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110 Cards in this Set
- Front
- Back
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What is the clinical significance of vital capacity? |
-The volume of air at max inhalation and exhalation. -Measuring someone's vital capacity can let a doctor know if a person is suffering from a lung disease. A low vital capacity could mean lung disease, chronic respiratory disease, or obesity. |
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How does smoking affect the various aspects of lung capacity? |
-Smoking causes particulates to overwhelm the white blood cells in the alveoli, whose main job is to engulf foreign particles. This can cause inflammation and permanent reduction in lung capacity. |
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How would you measure the effects of exercise on vital capacity? |
First the subject would exercise and then they would blow into a spirometer or wet spirometer, which measures the volume and flow of air inhaled and exhaled. |
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Where does a sea star larva get its nutrition before the bipinnaria stage? |
Its cilia are able to obtain the larva's nutrition by inhaling it into the gut
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More recently evolved organisms have modified the stages of embryological development. Would you expect the early or later stages to be modified the most? Explain. |
Earlier stages because its key features are developed during these stages. Evolution is change over time, and sexually reproductive species can produce offspring that can evolve to survive changes in the environment. This change must happen in early stages when the reproductive system, nervous, etc are being formed.
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The basic stages of embryological development are remarkably similar for a wide range of organisms. How would you explain such consistency? |
Almost all forms of life share the same genetic code, meaning we come from a common ancestor who also shared this genetic code, which would explain why the stages of development are so similar for a variety of organisms. |
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Are you aware of all activity within your nervous system at all times? Why is this advantageous? |
No; sensory adaptation causes repeated stimuli to be tuned out, which is advantageous because it allows us to hone in on more important stimuli. For instance, without sensory adaptation, we would be overwhelmed with so much stimuli (the every beat of our heart, the clothes on our back) that changes to our environment may not be detected because of the overload of stimuli. If we are overloaded, we may not sense the car that is approaching us, etc.
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How would you show whether there are specific receptors in your skin that respond to heat and cold? |
You would first stimulate your sensory receptors by placing your hands in both cold and hot water for 60 seconds. Then you would place them in room temperature water. The room temperature water would feel cold to the hand that was originally in hot water and vie versa because our skin does not sense actual temperature, but rather changes in temperature. |
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Are all regions of your body equally sensitive to touch and temperature? Explain. |
No; some areas of the body, such as the fingertips, have more densely compacted mechanoreceptors, so their sensitivity to touch and pressure is much greater. |
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All animals do not perceive their environment in the same way. Describe some examples. |
-invertebrates can not see images; they sense light intensity and direction/ vertebrates can see images, but some have single lens eyes and some have compound eyes.
-eels and sharks can sense electricity -snakes can sense heat through the pit organ |
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DNA genotypes are expressed as ____ |
-proteins -molecular basis for phenotypic traits |
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A particular gene: |
-a linear sequence of many nucleotides -specifies a polypeptide |
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flow of information: |
-DNA -> RNA -> polypeptide -> trait |
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two processes of genetic info flow: |
-DNA -> RNA = transcription -RNA -> polypeptide = translation |
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codons: |
-the words of the DNA language -triplets of bases -specify the amino acid sequence of a polypeptide -each codon corresponds to one amino acid (amino acids may have 1-6 codons) |
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genetic code is nearly the same in all organisms |
OK |
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transcription in eukaryotes: |
-DNA sequence transcribed into mRNA sequence -DNA helix unzips in the nucleus -mRNA nucleotides line up along one strand of DNA, following the base pair rule -enzyme moves along DNA strand and adds corresponding complementary mRNA nucleotides -DNA strands rejoin -transcription processed before leaving nucleus |
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eukaryotic transcription processing of mRNA
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-eukaryotic mRNA is processed before leaving nucleus
