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Biology101 Exam #4 Study Guide

by: emilyecclestone

Biology101 Exam #4 Study Guide BIO101

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This Study Guide covers the following...Physiology-Homeostasis, Thermoregulation, the Digestive System, the Cardiovascular system, the Respiratory System, the Central Nervous System (with the brain...
Biology 101
Dr. Carole Gibson
Study Guide
Biology, bio101, Physiology, homeostasis, thermoregulation, Digestive System, cardiovascular system, Respiratory system, central nervous system, immune system, Reproductive system
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This 17 page Study Guide was uploaded by emilyecclestone on Thursday February 11, 2016. The Study Guide belongs to BIO101 at Wake Forest University taught by Dr. Carole Gibson in Fall 2015. Since its upload, it has received 21 views. For similar materials see Biology 101 in Biology at Wake Forest University.


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Date Created: 02/11/16
Biology  Exam  #4  Notes   Physiology   Homeostasis   1.   What  is  it?     •   Maintenance  of  a  relatively  stable  internal  environment  even  when  the  external   environment  changes,  including:   o   Blood  pH   o   Carbon  dioxide  concentration   o   Blood  glucose  concentration   o   Body  temperature   o   Water  balance   2.   How  does  it  work?   •   Body  temperatureànegative  feedback   o   HIGH  temperature   §   Stimulusà  increased  body  temperature     §   Thermostat  in  hypothalamus  activates  cooling  mechanisms   §   Option  A:  Skin  blood  vessels  dilate àcapillaries  fill  with  warm  blood;   heat  radiates  from  skin  surface   §   Option  B:  Sweat  glands  activated,  increasing  evaporative  cooling   §   Body  temperature  decreases àthermostat  shuts  off  cooling   mechanisms   o   LOW  temperature   §   Stimulusà  decreased  body  temperature     §   Thermostat  in  hypothalamus  activated  warming  m echanisms   §   Option  A:  Skin  blood  vessels  constrict àdiverting  blood  from  skin  to   deeper  tissues  and  reducing  heat  loss  from  skin  surface   §   Option  B:  Skeletal  muscles  activated àshivering  generates  more  heat   §   Body  temperature  increases   àthermostat  shuts  off  warming   mechanisms   •   Blood  glucose  levels     o   HIGH  blood  glucose  levels -­‐  Hyperglycemic  >120mg%     §   Stimulusà  rising  blood  glucose  level     •   After  eating  a  carbohydrate  rich  meal   §   Beta  cells  of  pancreas  stimulated  to  release  insulin  into  the  blood   §   Insulinà  Body  cells  take  up  more  glucose  OR  liver  takes  up  glucose  and   stores  it  as  glycogen   §   If  body  cells  take  up  more  glucoseàblood  glucose  level  declines  to  set   point   §   Stimulus  for  insulin  release  diminishes     o   LOW  blood  glucose  levels-­‐  Hypoglycemic  <80mg%   §   StimulusàRemoval  of  excess  glucose  form  blood,  low  blood  glucose   level   •   After  skipping  a  meal   §   Alpha  cells  of  pancreas  stimulated  to  release  glucagon  into  the  blood   §   Glucagonà  liver  breaks  down  glycogen  and  releases  glucose  to  the   blood   §   Blood  glucose  level  rises   §   Stimulus  for  glucagon  release  diminishes   3.   What  does  it  do?  Why  is  it  important?   •         Thermoregulation   1.   What  is  it?   •   Maintenance  of  a  relatively  stable  internal  body  temperature  (98.6*F,  37*C)   2.   How  does  it  work?   •   Hypothalamus  releases  hormones  acting  on  the   pituitary  gland  to  release  hormones   •   Pituitary  gland  sends  hormones  to  thyroid   •   Thyroid  stimulating  hormone   o   Thyroid  gland   §   Releases  thyroxinàregulates  metabolic  rate   •   Animals  capable  of  temperature  regulation  maintain  a  constant  body  temperature   through  a  negative  feedback  loop   o   The  hypothalamus  acts  as  a  control  center  by  responding  to  fluctuations  in  body   temperature   o   The  skin  possesses  thermoreceptors  also  and  relays  this  information  to  the   hypothalamus   •   When  body  temperature  rises,  the  following  cooling  mechan isms  