Capillary brings oxygen nutrients hormones to cells Cells give CO 2 hormones nitrogenous wastes back to capillaries Nutrients Exchanged Filtration and diffusion occur due to osmotic and blood pressure ID: 476813
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Slide1
What Is Exchanged?
Capillary brings oxygen, nutrients, hormones to cells
Cells give CO
2
, hormones, nitrogenous wastes back to capillariesSlide2
Nutrients Exchanged
Filtration and diffusion occur due to osmotic and blood pressure
most of what is exchanged is dissolved in plasma
Plasma squeezes out between capillary cells like water through a strainer
Oxygen, carbon dioxide, hormones diffuse across capillary easilySlide3
Double Pump
Right side pumps to the lungs and back to left atrium (PULMONARY CIRCUIT)
Left side pumps to the entire body and returns blood to right atrium (SYSTEMIC CIRCUIT)
Oxygenated & deoxygenated blood never mix! Slide4
The mammalian cardiovascular system
Pulmonary
vein
Right atrium
Right ventricle
Posterior
vena cava
Capillaries of
abdominal organs
and hind limbs
Aorta
Left ventricle
Left atrium
Pulmonary
vein
Pulmonary
artery
Capillaries
of left lung
Capillaries of
head and forelimbs
Anteriorvena cava
Pulmonary
artery
Capillaries
of right lung
Aorta
Figure 42.5
1
10
11
5
4
6
2
9
3
3
7
8Slide5
The Heart
About the size of a clenched fist
Made up of mostly cardiac muscle tissue
:
involuntary
Atria have thin walls, ventricles have thicker walls
Why??
Ventricles must pump blood through the pulmonary & systemic circuits. (LONG DISTANCE)Slide6
The Heart: Structure and Function
AV Valves:
Located between each atrium and ventricle
Keep blood from flowing back into the
atria
Thin structures
Mitral valve: located between left ventricle and atrium
Tricuspid valve: located between right ventricle and atrium
Closing makes the
lub of the heart beatSlide7
The Heart: Structure and Function
Semilunar Valves:
Located at the exits of the heart (at the bottom of each ventricle)
Prevent blood from flowing back into the
ventricles
Thicker, reinforced tissue to prevent from turning inside out
Shaped like two half moons
Aortic valve: between aorta and left ventricle
Pulmonary valve: between pulmonary artery and right ventricle
Closing makes the dub of a heart beatSlide8
The Cardiac Cycle
Refers to change in blood pressure during heart beat
A single cycle consists of two phases: diastole and systole
Diastole is the relaxing of the ventricles, where the heart fills with blood
Systole is the contraction of the ventricles,
shotting
blood in the arteries
http://www.youtube.com/watch?v=rguztY8aqpk
shows valves
working in the cardiac cycleSlide9
The Cardiac Cycle
Muscle contractions are myogenic
They occur on their ownSlide10
Nervous Control of Heart Beat
SA (
sinoatrial
) node is the pacemaker
In right atrium
Causes atria to contract
Sends electrical impulse that hits the AV (
atrioventricular
) node, which causes the ventricles to contract moments laterSlide11
Nervous Control of the Heart
Parasympathetic nervous system slows the heart rate
Lets you rest and digest
Sympathetic nervous system speeds up the heart rate
Lets you fight or flightSlide12
Chemical Control of Heart Beat
Acetylcholine is a neurotransmitter
Used to slow down the heart rate
Affects the SA node, slowing its nerve impulses
Epinephrine (adrenaline) is a neurotransmitter
Used
to speed up the heart
Increases the force the heart pumpsSlide13
Blood Pressure
Simple test to find out blood pressure
Use
sphygmomanometer
Blood pressure cuffs used at doctor, pharmaciesSlide14
What Does the Systolic Blood Pressure Number Mean?
Heart beats
, it contracts and pushes blood through the arteries to the rest of your body.
T
his
force creates pressure on the arteries.
This
is called systolic blood pressure.
A normal systolic blood pressure is below 120Slide15
Systolic Steps
Isovolumetric
Contractions
AV
valves close at the beginning of this phase
interval between the closing of the AV valves and the opening of the semilunar valves
Ejection
Semilunar valves openSlide16
What Does the Diastolic
Blood Pressure Number Mean?
The diastolic blood pressure number or the bottom number indicates the pressure in the arteries when the heart rests between beats.
A normal diastolic blood pressure number is less than 80.Slide17
Diastole Steps
Isovolumetric
Relaxation
During previous steps, the atrium
in diastole has been filling with blood on top of the closed AV valve, causing atrial pressure to rise
Rapid Inflow
AV
valves are open the blood that has accumulated in atria flows into the
ventricleAtrial Systole
End of diastolethe atrium contractsSlide18
ECG
ECG stands for electrocardiogram
Records heart’s electrical activity
The "P Wave" represents the electrical activity of the SA Node and contraction of
atrium
Atrial SystoleSlide19
ECG
The
"QRS Interval" represents the electrical activity of the ventricle
.
Ventricular Systole
The "T Wave" represents the ventricle relaxing ready for the next electrical impulse - known as
repolarization.
End of Ventricular Systole
"Q-T Interval" is the measurement of
repolarization.Slide20
Factors influencing Blood Pressure
Dehydration
Blood is mostly plasma, which is mostly water
Leads to low blood volume
Exercise
Increase temporarily, decrease with regular use
Caffeine and other stimulants
Weight
The more tissue you have, the further blood has to travel
SmokingConstricts the blood vessels, increasing heart rateSlide21
Factors Influencing Blood Pressure
Diseases and genetic heredity
Narrowing of the blood vessels can be caused by a few diseases
Resists blood flow, raising blood pressure
Environmental Factors
Air temperature
Predator Risks
Diet
Not getting enough nutrients, or too much fat
Stress