-noncoding segments called introns are spliced out -coding segments (exons) are joined by enzymes -cap and tail are added to ends -mature transcript leaves nucleus |
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translation
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-nucleotide sequence of mRNA transcript is translated into amino acid sequence
-rRNA molecule within ribosome binds to start sequence of mRNA and moves along three nucleotides at a time -then disengages at stop signal -occurs in cytoplasm |
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gene expression = transcription + translation
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ok
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ribosomes
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-workbench for protein synthesis
-consists of two subunits made of proteins and rRNA -subunits of a ribosome hold tRNA and mRNA close together during translation |
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transfer RNA
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-each tRNA molecule is a folded molecule bearing a base triplet called an anticodon on one end and a specific amino acid attached to the other end
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translation series of steps:
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-initiation
-elongation -translocation -termination |
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start and stop signals:
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-specified by particular codons -1 start codon, 3 stop codons |
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initiation |
-begins when initial portion of mRNA molecule binds to rRNA in a ribosome -tRNA molecule with complementary anticodon binds to exposed codon on mRNA |
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elongation |
-mRNA codon adjacent to the initiating codon exposed -ribosome positions second codon for second tRNA -amino acids bind together with peptide bonds |
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translocation |
-first tRNA released, ribisome moves down mRNA transcript -amino acids added until stop codon reached |
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termination |
-stop codons are recognized by release factors -release the newly made polypeptide from the ribosome -ribosome subunits break apart, move to start of a new transcript |
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mutation |
-change in the DNA base sequence -caused by errors in DNA replication or recombination or by mutagens (physical or chemical agents that damage DNA) -ex of mutagen: UV light -substituting, inserting, or deleting nucleotides alters a gene -with varying effects on organisms -ex: sickle cell anemia |
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3 phases of gas exchange: |
-breathing -transport -exchange |
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air breathing |
-alternation of inhalation and exhalation -ventilates the lungs |
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air breathing in mammals and reptiles: |
-two-way flow of air across lungs -negative pressure (suction) -diaphragm contracts, rib cage expands, air sucked in -residual volume present (keeps lungs partially inflated) |
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air breathing in amphibians: |
-two-way flow across lungs -positive pressure -air gulped in then moved to lungs -supplemented (or sole method) by cutaneous respiration (through skin) |
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air breathing in birds: |
-one-way flow across lungs -negative pressure -air sacs fill and store air -most efficient mode of air breathing -5% more O2 than mammals |
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control of breathing: |
-breathing control centers in the brain -monitors CO2 level in blood by detection of pH changes -CO2 increased --> pH decreased -increase breath rate and depth -CO2 and O2 sensors also in aorta |
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transport |
-heart pumps oxygen-poor blood to lungs -picks up O2, drops off CO2 -heart pumps the oxygen-rich blood to body cells -drops off O2, picks up CO2 |
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partial pressure gradients |
-gases diffuse down partial-pressure gradients in a mix of gases (O2, CO2)/ each individual gas has its own concentration gradient -in the lungs, O2 moves from alveoli --> blood and CO2 moves from blood --> alveoli -in the tissues, O2 moves from blood--> cells and CO2 moves from cells --> blood |
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transport
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-hemoglobin in red blood cells transports O2, helps buffer the blood and carries some CO2
-most CO2 in blood is transported as bicarbonate ions in the plasma -CO2 + H2O <--> H2CO3 <--> H + HCO3 ( see notes) |
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exchange
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-respiratory surfaces must be thin and moist for diffusion of gases
-increased surface areas allows for greater gas exchange |
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in most animals: |
-specialized body parts provide large respiratory surfaces for gas exchange -some animals use their entire skin as gas exchange organ -ex: earthworm |
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gills: |
