Missouri Baptist University The Cardiovascular System Summary

Michèle Shuster • Janet Vigna • Matthew Tontonoz
Biology for a Changing World
FOURTH EDITION
Lecture Slides
Chapter 27
Digestive System
Macmillan Learning © 2021
Chapter 27
•
Digestive System
Driving Questions
1. What are the anatomy and physiology of the digestive
system?
2. How is food broken down and utilized as it moves through the
digestive tract?
3. How does bariatric surgery change the digestive tract and
digestion, and what are the risks and benefits of bariatric
surgery?
Obesity Complications
• Severe obesity is a risk
factor for the
development of
medical conditions,
many of which have
serious health
consequences.
Bariatric Surgery (1 of 2)
• Surgically reduces the size of
the stomach, either temporarily
or permanently
• Reduces the amount of food the
stomach can hold
• Prevents a person from
overeating
Bariatric Surgery (2 of 2)
The Digestive System (1 of 2)
Digestive system: breaks down food
molecules into smaller subunits,
absorbs nutrients, and eliminates
waste.
• Digestive tract: organs that house
the food as it breaks down
• Accessory organs: organs that
secrete enzymes and other
substances to assist in digestion
The Digestive System (2 of 2)
Digestion: breakdown of food
• Mechanical (physical)
digestion is physically
breaking up particles.
• Chemical digestion involves
chemical changes.
• Digestion begins
immediately after ingestion.
The Upper Digestive System (1 of 3)
Mouth
• Teeth and tongue
mechanically process
food.
• Salivary glands
produce amylase to
digest carbohydrates.
The Upper Digestive System (2 of 3)
Esophagus
• Transports food from
mouth to stomach
• Movement via
peristalsis: waves of
muscular contractions
The Upper Digestive System (3 of 3)
Stomach
• Secretes acids and an
enzyme called pepsin
to digest proteins
• Uses peristalsis to mix
food
• Acidic mix of food and
enzymes called chyme
Bariatric Surgery (1 of 3)
Before surgery
• The stomach can stretch
from the size of a large
sausage to hold 3–4 liters of
food.
• Chyme made in the stomach
enters the small intestine,
where digestion releases
food nutrients.
Bariatric Surgery (2 of 3)
Sleeve gastrectomy
• The stomach is dramatically
reduced, to the size of a
banana.
• Stomach contents are still
released into the upper small
intestine for further
processing.
Bariatric Surgery (3 of 3)
Gastric bypass
• The stomach is reduced to
the size of a golf ball.
• Food bypasses the upper
part of the small intestine.
• Digestive juices from the
stomach and accessory
organs still flow into the
small intestine.
The Small Intestine
•
•
•
Food molecules are
absorbed by epithelial
cells lining the small
intestine.
Epithelial cells are folded
into microscopic villi to
increase surface area.
Digested food molecules
pass through epithelial
cells into capillaries.
The Small Intestine and Accessory Organs
(1 of 3)
Liver
• Makes bile salts and secretes
them into the gallbladder
– Bile salts emulsify fats, breaking
them up into smaller droplets.
Gallbladder
• Stores bile salts and passes them
into the small intestine when food
enters the duodenum
The Small Intestine and Accessory Organs
(2 of 3)
Pancreas
• Secretes juices into the small
intestine to neutralize acids
and break down
carbohydrates, proteins, fats,
and nucleic acids
• Includes the enzyme lipase,
which breaks down fats
The Small Intestine and Accessory Organs
(3 of 3)
Small intestine
• First portion called
duodenum, where
pancreatic enzymes and bile
salts mix with chyme
• Produces some digestive
enzymes
• Where most chemical
digestion happens
The Large Intestine
Absorption
• Absorbs remaining
water, salts, vitamins
• Bacteria help finish
digestion.
Elimination
• Collects leftover
material to expel from
the body in stool
Hormones and Hunger
•
Ghrelin is produced by the
empty stomach.
–
•
Food in the digestive tract
stimulates digestive enzymes.
–
•
Leads to other hormones that
stimulate eating
Leads to hormones that inhibit
eating
Fat tissue produces leptin,
which reduces appetite.
Does bariatric surgery work? (1 of 3)
• People who had gastric
bypass surgery lost 21%
more weight over 10 years
than those who tried
nonsurgical methods.
Does bariatric surgery work? (2 of 3)
• People who had
gastric bypass
surgery lived longer
than those who tried
nonsurgical methods.
Does bariatric surgery work? (3 of 3)
• Not an easy road:
– Some patients like Amy Jo
Smith have persistent
pain and nausea.
