1. Human Systems
Let’s talk digestion

2. Why do we need to digest food?
To get the nutrients needed for our body to function by making it small enough to pass through our cell membranes.
Major events of digestion:
Ingestion
Digestion
Absorption
Transport

3. Making molecules your own
Most of the foods you eat are composed of plant or animal cells.
When we digest foods we break them down into their smallest components (by way of hydrolysis).
These components then can be reassembled into larger molecules that are useful to our bodies.

4. Molecules we eat to get the molecules we need
Molecule type
Molecular form ingested
Molecular form after digestion
Protein
Amino acids
Lipids
Triglycerides
Glycerol & fatty acids
Carbohydrates
Polysaccharides, disaccharides, monosaccharide
Monosaccharide
Nucleic acids
DNA, RNA
Nucleotides

5. The roles of enzymes during digestion
You have certain enzymes for specific food types.
They act as catalysts for reactions
They help a reaction proceed at high rates in lower temperatures.
Below are some examples of digestive enzymes
Enzyme type 
Salivary amylase
Pepsin (a protease)
Pancreatic lipase
Source
Salivary glands
Stomach cells
Pancreas cells
Substrate
Amylose (starch)
Proteins
Lipids
Products
Maltose & glucose
Amino acids
Glycerol & fatty acids
Optimum pH
Neutral (pH 7)
Acidic (pH 3)

6. Digestive system (alimentary canal)
Alimentary canal consists of:
Mouth
Oesophagus (esophagus)
Stomach
Small intestine
Large intestine (colon)
rectum

7. Oesophagus (esophagus)
Food is first chewed by the mouth with the help of saliva which carries amylase enzymes and is then swallowed down the oesophagus.
Food travels down the oesophagus by a sequential series of smooth muscle contractions: peristalsis

8. Stomach
Food is held here for a period of ~2hrs.
This is so gastric juices have a chance to mix the food.
pepsin is most effective in lower pH’s so the hydrochloric acid not only breaks down food, & kills bacteria, but provides an environment for pepsin to be active.
Helps breakdown proteins
Mucus lines the inside of the stomach to prevent damage that may be causes by the hydrochloric acid

9. Small Intestine
When food finishes in the stomach it is deposited into the 1st part of the small intestine called: duodenum
Trypsin (a protease), lipase, & bicarbonate

10. Pancreas, Liver, & Gall bladder
Liver: makes & secretes bile to emulsify fats. The bile is sent to the duodenum. Stores excess glucose in the form of glycogen.
Pancreas: secretes digestive juices (pancreatic lipase) in the duodenum.
Gall Bladder: holds the bile until sent to the duodenum.

13. Villi of the small intestine
Why is your small intestine infested with villi?

14. Function of villi Location of absorption of molecules
All but the fatty acids are absorbed into the
capillaries.
Fatty acids are absorbed into the lacteal.
Lacteal is a vessel that is part of the lymphatic system
Villi are thin for easy absorption & has an abundance of capillaries and lymph vessels.
All absorbed molecules are taken to body cells by the circulatory system
Nutrient molecule can be used for energy (glucose) or as a component to build a larger molecule (amino acids).
The process of building a bigger molecule is called: assimilation

15. Large intestine (colon)
After the absorption of nutrients is finished in the small intestine; what is left moves through to the large intestine along with the water.
Main function: water absorption
Home of bacteria Escherichia coli
We provide food, water, & warm environment & they provide us with vitamin K & maintain a healthy environment for us.
Anything left is eliminated as solid waste through the anus

16. Where does the breakdown of food end & the absorption of nutrients begin?
While food is still being broken down in the duodenum, it begins to be absorbed by the lower part of the small intestine.
By the time food is in the colon, it is no longer being digested, but water is still being absorbed.

17. Absorption vs Assimilation
Absorption occurs when the food enters the body as the food molecules pass through a layer of cells and into the bodies tissues. This occurs in the small intestine which has many villi that are specialized for absorption.
Assimilation occurs when the food molecules becomes part of the bodies tissue. Therefore, absorption is followed by assimilation.

18. What’s the difference between the digestive system & the excretory system?
Excretory- filters excess salts, water, & nitrogenous waste out of the blood stream.
Digestive- breaks down & absorbs nutrients from food.

19. Good things to eat for a good digestive system
FIBER, FOLIC ACID, & CALCIUM

20. Fiber
Fiber is not digested by our body. It helps us not be constipated, helps lower cholesterol & glucose levels
There are 2 types:
Soluble-dissolves in water & becomes gel-like; helps lower cholesterol by lowering low-density lipoprotein, or "bad," cholesterol levels & glucose levels by slowing the absorption of sugar.
Apples, oats, citrus fruits, peas, beans…
Insoluble- does not dissolve in water; promotes movement of material through digestive system
Whole-wheat flour, wheat bran, nuts, and vegetables

21. How much fiber do you need?
How much fiber do you need each day? The Institute of Medicine, which provides science-based advice on matters of medicine and health, gives the following daily recommendations for adults:
Age 50 or younger
Age 51 or older
Men
38 grams
30 grams
Women
25 grams
21 grams
Institute of Medicine, 2012

22. Folic acid (a type of vitamin B)
Key for growth and metabolism
It aids in rapid cell division (which occurs in the stomach lining)
Folic acid supplements are standard for pregnant women and women who plan to become pregnant.
lower the risk of preeclampsia and early labor.
Reduces the risk for devastating birth defects of a baby’s brain and spine -- spina bifida and anencephaly -- by 50% to 70%.

