Biology Test #2 Flashcards
Hierarchy of systems in the body
Cells - tissues - organs - organ systems - organism
Four different types of tissues
Connective tissue - supports, binds, and connects cells and tissues. Consists of cells that can range from a liquid (in blood) to elastic materials that can stretch (in ligaments) to mineral deposits (in bone).
Epithelial tissue - line the surface of the body as a body covering and between internal organs. Made of cells with strong connections, so they form a barrier.
Nervous tissue - made of neurons that have finger-like projections to receive and transfer signals. Coordinates body actions as well.
Muscle tissue - designed to change their shape. Act by shortening or lengthening.
Describe how blood flows in and out of the heart. (Correct terminology).
Blood enters the heart into the right atrium where it is stored for a moment. Then it flows to right ventricle which pumps to the lungs. Blood from the lungs returns to the heart and enters the left atrium and stores it briefly. Then flows to left ventricle which pumps blood to the rest of the body. *Both atriums pump at the same time and both ventricles pump at same time.
Describe the function of the respiratory system.
To bring air to the blood stream so that oxygen can be exchanged with CO2 and CO2 can be exhaled out the body.
Describe the functions of the digestive system.
2 functions: first is take in food and break it down into nutrients that can be absorbed into the blood stream. Second is to remove waste from the blood stream along with indigestible food and remove it from the body.
Describe the functions of the circulatory system.
3 functions: first is to carry nutrients from the small intestine to every cell in the body and carry waste from every cell back to the small intestine. Second is to carry oxygen from the lungs to every cell in the body and carry CO2 from every cell back to lungs to be exhaled. Third is to fight diseases using white blood cells.
Main organs in the digestive system and their functions.
Mouth - teeth chop and grind food and the tongue moves food to back of the mouth to be swallowed.
Esophagus - connects pharynx (which has an epiglottis and that is a flap that makes sure food goes down the esophagus) to the stomach and it is a muscle that moves food down.
Stomach - mechanically breaks down food by churning. Chemically breaks down food with (hydrochloric acid breaks down food and bacteria, pepsin breaks down proteins).
Small intestine: first meter - digestive enzymes enter small intestine from the gall bladder and pancreas. Also mechanically breaks down food by churning. 2-5 meters are where nutrients/waste are exchanged with the blood stream through microvilla.
Liver - produces bile which breaks down fats. Also removes toxins and stores vitamins and sugars for energy.
Large intestine - includes the colon, rectum, and anus. Indigestible food/waste move from small to large intestine. Water and vitamins are absorbed into the blood stream. Waste passes into rectum and is discharged through anus.
Main organs in the circulatory system and their functions.
Blood - liquid that carries oxygen, CO2, nutrients, and waste through the body.
Blood vessels - flexible tubes that carry blood through the body. There are 3 types.
Arteries - carry oxygenated blood and nutrients AWAY from the heart and to every cell in the body. (Is red).
Veins - carry deoxygenated blood and waste from every cell in the body back to the lungs and small intestine. (Is blue).
Capillaries - where arteries and veins join. Are very thin so they can touch every cell in the body and are where oxygen and CO2, and nutrients and waste are exchanged. Wrapped around alveoli in lungs, microvilla in small intestine, and every cell in body.
Heart - organ that pumps deoxygenated blood to the lungs then pumps oxygenated blood to the rest of the cells in body.
Describe main organs in the respiratory system and their functions.
Nasal cavity - space behind the nose where air collects to go down the trachea.
Trachea - tube that connects pharynx to the lungs.
Lungs - the two spongy air filled sacs that contain bronchus, bronchioles, and alveoli. Lungs are not a muscle.
Bronchus - two main passage ways into the lungs. As soon as these tubes split AGAIN they’re called bronchioles. They get smaller and smaller until they reach the end where alveoli are.
Alveoli - the destination of air that’s breathed in. Are tiny air sacs surrounded by blood vessels and is where O2 and CO2 are exchanged with the blood.
Diaphragm - muscle that’s attached to the lungs and causes them to expand and contract to bring in and push out air.
What organs does food go through and doesn’t go through in the digestive system?
Goes through - mouth, esophagus, stomach, small intestine, and large intestine.
Doesn’t go through - liver, gall bladder, pancreas.
Describe how oxygen and carbon dioxide are exchanged with the blood stream in the lungs.
Oxygen is pulled into the body, goes down the trachea to the bronchus which splits the air between the two lungs. Air continues to split at bronchioles, then flows through smaller tubes to the alveoli. Capilleries wrap the alveoli and there is a skin layer between the blood and air where oxygen and CO2 are exchanged. Oxygen is taken to each cell in the body through blood. CO2 is breathed out.
Describe how nutrients are exchanged with waste in the small intestine.
Inside walls of the small intestine are lined with villi and microvilla. The surface of these is where nutrients, water, and waste are exchanged with the blood stream. Capillaries wrap the microvilla and there is one layer of skin. Nutrients from small intestine diffuse across this layer of skin into blood stream to be taken to all cells. Waste from blood stream also diffuses across this layer of skin into small intestine to go to large intestine and then out of the body.
3 types of cells in the blood and what they do.
Red blood cells - carry oxygen in hemoglobin.
White blood cells - fight diseases.
Platelets - tiny, colourless pieces of cells that stop bleeding by creating blood clots.
Describe what a stem cell is, the medical potential, and the different types.
Stem cells are unspecialized cells that will become specialized to form a tissue or an organ. These are important because they have medical potential to grow specialized cells that don’t naturally grow on their own. More unspecialized the cell is, more potential it has to become any cell.
3 types of stem cells:
Totipotent - are the first cells formed through cell division in the first 5 days after an egg is fertilized. Can form ANY type of cell or tissue in the body.
Pluripotent - Form after day 5. Specialized cells that are less versatile because they can only form one of the types of tissues in the body. Muscle cell can only produce more muscle cells for example.
Adult - later in development and after birth, people only have adult stem cells.
What is the first cell after conception called?
Zygote.