– Other complications are
possible.
Summary (1 of 3)
What are the anatomy and physiology of the digestive
system?
• The digestive system has a central digestive tract and
accessory organs.
– Its function is to break down food molecules, absorb nutrients,
and eliminate waste.
• Digestion is coordinated by a variety of hormones.
– Ghrelin: hunger hormone
– Leptin: satiety hormone
Summary (2 of 3)
How is food broken down and utilized as it moves through the
digestive tract?
• Digestion begins in the mouth, passes through the esophagus to the
stomach by peristalsis.
• In the stomach, food mixed with acid and pepsin, becomes chyme.
• Enzymes from the stomach (pepsin enzyme) and pancreas (lipase
enzyme), and bile salts from the liver help digest food molecules.
• Most digestion happens in the small intestine.
• Additional absorption happens in the large intestine, where stool forms.
Summary (3 of 3)
How does bariatric surgery change the digestive tract and digestion,
and what are the risks and benefits of bariatric surgery?
• Bariatric surgery changes the anatomy of the digestive tract by
decreasing the size of the stomach alone and/or by rerouting food to
bypass portions of the digestive tract.
• Bariatric surgery may also change hormonal regulation of appetite and
hunger.
• Bariatric surgery can result in weight loss and improvements in overall
health, but is not without risks, including surgical complications and
micronutrient deficiencies.
Interpreting Data (1 of 5)
• A 2012 study compared the impacts of medical therapy and
bariatric surgery in obese people with uncontrolled type 2
diabetes.
• Patients were randomly assigned to receive aggressive medical
therapy for their diabetes (including medications and diet and
lifestyle modifications) or bariatric surgery.
• Several dependent variables were measured for 1 year. Two of
these variables—average BMI and average number of diabetes
medications—are shown in the table on the next slide.
Interpreting Data (2 of 5)
a. Draw two graphs:
Graph 1: plot the
average diabetes
medications over time
for the group receiving
medical therapy and
for the group receiving
surgery.
Treatment Variable
Baseline
Time after Time after
treatment: treatment:
3 Months 6 Months
Medical
therapy
Average BMI
36.3
35.4
34.8
34.5
34.4
Average
number of
diabetes
medications
2.8
3.1
3.1
3.0
3.0
Average BMI
37.0
31.8
28.2
26.9
26.8
Average
number of
diabetes
medications
2.6
1.1
0.6
0.4
0.3
Gastric
bypass
Time after
treatment:
9 Months
Time after
treatment:
12 Months
Interpreting Data (3 of 5)
a. Draw two graphs:
Graph 2: plot the
change in BMI from
baseline for the two
groups (set the
baseline values at 0
on the time axis
because by definition
no change could have
taken place yet).
Treatment Variable
Baseline
Time after Time after
treatment: treatment:
3 Months 6 Months
Medical
therapy
Average BMI
36.3
35.4
34.8
34.5
34.4
Average
number of
diabetes
medications
2.8
3.1
3.1
3.0
3.0
Average BMI
37.0
31.8
28.2
26.9
26.8
Average
number of
diabetes
medications
2.6
1.1
0.6
0.4
0.3
Gastric
bypass
Time after
treatment:
9 Months
Time after
treatment:
12 Months
Interpreting Data (4 of 5)
b. From these graphs,
how does gastric
bypass compare to
medical therapy for
diabetes
management in
obese patients with
type 2 diabetes?
Treatment Variable
Baseline
Time after Time after
treatment: treatment:
3 Months 6 Months
Medical
therapy
Average BMI
36.3
35.4
34.8
34.5
34.4
Average
number of
diabetes
medications
2.8
3.1
3.1
3.0
3.0
Average BMI
37.0
31.8
28.2
26.9
26.8
Average
number of
diabetes
medications
2.6
1.1
0.6
0.4
0.3
Gastric
bypass
Time after
treatment:
9 Months
Time after
treatment:
12 Months
Interpreting Data (5 of 5)
c. The data shown in the
table are for 41 patients
who had medical therapy
and 50 patients who had
gastric bypass. From this
information and any
other limitations you can
identify, are these data
sufficient to make a
recommendation of
surgery for diabetes
management? Why or
why not?
Treatment Variable
Baseline
Time after Time after
treatment: treatment:
3 Months 6 Months
Medical
therapy
Average BMI
36.3
35.4
34.8
34.5
34.4
Average
number of
diabetes
medications
2.8
3.1
3.1
3.0
3.0
Average BMI
37.0
31.8
28.2
26.9
26.8
Average
number of
diabetes
medications
2.6
1.1
0.6
0.4
0.3
Gastric
bypass
Time after
treatment:
9 Months
Time after
treatment:
12 Months
Mini Case
• Alicia has had her gallbladder removed. She must be careful
not to eat high-fat meals, or else she is likely to experience
greasy diarrhea.
