Human and Plant Systems Test Review Notes

Purpose of the digestive system:
1. Take in food.
2. Digest the food to supply chemical energy and other nutrients to cells.
3. Excrete the remaining waste.
Steps of digestion:
1. Food is put into the mouth.
2. The teeth chew the food.
3. The food is swallowed down the esophagus to the stomach.
4. The acid in the stomach begins the chemical breakdown of the food.
5. The food moves from the stomach into the small intestine.
6. The nutrients in the food are absorbed in the small intestine.
7. Water is absorbed in the large intestine, leaving solid waste.
8. Solid waste passes from the digestive system out of the body.
The process of digestion usually takes 20-30 hours.

'Pulmonary' refers to the lungs/respiratory system.
The epiglottis prevents food from entering the respiratory system.
Diffusion: The movement of a substance from an area of high concentration to an area of low concentration.
- Importance in the respiratory system:
  - Oxygen in the alveoli diffuses into the bloodstream to be distributed to the rest of the body by the circulatory system.
  - Carbon dioxide diffuses out of the blood into the alveoli to be removed from the body.
Journey of air through the respiratory system:
1. The diaphragm contracts, changing the pressure in the thoracic cavity.
2. Air is sucked in through the nostrils, through the pharynx, and into the trachea.
3. It branches off at the bronchus, down through the bronchioles into the lungs.
4. In the alveoli, gas exchange occurs.
5. $O_2$ moves by diffusion out of the capillaries and into the alveoli.
6. $CO_2$ moves by diffusion from the lung to the blood.
7. The diaphragm relaxes, pushing air out of the alveoli, through the bronchioles, through the bronchus, up the trachea, past the pharynx, and out the mouth.

Journey of a blood cell through the circulatory system:
1. A deoxygenated blood cell returns to the heart via the vena cava.
2. It enters the right atrium.
3. The right atrium pumps it through the tricuspid valve to the right ventricle.
4. The right ventricle pumps the blood cell out the pulmonary artery to the lungs.
5. The oxygenated blood cell returns to the heart via the pulmonary veins.
6. The left atrium pumps it through the mitral/bicuspid valve.
7. The left ventricle pumps the cell out to the body through the aorta.
Red blood cells carry oxygen and nutrients.
White blood cells fight infection.
Matching:
- Veins: A large blood vessel that carries blood toward the heart under low pressure.
- Capillaries: A thin-walled blood vessel that allows the exchange of gases, nutrients, and wastes between the blood and body tissues.
- Arteries: A large, muscular blood vessel that carries blood away from the heart under pressure.
The body needs a constant supply of oxygen and nutrients, as well as the removal of carbon dioxide and waste. Blood is pumped through the circulatory system by the heart. Blood vessels branch out from the heart and grow smaller towards the cells.

Importance of the skeletal system:
1. Protection
2. Movement
The human body has 206 bones.
Compound (open) fracture: A fracture in which the bone is sticking through the skin.
Simple (closed) fracture: A fracture where the bone has not broken through the skin.

Liver: Digestive accessory organ that produces bile to help in the breakdown of fats.
Pancreas: Digestive accessory organ that produces insulin which regulates glucose concentrations in the blood.

A ligament connects bone to bone, and a tendon connects muscle to bone. Both are connective tissues.

Two major parts of the nervous system:
- Brain: Controls nearly all functions of the body.
- Spinal Cord: Primarily transmits signals between the brain and the peripheral nervous system; also controls certain reflex actions.
Purpose of the nervous system: Carries messages throughout the body, allowing interaction with the environment.
Neuron Structure: A neuron must send and receive signals from other cells. It has a cell body with many dendrites that receive information. The cell body is attached to a long axon that conducts an electrical signal to the end of the axon, which has many branches to relay the message.
Steps to react to external stimuli:
1. Sensory receptors receive information from the external environment.
2. Signals are sent along the peripheral nerves to the CNS.
3. The brain processes the information and sends a signal back to the PNS to coordinate a response.

Three types of muscle:
1. Skeletal muscle: Attached to bones all over the body; allows for voluntary movement.
2. Smooth muscle: Involuntary muscles found in the digestive system and blood vessels; help move blood in the arteries and food through the digestive system.
3. Cardiac muscle: Found in the heart; involuntary muscle that pumps blood through the circulatory system.
Peristalsis: Term used for the involuntary contraction of the smooth muscles of the digestive system.

Chloroplasts: Organelle, found only in plant cells, necessary for photosynthesis.
Three tissue types found in plants:
1. Vascular tissue
2. Dermal tissue
3. Ground tissue
Two systems found in plants:
1. Root System:
  - Anchors the plant to the ground
  - Absorption of water and minerals from the soil
  - Energy and nutrient storage
  - Conducts water and nutrients
2. Shoot System (flower, leaf, and stem):
  - Photosynthesis
  - Conducts energy and water
  - Reproduction
Xylem: Elongated cells that transport water from roots to the leaves (no longer living tissue once mature).
Phloem: Vascular tissue that transports sugars and other soluble organic material throughout the plant.