Download Chapter 10 The Digestive System Overview Animals use energy

Chapter 10 The Digestive System Overview
Animals use energy released from, carbohydrates, lipids, proteins, and nucleic acids – known as
macromolecules- to perform metabolic functions. These macromolecules are broken down
during the process of digestions. Water, vitamins, and minerals are also essential for metabolic
function.
The alimentary canal varies among animals. In general, herbivores have longer intestines than
carnivores to accommodate their different diets. As food moves through the human alimentary
canal, it is processed in four stages.
1. Ingestion: takes place in the mouth.
2. Digestion: begins in the mouth and continues through the small intestine.
3. Absorption: takes place in the small and large intestines.
4. Elimination: takes place at the anus.
Physical digestion breaks food down into smaller pieces. In chemical digestion, enzymes and
acids break macromolecules down into smaller molecules that can be absorbed through the cells
that line the small intestine.
Several disorders such as peptic ulcers, hepatitis, and diabetes can affect the functioning of the
digestive system. We have developed diagnoses and treatments for many of these diseases and
research is ongoing.
Chapter 11 The Respiratory System Overview
Body cells need a constant supply of oxygen to carry out metabolic functions. The respiratory
system is responsible for bringing oxygen into the body, delivering it to cells in all parts of the
body, and carrying carbon dioxide away from the cells and out of the body.
Animals in different environments have a variety of types of respiratory systems. Fish obtain
oxygen by passing water over gills, earthworms obtain oxygen through their skin, and insects
have a network of branching tracheae that bring air close to tall their body cells, where diffusion
can occur.
In many animals, including humans, inhaling brings air into the lungs. Air travels through the
nasal passages, pharynx, and larynx; into the bronchus; and through two bronchioles into two
lungs protected by the ribs.
In the alveoli of the lungs, oxygen diffuses from the air into tiny capillaries. Oxygen-rich blood
is then transported by the circulatory system to cells around the body. Carbon dioxide-rich
blood is transported to the lungs, where the carbon dioxide diffuses from the capillaries into the
air. The air is then released from the body by exhaling.
Some disorders of the respiratory system, such as pneumonia and bronchitis, can often be treated
with antibiotics. For other disorders – including asthma, cystic fibrosis, and emphysema –
treatments are used to relieve symptoms. Gene therapy is being explored as a cure for cystic
fibrosis.
Chapter 12 The Circulatory System
In multi-celled animals, the circulatory system transports gases, nutrients, wastes and other
chemical substances from one part of the body to another. It also regulates body temperature
and protects against blood loss and disease.
Vertebrates and other large complex animals have closed circulatory systems. A heart pumps
blood into thick, elastic arteries, which carry the blood to small, thin capillaries. Materials
diffuse from the capillaries into body cells and from body cells into the capillaries. Veins carry
blood back to the heart.
Humans have a double circulatory system – the circulation of blood around the body (systemic
circulation) is separate from the circulation of blood to the lungs (pulmonary circulation).
Separate chambers in the heart pump blood in each part of the system. To pump the blood, the
SA node and the AV node (two areas of specializes tissue in the heart) emit electric signals that
cause the heart muscle to contract and relax rhythmically. We experience this rhythmic
pumping as a heart beat. Valves in the heart and in the veins prevent blood from flowing
backward.
Many factors can be measured to help monitor the health of the circulatory system, including
electrical activity in the heart, blood pressure, stroke volume, and cardiac output.
Disorders of the circulatory system include arteriosclerosis, arrhythmias, congenital heart defects,
stroke, hemophilia, and leukemia. Many common disorders can be prevented and controlled by
lifestyle choices. Some, however, have other causes. Hemophilia is caused by a genetic
sex-linked trait. Most causes of congenital heart defects are unknown.
Medical technology has brought some creative solutions to the treatment of circulatory system
disorders, including angioplasty, bypass surgery, pacemakers, and xenotransplants.
Review Practice Questions
1. List 6 Vitamins or minerals and state the function for each
Vitamin or Mineral Function in the Human Body
Calcium
Iron
Magnesium
forms bone, conducts nerve signals, contracts muscle, clots blood
produces hemoglobin to transport oxygen in the blood
supports enzyme function and is needed to produce protein
Vitamin A
promotes good vision, and healthy skin and bones
Vitamin D
helps absorb calcium and form bone
Vitamin E
strengthens red blood cell membranes
2. List three macromolecule nutrients, a key function each one performs in the body, and a food that
each one can be found in.
Answers may vary but sample: Carbohydrates provide the cell with quick energy; rice. Lipids
insulate and cushion internal organs; butter. Protein helps muscles move; salmon.
3. Name the parts of the alimentary canal where each part of the digestive process occurs (ingestion,
digestion, absorption). Refer to page 408 in your textbook for help.
Ingestion: mouth, throat, esophagus
Digestion: gizzard, stomach, small intestine
Absorption: intestines (large and small)
4. Name two organs that help break up food physically. How do they help?
The tongue and teeth. They work together to chew the food, forming a bolus that will then
travel down the esophagus.
5. Where do most of the enzyme reactions related to digestion occur?
Mouth, stomach, small intestine
6. Why is protein breakdown mostly in the stomach?
The stomach has a pH of 2 and pepsin, which breaks down protein, works best at a low pH
7. Complete the table below
Carbohydrates
Organs in which
chemical digestion
takes place
Enzymes involved
End Products
Function(s) in the body
Proteins
Lipids
mouth, small
intestine
stomach, small
intestine
small intestine
salivary amylase,
pancreatic amylase,
sucrase, maltase,
lactase
pepsin, proteases
(trypsin and
chymotrypsin),
peptidases
bile, lipases
monosaccharides
amino acids
glycerol, fatty acids
energy
energy, enzymes,
protein
energy, cushioning
8. Some components of the human digestive system play a role in the respiratory system as
well. What are the components, and what additional role does each one serve?
