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Flashcards in Biology S3 Deck (53):

Flow of blood

Flow of blood (circulatory system):
1. Deoxygenated blood is return from the body through the inferior and superior vena cavas to the right atrium.
2. Deoxygenated blood is then pumped through the tricuspid valve (right atrioventricular valve) to the right ventricle.
3. Right ventricle contracts pushing the deoxygenated blood through the pulmonary semilunar valve into the right/left pulmonary artery.
4. Pulmonary artery directs deoxygenated blood to the lungs where CO2 is eliminated and 02 is absorbed.
5. Oxygenated blood travels back to the heart via the right/left pulmonary veins into the left atrium.
6. Left atrium contracts and pushes the oxygenated blood through the bicuspid valve (mitral valve, left atrioventricular valve) into the left ventricle
7. Left ventricle contracts pushing the oxygenated blood through the aortic semilunar valve into the aorta to the rest of the body
8. The blood flows through the body due to the network of veins bring blood back to the heart and arteries carrying blood away from the heart.


Circulatory system function

Circulatory system:
•Transports blood, nutrients, gases and wastes
•Picks up and transports nutrients (from small intestine) and oxygen to cells and carries wastes to the organs responsible for eliminating them
•Includes: heart, blood vessels, and blood


Heart disease and stroke

• Heart disease: caused by narrow passageway for blood. This is because of the thickening of the walls of the arteries caused by plaque and blockage in the arteries caused by blood cots. A section of the heart does not have enough oxygen to function and therefore causes permanent damage to the heart.
• Stroke: sudden loss of brain function due to brain cells dying. stroke occurs when part of the brain is damaged due to oxygen deprivation (clots). arteries narrowed due to plaque caused formation of blood clots that blocks vessels near the brain


Arteries and veins (including smaller vessels-transports blood)

Arteries are thicker than veins
Arteries →arteriole→capillaries

Order of blood flow through the human circulatory system:
Heart, arteries, arterioles, capillaries, venules, veins


Digestive system function

Digestive system:
• Takes in food and breaks it down physically and chemically
• Absorbs nutrients
• Removes solid waste from the body
• Includes mouth, pharynx (passes), esophagus, stomach, pancreas, gall bladder, liver, intestines


Oropharyngeal stage in digestive system

Oropharyngeal Stage:
Digestion begins in the mouth:
• The teeth mechanically breakdown the food into smaller pieces.
• Saliva (amylase: enzyme in saliva) chemically breaks down the food
• Food pressed to top of mouth by tongue and backwards into pharynx
Food travels down tube:
• The epiglottis blocks the trachea and the uvula blocks the nose and nasal passageway →laryngeal muscles contract
• After the food is swallowed, the food passes through the pharynx and into a muscular tube called the esophagus →No breathing as epiglottis and uvula block passageway


Esophageal Stage

• Esophageal Stage: Muscular walls of the esophagus contract and relax, pushing each chunk of food until it reaches the stomach →called peristalsis. There is secondary peristalsis if the food bolus is sticky


stomach digestion

• Stomach: breaks down food physically (mixing and churning) and chemically (enzymes and acids in stomach) to turn food into a liquidy paste.

In the stomach:
• When the food is in the stomach, food chunks are chemically broken down by the gastric juices such as hydrochloric acid and the enzyme pepsin (secreted by the epithelial tissue that lines the stomach). Gastric juices must be acidic because pepsin (breaks down protein), needs an acidic environment to function)
• Stomach lining also secretes mucus (protects stomach wall from breaking down in the presence of those protein-digesting juices)
• Nerves in the muscular wall of the stomach sense the presence of food and force the stomach to continue the mechanical (physical) breakdown → forms liquid
• Result: breaks down food into smaller pieces


Small and large intestine

• Small Intestine: chemically breaks down food (digestion) using chemicals produced by liver, pancreas and gallbladder. Also absorbs nutrients into blood stream through villi (small folds)

Small intestine:
• 6 m in length
• Duodenum, jejunum, ileum make up the small intestine
• Duodenum: most digestion takes place (small tubes called ducts that connect to the pancreas, liver and gall bladder) - chemical breakdown is completed here
• Liver produces bile (stored in gall bladder)→breaks down fat into small droplets
• Pancreatic: break down fat into smaller particles
• Movement into the ileum signals absorption into the body
• Small intestine covered with millions of interior folds, called villi and microvilli (maximizes surface area so that water and nutrients can be absorbed into the bloodstream. Contain specialized cells that transports substances into bloodstream)
• Majority of absorption occurs in small intestine
Large intestine:
• Larger diameter but shorter length than small intestine (1.5 m long)
• Includes colon, rectum, and anus.
• Main function is to absorb water, vitamins, and salts from the digested food
• Other function is to eliminate solid waste/undigested food
• Bacteria in large intestine to help finish the digesting process
• Many plant product cannot be digested and are eliminated by the large intestine
• Anus: opening where solid wastes are eliminated


