Biology
Concepts and Applications | 9e
Starr | Evers | Starr
Chapter 33
Circulation
© Cengage Learning 2015
© Cengage Learning 2015
33.1 How Do Animals Move Materials To
and From Body Cells?
• The circulatory system supplies animal cells with nutrients
and oxygen
– Also rids cells of waste products
© Cengage Learning 2015
Open and Closed Circulatory Systems
• Closed circulatory system: heart pumps blood through
continuous vessel system
– Artery: large-diameter vessel that carries blood away from the
heart
– Capillary: small-diameter blood vessel; exchanges substances
with interstitial fluid
– Vein: large-diameter vessel that returns blood to the heart
– All vertebrates and some invertebrates have a closed system
© Cengage Learning 2015
Evolution of Vertebrate Circulatory
Systems
• Pulmonary circuit: blood flows from the heart to the lungs
and then back to the heart
• Systemic circuit: blood flows from the heart to body
tissues and then back to the heart
© Cengage Learning 2015
33.3 How Does the Human Heart
Function?
• Atrium: heart chamber that receives blood from veins
• Ventricle: heart chamber that pumps blood into arteries
• Atrioventricular (AV) valve: located between the two
chambers; functions like a one-way door to control blood
flow
© Cengage Learning 2015
How Does the Human Heart Function?
superior vena cava
(flow from head, arms)
aorta (to body)
trunk of pulmonary
arteries (to lungs)
pulmonary valve
(closed)
right pulmonary
veins (from lungs)
aortic valve (closed)
left pulmonary
veins (from lungs)
Left Atrium
Right Atrium
right AV valve
(open)
left AV valve
(open)
Right Ventricle
Left Ventricle
inferior vena cava
(from trunk, legs)
© Cengage Learning 2015
cardiac muscle
septum
How Does the Human Heart Function?
• Oxygen-poor blood is delivered to the right atrium by the
superior and inferior venae cavae
• Blood flows through the right AV valve into the right
ventricle
• Right ventricle pumps blood through the pulmonary valve
into the pulmonary arteries, and through the pulmonary
circuit
© Cengage Learning 2015
How Does the Human Heart Function?
• Oxygenated blood returns to the left atrium via pulmonary
veins
• Blood flows through the left AV valve into the left ventricle
• Left ventricle pumps the blood through the aortic valve
into the aorta and then to the body’s tissues
© Cengage Learning 2015
33.4 What Are the Functions and
Components of Blood?
• Functions of blood:
– Carries oxygen and nutrients to cells
– Carries metabolic wastes to organs for disposal
– Facilitates communication by distributing hormones
– Transports cells and proteins that protect and repair tissues
– Maintains a stable internal temperature
© Cengage Learning 2015
33.7 How Does Blood Exchange
Substances With Body Cells?
• Materials move between capillaries:
– Plasma fluid is forced out through spaces
– Oxygen diffuses into interstitial fluid; nutrients are transported
into interstitial fluid
– Carbon dioxide (CO2) diffuses into capillaries; wastes are
transported into capillaries
– Water moves by osmosis from the interstitial fluid into the
plasma near venous end
– Fluid is returned by the lymphatic system
© Cengage Learning 2015
33.9 What Causes Common Heart
Problems?
• The leading cause of death in the United States is
cardiovascular disease
– Kills about one million people every year
• Risk factors:
– Smoking, family history, hypertension, high cholesterol,
diabetes mellitus, and obesity
© Cengage Learning 2015
What Causes Common Heart Problems?
• Arrhythmias: abnormal heart rhythms
– Examples: bradycardia, tachycardia, atrial fibrillation, and
ventricular fibrillation
• Atherosclerosis: buildup of lipids in the arterial wall
causes narrowing of the blood vessel
– Increased LDL levels are a risk factor
– A heart attack occurs when a coronary artery is completely
blocked
© Cengage Learning 2015
What Causes Common Heart Problems?
plaque
clot
A Normal artery.
© Cengage Learning 2015
B Artery narrowed by an atherosclerotic
plaque. A clot has adhered to
the plaque, further narrowing the artery.
What Causes Common Heart Problems?
plaque flattened by
balloon angioplasty
© Cengage Learning 2015
stent (metal mesh) placed
to keep artery open
Biology
Concepts and Applications | 9e
Starr | Evers | Starr
Chapter 34
Immunity
© Cengage Learning 2015
© Cengage Learning 2015
34.1 What Is Immunity?
• Humans evolved defenses that protect our bodies
– Immunity: organism’s capacity to resist and combat infection
– Antigen: molecule or particle that the immune system
recognizes as nonself; triggers an immune response
– Complement: set of proteins that circulate in inactive form; play
a role in immune responses when activated
© Cengage Learning 2015
What Is Immunity?
