Human Body Systems Quiz

Study Notes

Chemical digestion: enzymes break down nutrients into smaller molecules
- Amylase in saliva breaks starch down into sugar
- Pepsin and trypsin in the stomach break proteins down into amino acids
- Lipase in the pancreas breaks fats down into glycerol

Path that air travels: Mouth → Trachea → Bronchus → Bronchiole → Alveoli
Ventilation:
- Breathing in:
  - Interal intercostal muscles relax and external intercostal muscles contract, pulling ribcage up and out
  - Diaphragm contracts, pulling down
  - Lung volume increases and air pressure inside decreases
  - Air is pushed in
- Breathing out:
  - External intercostal muscles relax and internal intercostal muscles contract, pulling ribcage down and in
  - Diaphragm relaxes, pushing up
  - Lung volume decreases and air pressure inside increases
  - Air is pushed out
Gas exchange:
- Happens in the alveoli
- Features: thin walls (one cell thick), large surface area, moist, and many blood capillaries

Double circulatory system: blood goes through the heart twice per loop
Arteries:
- Thick elastic muscle walls (withstand high blood pressure when taking from the heart)
- Flows out of the heart
Veins:
- Thinner less elastic walls, one-way valves
- Returns to the heart
Capillaries:
- Tiny blood vessels branching into all tissues
- Thin walls allow substances to diffuse in and out easily
Blood flow within the heart:
- Venacava: de-oxygenated blood into the right atrium
- Pulmonary Artery: de-oxygenated blood out of the RHS
- Pulmonary Vein: oxygenated blood into the LHS
- Aorta: oxygenated blood out of the LHS

Removal of substances like:
- Toxic materials
- Waste products of metabolism
- Excess substances from organisms
Blood is brought to the kidney in the renal artery
Kidneys filter blood and reabsorb useful materials like glucose
After purification, blood returns to circulation through the renal vein
Urine is taken from the kidney to the bladder by ureters
Examples:
- Skin: sweat glands produce sweat
- Lungs: excess CO2 and some water vapor
- Kidney: excess water, salts, and urea

Key points:
- Allows movement, provides support and protection for vital organs
- Muscles move the bones in the body
Function:
- To support the body
- To protect the vital organs
- To help body move
- To make blood cells
Movement:
- Some bones in the skeleton are joined rigidly and can’t move against each other
- Other bones are joined by flexible joints
- Muscles are attached to bones by tendons
- Skeletal muscles contract and relax to move bones
Making blood cells:
- Different blood cells include:
  - RBC: carries oxygen around the body
  - WBC: involved in destroying harmful bacteria

Antagonistic muscle pairs:
- Agonist: contracts and is agony
- Antagonist: relaxes and allows movement to occur
Joints:
- Ball and Socket: shoulder
- Hinge: elbow
- Fixed: skull

Mitosis, Meiosis, Growing and Developing
Difference:
- Growing: increase in size of an organism, requires an increase in the number of cells
- Developing: changing/maturing to become specialized for a certain function