P. Lobosco - PowerPoint Presentation

Slide1

P. Lobosco

The digestive and Urinary systemSlide2

The Digestive System

The Digestive System is a group of organs that work together to digest food so that it

c

an be used by the body.Slide3

Organs of the Digestive System

The digestive tract is a series of

tubelike

organs which food passes through.

The digestive tract includes your mouth, pharynx, esophagus, stomach, small intestine, large intestine, rectum and anus.Slide4

The Digestive SystemChapter 24-1

Objectives:

Compare mechanical digestions with chemical digestion.

Describe the parts and functions of the digestive system.Slide5

Other Organs

The liver, gallbladder, pancreas and salivary glands are also part of the digestive system.

Food does not pass through these organs.Slide6

Breaking Down Food

Digestion is the process of breaking down food into a form that can pass from the digestive tract into the blood stream.Slide7

Two Types of Digestion

There are two types of digestion : mechanical and chemical.

The breaking, crushing and mashing of food is called mechanical digestion.

In chemical digestion, large molecules are broken down into nutrients.

Nutrients are substances in food that the body needs for growth, maintenance and repair.Slide8

Catabolic and Anabolic

Catabolic reactions

Proteins from your food are made up of chains of amino acids.

Catabolism refers to the breakdown of proteins into amino acids.

This process releases energy in the form of ATP

Anabolic reactions

Anabolism refers to the process by which simpler substances (amino acids) are combined to form more complex molecules.Slide9

Enzymes

Substances called enzymes break some nutrients into smaller substances that the body can use.

Proteins are changed into smaller molecules called amino acids.Slide10

The Role of enzymes in Digestion

1. Enzymes break apart the long

c

hains of amino acids that make up proteins.

2. The small chains are then split by other enzymes.

3. Individual amino acids are then small enough to enter the bloodstream where they will make new proteins.Slide11

The Role of enzymesSlide12

Digestion

Nutrients

are the usable portions of food.

The six nutrients are protein, fat, carbohydrates, vitamins, minerals and water.

Proteins

are broken down into

amino acids.

Fats

are broken down into

fatty acids and glycerol

.

Carbohydrates

are broken down into

simple sugars.

Food is pushed through the digestive system by waves of muscular contractions called

peristalsis.

Bacteria

in the large intestine make

vitamins

for us.

Nutrients

are absorbed in the

small intestine.

Water and vitamins

are absorbed in the

large intestine.Slide13

Nutrients

Chemical digestion of

carbohydrates

begins in the

mouth

and ends in the

small intestine

.

Chemical digestion of

proteins

begins in the

stomach

and ends in the

small intestine

.

Chemical digestion of

fats

begins and ends in the

small intestine

.

Fats

are broken down into

fatty acids

and

glycerol

.

Proteins

are broken down into

amino acids

.

Carbohydrates

are broken down into

simple sugars

.Slide14

Digestion begins in the Mouth

Chewing creates small, slippery pieces of food that are easier to swallow.

Small pieces of food are easier to digest.Slide15

Digestion in the Mouth

Palate

– the “roof” of your mouth, tongue pushes against it to aid swallowing, separates the mouth and nasal cavities

Teeth

- crush food into smaller pieces to aid swallowing

Tongue

– tastes food, mixes food with saliva, pushes food between the teeth, helps in swallowing

Salivary Glands

- secrete saliva into the mouth to begin carbohydrate digestion and moisten food

Pharynx

– where mouth and nasal passages meet, leads to the trachea and esophagus

Epiglottis

– flap of tissue that closes over the trachea when you swallow to prevent food or drinks from going into the trachea which prevents choking

Esophagus

- connects the mouth and stomach, uses peristalsis (muscular contractions) to move food alongSlide16

Teeth

Teeth break and grind food.

The outermost layer of the teeth, enamel, is the hardest material in the body.

Enamel protects nerves and softer material inside the tooth.Slide17

Teeth

Your teeth have different shapes.

The molars are suited for grinding food.

The premolars are used for mashing food.

Incisors and canines are used for shredding food.Slide18

Saliva

The roof of the mouth is the palate.

