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
