Biology

• Homeostasis


  Essential for living organisms to maintain a stable internal environment
• Negative feedback


  A change happens to the body that is helpful, positive feedback promotes this change and keeps it going
• Negative feedback homeostasis


  • Sweating and shivering to maintain body temperature
• Pulmonary circulation


  Blood flow between the heart and the lungs, transports deoxygenated blood to the lungs to absorb oxygen and release carbon dioxide
• Systemic circulation


  Blood flow between the heart and the rest of the body, providing oxygen to the body
• Arteries


  • Carry blood away from the heart, have thicker walls to withstand pressure, carry oxygenated blood under higher pressure than veins
• Veins


  • Carry blood back into the heart, have thinner walls to allow blood to keep flowing, carry deoxygenated blood, have valves to get blood from limbs
• Heart beating


  Brain sends signals through nerves to the heart, brain stem supports vital organs
• Blood pressure


  Force of blood pushing against artery walls, measured with a sphygmomanometer or blood pressure machine
• The skeletal system gives the body structure and shape, allows movement, protects organs, makes blood cells and minerals
• Types of joints


  • Fixed - cannot bend (skull bones)
  • Hinge - allows forward/backward movement (elbow, knee)
  • Ball and socket - rounded bone in cavity (upper arm/shoulder, upper leg/hip)
• Muscular system


  Responsible for movement, mineral storage, warmth
• Types of muscle


  • Skeletal - attached to bones, controlled voluntarily
  • Cardiac - in the heart, responsible for pumping
  • Smooth - in walls of hollow organs, maintains blood pressure and flow, moves food in digestive system
• Muscles need glucose, minerals, electrolytes, oxygen, protein, water to function properly
• The main function of the respiratory system is to circulate air in and out of the body, moving oxygen in and carbon dioxide out
• Alveoli


  Responsible for oxygen entering the bloodstream and carbon dioxide being expelled
• Pressure and volume


  Impact inhalation and exhalation through the diaphragm
• Physical digestion is the physical breakdown of food, chemical digestion is further breakdown with enzymes
• Enzymes like amylase, protease, and lipase are produced in the pancreas and used in chemical digestion
• Carbohydrates, proteins, and lipids are first chewed then further broken down in the stomach, before being absorbed in the small intestine
• Blood flow through the heart: Left

  1. Now oxygenated blood goes back to the heart through the pulmonary vein 
  2. The blood goes through the mitral valve and into the left atrium 
  3.  left ventricle pumps the blood through the aortic valve and into the aorta 
  4. Blood leaves aorta and flows through the rest of the body in blood vessels Deoxygenated blood returns to the heart and the process is repeated.
• Blood flow through the heart: Right

  1. The blood enters the heart through the inferior and superior vena cava 
  2. Blood flows into the right atrium and through the tricuspid valve into the right ventricle
  3. Blood goes through the pulmonary valve and into the pulmonary artery 
  4. The pulmonary artery gets oxygen from the lungs