occur:   o   Vasodilation   §   The  skin  arterioles  dilate,  bringing  blood  into  closer  proximity  to  the   body  surface  and  allowing  heat  transfer  (convective  cooling)   o   Sweating   §   Sweat  glands  release  sweat,  which  is  evaporated  at  the  cost  of  latent   heat  in  the  air,  thus  cooling  the  body  (evaporative  cooling)   •   When  the  body  temperature  falls  the  following  heating  mechanisms  may  occur:   o   Vasoconstriction   §   Skin  arterioles  constrict,  moving  blood  away  from  the  surface  of  the   body,  this  retaining  heat  carried  within  the  blood   o   Shivering     §   Muscles  begin  to  shake  in  small  movements,  expending  energy  through   cell  respiration  (which  produces  heat  as  a  by -­‐product)   3.   What  does  it  do?  Why  is  it  important?   •       Hypothalamus   1.   What  is  it?   •   master  coordinator  region  of  the  brain  responsible  for  a   variety  of  physiological   functions   2.   How  does  it  work?   •     3.   What  does  it  do?  Why  is  it  important?   •       Feedback  loop   1.   What  is  it?   •   A  pathway  that  involves  input  from  a  sensor,  a  response  via  an  effector,  and  detection   of  the  response  by  the  sensor   2.   How  does  it  work?   •   Positive  feedback  loop:   o       •   Negative  feedback  loop:   o   When  a  variable  deviates  from  the  norm  the  result  of  the  effector  mechanism  is   to  return  the  variable  back  to  the  norm   §   Deviation  from  norm àreceptoràcoordinating   centeràeffectorsàreturn  to  norm   o   Body  temperature  is  an  example  (see  Homeostasis)   3.   What  does  it  do?  Why  is  it  important?   •       Pituitary  gland   1.   What  is  it?   •   An  endocrine  gland  in  the  brain  that  secrets  many  important  hormones   2.   How  does  it  work?   •     3.   What  does  it  do?  Why  is  it  important?   •       Glycogen   1.   What  is  it?   •   An  energy-­‐storing  carbohydrate  found  in  muscle  and  liver   2.   How  does  it  work?   •     3.   What  does  it  do?  Why  is  it  important?   •   Stores  glucose  in  the  liver   •   Glycogen  is  stored  in  the  liver     Glucagon   1.   What  is  it?   •   A  hormone  produced  by  the  pancreas  that  causes  an   increase  in  blood  sugar   2.   How  does  it  work?   •   Stimulates  transportation  of  glycogen  to  blood  stream   •   When  blood  glucose  levels  are  low  (after  exercise)   o   Released  from  alpha  cells  in  the  pancreas   §   Causing  an  increase  in  blood  glucose  concentration   3.   What  does  it  do?  Why  is  it  important?   •   Raises  blood  glucose  by  triggering  release  of  glycogen   •   May  increase  glycogen  breakdown   •   May  decrease  rate  of  cell  respiration   •   May  increase  release  from  adipose  tissue     Kidney   1.   What  is  it?   •   An  organ  involved  in  osmoregulation,  filtration   of  the  blood  to  remove  wastes  and   production  of  several  important  hormones   2.   How  does  it  work?   •   Filtration   o   Nephron   §   Glomerulus  &  bowman’s  capsule   §   Proximal  tubule   §   Loop  of  henle     •   Ultrafiltration     •   Excretion   3.   What  does  it  do?  Why  is  it  important?   •   Excretes  waste   •   Balances  water  and  salt  excretion   •   Removes  waste  and  extra  fluid  from  the  body  to  maintain  the  concentration  gradient  of   body  fluids     •   Most  dispensable  because  there  are  two  kidneys  within  the  organ  system,  therefore,   the  body  can  continue  to  function  proper ly  with  only  one     Osmoregulation   1.   What  is  it?   •   Maintenance  of  relatively  stable  volume,  pressure,  and  solute  concentration  of  bodily   fluids,  especially  blood   2.   How  does  it  work?   •     3.   What  does  it  do?  Why  is  it  important?   •   Inability  to  osmoregulate  may  result  in  edemaàswelling  of  tissues  or  organs  with  fluid     Metabolism   1.   What  is  it?   •   Rate  the  body  processes   2.   How  does  it  work?   •   Skinny  personàhigh  metabolism   3.   What  does  it  do?  Why  is  it  important?   •       Digestive  System   Digestion   1.   