-absorb O2 dissolved in H2O -allows CO2 to diffuse to environment -in a fish, gas exchange is enhanced by ventilation (movement of water across gills) -countercurrent exchange: -blood and water flow in opposite directions -always a concentration gradient between blood and water -can remove 80% of oxygen dissolved in water |
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a neuron consists of: |
-cell body -dendrites (receive signals) -axons (transmit signals) -schwann cells form an insulating myelin sheath -myelin sheath interrupted by nodes of Ranvier -axon ends in synaptic terminals |
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nervous system processes info in three stages: |
-sensory input: sensory neurons transmit signals from sensory receptors to the brain -integration: interneurons in brain integrate info and send response -motor output: motor neurons transmit signals to effectors (ex: muscle, organ) |
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resting potential of a neuron: |
-at rest, neuron's plasma membrane has an electrical voltage called the resting potential -negative inside cell, positive outside cell -caused by sodium potassium pump -move sodium out and potassium in -high potassium, low sodium inside -low potassium, high sodium outside |
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action potential |
-a stimulus alters the permeability of a portion of the membrane, allowing ions to pass through and changing the membrane's voltage -resting potential: sodium and potassium channels closed -at rest, inside of cell is negatively charged |
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action potential continued |
-stimulus opens sodium channels, letting sodium in -interior of cell becomes positively charged -sodium channels close, potassium channels open -potassium rushes out -interior of cell becomes more negative than exterior because of how fast potassium rushes out -potassium channels close slowly -interior of cell becomes more negative than resting potential (undershoot) -sodium-potassium pump restores resting potential -entire process called action potential |
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action potential properties: |
-self-propagated in a one-way chain reaction along a neuron (refractory period due to undershoot) -all-or-none events -the frequency of action potentials changes with strength of stimulus, but their strength doesn't change
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action potential propagation |
-uninsulated neuron (no myelin sheath): AP must pass through each portion of axon membrane -insulated neuron: AP cannot pass through insulated portion/jumps from node to node/ much faster |
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synapses |
-transmission of signals: -neuron --> neuron -neuron --? effector (takes place at synapses/gaps between cells/no direct physical contact between cells) -AP traveling down an axon releases neurotransmitter from vesicle into synapse -neurotransmitter crosses the synapse and binds to a receptor on the surface of the receiving cell, triggering AP in receiving cell |
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neurotransmitters |
-some excite the receiving cell (make AP more likely) -others inhibit the receiving cell (make AP less likely) -the summation of excitation and inhibition determines whether or not a neuron will transmit a nerve signal |
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radically symmetrical animals |
-ex: jellyfish -web-like system of neurons called a nerve net spread equally through body |
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most bilaterally symmetrical animals |
-cephalization: concentration of nervous system in head region -centralization: presence of a central nervous system (not spread out evenly through body) -ex: humans, squid |
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vertebrate nervous systems: |
-highly centralized and cephalized -advantages: efficient sensory processing in direction of motion (head first) -disadvantages: less efficient at 360 degree processing (all eggs in one basket) |
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two main divisions of vertebrate nervous systems |
-central nervous system: brain and spinal cord -peripheral nervous system: located outside CNS (nerves and ganglia) -nerves: bundles of fibers of sensory and motor neurons -ganglia: clusters of cell bodies of the neurons |
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reflex |
-automatic response to stimuli -knee jerk reflex -sensory receptor detects stretch -sensory neuron sends info to motor neuron and interneuron to spinal cord -motor neuron in spinal cord causes quads to contract -interneuron sends signal to motor neuron in hamstrings to relax |
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sensory receptors |
-specialized cells or neurons that detect stimuli -detect chemicals, light, heat, pressure, gravity -sensory transduction: converting stimulus into electrical signal -receptor potential: graded, not all or none like action potential (they can be stimulated a little or a lot) -neurotransmitter released to sensory neuron |
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sensory adaptation |
-repeated stimulus can lead to decreased sensitivity -trigger fewer AP -lose awareness of stimuli -new stimuli reactivates receptors |
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pain receptors |
-detect dangerous stimuli -heat, pressure, chemicals |
