Heart & Circulatory System General Information Part 3

VIII. Blood Clotting

a. Depends on blood cells called platelets, which adhere to site where blood vessel is damaged. Then, the platelets break apart and release substances called clotting factors. Clotting factors make nearby platelets sticky and activates a series of reactions in plasma

b. Fibrin (shown on left) threads trap red blood cells and additional platelets

e. Networks of threads and cells build up, eventually forming a patch stretching over torn tissue

IX. Anatomy of the Respiratory System

a. Structures

 - Mouth

 - Nose

 - Pharynx (passageways for air and mouth cross)

 - Larynx (pharynx leads to larynx; voicebox)

 - Trachea (Larynx leads to trachea; rigid structure with cartilage around it; water and air travels through it)

 - Lungs

     - Epiglottis

     - Bronchi (Trachea break into two bronchi, and it keeps splitting into smaller and smaller tubes)

     - Bronchioles (When bronchi become small enough that they do not have cartilage)

     - Alveoli (Bronchioles split into small air sacs called alveoli.)

 

Khanacademy

 http://www.yorku.ca/earmstro/journey/diaphragm.html (Click here to learn more about the diaphragm and watch an animation of it in action)

X. Breathing

a. Diaphragm

b. Inhale when diaphragm and rib muscles contract, which expands chest cavity (increasing volume of lungs, resulting in reduced air pressure)

c. Exhale when diaphragm and rib muscles relax, decreasing lung volume which causes higher air pressure in alveoli

XI. Breathing Regulation

a. Level of carbon dioxide determines breathing rate

b. Medulla oblongata of brain controls breathing

Source: http://www.pennardfr.org.uk/The%20heart/elecsystem.htm