What  is  it?   •   Mechanical  and  chemical  breakdown  of  food  into  subunits,  enabling  absorption  of   nutrients     2.   How  does  it  work?   •   Glucose  molecule  enters  the  mouth,  it  begins  as  a  carbohydrate  (i.e.  starch)  in  food   •   The  macromolecule  is  broken  down  into  a  micromolecule  by  the  e nzymes  in  saliva   (salivary  glands)  to  be  easily  absorbed  by  cells  to  be  used  by  the  body   •   The  molecule  then  passes  through  laryngopharynx  via  the  glottis,  to  be  swallowed   •   It  then  travels  down  the  esophagus  and  into  the  stomach  to  be  broken  down  by  proteins   (through  pepsin  enzymes)   •   The  molecule  then  passes  through  pyloric  end,  the  end  of  the  stomach  that  em pties  into   the  small  intestine   •   While  in  the  small  intestine,  it  passes  through  the  duodenum  leaving  the  pyloric  end,   into  the  jejunum  and  then  the  ileum   •   As  it  finishes  passing  through  the  small  intestine,  the  glucose  is   absorbed  into  the  blood   stream   •   The  blood  stream  then  carries  the  glucose  to  a  muscle  with  the  help   of  insulin  to  enter   the  muscle   3.   What  does  it  do?  Why  is  it  important?   •   Most  food  is  solid  and   in  the  form  of  large  complex  molecules  which  are  insoluble  and   chemically  inert   o   Large  molecules  need  to  be  broken  down  into  smaller  molecules  that  can  be   readily  absorbed  across  the  membrane  and  into  cells   o   Small  molecules  can  be  reassembled  into  new  produc ts     Pepsin   1.   What  is  it?   •   Protein-­‐digesting  enzyme  that  is  active  in  the  stomach   2.   How  does  it  work?   •     3.   What  does  it  do?  Why  is  it  important?   •       Lipase   1.   What  is  it?   •   Fat-­‐digesting  enzyme  active  in  the  small  intestine   •   Source:  pancreas   •   Substrate:  triglycerides   2.   How  does  it  work?   •     3.   What  does  it  do?  Why  is  it  important?   •       Villi/Villus   1.   What  is  it?   •   Fingerlike  projections  of  folds  in  the  lining  of  the  small  intestine  wall  that  are   responsible  for  most  nutrient  and  water  absorption     2.   How  does  it  work?   •     3.   What  does  it  do?  Why   is  it  important?   •   Increase  the  surface  area  to  help  absorption   o   Absorptionàtransfer  of  nutrients  from  the  digestive  tract  into  the  blood   stream,  usually  through  villi  in  the  small  intestine   •   The  villus  has  surface  cells  with  large  numbers  of  mitochondria,  whi ch  active  uptake  of   end  products  of  digestion   •   Holds  a  dense  capillary  network  beneficial  for  good  blood  supply  to  remove  water -­‐ soluble  absorbed  nutrients   •   The  lacteal  of  the  villus  removes  the  end  products  of  fat  digestion  and  lipid  soluble   vitamins     Insulin   1.   What  is  it?   •   Hormone  secreted  by  the  pancreas  that  causes  a  decrease  in  blood  sugar   2.   How  does  it  work?   •   When  blood  glucose  levels  are  high  (after  eating)   o   Released  from  beta  cells  in  the  pancreas   §   Causing  a  decrease  in  blood  glucose  concentration   3.   What  does  it  do?  Why  is  it  important?   •   May  increase  glycogen  synthesis   •   May  increase  rate  of  cell  respiration   •   May  increase  uptake  into  adipose  cells     Diabetes   1.   What  is  it?   •   Disease  characterized  by  chronically  elevated  levels  of  blood  sugar   2.   How  does  it  work?   •   Type  1  Diabetes:   o   Geneticàmutation   §   Usually  early  onset  (childhood?)   o   Insulin  dependent   o   Body  does  not  produce  insulin   §   Requires  insulin  injections   o   Caused  by  destruction  of  beta  cells   o   Too  much  glucose  in  blood  because  of  alpha  cells     o   Takes  water  out  of  blood   o   Pancreas  cells  don’t  function  properly   o   Stem  cells  can  help     •   Type  2  Diabetes:   o   Brought  on  by  obesity   §   Usually  late  onset  (adulthood?)   o   Is  not  insulin  dependent   o   Body  does  not  respond  to  insulin   §   Receptor  malfunction   o   Caused  by  down  regulation  of  insulin  receptors  (dietary   cause?)   