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thermoreceptors |
-heat and cold -ex: pit organ in snakes detects heat from prey |
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mechanoreceptors |
-mechanical energy -touch, pressure (air and water), sound, muscle stretch |
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chemoreceptors |
-respond to chemicals -internal and external chemicals (smell, taste) |
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electromagnetic receptors |
-electricity, magnetism, light -eels and sharks detect electricity -vision detects light |
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hearing |
-channels sound waves through outer ear (pinna) to eardrum (tympanum) -vibrations from eardrum transmitted by bones (incus, malleus, stapes) in middle ear -to fluid in coiled cochlea of inner ear |
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hearing continued |
-pressure waves in fluid of cochlea bend hair cells in organ of the corti against a membrane, triggering nerve signals to brain -vibrations from sound waves are amplified as they are transferred through the ear |
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volume vs pitch |
V- loud/quiet P-high/low |
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volume and pitch |
-louder sounds: more vigorous fluid movement in cochlea --> more APs -pitches stimulate different regions of organ of corti |
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organs of equilibrium in inner ear |
-semicircular canals: -oriented in 3 perpendicular planes -detect rotation or angular movement (left or right) -fluid in canals move hair cells -utricle and saccule: -position in respect to gravity -calcium carbonate particles move hair cells |
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photoreceptors contain: |
pigment molecules that absorb light |
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invertebrate eyes include: |
-simple eye cups that sense light intensity and direction but cannot see images -ex: planaria (flat worm) |
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2 major types of image-forming eyes: |
-compound eyes -single-lens eye |
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compound eye |
-ex: insects, crustaceans -1000s of ommatidia make up the compound eye -each ommatidia has its own lens, photoreceptors, and nerve that make them like individual eyes -the ommatidia together form a mosaic image -excellent motion detection and usually color vision (some see UV light) |
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single-lens eye |
-ex: humans, squid -single lens focuses image on receptors |
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structure of human eye |
-light passes over clear cornea -through pupil (controlled by iris) -through lens -to retina |
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focusing |
-cornea begins to focus image, lens changes shape to focus more -retina contains photoreceptors -fovea: center of focus, highest concentration of photoreceptors |
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two types of photoreceptors: |
-rods: dim light, shades of grey, edges of retina -cones: bright light, color, fovea |
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taste and smell |
-chemoreceptors that bind specific molecules -taste receptors located in taste buds on tongue -produce five taste sensations (sweet, salty, sour, bitter, savory) |
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olfactory sensory neurons |
-line nasal cavity -1000s of different types of olfactory receptors -taste and smell work together -various odors and tastes result from integration of input from many receptors |
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tracheal system of insects: |
-branched tubes connected to environment -direct exchange between the air and body cells -muscle contractions help move air |
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terrestrial vertebrates have lungs: |
-in mammals, air inhaled through nostril -passes through the pharynx and larynx into the trachea, bronchi, and bronchioles -the bronchioles end in air sacs called alveoli where gas exchange occurs |
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circulatory systems: |
-all cells must: -receive nutrients -exchange gases -remove waste -small animals, diffusion alone is ok -large animals, efficient transport mechanisms favored |
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functions of circulatory systems |
-transport oxygen and nutrients -arteries carry blood away from the heart -veins carry blood to the heart -capillaries are site of exchange between arteries/veins and interstitial fluid -transport absorbed food and metabolic waste from digestive system to excretory system |
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Regulation of circulatory system |
-hormone transport (hormones keep us in homeostasis) -temperature regulation |
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protection of circulatory system |
-blood clotting -immune defense |
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mechanisms of internal transport: |
-For many invertebrates: -gastrovascular cavity functions in both digestion and internal transport -no separate circulatory system |
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types of circulatory systems |
-open -closed |
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open circulatory systems |