• Innate immunity: set of immediate, general defenses
against infection
• Adaptive immunity: set of immune defenses that can be
tailored to specific pathogens encountered by an
organism during its lifetime
© Cengage Learning 2015
Three Lines of Defense
• First line of defense: physical, chemical, and mechanical
barriers
• Second line of defense: innate immunity
• Third line of defense: adaptive immunity
© Cengage Learning 2015
34.2 What Keeps Microorganisms on the
Outside of the Body?
• Normal flora: microorganisms that typically live on human
surfaces
– Includes microorganisms on the interior tubes and cavities of
the digestive and respiratory tracts
• Benefits of normal flora:
– Prevent dangerous pathogens from colonizing
– Help us digest food
– Make essential nutrients
© Cengage Learning 2015
Barriers to Infection
• Blood and tissue fluids are typically sterile
• Surface barriers prevent normal flora from entering the
body’s internal environment
• Examples:
– Tough outer layer of skin
– Epithelial tissues that line the body’s interior tubes
• Cells of epithelium contain lysozyme (enzyme that kills bacteria)
© Cengage Learning 2015
Barriers to Infection
© Cengage Learning 2015
Inflammation
• Inflammation: local response to tissue damage or
infection; characterized by redness, warmth, swelling, and
pain
– Inflammation begins when a white blood cell degranulates
– Blood flow increases, carrying immune cells to the infected
area
– Complement-coated invading cells are easy targets for the
phagocytic cells
© Cengage Learning 2015
Fever
• Fever: temporary internally induced rise in core body
temperature above the normal set point
– Cytokines stimulate brain cells to make and release
prostaglandins
• Prostaglandins act on the hypothalamus to raise the body’s internal
temperature set point
• Fever enhances immune defenses by increasing the rate
of enzyme activity
© Cengage Learning 2015
34.9 What Happens When the Immune
System Malfunctions?
• Allergen: normally harmless substance that provokes an
immune response
– Examples: drugs, foods, pollen, dust mite feces, fungal spores,
and venom
• Allergy: sensitivity to an allergen
• First exposure: B cells make/secrete IgE
• Later exposure: antigen binds to the IgE
– Histamines and prostaglandins are released
© Cengage Learning 2015
Overly Vigorous Responses
• Exposure to an allergen sometimes causes a severe,
whole-body allergic reaction called anaphylactic shock
– Huge amounts of inflammatory molecules are released all at
once
– Too much fluid leaks into tissues, causing a sudden and
dramatic drop in blood pressure
– Rapidly swelling tissues constrict the airways and may block
them
© Cengage Learning 2015
Autoimmune
Disorders
© Cengage Learning 2015
34.10 What Is AIDS?
• AIDS (acquired immunodeficiency syndrome): develops
as the result of infection by the HIV virus
• HIV mainly infects macrophages, dendritic cells, and
helper T cells
– With time, the immune system becomes progressively less
effective at fighting HIV
– Eventually, secondary infections and tumors kill the patient
© Cengage Learning 2015
Transmission and Treatment
• Routes of HIV transmission:
– Unprotected sex with infected partner
– Mother-to-child during pregnancy, labor, delivery, or breastfeeding
– Syringes shared by intravenous drug abusers
– Blood transfusions (more common in underdeveloped
countries)
© Cengage Learning 2015
Transmission and Treatment
• Drugs cannot cure AIDS, but they can slow its progress
• Most drugs target processes unique to retroviral
replication
• A three-drug mixture of one protease inhibitor plus two
reverse transcriptase inhibitors is currently the most
successful AIDS therapy
© Cengage Learning 2015
34.11 How Do Vaccines Work?
• Immunization: procedures designed to induce immunity
• Vaccine: elicits immunity to a specific antigen
• The first vaccine was developed in the late 1700s, a result
of desperate attempts to survive devastating smallpox
epidemics
© Cengage Learning 2015
How Do Vaccines
Work?
© Cengage Learning 2015
Biology
Concepts and Applications | 9e
Starr | Evers | Starr
Chapter 35
Respiration
© Cengage Learning 2015
© Cengage Learning 2015
35.1 What Is Respiration?
• Respiration: physiological process by which an animal
body supplies cells with oxygen and disposes of carbon
dioxide
• Gases enter and leave an animal body by diffusing across
a thin, moist respiratory surface
• A second exchange of gases occurs internally, at the
plasma membrane of body cells
© Cengage Learning 2015
What Is Respiration?