Answers may vary. For example: both air and food can enter through the mouth and
pass through the pharynx
9. Describe and give the cause and treatment for the following respiratory system disorders.
Pneumonia, bronchitis, asthma, emphysema, cystic fibrosis, lung cancer
Disorder
Description
Cause
Treatment
Pneumonia
- alveoli fill with thick fluid,
- bacterial infection
making gas exchange difficult (including
- can affect one or both lungs
Streptococcus
pneumoniae)
- viral infection
- antibiotics or anti-viral
medications
- a vaccine is available for
bacterial pneumonia
Bronchitis
- bronchi become red and
- bacterial infection
inflamed
- prolonged exposure to
- couching brings up mucus
dust, chemicals, or
- in chronic bronchitis, cilia
cigarette smoke can
lining the bronchi may be
cause chronic
destroyed, which limits the
bronchitis
lung’s ability to clear mucus
- chronic bronchitis is a chronic
obstructive lung disease
(COPD)
- antibiotics (short-term
bronchitis)
- chronic bronchitis cannot
be cured, but can be
treated by quitting
smoking, taking
medications, and
exercising
Asthma
- airways become inflamed and - inhaled irritants, such as - can be managed by using
bronchioles constrict, making pollen, dust, and smoke an inhaler to inhale
it difficult for air to pass
can cause an asthma
medication in mist or
- wheezing, coughing, and
attack in some people
powder form.
shortness of breath occur
- the medication relaxes the
muscles around the
airways
Emphysema
- alveoli lose elasticity, burst and- smoking is the main cause- no known cure
fuse into enlarged spaces,
- symptoms can be relieved
reducing surface area for gas
by using an inhaler to
exchange, and making it
open airways and a
difficult to get enough
slow-flow oxygen tank
oxygen
to boost the supply of
- a chronic obstructive lung
oxygen to the body
disease
Cystic
Fibrosis
- thick mucus in the lungs results- a gene mutation causes - gene therapy is being
in inflammation, infection,
cells lining the airways explored
infection due to trapped
to release thick mucus - symptoms can be treated
bacteria, and damage to lung- also causes ducts in the
with medicine that thins
tissue
pancreas to be blocked the mucus and with
antibiotics
Lung Cancer
- uncontrolled cell growth and - smoking is the main cause- radiation and
division causes cells to form- other causes include
chemotherapy to destroy
a carcinoma
pollutants, radon gas,
the cancerous cells
- cancerous cells can break away
and asbestos
- surgery or laser surgery to
and spread cancer to other
remove tumours
organs
10. How is the process of inhalation accomplished?
A decrease in pressure of the thoracic cavity
11. Diffusion of carbon dioxide between the blood and the body’s tissue cells is part of what
process?
Internal respiration
12. What is the additional volume of air that can be forced out of the lungs beyond a tidal
exhalation?
Expiratory reserve volume
13. Create and label a typical spirograph
See notes
14. Describe oxygen’s path in the circulatory system
Oxygen diffuses from the alveoli to capillaries, to the pulmonary vein and the left atrium, to
the left ventricle, to the aorta, through arteries to capillaries, then diffuses to body cells
15. Where do nutrients enter the human circulatory system?
In the villi of the small intestine
16. How does the SA node cause the heart to beat?
It emits an electric signal that is transmitted to cardiac muscle cells in the atria causing the
muscles to contract. This signal is also transmitted to the AV node, which emits an electric
signal causing the heart muscle in the ventricles to contract.
17. What technology can a doctor use to monitor the beating of a heart?
Stethoscope, electrocardiogram (ECG)
18. Define systolic and diastolic blood pressure
Systolic: the pressure inan artery during a ventricular contraction
Diastolic: the pressure in an artery between ventricle contractions
19. List the steps you would take to take someone’s blood pressure
See notes
20. When the average person is running, will their cardiac output be higher or lower than 4900
mL/min? Why?
Higher. They will require more oxygen while running so the heart pumps blood faster,
causing increased pressure
21. A person has a resting cardiac output of 4900 mL/min abnd a heart rate of 90 bpm. What is the
person’s stroke volume?
54 mL
22. An athlete has a normal cardiac output, but a very low heart rate. Why might this be?
The athlete’s heart muscle is strong and the heart can pump more blood with each beat - a
higher stroke volume
23. Which disorders primarily affect each part of the circulatory system?
a. the heart
b. the blood vessels c. the blood
a. heart valve disorders, arrythmia, congential heart defects
b. stroke, aneurysm, arteriosclerosis
c. hemophilia, leukemia
24. Create a table to compare the treatments on pages 500 and 501 of your textbook
(xenotransplants, artificial hearts, and targeted drug delivery). Include a description of each
treatment, advantages, and potential problems or issues.
Xenotransplants: living cells, tissues, or organs are transplanted from other species into
humans. Still experimental. Advantages - animal tissue and organs can be more readily
available than human tissue and organs. Potential problems or issues include organ
rejection, introduction of diseases, and the fact that animals must be killed to obtain the
organs
Artificial Hearts: transplanting a mechanical pump with batteries and a controller to
function (temporarily) as a heart. Advantages - can keep a person alive until a suitable
human heart becomes available. Potential problems or issues - an external battery pack
must be worn most of the time, risk of mechanical or battery failure.
Targeted drug delivery: drugs are released only when they come into contact with specific
enzymes or pH range (indicating cancerous or diseased tissue). Advantages - chemicals
used to kill pathogens or cancerous cells will not harm healthy body cells. Potential
problems or issues - unknown.