o   Controlled  by  monitoring  diet   §   Weight  lossàcure   o   Stem  cells  can’t  help   3.   What  does  it  do?  Why  is  it  important?   •       Organs  in  the  Digestion  System:   Digestive  Organ   Function   Features   Stomach   Stores,  mechanically  break   Strongly  acidic,  kills  pathogens,   down  and  digests  proteins  in   pepsin  stored  in  stomach  wall   foods,  acts  as  a  “storage  tank,”   (activated  by  presence  of  HCl)   where  protein  digestion  begins,   turns  food  into  a  paste  called   chyme,  empties  into  small   intestine   Small  Intestine   Site  of  where  bulk  of  chemical   Wall  of  small  intestine  c ontains   digestion  and  absorption  of   villi  to  increase  surface  area  and   food,  absorbs  nutrients  into  the   optimize  absorption,  enzymes   bloodstream,  empties  into  large   needed  for  digestion  come  from   intestine   small  intestine  wall,  bile  from   liver  is  released  here   Pancreas   Produces  enzymes  (i.e.  lipase)   Alpha  islet  cellàproduce   that  act  in  the  small  intestine   glucagon   and  secretes  a  juice  that   Beta  islet  cellsàproduce  insulin   neutralized  acidic  chyme ,   (islet  cells  are  in  the  pancreas)   carries  digestive  enzymes,   releases  insulin  and  glucagon   Liver   Produces  bile  salts  that  emulsify   Stores  glycogen   fats   Gallbladder   Stores  bile  salts  (from  liver)  and     released  them  as  needed  into   the  small  intestine   Large  Intestine   Absorbs  remaining  water  and   water  used  in  digestive  process     solid  waste  is  formed,  breaks   is  reabsorbed  back  into  body   down  waste   (via  osmosis)       Cardiovascular  System   Pulmonary  Circuit   1.   What  is  it?   •   Circulation  of  blood  between  the  heart  and  the  lungs   2.   How  does  it  work?   •     3.   What  does  it  do?  Why  is  it  important?   •       Systemic  Circuit   1.   What  is  it?   •   Circulation  of  blood  between  the  heart  and  the  rest  of  the  body   2.   How  does  it  work?   •     3.   What  does  it  do?  Why  is  it  important?   •       Heart   1.   What  is  it?   •   Muscular  pump  that  generates   force  to  move  blood  throughout  the  body   •   Myogenic  muscle   2.   How  does  it  work?   •   Blood  flow   o   Blood  returning  from  all  parts  of  the  body  (except  lungs)  enter  the  right  atrium   via  the  vena  cavaàthis  blood  is  relatively  deoxygenated   o   Blood  passes  from  the  right  atrium  to  the  right  ventricle  and  then  by  the   pulmonary  artery    to  the  lungs  (where  blood  is  reoxygenated)   o   Blood  returns  to  the  left  atrium  via  the  pulmonary  vein  and  passes  through  the   left  ventricle  to  the  aorta,  where  it  is  pumped  around  the  body   •   Heart  valves   o   Maintain  one  way  flow  of  blood   §   When  atria  contracts à  atrioventricular  (AV)  valves  open   §   Blood  flows  from  the  atria  into  the  ventricles   §   When  ventricles  contract àAV  valves  close  and  semilunar  valves  open   §   This  forces  blood  out  of  the  ventricles  and  into  the  a rteries   §   Arterial  pressure  rises à  semilunar  valves  close,  ensuring  one  way  blood   flow   3.   What  does  it  do?  Why  is  it  important?   •       Control  of  heart  beat   •   Contraction  of  heart  tissue  is  myogenic     o   Signal  for  cardial  contraction  arises  within  heart  muscle  itself   •   SA  nodeàsinoatrial  node     o   Initiates  contraction  of  the  cardiac  muscle   o   Acts  as  a  pacemaker   §   Regulating  sinus  rhythm       Regulation  of  heart  rate   •   Pacemaker  is  under  autonomic  control  from  the  brain   o   From  the  medulla  oblongata  (brain  stem)   •   Sympathetic  nerves  speed  up  heart  rate  by  releasing  neurotransmitters(i.e.   noradrenaline)àincrease  heart  rate   •   Parasympathetic  nerves  slow  down  heart  rate  by  releasing  a  neurotransmitter  (i.e.   acetylcholine)àdecrease  heart  rate   •   Heart  rate  may  be  increased  by  chemical  release  of  adren aline  hormone  into  the  blood   (from  