Transcript Chapter 35 - Cloudfront.net

Chapter 35 Section 1
1. Peristalsis
2. Pepsin
3. Bile
4. Gallbladder
5. Villus
Chapter 35 Section 2
Vocabulary
1. Mineral
2. Vitamin
3. Calorie
Chapter 35 Section 3
Vocabulary
1. Endocrine glands
2. Pituitary gland
3. Negative feedback system
4. Adrenal glands
5. Thyroid gland
Happy
Valentine’s Day
Digestive/Endocrine RQ!
1. Where does chemical digestion begin?
2. What enzyme does this there?
3. Which chemical substance breaks
down fats?
4. Which organ is crucial for both
digestive and endocrine functions?
5. Which part of the brain connects the
nervous and endocrine systems?
1.
What are the functions of the
digestive system?
To disassemble food into component
molecules to be used for energy
1. Food is ingested and moves through tract
2. It is broken down mechanically and
chemically
3. The system absorbs the molecules it can
use
4. The system eliminates the undigested
materials 
2. The Role of the Mouth
The first step to digestion
Chewing is a form of mechanical digestion
Saliva contains “amylase” which is the first
chemical digestion to occur
The food is swallowed and enters the esophagus
that connects to the stomach
Smooth muscles move food along through
“peristalsis”
The epiglottis covers your trachea when you
swallow so food doesn’t get into your lungs 
3. The Stomach
Stomach: a muscular, pouch-like
enlargement of the digestive tract
Both physical and chemical digestion
3 layers of involuntary muscles contract
and break down food
Food mixes with gastric juice which
contains pepsin and hydrochloric acid
Food remains here for 2 – 4 hours 
4. The Small Intestine
Nearly 6 meters long and 2.5 cm diameter
Duodenum  the first 25cm
- pancreas: secretes mixture that digests
carbohydrates, proteins, and fats
- liver: secretes bile which breaks down fats
- gall bladder: stores bile
Food stays here 3 – 5 hours
“villi” help absorb the nutrients from the food and
are the link between the digestive & circulatory
systems 
5. The Large Intestine
Undigestable material gets here
AKA colon
1.5 meters long, 6.5cm diameter
Functions in:
- water absorption & vitamin synthesis
- elimination of wastes: about 24 to 33
hours after food was eaten 
Random facts…
**Your stomach cells secrete hydrochloric acid, a
corrosive compound used to treat metals in the
industrial world. It can pickle steel, but the
mucous lining in the stomach wall keeps this
poisonous liquid safely in the digestive system.
**The body's longest internal organ is the small
intestine at an average length of 20 feet
6. Vital Nutrients
Carbohydrates  starches and sugars
- broken down into simple sugars
Fats  used for energy, insulation, to make
hormones
- broken down into glycerol & absorbed
Proteins  used for enzymes, antibodies,
hormones, blood clotting, muscles
- broken down into amino acids & absorbed
Minerals  inorganic substance
Vitamins  organic nutrients (fat & water soluble)
Water  body loses 2.5L each day 
7. Calories & Metabolism
Calorie  the amount of heat required to raise
the temperature of 1mL of water by 1’Celsius
Carbohydrates and proteins: 4 calories per gram
Fats: 9 calories per gram
In general males need more than females
Teenagers need more than adults
Metabolic rate is determined by body mass, age,
sex, and physical activity 
8. Describe what the “endocrine
system” is and what it controls.
Consists of a series of glands that release
chemicals directly into the bloodstream
Produces gradual changes
Chemicals are called “hormones”
These are released from the glands and travel to
target tissues where they bind to the receptors
on the cells
Ex:
- human growth hormone (hGH)
- blood glucose levels
- blood calcium levels 
9. Which portions of your brain are
involved in endocrine control?
Action is controlled by the pituitary
gland, which is the master endocrine
gland, which in turn is controlled by
the hypothalamus 
10. What is a negative feedback
system? Why is it important?
Negative feedback system  a selfregulating system such as the endocrine
system
Acts like a thermostat in your home
- maintains a certain temperature
- if temperature drops too low or goes too
high, the system switches on to correct
Ex: blood water levels detected by the
hypothalamus 
11. How is water level controlled in
your body?
Water levels drop..
Hypothalamus senses this and tells the
pituitary gland to release ADH
(antidiuretic hormone)
ADH tells the kidneys to keep more
water and lose less in urine
Water levels stabilize…
Hypothalamus stops stimulating the
release of ADH 
12. What controls your blood sugar
levels?
Normal blood sugar is 80 – 120 mg/dL
When blood sugar is HIGH…
The pancreas releases insulin, which tells
the liver & muscles to take in the glucose
When blood sugar is LOW…
The pancreas releases glucagon, which
tells the liver to release the stored
glycogen into the blood 
13. What
two main types of
hormones are there?
There are 2 types of hormones
1. Steroid: freely enter cells, activates the
synthesis of certain proteins
2. Amino Acid: open channels in the plasma
membrane and alter the behavior of
molecules inside the cell 
14. Adrenal Glands and Stress
Play an important role in preparing the
body for stressful situations
Located on top of the kidneys
Secrete steroid hormones that increase
blood glucose, raise blood pressure,
increase heart rate and rate of respiration
Causes the “adrenaline rush” before a
stressful situation 
15. Thyroid and Parathyroid Hormones
The thyroid gland regulates metabolism, growth
and development through “thyroxine”
Regulate blood calcium levels through a negative
feedback system
- thyroid makes calcitonin which increases calcium
uptake in bones
- parathyroid makes PTH which causes the release
of calcium from the bones
Calcium is needed for blood clotting, forming
bones and teeth, producing normal nerve and
muscle function 