Digestive System • The digestive system is the system which ingests food, and uses physical and chemical means to break down the food, absorb the nutrients, and excrete waste products. So THAT’S what it is!
Functions (food passes) • Mouth • As food is ingested, digestion begins immediately with chewing • Enzymes in the saliva begin to break down starches into smaller-sized molecules • Pharynx • The pharynx uses a series of muscles to constrict and push food to the esophagus • Helps prevent swallowing of air
Functions (food passes) • Esophagus • The food is soon swallowed and enters the esophagus. • The tube runs from the mouth and down to the stomach. • By using peristalsis, or rhythmic muscle movements, it forces food down into the stomach.
Functions (food passes) • Stomach • Contains gastric acid • Churns food and is mixed with a stomach acid called chyme • Contains 3 sections: fundus, corpus, antrum • Contains a layer of mucous so it doesn’t digest itself • Many layers of muscle to grind and pack-down food for transport in the rest of the digestive system
Small intestine? It’s not THAT small! Functions (food passes) • Small intestine (absorbs majority of nutrients) • Duodenum (1st part) • Adds bile from gallbladder (digestive enzyme which breaks down fats) • Jejunum (2nd part) • Absorbs carbohydrates, proteins, and vitamins • Ileum (3rd part) • Absorbs fat and fat-soluble vitamins • Many digestive enzymes added throughout the small intestine
Functions (food passes) • Large intestine (packs waste and removes water) • Cecum (vestigial in humans) • Digests plants • Taeniae coli • Three bands of muscle • Haustra • Gives the colon it’s “segmented” appearance, pushes waste along • Epiploic appendages • Small pouches of fat sitting on the colon/rectum My cecum pouch still functions!
Functions (food passes) • Large intestine (cont) • Transverse colon • Ascending colon • Descending colon
Functions (food passes) • Rectum • Where fecal matter is contained until it is excreted • Lower part of the large intestine • Anus • Final part of digestive system • Contains two sphincters • Internal, external (Cigarette) Butt
Functions (food does not pass) • Salivary glands • Secrete fluid containing water, electrolytes, mucous, and enzymes • Three major pairs of salivary glands • Parotid glands- produce watery secretion • Submaxillary glands- produce mucous secretion • Sublingual glands- secret more saliva (predominantly mucous) • Serous Cells (watery fluid saliva) • Mucous cells (mucous-rich saliva)
Functions (food does not pass) • Liver (accessory organ) • Makes bile (breaks down fats) • Removes toxins from blood • Stores vitamins • Pancreas (accessory organ) • Makes enzymes to break down food • Trypsin (breaks down proteins) • Chymotrypsin • Carboxypeptidase • Amylase • Phospholipase • Nucleases Accessory organs are STILL important!
Functions (food does not pass) • Gallbladder • Located by duodenum (on small intestine) • Stores bile (made from liver) • Releases the bile into the duodenum for digesting fats • Sphincters • Allow food to pass into the stomach • Allow waste to exit the anus
Essential? Heck yes! • Why is digestion of large food molecules essential? • The foods we eat contain large compounds, and must be broken-down in order for us to use them • Molecules must be small enough to fit through the walls of a cell, in order to be absorbed as nutrients and used to their full capacity.
Enzymes? • Bile • Breaks down fats (made by liver; stored in gallbladder) • Trypsin • Breaks down proteins (made by pancreas) • Amylose • Breaks down starches, found in saliva • These speed-up the process of digestion so that the nutrients may be absorbed quicker, and then used in other systems
Physical v. Chemical • Physical digestion • The act of chewing, swallowing • Usage of muscles • Grinding in stomach • Chemical digestion • The addition of • Acids • Enzymes
Carbohydrate Digestion • Carbohydrates • Digestion begins in mouth with salivary glands • Polysaccharides broken down into disaccharides monosaccharides • Then in the small intestine, enzymes are used to break down the disaccharides and monosaccharides • Maltase • Lactase • Sucrase
Proteins • Protein digestion begins in the stomach • The addition of trypsin (made by pancreas) breaks down the proteins into amino acids • They are then absorbed by the duodenum/jejunum (small intestine) to then be used
Lipids • Digestion begins mainly in stomach • Stomach churns to separate fats • Glycerols are broken down into fatty acids • Lipase and phospholipase are used in the small intestine
Digestive Disorders • Food poisoning • Caused by eating foods containing bacteria (salmonella, e-coli, listeria, etc) • Symptoms • Diarrhea • Cramps • Nausea • Fever • Prevalence- depends on what you eat! • Treatment includes: • Letting it run its course • Getting medication if necessary
Digestive Disordres • Crohn’s Disease • It is an unusual reaction in the intestines • Kills useful/harmless bacteria in intestines as if it were foreign • Symptoms • Abdominal pain • Diarrhea • Weight loss • Usually genetic/mutation/runs in families • Treatment includes: • Antibiotics • Other medications available
Digestive System • References: • http://dictionary.reference.com/browse/digestive+system • http://www.enchantedlearning.com/subjects/anatomy/digestive/ • http://www.britannica.com/EBchecked/topic/455238/pharynx • http://enel.ucalgary.ca/People/Mintchev/stomach.htm • http://www.beltina.org/health-dictionary/small-intestine-function-anatomy-parts-problems.html • http://www.news-medical.net/health/What-Does-the-Large-Intestine-Do.aspx • http://www.cchs.net/health/health-info/docs/1600/1699.asp?index=7041 • http://biology.about.com/library/organs/blpathodigest3.htm • http://krupp.wcc.hawaii.edu/BIOL100L/powerpoint/digestion.pdf • http://digestive.niddk.nih.gov/ddiseases/pubs/crohns/index.aspx#causes
Circulatory System • The circulatory system is the system that circulates blood throughout the body, transporting nutrients, hormones, fights diseases, controls body pH levels and temperature.