• Her friend Tammy is taking Alli, a weight-loss drug that inhibits
the fat-digesting enzyme lipase. Tammy must also avoid highfat meals if she wants to avoid oily stools, a possible side
effect of the drug.
• Why are both Alicia and Tammy at risk for similar digestive
upsets when their situations are different (gallbladder removal,
taking Alli)?
Michèle Shuster • Janet Vigna • Matthew Tontonoz
Biology for a Changing World
FOURTH EDITION
Lecture Slides
Chapter 28
Cardiovascular System
Macmillan Learning © 2021
Chapter 28
•
Cardiovascular System
Driving Questions
1. What structures make up the cardiovascular system, and how
does blood flow through the system?
2. What is the structure of the heart and of the different types of
blood vessel?
3. What is the composition of blood, and what does blood do?
4. What is cardiovascular disease, and what are some of the risk
factors for developing cardiovascular disease?
A Silent Epidemic
Cardiovascular
disease (CVD)
• Disease of the heart
or blood vessels or
both
• Number one killer in
the United States
and the developed
world
The Cardiovascular System (1 of 4)
• Transports nutrients,
gases, hormones, and
other critical molecules
throughout the body
• Consists of the heart,
blood vessels, and blood
• Works closely with the
respiratory system
The Cardiovascular System (2 of 4)
Heart
• Muscular pump
• Pumps blood throughout
the body
• Four chambers
– two paired atria receive
blood
– two paired ventricles
pump blood out
The Cardiovascular System (3 of 4)
Arteries
• Vessels that carry blood
away from the heart
Veins
• Vessels that return
blood to the heart
The Cardiovascular System (4 of 4)
Blood
• Composed of cells
and liquid
• Carries oxygen to
all tissues of body
• Carries away
carbon dioxide
waste
Cardiovascular Disease (1 of 3)
Atherosclerosis
• Disease that develops in
vessels, restricting blood
flow
• Accumulation of fibrous
plaques (fatty deposits)
• Fatty deposits develop in
arteries or heart muscle
• Reduces blood flow to
tissues
Cardiovascular Disease (2 of 3)
Consequences:
• If coronary arteries
are blocked, heart
cells die.
• Heart attack:
damage to the heart
muscle resulting
from the restriction
of blood flow to
heart tissue
Cardiovascular Disease (3 of 3)
• Risk factors for heart
disease:
– high blood pressure
– smoking
– high cholesterol levels
• Signs of heart disease
can begin to appear
even in teenagers.
Blood Vessels (1 of 2)
Arteries
•
•
High-pressure vessels
Heart propels blood through
arteries
Veins
•
•
Low-pressure vessels
Contractions of skeletal
muscles and one-way
valves propel blood through
veins
Blood Vessels (2 of 2)
Capillaries
• Tiny blood vessels
located in tissues
• Narrow with thin walls to
allow for gas and
nutrient exchange
Blood (1 of 2)
Blood components
• Complex tissue
• Cells
– red blood cells
– platelets
– white blood cells
• Liquid plasma
– water and protein
Blood (2 of 2)
Red blood cells
(erythrocytes)
• Carry oxygen
Platelets
• Involved in clotting
White blood cells
(leukocytes)
• Involved in immune
response
Blood Circulation (1 of 3)
Valves
• Heart has a set of valves in each chamber
• Ensure one-way flow of blood through the heart
Aorta
• Major heart artery leading to the rest of the body
• Carries oxygenated blood to the body’s other arteries
Blood Circulation (2 of 3)
• Blood passes through
the heart twice during
every trip through the
body.
• Each pass is on its own
circuit:
– pulmonary circuit
– systemic circuit
Blood Circulation (3 of 3)
Pulmonary circuit
• Circulation of blood between
the heart and the lungs
• Oxygenates the blood
Systemic circuit
• Circulation of blood between
the heart and the rest of the
body
• Uses up oxygen in the blood
Blood Pressure (1 of 3)
• Heart never stops beating
• Regulated by pacemaker cells
• Often 60–90 beats per minute
• Requires oxygenated blood for power
Blood Pressure (2 of 3)
Blood pressure
• Overall pressure in blood
vessels
• Based on action of heart
muscle
Blood Pressure (3 of 3)
Systolic pressure
• Blood pressure while heart is
pumping
• Can be felt in the pulse
Diastolic pressure
• Blood pressure in between
heart pumps
• Lower than systolic pressure
High Blood Pressure
Hypertension: high
blood pressure
• Stresses and
damages walls of
arteries
• May develop scar
tissue, then
atherosclerosis
Consequences of Hypertension
• Fatty deposits from
atherosclerosis can
also lead to blood
clots.