-no distinction between circulatory fluid and extracellular body fluid -Heart pumps with open ended vessels -blood mixes with interstitial fluid -ex: insects |
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closed circulatory systems |
-circulatory fluid is always enclosed within blood vessels -heart pumps with closed vessels -blood kept separate from interstitial fluid -ex: fish, mammals, earthworms |
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fish circulatory systems |
-2 chambered heart -1 atrium for collecting and 1 ventricle for pumping -single circulation -heart --> gill capillaries --> systemic capillaries --> heart |
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amphibians circulatory systems |
-3 chambered heart (2 atria, 1 ventricle) -partially divided ventricle reduces mixing -double circulation: -two loops: systemic, pulmocutaneous |
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reptiles: |
-3 chambered heart -partially divided ventricle reduces mixing -double circulation: systemic, pulmonary |
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birds, mammals, crocodiles |
-4 chambered hearts -no mixing |
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mammalian heart |
-2 thin-walled atria that collect and pump blood into the ventricles -2 thick-walled ventricles pump blood to all other body organs |
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cardiac cycle |
-sequence of filling and pumping -during diastole: -heart relaxes; blood flows from veins into heart chambers -during systole: -contraction of the atria pushes blood into ventricles -stronger contractions of the ventricles propel blood into large arteries |
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contraction of the heart |
-sinoatrial node: -bundle of muscle in the right atrium -acts as pacemaker for the heart -controls rate of contraction of atria |
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contraction of heart continued |
atrioventricular node: -relays signals from SA node to ventricles -controls contraction of ventricles |
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blood vessels |
-arteries and arterioles (smaller arteries): -epithelione (inner layer) -thick layer of smooth muscle -connective tissue -high pressure -veins and veinules (smaller veins) -epithelium -thinner layer of smooth muscle -connective tissue -lower pressure -skeletal muscles surrounding veins contract to move blood by squeezing the veins -one way venous valves prevent backflow |
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capillaries |
-thinnest wall -one cell thick -no muscle -site of exchange (picking up oxygen, dropping off glucose) |
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mammalian blood flow |
-blood collects from body in veins -veins --> RA -->atrioventricular valve --> RV -semilunar valve --> exits heart through pulmonary artery -blood enters lungs (gas exchange) -blood returned to heart via pulmonary vein |
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blood flow continued |
-LA --> AV valve --> LV -semilunar valve exits heart through aorta -body systemic -pulmonary arteries push blood away from heart -pulmonary veins pull blood to heart |
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fertilization |
embryonic development begins with fertilization |
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sperm penetration |
-sperm has an acrasome at the head (packet of enzymes) -enzymes digest outer layer of egg -receptor proteins bind, allowing fusion of plasma membranes -tail is discarded outside egg |
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activation |
-egg nucleus completes meiosis II -increase in metabolic activity -egg membrane changes to prevent other sperm from entering |
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nuclei fusion |
-fusion of 1n sperm nucleus with 1n egg nucleus -forms 2n zygote nucleus |
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embryonic development |
-embryonic cleavage (rapid series of mitosis) -initially, embryo doesn't increase in size -stages of cleavage |
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stages of cleavage |
-morula -blastula -gastrulation |
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morula |
-solid mass of 32 cells -each cell is a blastomere -fluid-filled cavity forms in center |
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blastula |
-hollow ball with fluid filled center (blastocoel) -each cell now in contact with different set of neighboring cells -cell-cell interactions help regulate development |
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gastrulation |
-cells migrate inward -form inward digestive cavity -initial opening called the blastopore -resulting gastrula has three layers of cells (primary germ layers): -ectoderm (outermost)- skin, nervous system -mesoderm (middle)- skeletal, muscular, circulatory system endoderm (innermost)- liver, pancreas, reproductive system |
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organogenesis |
-after gastrulation: -germ layers form specific organ systems -organogenesis |
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neurulation |
-formation of brain and spinal cord -mesoderm forms notochord (supporting rod) -ectoderm cells above notocord move inward, forming a neural groove -edges of neural groove come together and form neural tube -neural tube forms brain and spinal cord |
