Notes page• functions of the digestive system• single cell digestive system• simple gut one cavity• complete tube

sketch earthworm & label(next side of page) (leave space for each)grinding partsdigestive enzymesabsorptionwater removalelimination

Digestive System

The point of the digestive system: take in nutrients absorb nutrients eliminate wastes

It’s all about ATP!!

Type 1: (Earliest) Single Cell• LYSOSOMES are “bubbles”

in the cell that contain enzymes

Enzymes do HYDROLYSIS:Break down larger particles

LYSIS means to “break”

Cell Digestion using lysosomes

• “PHAGOCYTOSIS” = “CELL EATING”

Type 2: Simple Gut, one cavity

• One opening for entry & exit

• Gastrocavity

Type 3: COMPLETE TUBE:• Mouth for entry• Anus for exit of

waste• Tube based

intestines for absorption

Worms (Platys) thru Humans!

Worms thru Humans• Arthropods

Humans

First line of digestion: Mouth, Teeth

• Teeth physically break up food

• Saliva: breaks down sugars

Animals without teeth have “gizzards” to grind up food!

Esophagus: tube for eating• “phage” means

“to eat”• Expandable,

muscular• Movement

through digestive system = “PERISTALSIS”

STOMACH: digestion begins• Acidic (low pH)

• Activates Enzymes• Breaks bonds

Special adaptations: extra stomachs!

• Animals that eat tough plants have extra stomachs to house bacteria that help them digest

• “Ruminants”: digest over time

PANCREAS: secretes insulin• Insulin opens channels

on cells to let in sugar to make ATP!

• Diabetes type 1: cells that make insulin die.

• Diabetes type 2: receptors for insulin on cells don’t work

Small Intestine: absorbs nutrients!

• Lots of SURFACE AREA, due to finger like villi (remember rug?)

LARGE intestine: absorbs water!

Absorbs water, salt, vitamins back into your bodyAs it makes wastes more SOLID.

Appendix: once it stored waste

• Now its pretty useless, can sometimes become infected.

• Appendicitis: infection of appendix

LIVER: hundreds of functions• Main one for digestion:

BILE• Liver makes BILE, an

alkaline solution

• Neutralizes stomach acid

• Breaks down fats

CIRCULATORY SYSTEM• The point:

– TRANSPORT OF MATERIALS– NUTRIENTS TO CELLS– WASTE AWAY FROM CELLS

Type 1: simple diffusion (no blood)

Type 2: OPEN (not complete vessels)

• Animals have “heart”

• Vessels empty into body cavity

• NO BLOOD: • HEMOLYMPH

Type 3: CLOSED (true blood)• Blood always

enclosed in vessels

• Materials diffuse out of blood into cells

HEART: muscular organ that pushes blood

• Earthworm: AORTIC ARCHES• Arthropods: TUBULAR HEART• FISH… AMPHIBIANS…

MAMMAL: CHAMBERED HEARTS

Heart chambers

CHAMBER NAMES• ATRIA (atrium): entrance• VENTRICLES: BIG PUSH

WHICH SIDE IS RIGHT?WHICH SIDE IS LEFT?

V V

To lungs & body• ‘PULMONARY

’ means lungs

• AORTA means big bridge to body.

Protective Sack around heart: PERICARDIUM

• Peri- like perimeter

Cardiac Vessels• Supply heart

muscle with oxygen

• If they get blocked, they cause a “heart attack”.

• Bypass surgery

VESSELS: arteries & veins• ARTERIES carry blood away

from heart (red blood usually)

• VEINS carry blood towards heart (blue blood usually)

Color due to oxygen:

RED = oxygenBLUE = carbon

dioxide

ARTERIES• Arteries very muscular

& elastic• Blood moves due to

heart pumping

• Veins less muscular• Have valves to keep

blood going right direction VEINS: blood

moves due to your muscle movement

VARICOSE veins:Valves fail, blood pools in vein

Blood cell types• Red: oxygen

• Platelets: clotting

• White: immune system cells

Red blood cells: hemoglobin to carry oxygen

How carbon monoxide kills:Carbon monoxide binds to hemoglobin TIGHTER THAN OXYGEN CAN

One carbon monoxide is in the blood, it can’t come out

Your body can’t use carbon monoxide to make ATP

You die from lack of ATP

Diseases of digestive system:• ULCERS: caused by bacteria

attacking stomach lining

NOBEL PRIZE!

Diseases of digestive system• Eating Disorders

– ANOREXIA– BULEMIA– ETC.

• Immune System– CROHN’S DISEASE– IRRITABLE BOWEL

Diseases of digestive system• Food poisoning: bacterial!!!

• NOROVIRUS: viral stomach flu

• Both spread from contaminated food when someone sick prepares food

• Often in dorms, cruise ships hotels.

Diseases of circulatory system• Heart attack: clot

in coronary arteries causes heart muscle to die

• If muscle area is big enough, person can die.

• Fatty foods can cause narrowing of arteries

Diseases of circulatory system• Artherosclerosis : • “artery hardening”:• Arteries fill with

cholesterol & fat, narrowing channel

• Then clot can cause blood stoppage, stroke, death

Diseases of circulatory system• Babies can be born with hole in septum, allows

non-oxygenated blood through to body.

Diseases of blood cells:• Leukemia: cancer of white blood cells (too

many of them, and they don’t work properly) • Anemia: not

enough red blood cells

• Iron supplements to help make hemoglobin

Bone marrow transplants

Bone marrow transplants:

Heart transplants• Use a machine

to pump blood temporarily