adrenal  gland)     Blood  vessels   •   Arteries   o   Cary  blood  at  high  pressure   o   Outer  layer  contains  collagen  to  prevent  artery  from  rupturing  due  to  high  pressure   of  blood  flow   •   Veins   o   Carry  blood  under  low  pressure   o   Have  valves  to  prevent  blood  pooling  at  extremities   •   Capillaries   o   Involved  with  material  and  gas  exchange  with  surrounding  body  tissue   o   Blood  pressure  is  relatively  low   o   Wall  is  made  up  of  a  single  layer  to  allow  for  easy  diffusion   o   May  contain  pores  to  aid  the  transport  of  m aterial     Cholesterol   1.   What  is  it?   •   Lipid  that  is  transported  in  the  blood  by  specialized  proteins   2.   How  does  it  work?   •     3.   What  does  it  do?  Why  is  it  important?   •       Respiratory  System   Lungs   1.   What  is  it?   •   Major  respiratory  organ  in  humans     2.   How  does  it  work?   •     3.   What  does  it  do?  Why  is  it  important?   •   The  site  of  gas  exchange  between  air  and  the  blood     Respiration   •   Respiration  is  the  transport  of  oxygen  to  cells  where  energy  production  takes  place  and   involves  three  key  process:  Ventilation,  Gas  Exchange  and  Cell  Respiration   o   Ventilation   §   The  exchange  of  air  between  the  lungs  and  the  atmosphere;  achieved   by  the  act  of  breathing   o   Gas  Exchange   §   The  exchange  of  O2  and  CO2  in  the  alveoli  and  the  bloodstream;  it   occurs  passively  via  diffusion   o   Cell  Respiration   §   The  release  of  ATP  from  or ganic  molecules;  it  is  greatly  enhanced  by  the   presence  of  oxygen  (aerobic  respiration)       Alveoli   1.   What  is  it?   •   Air  sacs  in  the  lungs   2.   How  does  it  work?   •   Attached  to  the  bronchiole  in  the  lungs   •   During  gas  exchange  in  the  lungs,  oxygen  is  diffused  from  alveoli   into  the  blood  stream   and  carbon  dioxide  is  diffused   from  the  blood  into  the  alveoli   3.   What  does  it  do?  Why  is  it  important?   •   Gases  diffuse  between  air  and  blood   •   Increase  surface  area  to  volume  to  ratio   o   Why?  à  spherical-­‐shape  improve  surface  exchange   •   The  alveoli’s  thin  wall  is  made  of  a  single  layer  of  flattened  cells  so  that  the  diffusion   distance  is  small   •   Alveoli  are  covered  by  a  dense  network  of  capillaries  that  help  to  mai ntain  a   concentration  gradient   •   Some  cells  in  its  lining  secret  fluid  to  allow  gasses  and  to  prevent  an  alveoli  fro m   collapsing  (through  cohesion)   Erythropoietin  (EPO)   1.   What  is  it?   •   Hormone  that  stimulates  red  blood  cell  production   2.   How  does  it  work?   •     3.   What  does  it  do?  Why  is  it  important?   •   Risks  and  benefits  of  using  EPO  (erythropoietin )  and  blood  transfusions  to  improve   performance  in  sports   o   Erythropoietin  (EPO)à  a  glycoprotein  hormone  produced  in  the  kidneys  that  is   responsible  for  red  blood  cell  production  (erythropoiesis)   o   Blood  transfusionsà  involve  the  intravenous  injection  of  blood  components  (i.e.   red  blood  cells)  into  the  body   Benefits   Risks   •   Both  increase  levels  of  red   blood  cells   •   Too  many  red  blood  cells  can  produce   (EPO  increases  production,  blood   damage  in  capillaries  by  increasing   transfusion  increases  supply)   blood  clotting,  leading  to  heart  failure   and  strokes   •   More  red  blood  cells  means  more   •   Risk  of  disease  transmission  or   hemoglobin,  allowing  for  greater  levels   possible  rejection  when  undergoing   of  oxygen  transport  to  respiring   blood  transfusions   muscles   •   Improves  performance  and  endurance   •   Increased  blood  viscosity  (due  to   compared  to  athletes  that  do  not  use   higher  cell  count)  increases  blood   these  methods   pressure   •   Limited  information  on  long-­‐term   health  effects  (more  relevant  to  EPO)   •   Unfair  advantage  to  athletes  can   result   in  banning  or  disqualification  from   competitions     Central  Nervous  System   Nervous  System   •   Central  Nervous  System àbrain  and  spinal  cord   •   Peripheral  Nervous  System   •   The  nervous  system  is  composed  of  cells  called  neurons  that  carry  rapid  electrical  impuls es     Neuron   1.   