Download digestive,excretory systems

The Digestive System
35.1 Notes
Pg. 124
E.Q. – How does absorption
happen in the small intestine?
What are the structures and
functions of the digestive system?
structures of the digestive system
• Structures:
–
–
–
–
–
–
–
Mouth
Esophagus
Stomach
Pancreas
Liver (Gallbladder)
Small Intestine
Large Intestine
• (colon)
functions of the digestive system
• Functions:
– Ingestion – taking food in
– Digestion – breaking food down
– Absorption – taking nutrients in to the
circulatory system
– Elimination – getting rid of waste
Lets start in the Esophagus
& intestines
• Ingestion and the beginning of Digestion.
• #1 -Digestion begins in the mouth. The food is
ground up and moistened (mechanical digestion)
• #2 -Saliva contains enzymes (salivary amylase),
which start breaking down carbohydrates into
sugars. (chemical digestion)
• #3 -Once swallowed, muscular contractions of
the esophagus (peristalsis) massage the ball of
food (bolus) down into the stomach.
What happens in the Stomach?
• 3 mechanical tasks
• 2 chemical tasks
What happens in the Stomach?
• MECHANICAL
TASKS
– Stores the
swallowed food and
liquid.
– Grinds up the food,
liquid, and digestive
juice produced by
the stomach.
(chyme)
– Empties its
contents slowly into
the small intestine.
• CHEMICAL TASKS
– HCl – digests
everything
– Pepsin – digests
proteins
#1
#2
#3
We’re in the small intestine!
• Absorption!!
– The food is mixed with more digestive
enzymes (chemical) and it moves into the
lower parts of the small intestine: the
jejunum and the ileum.
– Nutrients are absorbed (mechanical) from the
ileum, by projections called villi.
– Each villus is connected to a mesh of
capillaries. This is how nutrients pass into the
bloodstream.
On to the large intestine!
We’re in the large intestine!
• Absorption and
Elimination
– Minerals and
vitamins and water
are absorbed.
– Waste can then be
eliminated from the
body through the
anus.
– This waste is called
feces.
What is the name, function and
place of secretion of this enzyme?
What is the name, function and
place of secretion of this enzyme?
• Protease
– Breaks down proteins into amino acids
– Secreted from the stomach and pancreas
What is the name, function and
place of secretion of this enzyme?
What is the name, function and
place of secretion of this enzyme?
• Amylase
– Breaks down carbohydrates (starches) into
glucose
– Secreted from: the mouth (in saliva),
pancreas, and small intestine
What is the name, function and
place of secretion of this enzyme?
What is the name, function and
place of secretion of this enzyme?
• Lipases:
– Breaks down lipids into mono, di and
triglycerides
– Secreted from the pancreas and small
intestine
What is the name, function and
place of secretion of this enzyme?
What is the name, function and
place of secretion of this enzyme?
• Nuclease:
– Breaks down nucleic acids (DNA) into
nucleotides
– Secreted from the small intestine and
pancreas
This is not an enzyme – What is its
name, function and place of
secretion?
This is not an enzyme – What is its
name, function and place of
secretion?
• Bile
– Breaks down fat globules into small droplets
– Secreted from the liver and stored in the
gallbladder
Digestive REView pg. 123
complete sentence explained answers!!
1. Identify/explain three functions of the
digestive system.
2. Explain the difference between mechanical
and chemical digestion.(give example of each)
3. What is peristalsis? Where does it happen?
4. Food is called ____ once it enter the stomach.
5. Write a 2-3 sentence explanation of what
happens in the small intestine. (villi,capillary)
6. Explain the difference between the small /
large intestines.
The Excretory System
34.3 Notes (pg. 138)
E.Q. – Identify/explain the three
functions of the Excretory system.
structures and functions of the
Excretory System
Structures and functions of the
Excretory System
• Structures:
– Skin (sweat glands)
– Kidneys (nephron)
– Liver
– Lungs
– Urinary Bladder
• Functions:
– Get Rid of Wastes (other than
digestive)
– Keep the blood clean
– Maintain Homeostasis (balance)
Kidneys & homeostasis
Kidneys and homeostasis
Function:
- Removes wastes
from the blood.
• Homeostasis:
– maintaining water
balance and pH
– excreting urine
– filtering wastecarrying blood.
A closer look at Kidneys
• NEPHRONS
–
–
–
–
Filtration
Re-absorption
Secretion
Formation of Urine
Your kidneys in action!
• 1 – Filtration – Urea (formed in the liver) is
•
•
•
filtered through the Bowman’s capsule of the
nephron.
2 – Re-absorption – Water is re-absorbed
from the filtrate back into the blood in the loop
of Henle
3 – Secretion – In the distal convoluted tubule,
toxins are secreted by the blood and absorbed
into the filtrate.
4 – Formation of Urine – Once the filtrate
enters the collecting duct it is called urine. The
urine travels through the ureter to the urinary
bladder where it is stored.
How do the kidneys work?
What is
the
function
of the
liver?
How does
the liver
maintain
homeostasis?
The Liver and homeostasis
• Function:
– stores glycogen
– breaks down toxic substances (alcohol)
– secretes bile.
– Filters blood to form urea.
• Homeostasis:
– glucose balance and blood detoxification
Your skin and homeostasis
• Function:
– PROTECTION!!!
• Homeostasis:
– The skin excretes water and salt (sweat)
from the body
Your lungs and homeostasis
• Function:
– Intake Oxygen and expel Carbon Dioxide.
• Homeostasis:
– The lungs excrete carbon dioxide from the
burning of glucose through respiration.
The End 
Of notes
Turn to pg. 137 for review questions.
Excretory Review pg. 137
(copy/fill in # 1)
1. Kidneys and the Liver both filter your _______
2. Arrange the following in correct order & explain each step
Formation of Urine, Filtration, Secretion, Reabsorption.
3. Identify two structures of the Excretory
system that are also parts of other systems &
explain their function.
4. Explain how the Excretory system helps
maintain homeostasis. (two examples)
5. Identify one kidney disorder, explain
symptoms, causes, and treatments. (pg. 1008)