External environment
(air or water)
Internal environment
(interstitial fluid)
O2
CO2
A
© Cengage Learning 2015
cells of the
respiratory
surface
other body
cells
B
The Airways
• In humans, air travels in the following sequence:
1. Nostrils: ciliated cells remove contaminants
2. Nasal cavity: warms and moistens air
3. Pharynx: throat
4. Larynx: voicebox
5. Trachea: airway to the lungs; windpipe
6. Bronchi: airways connecting trachea to lungs
© Cengage Learning 2015
The Lungs
• Thoracic cavity holds two cone-shaped lungs, one on
each side of the heart
• In the lungs, air flows through finer and finer branchings of
a “bronchial tree”
– Bronchiole: small airway that leads from a bronchus to alveoli
– Alveoli: air sacs in the lung; gas exchange with capillaries
occurs across lining
© Cengage Learning 2015
Muscles of Respiration
• Diaphragm: broad sheet of smooth muscle beneath the
lungs; separates the thoracic cavity from the abdominal
cavity
• Diaphragm and the intercostal muscles act together to
change the volume of the thoracic cavity during breathing
© Cengage Learning 2015
35.5 How Do We Breathe?
• Respiratory cycle: one breath in (inhalation); one breath
out (exhalation)
• Inhalation is always active:
– Diaphragm contracts; moves downward
– Intercostal muscles contract; lifts rib cage up and expands it
outward
– Pressure in the alveoli falls
– Air follows pressure gradient and flows into the airways
© Cengage Learning 2015
Control of Breathing
• Neurons in the medulla oblongata the brain stem act as
the pacemaker for inhalation
– Nerves relay action potentials to the diaphragm and intercostal
muscles
• Breathing rate increases with activity level in response to
increased CO2 levels
© Cengage Learning 2015
Control of Breathing (cont’d.)
Stimulus
CO2 concentration and
acidity rise in the blood
and cerebrospinal fluid.
Chemoreceptors
in wall of carotid
arteries and aorta
Response
Respiratory center
in brain stem
Diaphragm,
Intercostal muscles
Tidal volume and rate of breathing change.
© Cengage Learning 2015
CO2 concentration
and acidity decline
in the blood and
cerebrospinal fluid.
How Are Gases Exchanged and Transported? (cont’d.)
A
© Cengage Learning 2015
B
C
DRY INHALED AIR
How Are Gases Exchanged
and Transported?
160
MOIST EXHALED AIR
120
less than 1
27
inside alveoli
104
40
40
45
100
pulmonary
arteries
40
pulmonary
veins
45
100
start of
systemic
veins
© Cengage Learning 2015
40
start of
systemic
capillaries
O2
CO2
40
cells of body
less than 40
less than 45
Carbon Dioxide Transport
© Cengage Learning 2015
35.7 What Causes Respiratory Diseases and Disorders?
• Interrupted breathing:
– Apnea: breathing repeatedly stops and restarts spontaneously;
often occurs during sleep
– Sudden infant death syndrome (SIDS): infant does not awaken
from an episode of apnea
© Cengage Learning 2015
What Causes Respiratory Diseases and Disorders?
• Infectious diseases:
– Tuberculosis (TB): caused by Mycobacterium tuberculosis
• Symptoms: cough with bloody mucus, chest pain, difficulty breathing
– Pneumonia: lung inflammation caused by an infection
• Symptoms: cough, an aching chest, shortness of breath, and fever
© Cengage Learning 2015
What Causes Respiratory Diseases and Disorders?
• Bronchitis: inflammation of bronchial epithelium
• Asthma: inhaled allergen or irritant triggers inflammation
• Emphysema: tissue-destroying bacterial enzymes digest
the thin, elastic alveolar wall
© Cengage Learning 2015
35.8 Application: Effects of Smoking
• Tobacco smoke contains more than forty carcinogens
(cancer-causing chemicals)
• Once diagnosed with lung cancer, the majority of smokers
die within a year
• Tobacco smoke impairs respiratory function immediately
– Immobilizes cilia, kills white blood cells, and delivers a hefty
dose of carbon monoxide
© Cengage Learning 2015
Biology
Concepts and Applications | 9e
Starr | Evers | Starr
Chapter 36
Digestion and Human Nutrition
© Cengage Learning 2015
© Cengage Learning 2015
36.1 How Do Animals Process Their Food?
• Animal digestion involves four tasks:
– Ingestion: taking food into digestive chamber
– Mechanical and chemical digestion: breaking down food into
smaller components
– Absorption: movement of nutrient molecules from digestive
chamber to the internal environment
– Elimination: expelling leftover material that was not digested
and absorbed
© Cengage Learning 2015
What Are the Components of the Human Digestive
System?
