Download circulatory system objectives File

Unit 3
Maintaining Dynamic Equilibrium
Chapter 9 p. 298
HOMEOSTASIS - Obj 1
Chapter 9 p.298
The body has developed physiological (ex. enzymes) and
biochemical (ex. chemical reactions) mechanisms that allow it to
maintain its internal environment in a stable state.
The body copes with both internal and external stresses, such
as:
Temperature (external)
Infection (internal)
What happens to our bodies
as we vigorously workout?
-
?
?
So, what exactly is homeostasis? - Obj 1
a relatively stable internal environment and the ability of an
organism to maintain the constant or stable conditions needed
for life.
Dynamic equilibrium: State of balance achieved in an environment
as the result of internal control mechanisms that constantly go
against the outside forces that tend to change the environment.
Healthy people around the world share these
constants:
o blood glucose: 100mg/ml
o blood pH: ~7.4
o body temperature: ~37OC
o blood pressure: ~120/80 mm Hg (mercury)
The internal environment of a cell has to remain constant at all
times. If the homeostasis of a cell is disrupted, the cell could die.
The body’s systems are used to regulate
homeostasis:
(Figure 9.2, p. 301)
Circulatory system
Respiratory system
Digestive system
Excretory system
Immune system
Nervous system (Biology 3201)
Endocrine system (Biology 3201)
TEMPERATURE REGULATION - Obj 2
Homeotherm: A new word for warm-blooded. This
refers to organisms that keep their body temperature
relatively constant. (eg. birds and mammals)
Poikilotherm: A new word for cold-blooded. The
body temperature of these organisms fluctuates
depending on the temperature of the external
environment. (eg. amphibians and reptiles)
(Many animals are not complete homeotherms or
complete poikilotherms, they fall somewhere in
between the two extremes.)
p.300
HUMAN TEMPERATURE REGULATION - Obj. 4 p.302
The Circulatory system plays a major role in the regulation
of heat. Blood coming to the skin from the heart is warmer
than the skin itself.
As more blood passes by the skin more heat is lost from the
body.When you are cold your body needs to conserve
heat. So the blood vessels close to the skin’s surface
constrict to limit the blood flow. (Vasoconstriction)
This is why your extremities such as your fingers, toes,
ears, and nose get cold first.
p. 302
When your body needs to release heat,
blood vessels just under the skin
dilate to increase the blood flow just
under the skin’s surface.
(Vasodilation) Your skin may feel
hot or look flushed.
CIRCULATORY SYSTEM
330
What is the circulatory system? (Figure
9.6, p.305)
p.304-
CIRCULATORY SYSTEM
p.304-330
What is the circulatory system? (Figure
9.6, p.305)
A transport system that allows the transfer of
nutrients, gases, and wastes to and from the
cells.
Large multicellular organisms such as humans
require a circulatory system.
obj.5
Circulatory System cont’d
Unicellular and some small multicellular organisms can depend on
diffusion to transport nutrients, gases, and wastes to and from
the cells.
However large multicellular organisms (humans) are much bigger
and diffusion alone is an ineffective means of transport.
Blood vessels are arranged into three primary cycles p.305
Cardiac (coronary) circulation
Pulmonary circulation
Systemic circulation
Blood vessels are arranged into three primary cycles p.305
obj. 7
Cardiac (coronary) circulation: The
path taken by blood within the
heart.
Pulmonary circulation: The pathway
of blood from the heart to the lungs
and back.
Systemic circulation: The pathway of
blood from the heart to the rest of
the body and back.
(refer to your handout “Pulmonary and Systemic Circulations”)
What makes up a circulatory system?
1) Transport vessels
2) Transport medium
3) Pumping Mechanism
(The heart)
1)Transport Vessels
307
obj 6
There are three types of transport vessels.
a. Arteries
b. Veins
c. Capillaries
(Figure 9.8, p.306)
p. 305-
a.Arteries
Have three different structural layers:
The outer layer is made of connective tissue (elastic).
The middle layer, which is the thickest, is composed of circular bands of
elastic fibers and smooth muscle.
The inner layer is only a single epithelial cell thick.
Arteries have elasticity. This allows for expansion, which helps keep blood
flowing in the right direction.
Arteries carry blood Away from the heart. (mostly oxygenated blood - red)
exception?
Arterioles are small arteries.
b. Veins
Veins have thinner walls and a larger
inner circumference than arteries.
lack elasticity but contain a greater
amount of blood.
Veins have one-way valves to ensure blood is
flowing in the right direction.
Muscle contractions assist blood in moving.
They carry blood back to the heart. (mostly
deoxygenated - blue) exception?
Venules are small veins.
c. Capillaries
The smallest of the transport
vessels. Only one blood cell
can pass through at a time.
Regulates movement of materials into and out of the blood stream
Blood is always contained in the transport vessels; it never flows out and
directly contacts the body’s cells.