• This obstructs blood
flow.
• Stroke
– disruption in blood
supply to the brain
Risk Factors (1 of 4)
Risk factors
• Family history of CVD
• High salt diet
• Obesity
• Low physical activity
• Drinking in excess
• Stress
• High cholesterol
• Smoking cigarettes
Risk Factors (2 of 4)
Cholesterol
• Lipid transported in
the blood
• Proteins bind and
help transport it –
lipoproteins
Risk Factors (3 of 4)
High-density lipoproteins
(HDL)
•
•
“Good” cholesterol
Transport cholesterol out of
bloodstream to the liver
Low-density lipoproteins
(LDL)
•
•
“Bad” cholesterol
More likely to to accumulate
in lining of blood vessels
Risk Factors (4 of 4)
Obesity
• BMI of 30 or
above
• Heart works
harder
• Leads to high
blood pressure
• Leads to type 2
diabetes
Cardiovascular Disease
• Diet, activity level, and
smoking can influence
the risk for developing
this disease.
• Southern states have
the highest rates of
CVD in the United
States.
ABCs of a Healthy Heart
• Avoid tobacco.
• Be more active.
• Choose healthful foods.
Summary (1 of 4)
What structures make up the cardiovascular system, and how
does blood flow through the system?
• The cardiovascular system transports nutrients, oxygen, hormones,
and other substances throughout the body.
–
•
It consists of the heart, blood vessels, and blood.
The heart pumps blood in a double circulation pattern:
–
–
The pulmonary circuit moves blood between the heart and the lungs.
The systemic circuit moves blood between the heart and the rest of
the body.
Summary (2 of 4)
What is the structure of the heart and of the different types
of blood vessels?
• The heart has four chambers:
–
–
Two atria receive blood.
Two ventricles pump blood out of the heart.
• Different types of blood vessels have different structures and
functions.
–
–
–
Arteries transport blood away from the heart.
Veins transport blood to the heart.
Capillaries are the sites of nutrient and gas exchange in tissues.
Summary (3 of 4)
What is the composition of blood, and what does blood do?
• Blood is composed of cells, water, gases, hormones, nutrients,
and traces of whatever else we put in our body.
• Red blood cells carry oxygen.
• White blood cells participate in immune defenses.
• Platelets help the blood clot.
Summary (4 of 4)
What is cardiovascular disease, and what are some of the risk factors
for developing cardiovascular disease?
• Atherosclerosis, or hardening of the arteries, is a common cause of
CVD.
–
–
•
Cholesterol, fats, and other substances build up in the wall of a blood
vessel, forming plaques that can obstruct the flow of blood.
Atherosclerosis in coronary arteries can cause heart attack.
Risk factors include high blood pressure (hypertension), obesity, high
cholesterol, and smoking.
–
–
Cholesterol is transported in the form of LDL or HDL lipoproteins.
Too much LDL cholesterol relative to HDL in the blood due to unhealthful
diet choices can contribute to atherosclerosis.
Interpreting Data
a. Look at the 2018 data for Texas,
Arizona, California, South Dakota,
and your home state. For each
state, record the average
percentage of adults with BMI ≥ 30.
b. Determine the total population of
each state as of July 1, 2018 (you
can find census data at
https://www.census.gov/quickfacts/
table/PST045216/00).
c. Determine the total number of
people in each of those states with
a BMI of at least 30.
Mini Case (1 of 2)
• Steven is 14 years old.
– He is an ace goalie for his soccer team, which practices twice
during the week and plays a game every weekend.
– He is also an ace online gamer, holding the highest player skill
level in World of Warcraft.
– After many long afternoons of playing, Steven has become a
very good graphic designer and his mother pays him to design
computer-generated fliers for her business.
Mini Case (2 of 2)
• Steven’s mother prepares healthful meals with lots of whole
grains, fruits, and dairy (milk and cheese), and she gets
regular checkups to monitor her elevated blood pressure.
• Steven spends some of his money on chocolate bars and
potato chips. He is a big guy, and in the heaviest 5% of his
age group.
• From what you’ve read in this chapter, what cardiovascular
risk factors do you identify in Steven?
• What could you say to Steven and his mother about Steven’s
potential risk and reducing that risk?

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