What  is  it?   •   Specialized  cells  of  the  CNS  that  generate  electrical  signals  in  the  form  of  action   potentials   2.   How  does  it  work?   •   Dendritesàbranched  extensions  from  the  cell  body  of  a  neuron,  which  receive  incoming   information   •   Axonàlong  extension  of  a  neuron  that  conducts  action  potentials  away  from  the  cells   body  toward  the  axon  terminal   3.   What  does  it  do?  Why  is  it  important?   •   Sensory  neuronàcells  that  convey  information  from  both  inside  and  outside  the  body   to  the  cells   •   Motor  neuronàneuron  that  control  the  contractions  of  skeletal  muscles       How  Nerves  Conduct  Impulses   •   From  receptors  to  the  CNS  by  sensory  neurons     •   Within  the  CNS  by  relay  neurons   From  the  CNS  to  effectors  by  motor  neurons   Synaptic  Transfer   •   The  junction  between  two  neuro ns  is  a  synapse,  it  forms  a  physical  gap  between  the  pre -­‐   and  post-­‐synaptic  neurons   •   An  action  potential  (electrical  signal)  cannot  cross  the  synaptic  gap,  so  it  triggers  the  release   of  chemicals  (neurotransmitters)  to  continue  the  signal   •   Chemical  transfer  across  the  membrane   o   When  an  action  potential  reaches  the  axon  terminal,  it  triggers  the  opening  of   voltage-­‐gated  calcium  channels   o   Calcium  ions  (Ca2+)  diffuse  into  the  cell  and  promote  fusion  of  vesicles  (containing   neurotransmitters)  with  the  plasma  membra ne   o   The  neurotransmitters  are  released  from  the  axon  terminal  by  exocytosis  and  across   the  synaptic  cleft     o   Neurotransmitters  bind  to  receptors  on  the  post -­‐synaptic  membrane,  opening   ligand-­‐gated  channels   o   The  combination  of  chemical  messengers  received  by  de ndrites  determines  whether   the  threshold  for  an  action  potential  is  reached   o   Neurotransmitter  molecules  released  into  the  synapse  are  either  recycled  (by   reuptake  pumps)  or  degraded   •   Synaptic  transmission   1.   Action  potential  reaches  axon  terminal     2.   Calcium  channels  open   3.   Ca2+  causes  vesicles  to  release  neurotransmitter   4.   Neurotransmitter  crosses  synapse   5.   Neurotransmitter  binds  to  neuroreceptors     6.   Trigger  signal  in  post-­‐synaptic  neuron     Resting  Potential   •   The  charge  difference  across  the  membrane  when  a  neuron  is  not   firing,  as  maintained  by   the  sodium-­‐potassium  pump     Action  Potential   •   The  charge  difference  across  the  membrane  when  a  neuron  is  firing   o   Depolarization     §   The  charge  from  a  negative  resting  potential  to  a  positive  action  potential   (caused  by  the  opening  of  sodium  channels)   o   Repolarization   §   The  charge  from  a  positive  action  potential  to  a  negative  resting  potential   (by  opening  of  potassium  channels)     Nerve  Impulses   •   Generation  of  a  Resting  Potential   o   The  NA+/K+  pump  maintains  the  electrochemical  gradient  of  the  r esting  potential     o   It  uses  active  transport  to  exchange  Na+  and  K+  ions  across  the  membrane  (antiport   mechanism)   o   It  expels  3  Na+  ions  for  every  2  K+  ions  admitted   o   This  makes  the  inside  of  the  membrane  relatively  negative  compared  the  outside   •   Transmission  of  an  Action  Potential   o   Na+  and  K+  channels  are  voltage -­‐gated,  meaning  they  open  and  close  depending  on   voltage   o   In  response  to  a  signal  at  a  receptor  or  dendrite,  Na+  channels  open  and  Na+  enters   the  neuron  passively   o   The  influx  of  sodium  causes  the  membrane   potential  to  become  positive   (depolarization)   o   If  a  sufficient  change  in  membrane  potential  is  achieved  (threshold  potential),   adjacent  voltage-­‐gated  Na+  channels  open   o   This  generate  a  wave  of  