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96 Cards in this Set
- Front
- Back
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What is the purpose of the circulatory system?
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transport nutrients, respiratory gases, hormones, metabolic products, etc throughout body; temperature control
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What are the structural elements of the circulatory system?
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Pump (heart), conduits (vessels), transport medium (blood)
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Where does de/oxygenated blood flow in a vertebrate?
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Deoxygenated to gills or lungs to get oxygen, oxygenated to rest of body (systemic)
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Where does the right side of the heart pump blood to (looking at heart, is left)
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To the lungs
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Where does the left side of the heart pump blood to (looking at heart, is right)
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To the rest of the body
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What prevents backflow of blood into heart?
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Valves
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What is systole?
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The contraction phase of the heart
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What is diastole?
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The relaxation phase of the heart
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What makes the heart sounds?
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Heart valves closing
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What does effective heart pumping require?
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Sequential contraction of chambers, coordinated contraction of muscle cells within chamber
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Are cardiac muscle striated?
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Yes
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Why are cardiac muscles striated?
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The arrangement of actin and myosin filaments are aligned at regular intervals; muscle contraction depends on these filaments sliding past each other
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What do the chambers in the heart depend on for regular contractions?
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Specialized cells in the sinoatrial node, atrioventricular node, and Bundle of His and Purkinje fibers
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What cells initiate heartbeats?
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Pacemaker cells in sinoatrial node
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How are contractions of muscle cells coordinated in chambers?
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Gap junctions allow electrical continuity which leads to rapid spread of action potential
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What ion channels are involved in heart action potenetials?
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Na+ and Ca2+
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What are mechanisms for regulation in the heart?
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Specific electrical events
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What does P stand for on an ECG graph?
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Atrial depolarization
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QRS?
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Depolarization of ventricles
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T?
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Relaxation and repolarization of ventricles
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What are some abnormal ECGs?
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Accelerated, Uncoordinated contraction, blockage of electrical system
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What are sympathetic nerves?
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Release (nor)epinephrine to increase heart rate (fight or flight mode)
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What are parasympathetic nerves?
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Release acetylcholine, decrease pacemaker activity, which slows heart rate (rest and digest)
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How does norepinephrine effect action potentials?
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Makes Na+ and Ca2+ more permeable, so resting potential rises quicker and action potentials are closer together
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How does acetylcholine effect action potentials?
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Decreases permeability of Na+ and Ca2+, so resting potential rises more slowly, and action potentials are farther apart
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What are the five different types of vessels in the circulatory system?
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Arteries, arterioles, capillaries, venules, and veins
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In what order do the vessels proceed, starting from the heart?
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Arteries, arterioles, capillaries, venules, veins
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What are arteries and arterioles composed of?
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Elastic fibers to withstand high pressure, smooth muscle cells for contraction and expansion (altering blood flow and resistance)
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What are veins composed of?
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Valves to prevent backflow
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What controls blood flow to capillaries?
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Precapillary sphincter in arterioles
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What controls direction of blood?
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Balance between blood pressure and osmotic pressure; squeezed out of capillary via blood pressure, pulled back in via osmotic pressure
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What helps carry blood back to the heart?
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Skeletal muscles contractions (and gravity), help veins and lymphatic vessels carry blood and fluid back to the heart
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What is blood composed of?
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Plasma, red blood cells, white blood cells, and platelets
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What promotes diffusion in the alveoli?
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Rapid movement of blood through surrounding capillaries which maintains CO2 and O2 concentration gradients
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What increases the O2 capacity of blood?
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Hemoglobin (x60)
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What is the binding of O2 to hemoglobin dependent on?
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The pressure of O2
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What is red blood cell production stimulated by?
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Low oxygen content in tissues (transcription factor HIF-1, kidney produces erythropoeitan which stimulates stem cells in bone marrow)
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How is CO2 removed from tissues?
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Carbonic anhydrase maintains CO2 gradient from cells (high) to plasma (low); some CO2 complexes with deoxygenated HgB
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What is the purpose of the excretory systems?
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Filtration and to maintain osmotic balance
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Why does blood require filtration?
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Since blood carries nutrients AND waste, it requires filtration to get rid of the garbage
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What are the waste products of metabolism?
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Nitrogenous products
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What are the vertebrate excretory systems composed of?
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Kidneys
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What is the functional unit of the kidney?
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The nephron unit
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What is the nephron unit composed of?
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Renal corpuscle, Renal tubule, Collecting duct
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What is the renal corpuscle and what does it do?
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Glomerulus, and Bowman's capsule, filtration site
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What is the renal tubule and what does it do?
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Site of tubular secretion and absorption, surrounded by capillaries;
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What is the collecting duct and what does it do?
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Site of urine processing; concentration or dilution
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What does the concentrating ability of the mammalian kidney depend on?
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It's anatomy; entry/exit on the concave side, nephrons regularly arranged within the kidney
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How are nephrons arranged in kidney?