23. How much folic acid do you need?
Category
Folate (Folic Acid) Recommended Dietary Allowance (RDA)
For children under 1, only an adequate intake (AI) is available
0-6 months
65 micrograms/day Adequate Intake (AI)
7-12 months
80 mcg/day Adequate Intake (AI)
1-3 years
150 mcg/day
4-8 years
200 mcg/day
9-13 years
300 mcg/day
14 years and up
400 mcg/day
Pregnant women
600 mcg/day
Breastfeeding women
500 mcg/day
The recommended dietary allowance (RDA) includes the folic acid you get from both the food you eat and any supplements you take.

24. How Do Essential Fatty Acids Aid the Body?
Essential fatty acids (omega 3 and 6) assist in the development and function of the brain and nervous system, and they help regulate proper thyroid and adrenal activity. They play a role in thinning your blood, which can prevent blood clots that lead to heart attacks and stroke. They also possess natural anti-inflammatory qualities that can relieve symptoms of both arthritis and other autoimmune system diseases.
Essential fatty acids regulate blood pressure, immune responses and liver function, as well as help with blood clotting and breaking down cholesterol. They also help you look good, as a diet low in these fatty acids has been shown to create skin problems, including eczema, dandruff, split nails and brittle hair.

25. Calcium Helps promote good teeth. Calcium Requirements
SCHOOL AGE CHILDREN AGES 4 TO 8 REQUIRE 1,000 MG OF CALCIUM PER DAY.
AS CHILDREN REACH PUBERTY, A TIME OF INCREASED GROWTH AND DEVELOPMENT, FROM AGE 9 TO 18, CALCIUM REQUIREMENTS INCREASE TO 1,300 MG EACH DAY.
DURING ADULTHOOD, AGES 19 TO 50, CALCIUM REQUIREMENTS DROP BACK TO 1,000 MG EACH DAY.
ADULTS OVER THE AGE OF 50 REQUIRE 1,200 MG OF CALCIUM PER DAY.

26. Digestive Disorders
Celiac disease: the body's immune system is triggered by gluten in food. Antibodies attack the intestinal lining, damaging, flattening, or destroying the tiny hair-like projections (villi) in the small intestine. Damaged villi can't effectively absorb nutrients through the intestinal wall. As a result, fats, proteins, vitamins, and minerals get passed through the stool. Over time, this can lead to malnutrition.
Lactose Intolerance- body is lacking the enzyme (lactase) to break
down the sugar in milk or other dairy products.
Constipation: Best avoided through regular exercise and a diet high in fiber from whole grains, fruits, and vegetables. To older folks, who tend to get constipated more frequently: Be sure you're hydrating properly and aware of any medications that might be causing the holdup.

27. A challenge….an inexpensive colon check up.
Eat a half cup of corn and record the date and time of consumption.
Keep an eye out for the corn to come out in your bowel movement.
While you are looking at your feces, observe the color, shape, density and frequency.

28. Checking your “poop” IDEAL Density: Color: Shape: Frequency:
sinks floats/sinks slowly floats
Black-coffee brown coffee-with-cream yellowish brown
Eat more fiber
Eat fewer processed foods
Eat less fiber
Lower your stress level
Rounded, small pieces size & shape of your colon diarrhea
Less than once per day times/day times/day

29. What about other organisms?

30. Gastrovascular Cavity
Mouth and anus are the same opening

31. Food is moistened and stored in the crop. Most of the digestion occurs.
Gizzard pulverizes food

32. Circulatory System
Pumps your blood!!!

33. The Human Heart “Pumps Your Blood”
Valves close to prevent backflow
venules
arterioles
Closing of the valves produces the “lub dub” sound of you heart
Why is the muscle thicker at the left ventricle?

34. Where would you suppose the highest blood pressure is and why? 
The aorta because this is the first place blood travels from the heart pumping it out.
Where would you suppose the lowest blood pressure is and why? 
Veins- this is the last area blood travels before entering the heart again. They have valves to prevent back flow

35. Control of your heart rate
Hearts are made of muscle tissue; cardiac muscle.
Contracts & relaxes = myogenic muscle contraction
Mass of tissue in the right atrium known as the sinoatrial node (SA node)
Acts as a pacemaker by sending electrical signals for the artrias to contract (aka stimulate the myogenic contraction)
2nd mass is known as the atrioventricular node (AV node)
On a 0.1 second delay from the SA node in which it sends a signal for both ventricles to contract.