Small intestine organ functions

o Pancreas: produces a digestive juice that contains a wide array of enzymes to break down fat, carbohydrate and protein in food.
o Liver: produces bile to dissolve fat and processes and purifies blood before going to rest of body
o Gall Bladder: storage sace for excess bile until it’s needed
o Duodenum: first metre of small intestine/most digestion occurs


Large intesine organ functions

o Colon: absorbs H2O, manufacturers vitamins, produces mucous, forms and expels feces.
o Rectum: holds feces (waste) until evacuated
o Anus: evacuates feces (holds until evacuated)


Respiratory system function

Respiratory system:
• Controls breathing
• Exchanges gases in lungs
• Removes carbon dioxide


Respiratory system tract

• System is connected to circulatory system (pulmonary arteries and veins)
• Diaphragm begins process (moves down during inhalation)
Passageway of Air: Nose →Pharynx →Larynx →Trachea →Bronchi →Bronchioles →Alveoli


Gas exchange in lungs

Gas exchange: occur in lungs
• Alveoli are surrounded by capillaries
• Oxygen travels through air sacs and into blood stream
• →When deoxygenated blood (capillaries) passes by the alveoli it picks up oxygen and leaves Carbon dioxide
• Carbon dioxide moves from blood into air; oxygen moves from air into blood/capillaries
• The oxygenated blood then travels back to the heart and then to the body
• When you exhale the Carbon dioxide is eliminated
• Process called gas exchange


Respiratory diseases

• Emphysema: damage to the alveolar sacs inhibiting gas exchange. Alveoli becomes larger as the sacs fill up with air and the air cannot escape and therefore is trapped. Furthermore, the lungs becomes less elastic, which results in the increase of work of respiratory muscles. This results in a reduce in the amount of oxygen transferred by lungs to bloodstream and thus more difficult to breathe. --> caused by smoking, as the particles coat the alveoli and prevent gas exchange.
• Asthma: inflammation of the bronchiole tubes inhibiting air flow. The smooth muscles that line the bronchioles contract. Results in thinner bronchi for air flow


Excretory system function

Excretory system:
• Removes liquid wastes from the body

Blood waste→ kidneys →ureters →bladder →Urethra
• Water and other materials absorbed through the large intestine move into blood vessels
• Blood passes through the kidneys and is filtered and wastes are removed
• As the blood is filtered, urine containing water and unneeded salts is formed
• Urine is stored in the bladder (muscular)→ when full, urine is flushed from body
• Excretory system must interact with digestive and circulatory systems


Root and shoot system

Root system: an organ system in a plant, which takes in water and minerals from the soil and transports these substances to the shoot system
• Responsible for taking in water and minerals from the soil
• Takes in water and nutrients from the soil and moves these substances to the stem
• Consists of the roots (organs below the ground)
Shoot system: an organ system in a plant, which supports the plant, performs photosynthesis, and transports sap
• Responsible for supporting the plant, performing photosynthesis, and transporting water, nutrients, and sugars
• Consists of organs above the ground

• Root and shoot systems connected by flow of water, nutrients, and various hormones through vascular bundles that contain xylem and phloem. →essential for plant’s ability to survive
• Too much water has negative effect→fill up spaces between soil molecules and not enough room for oxygen for cellular respiration
• Nutrients and water are transported into the root by osmosis


Digestion in plants

• Plants do not have digestion system
• Roots anchor the plant to the ground and allow the plant to absorb nutrients, water, and salt from the soil


Circulation in plants

Xylem: vascular tissue. larger vessel than phloem. Carries and transports water and minerals from roots to other parts of the plant.
Phloem: carries and transports nutrients (food) produced by photosynthesis (and some water) to other parts of the plant.
Transpiration: movement of water and nutrients from roots to leaves. Process through vascular tissue (xylem). Moves water up the xylem. Water molecules carry small electric charge and therefore are attracted to each other (cohesion: holds water column) →links water molecules. At leaves, water escapes plant through pores known as stomata. Pulling tension. *Sun causes water to evaporate


Respiration in plants

Respiration in plants:
• Photosynthesis and chloroplasts. Absorb carbon dioxide and water and release oxygen while producing glucose.


