists of fluid held under pressure in a closed body compartment	21
5210452048	Peristalsis	A type of movement on land produced by rhythmic waves of muscle contractions	22
5210458084	Exoskeleton	A hard encasement deposited on the surface of an animal	23
5210462956	Endoskeleton	Consists of hard supporting elements, such as bones, buried in soft tissue	24