depolarization  (action  potential)  that  spreads  down  the   axon   o   The  change  in  membrane  potential  also  activates  voltage -­‐gated  K+  channels,  causing   potassium  to  exit  the  neuron  passively   o   The  efflux  of  potassium  causes  the  membrane  potential  to  become  negative  again   (repolarization)   o   Before  a  neuron  can  re -­‐fire,  the  original  distribution  of  ions  (Na+  out,  K+  in)  must  be   re-­‐established  by  the  Na+/K+  pump   o   Then  inability  to  propagate  another  action  potential  during  this  time  (refractory   period)  ensures  nerve  impulses  only  travel  in  one  direction   •   Stages  of  an  action  potential   1.   Resting  potentialàNa+/K+  pump   2.   Depolarizationàvoltage-­‐gated  Na+  channel   3.   Repolarizationàvoltage-­‐gated  K+  channel   4.   Resting  potentialàNa+/K+  pump     Glial  cell   1.   What  is  it?   •   Supporting  cells  of  the  nervous  system   2.   How  does  it  work?   •     3.   What  does  it  do?  Why  is  it  important?   •   Maintain  constant  environment  for  axons     Neurotransmitter   1.   What  is  it?   •   Chemical  signaling  molecule  released  by  a  neuron  to  transmit  a  signal  to  a  neighboring   cell   2.   How  does  it  work?   •   Dopamineàneurotransmitter  that  is  involved  in  conveying  a  sense  of  pleasure  in  the   brain   3.   What  does  it  do?  Why  is  it  important?   •       Electrochemical  gradient   1.   What  is  it?   •   Charge  gradient   2.   How  does  it  work?   •   Whenever  there  is  a  positive  charge  it  can  work   •   More  positive  outside  than  inside   3.   What  does  it  do?  Why  is  it  important?   •       The  Brain/Mental  Health   Parts  of  the  brain:   Part  of  the  Brain   Function   Location   Cerebellum   Part  of  the  brain  that  processes     sensory  information  and  is   involved  in  movement,   coordination  and  balance   Brain  Stem   Part  of  the  brain  that  is  closest   Midbrain     to  the  spinal  cord  and  which   controls  vital  functions:   Heart  rate,  breathing  and  blood   pressure   Diencephalon   Brain  region  located  between     brain  stem  and  cerebrum  that   includes  thalamus  and   hypothalamus  and  regulates   homeostatic  functions:   Body  temperature,  hunger,   thirst,  and  sex  drive   Cerebrum   Region  of  the  brain  that     controls  intelligence,  learning,   perception  and  emotion ;   integration   Cerebral  Cortex   Outer  layer  of  the  cerebrum;   Frontal   involved  in  many  advanced   brain  functions,  “the  boss”   Hippocampus   Subregion  of  brain  involved  in     learning  and  memory   Amygdala   Subregion  of  brain  that     processes  emotions,  especially   anxiety  and  is  the  seat  of   emotional  memories   Thalamus   Sorts  data         Occipital   •   Function   o   Eye  sight     Temporal   •   Function   o   Sensesàsmell,  taste,  touch     Right  Hemisphere   •   Function   o   Face  recognition     Left  Hemisphere   •   Function   o   Mathematical   o   Linearly  processes   o   language     Basal  ganglia   •   Function   o   Motor  control   o   Problems  with  basal  ganglia àParkinson’s  disease     Mental  Health     Disorder   Symptoms   Genetic   Epigenetics   Neurotransmitters   Location   Component   Effected   Schizophrenia   Delusions   Many  genes   Prenatal   Dopamine-­‐  excess   Prefrontal   Hallucinations   10%  family   stress   of  dopamine   cortex-­‐   Disorganized   members   Physical,   Glutamate  excess-­‐   planning,  etc.     thinking  or   50%  for   mental  or   hippocampus   Basal  ganglia-­‐   speech   identical  twins   sexual     where   abuse   antipsych   Drug  use   drugs  target   dopamine   Bipolar   Dramatic   Multiple  genes   Trauma  or  a   Serotonin   Prefrontal   mood  swings   involved   traumatic   Dopamine   cortex  is  less   Mania  (high   20-­‐25%  if   event,  or   norepinephrine   active   energy  &   parents   other   impulsive   Serotonin  &   experiences   norepinephrine   (the  reward   Alcohol  or   system)  too   drug  use   high  or  too  low     Depression   Hopelessness   Serotonin   Stressful  life   Serotonin   Amygdala-­‐ Loss  