36. What happens during exercise?
Increased demand for oxygen so heart beat speeds up.
Also an increased build up of CO2 in the bloodstream.
The medulla chemically senses the rise of CO2
sends signal through the cardiac nerve to the SA node to increase your heart rate
Later sends another signal to decrease heart rate through the vagus nerve

37. Adrenaline Chemical that is able to influence your heart rate.
High stress times and times of excitement triggers the adrenal glands to release adrenaline into your bloodstream.
The SA node “fires” more frequently causing an increase in your heart rate.

38. The different blood vessels
Arteries- take blood away from heart
thick walled
internal pressure is high
Veins- return blood from capillaries to the heart
thin walled
internal pressure is low
have internal valves
Valves close to prevent backflow
Capillaries- thin walled (fits one cell at a time)
all exchanges occur here
internal pressure low

39. Components of blood WHAT IS TRANSPORTED BY OUR BLOOD? leucocytes
erythrocytes
WHAT IS TRANSPORTED BY OUR BLOOD?
NUTRIENTS HORMONES
OXYGEN ANTIBODIES HEAT
CARBON DIOXIDE UREA

40. WHAT IS IN OUR PLASMA? 90% water
Salts in the form of dissolved ions (aka blood electrolytes)
The concentration of these ions maintains osmotic balance of the blood.
Human blood pH 7.4
Plasma proteins- act as a buffer against pH change, help maintain osmotic balance, contributes to blood’s thickness (viscosity)

41. Vertebrate circulatory systems

42. Atherosclerosis

43. You are now going to diagram the circulatory system!!!!
Things to include:
-Heart in detail
4 chambers
valves
veins & arteries
-lungs & upper of lower body
-arteries
-arterioles
-veins
-venuoles
-capillaries
-make your diagram a circuit
-indicate by color the deoxygenated
and oxygenated blood
You will do a presentation showing & naming the parts.
Everyone in your group will talk.

44. Pump, pump, pumps your blood.
The right atrium's where the process begins, Where the C02 blood enters the heart Through the tricuspid valve to the right ventricle The pulmonary artery and lungs. Once inside the lungs it dumps its carbon dioxide And picks up its oxygen supply Then it's back to the heart through the pulmonary vein Through the atrium and left ventricle." "Pump, pump, pumps your blood.
"The aortic valve’s where the blood leaves the heart Then it's channeled to the rest of the bod
The arteries, arterioles, and capillaries too Bring the oxygenated blood to the cells The tissues and the cells trade off waste and CO2 Which is carried through the venules and the veins Through the larger vena cava to the atrium and lungs And we're back to where we started in the heart. Pump, pump, pump, pumps your blood

45. RESPIRATORY SYSTEM
GAS EXCHANGE

46. Anatomy of the respiratory system
Our lungs act together with our heart & blood vessels

47. Overview of our respiratory system
Aerobic cell respiration
Ventilation
Process of delivering oxygen to our cells and releasing CO2
-chemical bonds in a glucose molecule are broken to release energy. Energy is then stored as ATP.
-Process requires O2 & the C molecules in glucose are given off as a CO2
molecule
Breathing in air to our lungs and releasing CO2 into the air from our lungs
-oxygen diffuses from the lungs to the bloodstream by way of the alveoli & capillaries. CO2 diffuses the same way in reverse.

48. Why do we need a ventilation system for gas exchange
Why do we need a ventilation system for gas exchange? Why can’t we just take in oxygen by diffusion through our cells?
Our bodies are too thick. Only the cells exposed to the outside would participate in the gas exchange.
Also, it ensures that the concentration of gases within the lungs encourages the diffusion of each gas in a direction that’s beneficial to our bodies.

49. Gas exchange within the alveoli
There are ~300 million alveoli in each of our lungs.
Where does the blood come from prior to entering the lungs?
Right ventricle
Diffusion of oxygen and carbon dioxide occurs simultaneously as long as you keep breathing; it replenishes the gases in the alveolus by keeping the concentration gradients

50. Structure & Function of the Alveoli
The round shape provides a large surface area for the gasses to diffuse
The thinness (single cell) of each alveoli as well as the capillary beds surrounding the alveoli allows for quick & efficient diffusion
Moist inner lining (surfactants) of the alveolus allows the alveoli not to stick to each other & tear causing scar tissue.
Premature babies have not developed the surfactant & need to be on a ventilator.

51. MECHANISM FOR BREATHING
What muscles are involved in breathing?
Diaphragm
Abdomen
Intercostal (surrounds the rib cage)
Breathing is based on the inverse relationship between pressure & volume.
- an increase in volume will lead to a decrease in pressure (& vice versa).

52. Draw the pathway that an oxygen molecule travels starting with going in through the nose and ending with being delivered at a cell in your big toe.
LIST AS MANY PARTS AS POSSIBLE

53. What about other animals?
Aquatic

54. Bony Fish
It is a bit more difficult for gas exchange than for land animals. Why?
Density & O2 availability
Blood flows in the direction opposite to the movement of water past the gills.
As blood moves through a gill capillary it becomes more and more loaded with oxygen but it simultaneously encounters water with ever higher oxygen concentrations because the water is just beginning its passage over the gills.