Tissues in plants

-transports materials around the plant (water, nutrients, and minerals)
-supports the plant
-consists of xylem and phloem
-outermost tissue that surrounds the plant
-barrier from the plant to the environment
-protects inner parts of plants
-controls gas and water exchange
-consists of epidermis
-consists of the mesophyll cells (palisade and spongy)
-performs photosynthesis
-some cells support plant



Composes of specialized cells


Stem cells

Unspecialized cells whose only function is to divide


Ethics relating to embryonic stem cells

-obtaining embryonic stem cells kills the embryo

-pluripotent stem cells (adult) that are created, are created with viruses, which causes potential problems with existing DNA and could result in death -->called induced pluripotent stem cells


Explain how small intestine and alveoli are structured to maximize absorption

In the small intestine, there are thousands of interior folds known as villi and microvilli, which help maximize surface area for absorption. In the lungs, the alveoli are surrounded by capillaries in which makes the alveoli larger for more absorption into the bloodstream.


Sounds of heart

Lub: atrioventricular valves closing
Dub: semilunar valves closing


Membrane around the heart?



What causes us to hear sounds using stethoscope?

movement of blood through the artery


Arteries closer to heart have a stronger ______



Purpose of valves in veins

to regulate blood flow and back flow


Difference between plants circulatory system and animal circulatory system

Plants do not have blood and therefore do not have to transport blood.
Animals are more complicated (various interactive systems) whereas plants only have shoot and root system and are smaller.


Dialysis machine?

-Acts as a replacement for people who have kidney failure.

The dialysis machine basically filters blood by eliminating wastes and unwanted water.


Plants absorb what in roots?

Water and nutrients


Diffusion and Active transport in digestive system?

•Diffusion allows parts of the food such as nutrients digested to get into the blood stream. The digested foods diffuse through walls of the intestine and into the blood stream. Through diffusion, the walls of the intestine can absorb nutrients, water etc.
Active transport moves glucose and amino acids into the intestinal cells, then out where they are picked up by capillaries.


Function of nasal cavity (respiratory system)

•Nasal cavity: filters (cilia), warms (blood), and moistens (mucous membranes) incoming air. Secretes mucous. Mucous and cilia keep foreign particles out


Function of epiglottis (respiratory system)

•Epiglottis: prevents food from entering the trachea


Function of trachea (respiratory system)

•Trachea: carries air to the bronchi (pipe)


Function of bronchi/bronchus

•Bronchus/bronchi: Tubes that carry air to the lung.


Function of bronchioles

•Bronchiole: smaller tubes that carry air to alveoli


Function of Alveoli

•Alveoli: gaseous exchange takes place. Keeps bacteria and viruses out of bloodstream while allowing gases to cross. Oxygen is absorbed into the blood stream while carbon dioxide is eliminated through respiration.


Function of diaphragm

•Diaphragm: controls the flow of air to lungs. It begins the respiration process (moves down)


Rib cage

•Rib cage: acts as a cage that protects the lungs and heart. It also provides strong support and is important in the process of respiration.


Sinus (respiratory system)

•Sinus: lighten the skull, produce mucous that warms and moisturizes incoming air.


Origins and fate of oxygen:

Origins of oxygen:
•Come from the air we breathe (air comprises of a mixture of gases, including oxygen)
Fate of oxygen:
•Oxygen is inhaled into the body during the process of respiration
•Oxygen is absorbed into the bloodstream to become oxygenated blood
•Heart pumps oxygenated blood to all of the body (through the arteries)
•Body cells, organs, tissues use oxygen to function


Origins and fate of carbon dioxide:

Origins of carbon dioxide:
•Humans exhale carbon dioxide as it is produced during respiration
•When the oxygen travels throughout the body, it converts into carbon dioxide
Fate of carbon dioxide:
•Carbon dioxide is eliminated from the body during respiration (exhalation)
•It returns back into the atmosphere
•Plants exchange O2 for CO2


Diffusion in respiratory system

•Occurs in lungs: carbon dioxide from the blood diffuses into the lungs and oxygen from the lungs diffuses into the blood through the alveoli.
•Occurs in cells: carbon dioxide diffuses from a cell into blood stream whereas oxygen diffuses into a cell from the blood stream.


Function of heart

•Heart: propel and pump blood throughout the body via the circulatory system. Has 4 chambers (upper: Left right atrium/atria Lower: left right ventricle(s)


Function of Blood vessels

•Blood vessels: carry and transport blood


Function of arteries

•Arteries: transport oxygenated blood away from the heart and throughout the body. Only exception is the pulmonary artery, which carries deoxygenated blood.


Function of veins

•Veins: transport deoxygenated blood towards the heart. Only exception is the pulmonary veins, which carries oxygenated blood.



•Capillaries: smallest vessel that permits the diffusion of gases, nutrients, and wastes between plasma and other fluids. Help oxygen and nutrients in the blood get to tissues in the body.


Immune system function

Immune system:
• Defends body against infections


Function of larynx

contains voice box
air passes through larynx and into the trachea
function in digestive system: pushes up epiglottis to block trachea