of   transporter   event,   (happiness)   emotion   interest   gene  (SSRIs)   death,   Dopamine  (reward   center   Sadness  &   Very  heritable   social   system)   Thalamus-­‐   anxiety   Very  likely  in   isolation   sensory  &   Loss  of   families   Relationship   recovery   energy   100%  in   conflict   Hippocampus-­‐   Changes  in   identical  twins   Health   memory  &   appetite   issues   chronic  stress   Autism   Trouble   Over  200  genes   Inutero   Serotonin-­‐  non     interacting   affected   difficulty     synthesized   Delayed   A  spectrum   normally   development   Very  heritable,   Glutamic   Inappropriate   up  to  100%   imbalance   language  use     Conclusionà  mental  healthà  largely  genetic   Schizophreniaà  geneticàenvironment  determines  if  the  genes  are  expressed     Reproductive  System   Hormones  in  the  menstrual  cycle   •   FSH  and  LH  are  released  from   the  anterior  pituitary  and  act  on  ovaries   •   Estrogen  and  progesterone  are  released  from  the  ovaries  and  act  on  the  uterus  (endometrium)   Hormone   Function   FSH   •   Stimulates  follicle  growth   •   Stimulates  estrogen  secretion  (from   follicles)   Estrogen   •   Development  of  endometrium   •   Stimulate  LH  secretion  (follicular  phase)   •   Inhibit  LH  and  FSH  secretion  (luteal   phase)   LH   •   Surge  causes  ovulation   •   Development  of  corpus  luteum   •   Stimulates  progesterone  secretion   Progesterone   •   Thickening  of  endometrium   •   Inhibits  LH  and  FSH  (luteal  phase)     Summary  of  menstrual  cycle   1.   Follicular  phase   •   FSH  stimulates  growth  of  several  follicles     •   Dominant  follicle  secrets  estrogen   •   Estrogen  stops  other  follicle’  growth  (and  FSH)   •   Estrogen  stimulates  endometrial  development   2.   Ovulation   •   A  surge  in  LH  causes  o vulation  (egg  release)   •   Rupturing  of  follicle  creates  an  corpus  luteum   3.   Luteal  phase   •   Corpus  luteum  secrets  estrogen/progesterone   •   Progesterone  stimulates  endometrial  growth   •   Estrogen  and  progesterone  inhibit  FSH  and  LH   •   Corpus  luteum  degrades  over  time   •   Progesterone  levels  drop     •   Endometrium  is  sloughed  away  (menstruation)     Testosterone  in  males   •   Pre-­‐natal  development  of  male  genitalia   •   Development  of  secondary  sex  characteristics   •   Maintenance  of  sex  drive     In  Vitro  Fertilization     •   In  vitro  fertilization  refers  to  fertilization  outside  of  the  body   o   Stop  menstrual  cycle  (with  drugs)   o   Hormone  treatment  to  develop  follicles   o   Extract  multiple  eggs  from  ovaries   o   Sperm  selection  (capacitation)   o   Fertilization  occurs  in  glass  dish   o   Implantation  of  embryos  into  uterus   o   Test  for  pregnancy   •   Advantages   o   Allows  infertile  couples  to  have  children   o   Genetic  screening  of  embryos  could  reduce  occurrence  of  genetic  diseases   o   Spare  embryos  can  be  stored  for  future  attempts  or  used  in  stem  cell  research   •   Disadvantages   o   IVF  is  expensive  and  might  not  be  equally  accessible  to  all     o   Success  rate  is  low  and  hence  may  be  stressful  for  couples   o   It  could  lead  to  eugenics  (gender  choices)     o   Often  leads  to  m


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StudySoup has more than 1 million course-specific study resources to help students study smarter. If you’re having trouble finding what you’re looking for, our customer support team can help you find what you need! Feel free to contact them here:

Recurring Subscriptions: If you have canceled your recurring subscription on the day of renewal and have not downloaded any documents, you may request a refund by submitting an email to

Satisfaction Guarantee: If you’re not satisfied with your subscription, you can contact us for further help. Contact must be made within 3 business days of your subscription purchase and your refund request will be subject for review.

Please Note: Refunds can never be provided more than 30 days after the initial purchase date regardless of your activity on the site.