Functions • Arteries • Blood vessels • Carry oxygenated blood away from the heart (excluding pulmonary and umbilical arteries • Outside is tough, inside is smooth • Blood should flow easily with minimal obstacles • Has 3 layers; thicker walls
Functions Yay for Oxygen! • Capillaries • Very thin blood vessels • Receive oxygen-rich blood to transport • Exchange oxygen-ridden blood with carbon dioxide ridden-blood • Flow in “single file” • “waste blood” is carried back to the heart • Appear like a “web” • Do not run parallel
Functions • Veins • Carry waste blood back to lungs and heart • Not as tough as arteries • Veins use valves to help blood flow in one direction • Blood flows against the force of gravity • Has 3 layers; thinner walls
Blood Route • Oxygenated blood from lungs to left atrium (carried by pulmonary veins) • From the left atrium, blood flows into the left atrioventricular valve, and then into the left ventricle • Blood is then forced into the aorta, the atrioventricular valve closes to stop backflow of blood back into the atrium • The aorta is then closed off from the left ventricle by the aortic semilunar valve
Blood Route (cont) • Other arteries branch off the aorta, and carry oxygen-rich blood throughout the body • The systematic circulation brings blood to the neck and head and to the rest of the body • Systemic circulation gives oxygen to body parts and received carbon dioxide • Blood is then returned to the heart
Blood Composition • Red blood cells (ethrocytes) • Disc-shaped • make up 99% of the cells in the blood • Hemoglobin molecules • Large surface area- easier release of oxygen and better absorption
Blood Composition • White Blood Cells (leukocytes) • Used for defense in the immune system • Clean up dead cells and debris • Five classes: • Neutrophil • Eosinophil • Basophil • Monocyte • Lymphocytes • Fights infections, • Helps determine infections
Blood Composition • Plasma and platelets • Platelets go to the injury site • Plasma contains dissolved proteins • Both play a role in blood plotting • Puss
Erythrocytes • Red blood cell • Contains hemoglobin, carrys oxygen • They are biconcave in shape, thus increasing the cell’s surface area • Makes facilitated diffusion of oxygen and carbon dioxide easier • The shape is kept with the cell’s unique cytoskeleton composed of proteins • They are very flexible and can change shape in capillaries • Makes transport of cells easier
Open or closed? That is the question. • Closed circulatory system • This is when blood travels in veins • Dogs • Rats • Open circulatory system • This is when the blood ‘sloshes’ around and ‘bathes’ the organs • Clams • Earthworms
One-loop circulatory • Fish! • One-chamber heart • Blood travels in a single-loop around the body • The oxygenated blood goes from the gills, then to the body parts. • Deoxygenated blood goes from the body parts, into the sinus venosus, to the atrium, into the heart, and then to the gills again
Two-loop circulatory • Frogs! Amphibians! Oh my! • Two-chamber heart • Blood travels in two loops around the body • The oxygenated blood travels from the lungs and goes to the left atrium, then to the ventricle, and then to the conusateriosus, and heads to the body organs • The deoxygenated blood leaves the body, goes to the sinus venosus, then to the right atrium, and to the ventricle, and finally the conusateriosus • The ventricle has a dividing wall so the oxygenated blood and deoxygenated blood don’t mix
Four chamber heart! • More efficient! • In mammals and birds • High/low oxygen blood kept separate by the complete septum in the ventricle • Veins return the blood to the heart, arteries carry it away • Pulmonary blood vessels carry blood to and from lungs
Cardiovascular Disorders • Coronary Heart Disease • Plaque builds-up inside of the coronary arteries. The oxygen-rich blood cannot reach your heart muscle as easily if these are clogged. • Symptoms: • Blood clots, heart attack • Blocked arteries • Pain/discomfort in chest/shoulders • Most common form of heart disease, #1 killer of men and women • Can be fixed through bypass surgery • Some medications available