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Glomeruli in cortex; renal tubules loop through medulla; collecting ducts start at cortex, pass through medulla, empty into ureter
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Where is most of the volume of blood reabsorbed?
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The proximal tubule
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What are the glomeruli?
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Highly permeable capillary beds
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What are podocytes?
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Surface cells of Bowman's capsule;
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What do the Bowman's capsules surround?
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The glomeruli
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What are the specialized zones of the renal tubule?
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Proximal convoluted tubule; loop of Henle; distal convoluted tubule; collecting duct
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What is the function of the proximal convoluted tubule?
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Transports NaCl out of tubular fluid and H2O follows; also transports glucose and amino acids out of tubular fluid
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What is the function of the loop of Henle?
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Permeable to H2O and small molecules
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What is the function of the distal convoluted tubule?
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Transports NaCl out of tubular fluid
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What is the function of the collecting duct?
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Urine concentration through osmosis, little active transport
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What regulates the pH in the kidney and how?
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Secretion of H+ and reabsorption of bicarbonate
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What is the structure of the proximal convoluted tubule?
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Microvilli on cells on lumen face; many mitochondria for active transport
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What part of the kidney is a counter-current multiplier?
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The loop of Henle
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What does countercurrent exchange in the kidney do?
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Creates a concentration gradient in the medulla
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What does the degree of urine concentration depend on?
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The magnitude of the gradient in the collecting duct
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What are aquaporins?
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Family of water channels; integral membrane proteins that form water-selective channels; expressed in tissues with high water permeability
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What disease can result from a mutation in aquaporins?
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Diabetes insipidus
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What does local autoregulation in the kidneys do?
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Incoming renal arterioles dilate to maintain flow through capillaries if systemic pressure increases
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What is the renin-angiostensin-aldosterone system?
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Response to decreased blood volume and blood pressure, increases local and systemic blood pressure by effects on vessels and fluid intake
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How is blood pressure regulated by systemic systems?
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ADH system as a response to increases osmolarity; increase water reabsorption to concentrate urine; increases water permeability of collecting duct via effects on aquaporin content
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What are responses in the case of low blood pressure?
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RAA and ADH
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What are the responses in the case of high blood pressure?
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Atrial natriuretic peptide (ANP) decreases salt and water uptake
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What is a sensory cell?
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A modified neuron (receptor cell)
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What do sensory cells do?
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Transduce physical or chemical stimuli into signals that are transmittable and interpretable
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How do the sensory cells detect a stimulus?
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Membrane receptor proteins detect a stimulus and respond by altering the flow of ions across the plasma membrane
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How is the intensity of the stimulus recorded?
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The frequency of the action potentials produced
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How is the energy from a stimulus transduced?
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Made into action potentials by opening or closing of ion channels
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What do sensory cells form?
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Sensory organs (eyes, nose, ears, etc)
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What determines what a stimulus is interpreted as?
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It depends on which cells in the CNS receive the signal
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What is ionotropic sensory detection?
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Receptor protein is part of ion channel and by changing its conformation, opens/closes the channel pore
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What is metabotropic sensory detection?
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Receptor protein is linked to a G protein that activates a cascade of intracellular events that eventually open/close ion channels
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What is adaptation?
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When a sensory cell responds less when stimulation is repeated
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What does olfaction depend on?
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Chemoreceptors
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Where are olfactory sensors in vertebrates?
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Neurons embedded in epithelial cells in nasal cavity
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What is the sequence following an odorant binding to olfactory receptor proteins?
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G protein activated, activates enzyme that increases the level of the second messenger cAMP, cAMP opens Ca2+ channel, leads to opening of Cl- channel which depolarizes the membrane potential and action potential fired
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What provides for the identification of almost limitless number of different odorant molecules?
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Most odorants activate more than one type of olfactory receptor
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What is gustation?
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Sense of taste
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What are papillae?
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Raised bumps on human tongues
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What increases the surface area of taste buds?
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Microvilli
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What are the five basic tastes a taste bud can detect?
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Sweet, Bitter, Umami (savory), Salty, and Sour
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Which tastes are detected by ion channels, and which by G-protein coupled receptors?
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Ion: Salty and Sour
G-protein: Sweet, Bitter, Umami |
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What are mechanoreceptors?
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Cells sensitive to mechanical forces
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What causes mechanoreceptors to recognize a stimulus?
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Distortion of the plasma membrane causes ion channels to open
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What are Merkel's discs?
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Provide continuous information about things touching the skin
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Meissener's corpuscles?
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Very sensitive mechanoreceptors found mostly in non-hairy skin. Adapt rapidly and provide info on changes in things touching skin
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Ruffini endings?
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Provide info about vibrating stimuli of low frequencies
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Pacinian corpuscles?
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Provide info on vibrating stimuli of higher frequencies
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What are stereocilia?
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Like microvilli; when bent in one direction, receptor potential is pos; vice versa
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