Biology 20 Unit D Human Systems Section 103 pg 328335 Cardiac Output Cardiac Output The amount of blood that flows is pumped from the heart each minute Amount of blood pumped from right side amount of blood pumped from left side ID: 461333
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Slide1
Regulation of Blood Flow
Biology 20 – Unit D: Human Systems
Section 10.3 (pg. 328-335)Slide2
Cardiac Output
Cardiac Output:
The amount of blood that flows (is pumped) from the heart each minute
Amount of blood pumped from right side = amount of blood pumped from left sideSlide3
Stroke Volume
Stroke Volume:
The quantity of blood pumped with each beat of the heart = ~70 mL/beat (resting)
Cardiac
Output
=
Stroke Volume
x
Heart Rate
Cardiac Output
=
70 mL/beat x 70 beats/min
Cardiac Output
=
4900 mL/minSlide4
Cardiac Output Calculation
What’s your weight in kg? (
lbs
x 0.45)
What’s your heart rate?
Come up and tell meSlide5
Question 1
What is Cardiac Output?
(a) volume of blood that is pumped with each heart beat
(b) volume of blood that is pumped by the heart each minute
(c) The number of times the heart contracts per minute
(d) The number of times the
sinoatrial
node stimulates the heartSlide6
Blood Pressure
The force of the blood on the walls of the arteries
Measured by a sphygmomanometer
Gauge measures the pressure exerted by the blood during ventricular contraction
Bladder increases until a low-pitched sound can be detected – systolic blood pressure
Bladder is deflated even more until sound disappears – ventricular relaxation – diastolic blood pressureSlide7
Blood Pressure
Measured in mmHg (mm of Mercury)
Systolic pressure/Diastolic pressure
= Pressure in Arteries/pressure in Veins
Normal = 90/60 – 140/90; Average = 120/80
Example of High Blood pressure = 160/100
Hypertensive
Example of Low Blood pressure = 80/50
HypotensiveSlide8
Blood Pressure
Systolic = pressure in arteries
Diastolic = pressure in veins
BP = Systolic/Diastolic
BP = 120/80 (Normal)Slide9
Question 2
True or False. Pressure increases as blood flows away from the heart.Slide10
Blood Pressure
Depends on:
Cardiac output
(as cardiac output increases, blood pressure increases and vice versa)
Arteriolar resistance
(diameter of arteriole is regulated by smooth muscle)
Constriction closes the opening - reduces blood flow through the arteriole and increases blood pressure =
vasoconstriction
Arteriole dilation increases blood flow and decreases blood pressure =
vasodilation
Responds to neural and hormonal controlsSlide11
Blood Vessel Regulation
Diameter of arterioles adjusts in response to metabolic products such as
Glucose by-products (in the break down of glucose)
Carbon dioxide
Lactic acid
Causes relaxation of arterioles
dilation blood flow (increase of oxygen) increases
How the body maintains equilibriumSlide12
Hypertension
High blood pressure
Increased resistance to blood flow
Could cause vessels to weaken and rupture
Body increases the amount of connective tissue – leading to hardened/less elastic arteries.
Diet is mainly responsible
E.g. too much salt
higher blood pressure
Heart Attack/Stroke!Slide13
Hypotension
Low blood pressure
Reduces your capacity to transport blood
and oxygen
Adjusted by the sympathetic nervesSlide14
Blood Vessel Regulation
Vaso
constriction
: the narrowing of blood
vessels/arterioles
(less blood to tissues)
Increases blood
pressure
Caused
by a nerve impulse that contracts smooth muscle
Less O
2
to
tissues
Vaso
dilation
: the widening of blood
vessel/arterioles
(more blood to tissues)
Decreases blood
pressure
Relaxation
of smooth muscle
Helps you release excess
heatSlide15
Blood Pressure Regulation
Auto
nomic nervous system
(controls motor nerves that regulates the diameter of arterioles; unconscious/involuntary) –
m
edulla
o
blongata in the brain
Parasympathetic
– decelerates heart beat
Sympathetic
– accelerates heart beatSlide16
Question 3
A blood pressure regulator in the brain is called the _____________ ______________.
(don’t worry about spelling)Slide17
Blood Pressure Regulation
Blood pressure receptors are called baroreceptors are located in the aorta and the carotid arterySlide18
What happens when blood pressure drops…?