Cardiovascular Disorders • Cerebrovascular Disease • Limited/no blood flow to brain • Caused by atherosclerosis • Symptoms: • Stroke • Dementia • Transient ischemic attacks • Common in those with atherosclerosis • Plaque build-up • Some medications available, some surgeries
Circulatory System • References • Prior zoology knowledge • http://www.health-massagers.co.uk/gbu0-display/art.html • http://www.sumanasinc.com/webcontent/animations/content/human_heart.html • http://simscience.org/membranes/advanced/essay/blood_comp_and_func1.html • http://www.medterms.com/script/main/art.asp?articlekey=3309 • http://www.biology-resources.com/drawing-fish-circulatory-system.html • http://bioserv.fiu.edu/~walterm/human_online/cardio_sys/circulatory_system.htm • http://www.nhlbi.nih.gov/health/health-topics/topics/cad/ • http://www.medicalnewstoday.com/articles/184601.php
Respiratory System • The respiratory system is the system that performs gas exchange (the exchange of carbon dioxide, oxygen, and transporting it to and from cells via the multitude of respiratory organs).
Functions Alveoli Birthday Party! • Alveoli • Primary gas exchange unit • Attached to branches of bronchial passages • Inflates with inhalation • Deflates with exhalation • TINY BALLOONS! • Covered in mucous tissue/fluid • Great surface tension (like a balloon!) • Allows for sufficient gas exchange
Functions • CO2 and O2 transportation • Simple diffusion • O2 diffuses from the alveoli and then into the blood • CO2 goes from the blood and into the alveoli • Diffusion- concentration gradient • The pressure of the O2 must be higher in the alveoli than in the blood • CO2 in the alveoli need to be kept at a lower pressure that in the blood
Functions • Pathway of O2 to RBC • Nose/mouth • Filters air as it enters • Nasypharynx • Allows air to pass • Oropharynx/Laryngopharynx • Passage for air (and food!) • Larynx • Connects the laryngopharynx to the trachea
Functions • Pathway of O2 to RBC (cont) • Trachea • Passage for air to reach the bronchi • Filters the air, use cilia on the walls to remove foreign molecules and send them to the mouth • Primary bronchi • Branches both left and right from the trachea • Connects to secondary bronchi • Secondary bronchi • Passageway for air to each lobe of the lungs and joins to the tertiary bronchi (three for right lung, two for left lung)
Functions • Pathway of O2 to RBC (cont) • Tertiary bronchi • Passageway for the air to get to the bronchioles • Bronchioles • These branch into smaller tubes until they become terminal bronchioles • Terminal bronchioles • Continue to divide (wow!) into microscopic branches called the respiratory bronchioles • Respiratory bronchioles • Continue division into alveolar ductsM
Functions • Pathway of O2 to RBC (cont) • Alveolar ducts • Deliver the air to the alveoli • Alveoli • The place of exchange of O2 and the bloodstream MISSION O2 to RBC ACCOMPLISHED
Functions • Inhaling • Diaphragm • Located below the lungs • Dome-shaped muscle • Diaphragm contracts and moves downward • Exhaling • Diaphragm relaxes up • Allows lungs to empty the air • Functions depends on air pressure (high pressure=difficult to breathe, health, and the amount of O2 present
Respiratory Disorders • Asthma • Disorder causing lungs/bronchial tubes to narrow, causing difficulty breathing • Symptoms: induced by allergies, exercise, etc. • Quite common; usually runs in families. • Also common if the person has a preexisting disorder • Treatment: medication, inhalers
Respiratory Disorders • COPD (Chronic Obstructive Pulmonary Disease) • Causes difficulty breathing • Chronic bronchitis- involved long-term cough with mucous • Emphysema- involves destruction of lungs over time • Caused by smoking/exposure to gases • Happens to people who smoke, but not all • No cure is available, but there is medication available, and therapy (O2 and steroidal injections)
Respiratory System • References • http://hyperphysics.phy-astr.gsu.edu/hbase/ptens2.html • http://people.eku.edu/ritchisong/301notes6.htm • http://www.ann.com.au/MedSci/oxygen.htm • http://www.authentic-breathing.com/how_the_diaphragm_works.htm • http://www.ncbi.nlm.nih.gov/pubmedhealth/PMH0001153/
Immune System • System in which protects the body’s organs from invasive organisms and parasitic involvements