• Food enters the body through the mouth
• Mechanical digestion begins when teeth rip and crush
food
• Movements of the tongue help mix food with saliva
secreted by salivary glands (exocrine glands in the
mouth)
– The enzyme salivary amylase begins the process of chemical
digestion
© Cengage Learning 2015
What Are the Components of the Human Digestive
System?
• Food is forced into the pharynx (throat) by swallowing
– Epiglottis blocks food from entering airways
• Food then enters the esophagus: tube between the
pharynx and stomach
– Peristalsis: smooth muscle contraction that propels food to
stomach and beyond
• Stomach: stretchable sac that stores food, secretes acid,
and digestive enzymes
© Cengage Learning 2015
What Are the Components of the Human Digestive
System?
• The stomach empties into the small intestine: region
where most nutrient molecules are digested and absorbed
– Secretions from the liver and pancreas assist the small
intestines
• The large intestine absorbs water and ions, thus
compacting digestive wastes
– Wastes are briefly stored in the rectum before being expelled
from the anus
© Cengage Learning 2015
36.3 What Is the Role of the Stomach?
• The human stomach is a muscular, stretchable sac with a
sphincter (ring of muscle) at either end
• The stomach has three functions:
– Stores food; controls rate of passage to small intestines
– Mechanically breaks down food
– Secretes substances that aid in chemical digestion
© Cengage Learning 2015
What Is the Role of the Stomach?
• Gastric fluid: secreted by the stomach lining; contains
digestive enzymes, acid, and mucus
• Chyme: mix of food and gastric fluid
© Cengage Learning 2015
36.4 How Does the Structure of the
Small Intestine Enhance Its Function?
• Most digestion and absorption takes place at the lining of
the small intestine
• The many folds and projections of the small intestinal
lining increase its surface area by hundreds of times
– Villi: multicelled projections
– Microvilli: thin projections that increase the surface area of
epithelial cells
• Brush border cells: epithelial cell with microvilli
© Cengage Learning 2015
How Does the Structure of the Small Intestine Enhance
Its Function?
villi
blood vessels
lymph vessel
A Longitudinal cross-section
through the
small intestine showing its
folded lining.
© Cengage Learning 2015
B Intestinal fold
with
villi at its
surface.
C One villus with
brush border cells
at its surface.
D A brush border
cell with microvilli
at its free surface.
E Micrograph of
microvilli
on a brush border
cell.
How Does the Structure of the Small Intestine Enhance
Its Function?
© Cengage Learning 2015
How Are Components of Food Broken Down and
Absorbed?
© Cengage Learning 2015
36.6 What Are the Functions of the Large Intestine?
• Substances move from the small intestine to the large
intestine:
– Indigestible material, dead bacteria and mucosal cells,
inorganic substances, and some water
– As wastes travel through the large intestine, they become
compacted as feces
© Cengage Learning 2015
What Are the Functions of the Large Intestine?
• The first part of the large intestine is a cup-shaped pouch
called the cecum
– An herbivore cecum contains many bacteria that help
breakdown cellulose
– In humans and many other mammals, a short, tubular appendix
projects from the cecum
• Serves as a reservoir for beneficial bacteria
© Cengage Learning 2015
36.7 How Does the Body Use
Carbohydrates, Fats, and Proteins?
• Dietary carbohydrates, fats, and proteins are
macronutrients: substances that we require in large
amounts
– Needed for energy and raw materials
– Breakdown products of these molecules serve as reactants in
aerobic respiration
© Cengage Learning 2015
How Does the Body Use Vitamins and Minerals?
© Cengage Learning 2015
36.9 What Are Components of a Healthy Diet?
© Cengage Learning 2015
Minimal Added Salt And Sugar
• Eating foods with added salt elevates the body’s sodium
level, which raises the risk of high blood pressure
• Commercially prepared foods and drinks are often high in
added sugar
© Cengage Learning 2015
A Healthy Diet
© Cengage Learning 2015
36.10 What Determines Our Weight?
• When the food you eat contains more energy than you
need, you store the excess as bond energy in organic
compounds
– The body’s largest energy store is fat in adipose tissue
© Cengage Learning 2015
What Determines Our Weight?
• For most of our species’ history, an ability to store energy
as fat in adipose tissue was selectively advantageous
– However, most people in the United States now have more
than enough food all of the time
– As a result, about two-thirds of adults are overweight or obese
© Cengage Learning 2015
What Determines Our Weight?
© Cengage Learning 2015
•Wednesday 9/24 Chap 33,34,35,36
•Friday 9/26 Chap 37,38
•Wednesday 10/1 EXAM #1
Bring Scantron