Nervous System
Parasympathetic Sympathetic
Blood Vessels/Arterioles
Dilate (widen)
constrict (narrow)
Blood Pressure
Decreases
Increases
Cardiac Output
Increases
DecreasesSlide19
Question 4
When a someone becomes hypertensive, the body tries to regulate itself by
Stimulating the ________________ nervous system
Causing arterioles to ________________
Which ______________ blood pressure
And _____________ their cardiac output.Slide20
Regulating Body Temperature
Thermoregulation: maintenance of body temperature within a range that enables cells to function efficiently
Consider the exchange of heat between the body and the environment
What is normal body
temperature?Slide21Slide22
Question 5
Which of the following regulates a body that has become too hot?
Blood vessels dilate and shivering
Blood vessels constrict and shivering
Blood vessels dilate and sweating
Blood vessels constrict and sweatingSlide23
Thermoregulation
Hypothalamus: a region of the brain that is responsible for coordinating many nerve and hormone functions
Stimulus
Physiological Response
Result
Decreased Environmental
Temperature
Constriction of blood vessels in skin
Body hairs become erect (
goosebumps
)
Hypothalamus initiates
s
hivering
Heat is conserved
More
head is generated by increased metabolism (skeletal muscle movement)
Increased Environmental
Temperature
Dilation of blood vessels
Sweating
Heat is dissipatedSlide24
Capillary Fluid Exchange
Every tissue is within 0.1mm of a capillary
Capillaries provide cells with oxygen, glucose, and amino acids
Fluid exchange between the blood and the surrounding extracellular fluid
Water passes through spaces between the capillary cells
Fluid & Osmotic pressure influence water movement
Water moves from an area of higher pressure to an area of lower pressureSlide25Slide26
Precapillary SphinctersSlide27Slide28
Capillary Fluid ExchangeSlide29Slide30
Question 6
When fluid pressure outside of a capillary is greater than the fluid pressure inside a capillary, the water moves
(a) into the capillary
(b) out of the capillary
(c) along side the capillary
(d) nowhereSlide31
The Lymphatic System
Lymph:
the fluid found in lymph vessels that contains some proteins that have leaked through capillary walls
Leaked
proteins
drain from the extracellular fluid (ECF) and return to the circulatory system by way of the lymphatic systemSlide32
Lymph is transported in open-ended lymph vessels (similar to veins)
Low pressure return system uses muscle contractions
Lymph is returned to the venous systemSlide33Slide34
Lymph Nodes
Are enlargements that house white blood cells that filter out any bacteria
F
ilter damaged cells and debris from the lymph and store lymphocytes
Red bone marrow
is where all types of blood cells are produced
White blood cells
Spleen
– has many blood sinuses (each hold ~150mL blood) – reservoir
Lymphoid OrgansSlide35
Question 7
Which of the following does the lymphatic system
NOT
do?
Return leaked protein to the circulatory system
Houses white blood cells
Transports lymph into open-ended lymph vessels
Transports oxygen and carbon dioxideSlide36
Edema (a.k.a. Swelling)
Results when small blood vessels become leaky and release fluid into tissues. The fluid accumulates causing tissues to swell.Slide37
Response of the Circulatory System to Exercise
Go for a run!
Oh no! Lactic acid buildup in your calf!
Sympathetic nerves stimulate the adrenal glands which release epinephrine/adrenaline
Epinephrine travels through the blood and stimulates the release of red blood cells from the spleen
Increased numbers of red blood cells aid in oxygen delivery
Epinephrine and stimulation from sympathetic nerves increases heart and breathing rates
higher levels of blood and faster oxygen transport & wastes are removed!Slide38
Summary
Cardiac output
is the amount of blood the heart can pump each minute
Blood pressure
is the force of blood on the walls of the arteries. It is measured as
systolic
and
diastolic
blood pressure in
millimetres
of mercury (
mmHg
)
Blood pressure is higher in vessels
closer to
the heart
Increased cardiac output
increases
blood pressure. If arteries are constricted, blood flow is
slower
and blood pressure is
higherSlide39
Summary
Capillaries are associated with
fluid exchange
between blood and extracellular fluid
The movement of water between blood and the ECF is regulated by
fluid pressure
and by
osmotic pressure
Water moves from an area of
high
fluid pressure, the capillary, to an area of
low
fluid pressure, the ECF
Proteins
and dissolved
minerals
in the blood cause fluid from the ECF to move into the blood by osmosisSlide40
Summary
Proteins in the ECF are returned to the
circulatory
system by the
lymphatic
system
Lymph
nodes house
white blood cells
that filter bacteria
Red
bone marrow is where all types of
blood
cells are produced
The
spleen
stores and purifies blood. The spleen releases red blood cells in response to
low
blood pressure or
low
oxygen levels in blood.