Chapter 35 Section 1

1. Peristalsis2. Pepsin3. Bile4. Gallbladder5. Villus

Chapter 35 Section 2 Vocabulary

1. Mineral2. Vitamin3. Calorie

Chapter 35 Section 3 Vocabulary

1. Endocrine glands2. Pituitary gland3. Negative feedback system4. Adrenal glands5. 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 MouthThe first step to digestionChewing is a form of mechanical digestionSaliva contains “amylase” which is the first chemical digestion to occurThe food is swallowed and enters the esophagus that connects to the stomachSmooth 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 tractBoth physical and chemical digestion3 layers of involuntary muscles contract and break down foodFood mixes with gastric juice which contains pepsin and hydrochloric acidFood remains here for 2 – 4 hours

4. The Small IntestineNearly 6 meters long and 2.5 cm diameterDuodenum the first 25cm- pancreas: secretes mixture that digests carbohydrates, proteins, and fats- liver: secretes bile which breaks down fats- gall bladder: stores bileFood 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 IntestineUndigestable material gets hereAKA colon1.5 meters long, 6.5cm diameterFunctions 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 NutrientsCarbohydrates starches and sugars- broken down into simple sugarsFats used for energy, insulation, to make hormones- broken down into glycerol & absorbedProteins used for enzymes, antibodies, hormones, blood clotting, muscles- broken down into amino acids & absorbedMinerals inorganic substanceVitamins organic nutrients (fat & water soluble)Water body loses 2.5L each day

7. Calories & MetabolismCalorie the amount of heat required to raise the temperature of 1mL of water by 1’CelsiusCarbohydrates and proteins: 4 calories per gramFats: 9 calories per gramIn general males need more than femalesTeenagers need more than adultsMetabolic 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 bloodstreamProduces gradual changesChemicals are called “hormones”These are released from the glands and travel to target tissues where they bind to the receptors on the cellsEx: - 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 self-regulating system such as the endocrine systemActs 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/dLWhen 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 hormones1. Steroid: freely enter cells, activates the synthesis of certain proteins2. 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 situationsLocated on top of the kidneysSecrete steroid hormones that increase blood glucose, raise blood pressure, increase heart rate and rate of respirationCauses 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 bonesCalcium is needed for blood clotting, forming bones and teeth, producing normal nerve and muscle function