Download Note Sheet: The Circulatory System

Note Sheet: The
Circulatory System
Section 34.1
The Functions of the Circulatory System include:

Maintaining homeostasis in the body

Transporting many important substances such as oxygen and nutrients

Carrying disease-fighting materials produced by the immune system

Distributing heat throughout the body to help regulate body temperature
The Circulatory System consists of:
1.
blood
2.
the heart
3.
blood vessels
4.
the lymphatic system
1. Blood Vessels
Types
arteries
capillaries
veins
Functions
carry blood away from the heart; can
withstand high pressure
microscopic blood vessels where the
exchange of important substances and
wastes occurs; walls are only one cell
thick
largest blood vessels; carry
deoxygenated blood back to the heart;
valves prevent backflow
Sketch
2. The Heart
Function
pumps oxygenated blood to body and pumps deoxygenated blood to lungs
Structure
made of cardiac muscle; size of fist; hollow; 4 chambers
How it Beats
--2 main phases- 1) atria fill with blood, atria contract and ventricles fill with
blood; and 2) ventricles contract to pump blood out of the heart
--SA node (pacemaker) signal the atria to contract; AV node signals the
ventricles to contract
the alternating expansion and relaxation of the artery wall caused by
contraction of the left ventricle
the measure of how much pressure is exerted against the vessel walls by the
blood; systole=highest pressure when heart contracts; diastole=pressure when
heart is relaxed 120(systole)/80(diastole) is normal
Pulse
Blood Pressure
Blood Flow in the Body 2 loops- heart to lungs to heart then heart to body to heart; right side pumps
deoxygenated and left side pumps oxygenated
3. Blood
Components of
Blood
1. plasma
Description
clear, yellowish liquid portion of blood; carries the breakdown products of
digested food, such as glucose and fats, hormones, wastes, and other chemicals
carry oxygen with hemoglobin; discs with pinched in centers; develops within
bone marrow; no nucleus
cell fragments that help blood to clot; platelets collect and stick together at
broken blood vessels; platelets release protein called fibrin
produced in bone marrow; help to fight infection; can live for months or years
2. red blood cells
3. platelets
4. white blood cells
Blood Types
A
B
AB
O
Can Donate To:
A or AB
B or AB
AB
A, B, AB, or O
Can Receive Blood From:
A or O
B or O
A, B, AB, or O
O
Rh Factor
What is it?
a marker found on the surface of red blood cells
When is it problematic?
during pregnancy: Rh- mom will make antibodies
against Rh+ baby
4. Lymphatic System (page 1086 in book)
The Functions of the Lymphatic System include:
 Filtering lymph and blood

Destroying foreign microorganisms

Absorbing fat
Lymph: fluid that leaks out of capillaries to bathe body cells; it circulates among tissue cells
Lymphatic vessels: collect lymph and return it to veins near the heart
Examples of lymphatic organs: lymph nodes, tonsils, spleen, thymus gland, and other lymphatic tissue
found in mucous membranes of the intestinal, respiratory, urinary, and genital tracts
Circulatory System Disorders
Disease
Atherosclerosis
Description
blocked arteries
Heart Attack
occurs when blood does not reach the heart muscle
Stroke
occurs when clots form in blood vessels supplying oxygen to the brain