So, what is the pathway that blood travels
through the arteries, veins and capillaries?
NOTE:
Blood travels from an artery to an
arteriole and then to a capillary
network where gases, foods, wastes,
and hormones are exchanged between
blood and interstitial fluid surrounding
each body cell. Capillaries then
empty into venules followed by veins,
which carry blood back to the heart.
(Figure 9.8, p.306 – VERY
IMPORTANT!)
https://www.youtube.com/watch?v=
whtNDBIhczQ - blood vessel
structure and function 3 mins
Transport Medium
p. 308-313
Blood- collection of specialized cells that
performs a specific task within an
organism. For this reason it is considered a
tissue.
Blood transports nutrients, dissolved gases,
enzymes, hormones, and wastes all around
the body.
obj 8
Blood
Blood contains cellular and non-cellular components.
Plasma- This fluid is composed of water, gases, proteins, sugars,
vitamins, minerals, and waste products.
Blood cells- Three main types are present each with special
functions.
What percent of each makes up blood?
55% plasma.
45% blood cells
Objective 8
Identify the main components of blood and explain the role of each.
Page 308-312
Include:
- erythrocytes
- leukocytes
- platelets
- plasma
Plasma
The medium (fluid) that contains blood
cells
contains protein (helps with blood volume
and pressure).
Other proteins in the plasma make up
antibodies (later – immune system) or
are involved in blood clotting.
(Table 9.2 and Figure 9.10, p. 308
Blood Cells
· There are three main types
of blood cells:
a)
b)
c)
Red blood cells (RBC)
White blood cells (WBC)
Platelets (cell fragments)
(Table 9.2, p. 308)
https://www.youtube.com/watch?v=R-sKZWqsUpw - parts of blood - 1
min
a)Red blood cells (erythrocytes)
9.11, p. 309)
44% of the total volume of your blood.
____
4.5 - 5.5 million RBC per milliliter of human blood.
______________
RBC are specialized for oxygen transport.
(Fig.
a) Red blood cells (erythrocytes) cont’d
mature cells have no nucleus.
contains the pigment hemoglobin - gives cells their red colour.
Hemoglobin binds to oxygen, allowing RBC to pick up and release
oxygen as the body requires.
How do you get carbon monoxide poisoning??
b) White blood cells (leucocytes)
____
1% of total blood volume. (This
number can double while fighting
infection.)
Unlike RBC, WBC appear colourless
and have a nucleus.
WBC
Two important disease-fighting WBC types are:
i. Macrophages
ii.Lymphocytes
i. Macrophages- phagocytic cells that can pass through capillary walls to
engulf foreign particles. (immune response)
ii. Lymphocytes- non-phagocytic cells that play a role in the body’s
acquired immune response (release antibodies or signals other cells for
help)
c) Platelets
Platelets are not cells. They
are cell fragments created
when large cells in the
bone marrow break apart.
Lasts for 7-10 days before breakdown.
Platelets play an important role in blood clotting and thus protect the
body.
3. The Heart
obj.9
(Figure 9.17, p. 314)
A hollow, muscular pump that pumps blood throughout the
circulatory system.
It pumps on average about 90,000 times per day, pumping blood in
two directions without any mixing of oxygenated and
deoxygenated blood.
How big is your heart?
A human heart is approximately the size of your fist.
https://www.youtube.com/watch?v=BEWjOCVEN7M - animated path of blood flow through the
heart - ~2mins
The Heart’s Main Parts
a)
b)
c)
d)
e)
f)
g)
h)
i)
Left and right atria (singular – atrium)
Left and right ventricles
Valves (bicuspid, tricuspid, semilunar)
Aorta
Pulmonary vein
Pulmonary artery
Septum
Superior (upper/anterior) vena cava
Inferior (lower/posterior) vena cava
http://www.wikihow.com/Draw-a-Human-Heart
a)Left and right atria: Hollow
chambers. Blood enters the heart
through the atria. Deoxygenated blood
enters the right atrium and oxygenated
blood enters the left atrium. Both
contract simultaneously.
b)Left and right ventricles:
Hollow chambers. Blood leaves
the heart through the ventricles.
Deoxygenated blood leaves the
right ventricle and oxygenated
blood leaves the left ventricle.
Both contract simultaneously.
c)Valves: Prevent blood from going the wrong way
through the cardiac cycle.
Bicuspid (mitral) valve: Has two cusps and is
located between the left atrium and the left
ventricle.
Tricuspid valve: Has three cusps and is
located between the right atrium and the
right ventricle.