Saliva mixes with food in your mouth.

Saliva is made in the salivary glands.It contains an enzyme that begins chemical digestion of carbohydrates by changing them into simple sugars.Slide19

Esophagus

After the food is very soft, the tongue pushes it into the throat, which leads to the

e

sophagus.

The esophagus squeezes the food with rhythmic muscle contractions called peristalsis, forcing the food into the stomach.Slide20

stomach

The stomach is a muscular saclike digestive organ between the esophagus and the small intestine that breaks down the food into a liquid by the action of muscles, enzymes and acids.Slide21

Stomach

The stomach continues the

m

echanical digestion of your meal by squeezing food with m

uscular contractions.

Glands in the stomach produce enzymes and acid which break food into nutrients.Slide22

Chyme

Stomach also kills bacteria that you swallow with food.

After a few hours of chemical and mechanical digestion, food turns into

chyme.Slide23

Small Intestine

The stomach releases the

chyme

into the small intestine through a small ring of muscle that works like a valve.

The valve keeps the food in the stomach until it has been mixed with digestive fluids.Slide24

Small Intestine

Since the stomach releases the

chyme

slowly, the small intestine has time to mix the chyme

with fluids from the liver and pancreas,

This help digest and stop the acids in

chyme

from hurting the small intestine.Slide25

The Pancreas and Small Intestines

When the

chyme

leaves the stomach, the

chyme

is very acidic so the pancreas makes fluids to protect.

The pancreas is an oval organ located between the stomach and small intestine. Slide26

Small Intestine

The small intestine is a muscular tube that is about 2.5 cm in diameter. It is about 6 m long when stretched out.

The inside wall is covered with fingerlike projections called villi.

The villi are covered with tine, nutrient absorbing cells.Slide27

duodenum

The duodenum precedes the

jejunum

and

ileum

and is the shortest part of the small intestine, where most chemical

digestion

takes place. The name

duodenum

is from the

Latin

duodenum

digitorum

, or twelve fingers' breadths.Slide28

The Liver

The Liver is a large, reddish brown organ that help with digestion. I human liver can be as big as a football.

It is located toward your right side, slightly higher than you stomach.

The functions of the liver are:

Store nutrients

Make bile to break up fat

Break down toxinsSlide29

Gallbladder

Bile is stored in a saclike organ called the gallbladder, which squeezes the bile into the small intestine where the breaking down of fats take place.

The bloodstream absorbs nutrients that have been broken down. Slide30

Liver and GallbladderSlide31

The End of the LIne

Material that can’t be absorbed into the blood is pushed into the large intestine.

The large intestine absorbs most of the water in undigested material and changes the liquid into semisolid waste material called feces, or stool.

Feces are stored in the rectum until they can be expelled.Slide32

Rectum and Anus

Feces pass to the outside of the body through an opening called the anus.

It has taken each of your meals about 24 hours to make this journey through your digestive system. Slide33

Summary of Functions of parts of the Digestive System

Teeth

– crush food into smaller pieces to aid swallowing

Liver

– secretes bile which breaks fat into smaller pieces

Gall bladder

– stores bile until needed in the small intestine

Large Intestine

– absorbs water and vitamins (made by bacteria living in the large intestine), stores waste, releases waste

Small Intestine

– all digestion is completed here (no nutrients are broken down past this point), nutrients are absorbed through the

villi

into the blood stream

Rectum

– end of large intestine, stores solid wastes until they leave the body

 Slide34

Digestion Summary

Anus

– opening to let out wastes

Mouth

– allows food to enter the body, contains teeth and tongue, carbohydrate digestion begins here due to the action of the enzymes in saliva

Salivary glands

– secrete saliva into the mouth to begin carbohydrate digestion and moisten food

Esophagus

– connects the mouth and stomach, uses peristalsis (muscular contractions) to move food along

Stomach

– churns food into a thick liquid called

chyme

, protein digestion begins here due to the action of gastric juice (enzymes and hydrochloric acid)

Pancreas

– secretes pancreatic juice into the small intestine to neutralize the acid from the stomach and to digest all types of foodSlide35

The urinary System

Chapter 24-2

Objectives:

To describe the path and function of the urinary systemTo explain how kidneys filter blood

To describe three disorders of the urinary systemSlide36

Excretion

Excretion is the process of removing waste from the body.

