Transcript Circulatory system

CIRCULATORY SYSTEM
Seph Rodriguez & Austin Stowell
BASIC OVERVIEW
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Circulatory system includes
Heart
Blood cells
Blood vessels/veins/arteries
BASIC OVERVIEW
CONT’D
 Basic functions include
• Internal distribution of materials
i.e. Delivery of O2
Nutrients
Hormones
Removal of carbon dioxide
Ammonia
and other metabolic wastes
BLOOD VESSELS
STRUCTURE AND
FUCNCTIONS
Blood Vessels
• Contain central Lumen lined with endothelium
(single layer of flattened epithelial cells)
• Smooth surface of endothelium minimizes resistance
to the flow of blood
• Surrounding endothelium are layers of tissue that
differ among capillaries, arteries, and veins, reflecting
their specialized functions
BLOOD VESSELS
STRUCTURE AND
FUCNCTIONS CONT’D
Capillaries
• Smallest blood vessels (diameter only slightly greater
than red blood cell)
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Have very thin walls consisting only of endothelium and
its basal lamina
Facilitates exchange of substances between blood,
capillaries, and interstitial fluids
BLOOD VESSELS
STRUCTURE AND
FUCNCTIONS CONT’D
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Veins and Arteries
More complex organization than those of capillaries
Have 2 layers of tissue surrounding endothelium:
outer layer of connective tissue containing elastic
fibers, allows vessels to stretch and recoil
• middle layer contains smooth muscle and more
elastic fibers
DIFFERENCES IN
ARTERIES AND VEINS
Ar teries
• Have wall 3x thicker than
vein
• Strong walls accommodate
high pressure blood pump
by the heart
• Elastic recoil maintains
blood pressure when heart
relaxes between heart
contractions
Veins
• Thinner walls bring blood
back to heart at lower
speeds and pressure
• Valves maintain
unidirectional flow of blood
in these vessels
CAPILLARIES, VEINS AND
ARTERIES
CAPILLARY
FUNCTIONS
 5-10% of bodies capillaries have blood flow
 However each tissues has many capillaries so every
part of the body has constant blood flow
 Capillaries in brain, heart, liver, and kidneys are filled
to capacity
 But other sites’ blood supply varies over time as
blood moves from one destination to another
CAPILLARY
FUNCTIONS CONT’D
Examples include
• Blood flow to the skin regulates body temperature
• Blood supply to digestive tract increases after a meal
BLOOD COMPOSITION
AND FUNCTION
Blood is a connective tissue whose cells are suspended
in a liquid matrix called plasma
Plasma contains dissolved ions referred to as blood
electrolytes
•Is also 90% water dissolve salts are essential to the
blood
•Concentration of ions effects the composition of
plasma
CELLULAR
ELEMENTS
Two types of cells
suspended in blood plasma
•Red blood cells
(erythrocytes)-transport
oxygen
•White blood cells
(leukocytes)-function in
defense
Blood contains platelets
that are involved in the
clotting process
CHAMBERS OF THE
HEART
The heart has 4 chambers
•Two atria (atrium)
•Two ventricles
Left and right atria
•Right--recieves oxygen-poor blood and pumps it to the
right ventricle
•Left—receives oxygen-rich blood from the lungs and
pumps it to the left ventricle
CHAMBERS OF THE
HEART CONT’D
Left and Right ventricles
•Right—receives oxygen-poor blood from the right
atrium and pumps it to the lungs
•Left—receives oxygen-rich blood from the lungs and
pumps it to the rest of the body
BLOOD PRESSURE
Blood pressure rises with each heartbeat and lowers
whenever the heart relaxes
BP can change from minute to minute with changes
in:
•Stress, exercise, stress, or sleep
Norm. blood pressure for an adult 20yrs+ should be
less than 120/80 mm Hg
•Less than 120 systolic and less than 80 diastolic
QUESTIONNAIRE
1. What are the main components of the circulatory
system?
2. What are the 3 types of blood vessels?
3. What 2 blood vessels differ in structure/function?
List at least 2 differences.
4. The capillaries of which organs are always filled to
capacity?
5. What are all of the chambers of the heart and their
functions?
WORK CITED
AP BIO Textbook chapter 42
http://www.webmd.com/heart/chambers-of-theheart
http://www.google.com/?safe=active&ssui=on#q=av
erage+blood+pressure+in+adults&safe=strict&ssui=on