Transcript CirculatorySystem

Objective: SWBAT list the structural components of a vertebrate circulatory
system and understand the concept of transporting oxygen and nutrients.
1. Air rushes into the lungs of humans during inhalation because
 A) a positive respiratory pressure is created when the diaphragm relaxes.
 B) gas flows from a region of lower pressure to a region of higher pressure.
 C) pulmonary muscles contract and pull on the outer surface of the lungs.
 D) pressure in the alveoli increases.
 E) the rib muscles and diaphragm contract, increasing the lung volume.
2. Breathing is usually regulated by
 A) hemoglobin levels in the blood.
 B) the lungs and the larynx.
 C) the concentration of red blood cells.
 D) erythropoietin levels in the blood.
 E) CO2 and O2 concentration and pH- level sensors.
3. In humans, the largest amount of the carbon dioxide produced in the cells is carried
to the lungs as
A.
Carbaminohemoglobin
B.
CO2 gas in solution in plasma
C.
CO2 gas in the red blood cells
D.
bicarbonate in the plasma
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E.
bicarbonate in the red blood cells
QUESTION TO PONDER??
 Why do scientists say that MOST
sharks will drown and die if they stop
moving in water?
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Circulatory Systems
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2008-2009
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In circulation…
 What needs to be transported

nutrients & fuels
 from digestive system

respiratory gases
 O2 & CO2 from & to gas exchange systems: lungs, gills

intracellular waste
 waste products from cells
 water, salts, nitrogenous wastes (urea)

protective agents
 immune defenses
 white blood cells & antibodies
 blood clotting agents

regulatory molecules
 hormones
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Circulatory systems
 All animals have:
circulatory fluid = “blood”
 tubes = blood vessels
 muscular pump = heart

open
hemolymph
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closed
blood
Open circulatory system
 Taxonomy

invertebrates
 insects,
arthropods,
mollusks
 Structure

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no separation
between blood &
interstitial fluid
Closed circulatory system
 Taxonomy

invertebrates
 earthworms, squid,
octopuses

vertebrates
 Structure

blood confined to
vessels & separate
from interstitial fluid
 1 or more hearts
 large vessels to smaller
vessels
 material diffuses
between blood vessels
& interstitial fluid
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closed system = higher pressures
Vertebrate circulatory system
 Adaptations in closed system

2
low
pressure
to body
number of heart chambers differs
3
4
low O2
to
body
high
pressure
& high O2
to body
What’s the adaptive value of a 4 chamber heart?
4 chamber heart is double pump = separates oxygen-rich &
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Biology
oxygen-poor
blood; maintains high pressure
Vertebrate cardiovascular system
 Chambered heart
atrium = receive blood
 ventricle = pump blood out
 Blood vessels
 arteries = carry blood away from heart


veins = return blood to heart

capillaries = thin wall, exchange / diffusion
 capillary beds = networks of capillaries
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Arteries: Built for high pressure pump
 Arteries

thicker walls
 provide strength for high pressure
pumping of blood
narrower diameter
 elasticity

 elastic recoil helps
maintain blood
pressure even
when heart relaxes
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Veins: Built for low pressure flow
Blood flows
toward heart
 Veins
thinner-walled
 wider diameter

Open valve
 blood travels back to heart
at low velocity & pressure
 lower pressure
 distant from heart
 blood must flow by skeletal muscle
contractions when we move
Closed valve
 squeeze blood through veins

valves
 in larger veins one-way valves
allow blood to flow only toward heart
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Capillaries: Built for exchange
 Capillaries

very thin walls
 lack 2 outer wall layers
 only endothelium
 enhances exchange across capillary

diffusion
 exchange between blood & cells
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Mammalian
circulation
systemic
pulmonary
systemic
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What
do blue vs. red areas represent?
Mammalian heart
Coronary arteries
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to neck & head
& arms
Heart valves
 4 valves in the heart


flaps of connective tissue
prevent backflow
SL
 Atrioventricular (AV) valve


between atrium & ventricle
keeps blood from flowing back
into atria when ventricles contract
 “lub”
 Semilunar valves


between ventricle & arteries
prevent backflow from arteries into
ventricles while they are relaxing
 “dub”
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AV
AV
Lub-dub, lub-dub
 Heart sounds


closing of valves
“Lub”
SL
 recoil of blood against
closed AV valves

“Dub”
AV
AV
 recoil of blood against
semilunar valves
 Heart murmur

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defect in valves causes hissing sound when
stream of blood squirts backward through valve
Cardiac cycle
 1 complete sequence of pumping
heart contracts & pumps
 heart relaxes & chambers fill
 contraction phase

 systole
 ventricles pumps blood out

relaxation phase
 diastole
 atria refill with blood
systolic
________
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diastolic
pump
(peak pressure)
_________________
fill (minimum pressure)
110
____
70
Measurement of blood pressure
 High Blood Pressure (hypertension)

if top number (systolic pumping) > 150
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if bottom number (diastolic filling) > 90
D.N.A
 In circulating by the shortest route from
the lungs to the foot, how many times
would a drop of blood pass through the
left ventricle?

A) 0 B) 1 C) 2 D) 3 E) 4
 Just after blood leaves the left ventricle
of the human heart, it passes through
the
A) pulmonary artery B) left atrium
 C) aorta
D) superior vena cava
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
 Sometimes a baby is born with its large
blood vessels reversed: The right
ventricle pumps blood out through the
aorta, and the left ventricle is
connected to the pulmonary artery.
The system is otherwise normal. How
would this alter blood flow? Why would
this be disastrous if not corrected by
surgery?
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