Three of the body systems have a role in excretion.

The integumentary

system releases waste products and water when you sweat.

The respiratory system releases carbon dioxide and water when you exhale.

The urinary system contains the organs that remove waste products from your blood.Slide37

Urinary System

As the body performs the chemical activities to keep the body alive, waste products, such as carbon dioxide and ammonia are produced.

The body has to get rid of these wastes to stay healthy.Slide38

Kidneys

The kidneys act as filters.

They filter about 2000L of blood a day. (You body

can only

hold about 5.6 L).

Inside each kidney is over 1 million

nephrons

.Slide39

Nephrons

Nephrons

are microscopic filters. They remove harmful substances, such as urea.

Urea is formed when cells use protein for energy. It contains nitrogen.Slide40

How the Kidneys Filter Blood

1. A large artery, called the renal artery, brings blood into each kidney.

2. Tiny blood vessels branch off the main artery and pass through part of each

nephron

. Slide41

How the Kidneys Filter Blood

3. Water and other substances are forced out of the blood vessels and into the

nephrons

.

4. The

nephrons

filter the wastes out of the blood and water, and allow the filtered blood and water to move back into the blood vessels. Slide42

How the Kidneys Filter Blood

5. As filtered blood and water go back into the blood vessels, waste materials are left in the

nephrons

.

6. Cleaned blood leaves each kidney in the renal vein to

recirculate

in the body.

7. The yellow fluid that remains in the

nephrons

is called urine. Slide43

How the Kidneys Filter Blood

8. Urine leaves each kidney through a slender tube called the

ureter

and flows into the urinary bladder.

9. Urine leaves the body through another tube called the urethra.

10. Urination is the process of expelling urine from the body. Slide44

Renal Artery, Renal Vein and UreterSlide45

Water Balance in Body

You drink water everyday but you lose water in sweat and urine. You need to get rid of as much water as you drink or your body will swell up.

When you are too warm, you sweat. The evaporation of water cools down the body.

As the water content of the body drops when you sweat, the salivary glands will produce less saliva and you will feel thirsty.

When you get thirsty a hormone, called

antidiuretic

hormone or ADH will be released.Slide46

ADH

ADH will signal the kidneys to take water from the

nephrons

. The nephrons will return the water to the blood stream and the kidneys will make less urine.

When your blood has too much water, small amount of ADH are released. The kidneys will react by allowing more water to stay in the

nephrons

and leave the body as urine.Slide47

Diuretics

Some beverages contain caffeine, which is a diuretic. Diuretics cause the kidney to make more urine, which decreases the amount of water in the blood.

When you drink a beverage that contains water and caffeine, the caffeine increases fluid loss. So your body will get less of the water from a glass of a caffeinated beverage than from a glass of water.Slide48

Urinary System Problems

Since the job of the urinary system is to remove wastes and regulate body fluids, any problems with water regulation can become dangerous for your body.Slide49

Bacterial Infections

Bacteria can get into the bladder and

ureters

through the uretha. If not treated, it can spread to the kidneys. Infections in the kidneys can permanently damage the

nephrons

.Slide50

Kidney Stones

Sometimes salts and other wastes will collect inside the kidney and form stones. Some interfere with urine flow.

If the body does not pass them, they must be removed.Slide51

Kidney disease

Damage to

nephrons

can prevent normal kidney functioning. If the kidneys do not function properly, a machine must be used to filter waste from the blood.Slide52

Urinary System Summary

The Urinary System

Kidney

– filters blood, controls water levels

Ureter

– carries urine from the kidneys to the bladder

Urethra

– carries urine out of the body

Bladder

– stores urine until it leaves the body

Blood vessels

– carries blood to the kidneys to be cleaned and carries cleaned blood to the body

Nephrons

– filter the blood, microscopic

Cortex

– contains the

nephrons