Semilunar valves: Located in the ventricles to prevent the backflow
of blood as it is leaving the heart (aortic semilunar and
pulmonary semilunar).
d)Aorta: The largest artery in the body. The aorta brings
blood to capillary networks in the body where exchange
of materials between blood and the body’s tissues takes
place. (oxygenated blood)
e)Pulmonary vein: oxygenated blood returns to the
heart from the lungs via the right and left pulmonary
veins. It then enters the left atrium.
f)Pulmonary artery: Deoxygenated blood leaves the
heart and goes to the lungs to pick up oxygen via the
pulmonary arteries.
g)Septum: The wall that separates the right
and left ventricles. (prevents oxygenated and
deoxygenated blood from mixing.
h)Superior vena cava: The main vein that
collects blood from the head and arms (upper
systemic circulation) and returns it to the right
atrium of the heart. (deoxygenated blood)
i)Inferior vena cava: The main vein that
collects blood from the trunk and legs (lower
systemic circulation) and returns it to the right
atrium of the heart. (deoxygenated blood)
Flow of blood through the heart
Vena Cava -> Right atrium -> tricuspid valve -> Right ventricle -> pulmonary
semilunar valve -> Pulmonary Artery -> Lungs ->Pulmonary Vein -> Left Atrium ->
bicuspid valve-> Left Ventricle ->aortic semilunar valve-> Aorta -> Body Tissues
(except lungs) -> superior/inferior vena cava-> Right Atrium -> (repeat!)
(see Figure 9.18 and handout)
How Does The Heart Act As A Double Pump?
Both sides of the heart contract at the same
time.
Both atria contract – filling the two ventricles
Then both ventricles contract at the same
time:
The right ventricle sends blood to the
pulmonary system (lungs)
While the left ventricle sends blood to the
systemic system ( to the heart and the
rest of the body)
Heart Beat Cycle
A specialized group of cardiac muscle cells, called the pacemaker
(sinoatrial node or SA node) is located in the right atrium.
It sends electrical impulses to both atria to make them contract.
Heart beat cycle
A delayed impulse is also sent to the
atrioventricular (AV node) which are
another group of specialized cells
located in the septum, between the
ventricles.
This delayed impulse caused the ventricles
to contract AFTER the atria contract.
This is what makes your heart beat in the
pattern that it does.
(draw diagram)
Human Blood Groups - see blood basics powerpoint
and worksheet
Human Blood Groups
(draw diagram)
Blood Pressure
Blood pressure is the force against the wall of an artery.
Blood leaving the heart from the aorta shows the highest blood pressure.
This pressure drops considerably in the capillaries and even more in the veins.
See Figure 9.8 p.306
When the ventricles contract, the blood pressure is higher and is called systolic
pressure.
When the ventricles relax, they are being filled with blood so the pressure drops
slightly.
Blood Pressure
Blood pressure is measured as
Systolic/Diastolic
The unit for this measurement
is mmHg (millimetres of
mercury)
The normal adult blood
pressure is 120/80 – this will
vary according to any
number of things eg. age
(teenagers – 110/65, size,
Recording Blood Pressure
Lab 
p. 323-324
Circulatory Diseases
p. 323-328
obj.10
Hypertension
Atherosclerosis
Arteriosclerosis
Coronary blockage
https://www.youtube.com/watch?v=xnyfElxkBlI
hypertension ~2min
Circulatory Diseases
Hypertension:
Also known as high blood pressure. Caused by an
increase in blood volume or reduced elasticity of
the arteries. Diets high in salt or cholesterol can
increase blood pressure. As a result the heart has
to work much harder to pump blood and weakens
over time.
Atherosclerosis:
Characterized by a narrowing of the
arteries due to cholesterol deposits on the
innermost layer of the artery walls. This
condition restricts blood flow. A diet low
in saturated fat and cholesterol and high in
fruits and vegetables can prevent
atherosclerosis
Arteriosclerosis:
A related condition whereby
cholesterol or fatty material deposits
under the inner lining of arteries. The
material builds up over years and
restricts blood flow. This condition
can cause damage to platelets, which
triggers the formation of a clot. Clots
can block the arteries. (Embolism)
Stroke:
A clot in the brain blocks a
vessel and the brain becomes
starved of oxygen. That region
can die and that part of the brain
loses function
Coronary Diseases
Coronary blockage:
Occurs when a clot reaches the heart and
obstructs blood flow. Aspirin can prevent
clotting. A clot-busting medicine can
dissolve blood clots. E.g. t-PA.
Obj.11
Angioplasty:
Inserting a plastic tube inside a
vessel. When the constricted site is
reached a tiny balloon is inflated
which forces open the vessel. (fig.
9.28)
Coronary Shunt
-tube used to redirect blood away from the site during bypass surgery.
-helps create a bloodless field of view for the surgery
- allows uninterrupted blood flow during surgery
Coronary bypass:
A common surgical procedure. A healthy
vessel is removed, usually from an arm or
a leg, and using it to create a new passage
around a blockage near the heart. The
terms double and triple refer to the
number of blockages that must be
bypassed. (fig. 9.29)
https://www.youtube.com/watch?v=j873zP6ir3o live transplant 1:20
https://www.youtube.com/watch?v=3Nf6Q2skGOM coronary bypass surgery ~4 mins