From%Cells%to%Organs% - jmazzabiology.comjmazzabiology.com/APbio.pdfFrom%Cells%to%Organs% ... (speech,%problem%solving,%etc.)% • EVERYTHING!% Nervous%System FUNCTION:))Allows&organisms&to&

From  Cells  to  Organs  

•  Stem  cells  are  the  star2ng  point  •  Cells  become  specialized  

•  Groups  of  specialized  cells  make  2ssues  

•  Tissues  form  organs  

•  Organs  work  together  in  organ  systems  to  maintain  homeostasis  in  the  body  

What  does  the  nervous  system  help  us  do?  

•  Movement  

•  Breathing  •  Regulates  heart  rate  and  blood  flow  •  Diges2ng  food  •  Sensing  our  environment:  see,  hear,  taste,  smell,  feel,  etc.  

•  Complex  tasks  (speech,  problem  solving,  etc.)  

•  EVERYTHING!  

Nervous  System  

FUNCTION:    Allows  organisms  to  sense  and  respond  to  s1muli  in  their  environment  

Made  of  two  major  divisions:  •  Central  Nervous  System  (CNS)  -­‐  

brain  and  spinal  chord  •  Peripheral  Nervous  System  

(PNS)  -­‐  all  nerve  cells  (neurons)  outside  of  the  CNS  

•  PNS  consists  of  two  major  types  of  neurons:  

The  CNS  and  the  PNS  lifeinthefastlane.ca  

CNS  and  PNS  

Sensory  Neurons  vs.  Motor  Neurons  

•  Sensory  neurons  carry  nerve  impulses  towards  the  brain  and  spinal  chord  (for  sensing  our  environment)  

•  Motor  neurons  carry  nerve  impulses  away  from  the  brain  and  spinal  chord  to  muscles/organs  (for  responding  to  our  environment)  

Knee-­‐jerk  reflex  

Regions  of  the  Neuron  

Dendrites  (branches)  -­‐ Receives  signals  from  other    neurons  

Axon  -­‐ Transmits  the  signal  (nerve  impulse  or  ac1on  poten1al)    

Axon  terminals  -­‐ Relays  signal  to  other  neurons  via  neurotransmiYers  

Synapse  -­‐  area  where  two  or  more  neurons  communicate  with  each  other  

What  is  a  neurotransmiYer?  

•  Chemicals  that  allow  one  neuron  to  “talk”  to  another  neuron.  

•  Every  neuron  releases  neurotransmiYers  at  one  end  and  has  receptors  for  them  at  the  opposite  end  

Respiratory  System  FUNCTION:    To  take  in  oxygen  and  exchange  

it  for  carbon  dioxide.  •  Pharynx  -­‐  throat  •  Larynx  -­‐  contains  vocal  chords  •  Trachea  -­‐  “windpipe”;  air  passes  through  

this  tube  on  way  to  the  lungs  •  Bronchi  -­‐  branches  of  trachea  going  to  

each  lung    •  Bronchioles  -­‐  smaller  branches  of  the  

bronchi  •  Alveoli  -­‐  air  sacs  surrounded  by  

capillaries  where  oxygen  is  exchanged  for  CO2  -­‐  (O2  rich  blood  returns  to  heart  from  here)  

 *    alveoli  can  be  damaged  during  smoking  leading  to  emphysema  

Alveoli  

alveoli  

Diaphragm  

•  The  diaphragm  is  a  flat  muscle  at  the  base  of  the  lungs  that  controls  the  movement  of  the  lungs  during  breathing  

•  Moves  downward  during  inhala2on  and  upwards  during  exhala2on  

•  Its  movement  is  controlled  by  the  CNS  

Circulatory  System  

Purpose:    Transports  O2,  CO2,  and  nutrients  around  the  body  

•  Arteries  (carry  blood  away  from  the  heart)  •  Veins  (carry  blood  towards  the  heart)  •  Capillaries  (where  nutrients  and  O2  diffuse  into  your  body  2ssues  and  cells)  

•  Heart  (pumps  blood  through  the  blood  vessels)  

Blood  Cells  and  Platelets  

•  Red  Blood  Cells  -­‐  transports  O2  and  CO2  in  the  blood  

•  White  Blood  Cells  -­‐  help  to  defend  the  body  against  infec2ons  (bacteria,  viruses)  and  cancer  cells  

•  Platelets  -­‐  func2on  in  blood  clobng  

*  All  three  are  produced  in  the  bone  marrow  (hematopoiesis)  

The  Heart  

•  Consists  of  4  chambers  •  Pumping  chambers  are  the  ventricles  

–  they  push  blood  out  of  the  heart  •  Receiving  chambers  are  the  atria  •  Valves  between  the  atria  and  

ventricles  prevent  the  backflow  of  blood        

Blood  Flow  through  the  Heart  

2. To lungs 2.  To  lungs  

3. from lungs 3. from lungs

1.  O2 poor blood from body

1.  O2 poor blood from body

4. O2 rich blood (to body)

The  Valves  of  the  Heart  

•  Consists  of  4  main  valves  to  prevent  the  backflow  of  blood  

•  Semi-­‐lunar  valves  are  where  blood  is  pumped  out  of  the  heart  into  major  arteries      -­‐  Pulmonary  semilunar  valve        (right  side)      -­‐  Aor1c  semilunar  valve  (leH        side)    

•  AV  valves  between  atria  and  ventricles  (tricuspid  on  right,  mitral  (aka  bicuspid)  on  the  lee)      

Coronary  Blood  Vessels  

•  Coronary  arteries  supply  the  heart  muscle  with  oxygen  and  nutrients  

•  Myocardial  infarc2ons  (heart  aYacks)  occur  when  a  blockage  occurs  in  a  coronary  artery,  cubng  off  oxygen  to  a  por2on  of  the  heart  muscle  

Diges2ve  System  

FUNCTION:    Breakdown  food  molecules  so  that  they  can  be  absorbed  into  the  bloodstream  AND  elimina2on  of  solid  wastes  

•  Mechanical  diges1on  -­‐  physical  breakdown  of  food  (chewing,  churning  of  the  stomach)  

•  Chemical  diges1on  -­‐  breakdown  of  food  by  enzymes  (occurs  in  mouth  (saliva),  stomach,  and  small  intes2nes)  

•  Large  intes2ne  reabsorbs  water  from  undigested  food  and  eliminates  the  solid  remains  

•  Liver,  gallbladder  and  pancreas  produce  diges2ve  secre2ons  that  aid  diges2on  

*see  handout  for  details  on  each  organ  

Villi  and  Microvilli