View
216
Download
0
Category
Tags:
Preview:
Citation preview
Circulatory system
Premedical
Endothermic way of life require 10x more energy (exothermic).
Cells of body require nutrients, oxygen and exclude carbon
dioxide and wastes.
Cardiovascular system:
•Blood - blood cells and plasma
•Vessels – arteries, veins, capillaries, arterioles, venules,
capillary bed
•Heart – atria and ventricles
Blood pressure
Double circulation : independent body and lung circulatory system supported by 4 chambered heart of mammals
Lungs
Body cells
double circulatory systemlymphatic system
the right side of the
system
deals with
deoxygenated
blood.
the left side of the
system
deals with
oxygenated
blood.
The Heart
These are arteries. They carry blood away from the heart.
This is a vein. It brings blood from the body, except the lungs.
Coronary arteries supply the heart with blood
first branches
The heart has four chambers
2 atria
2 ventricles
The Heart
left ventricle
left atriumright atrium
right ventricle
valve
vein from lungs
artery to head and bodyartery to lungs
vein from head and body
valve
How does the heart work?
blood from the body
blood from the lungs
The heart beat begins when the
heart muscles relax and blood
flows into the atria.
Heartbeat: STEP ONE
The atria then contract and
the valves open to allow blood
into the ventricles.
How does the heart work?
STEP TWO
How does the heart work?
The valves close to stop blood
flowing backwards.
The ventricles contract forcing
the blood to leave the heart.
At the same time, the atria are
relaxing and once again filling with
blood.
The heartbeat – the cycle repeats itself.
STEP THREE
Systole is a phase where the myocardium is contracting in
a coordinated manner in response to an endogenous
electrical stimulus
Diastole is the period of time when the heart fills with
blood after systole.
Cardiac output is the volume of blood being pumped by
the heart, in the time interval of one minute
Puls - frequency of contractions, normal 70 - 75 / minute
Heartbeat - valves close, impact of blood to valves
Heart murmur – defect of valve
Four valves prevent a backward blood flowing.
The AV valve on the right side of the heart is called the
tricuspid valve because it has three leaflets (cusps).
The AV valve on the left side of the heart is called the
bicuspid valve (or mitral valve) because it has two leaflets.
Semiluminar: the pulmonary valve
the aortic valve
Mechanism of heartbeat continuity:
Special cardiomyocytes cells with the ability to
generate the electrical impulses. They have internal
rhythm of contractions.
Pacemaker – Sinoatrial node – right atrium
Atrioventricular bundle - right side
EKG
Blood pressure – hydrostatic pressure
is a force exerted by circulating blood on the walls of blood
vessels. During each heartbeat, BP varies between a
maximum (systolic) and a minimum (diastolic) pressure.
Thoracic cavity
between the lungs and is contained in the
pericardial sac
• Epicardium – outer layer of heart wall
• Endocardium – inner layer that consists of
endothelial cells, which line the heart, covers the
heart valves, and lines the blood vessels.
• Myocardium – middle layer composed of cardiac
muscle.
There are 3 types of blood vessels
a. ARTERY
b. VEIN
c. CAPILLARY
The ARTERY
thick muscle with
elastic fibres
elastic fibres allow the
artery to maintain a
blood pressure
the thick muscle can
contract to push the
blood along.
The VEIN
thin muscle and elastic fibres
Veins have valves, which prevent a backward blood flow
Body muscles surround the veins so that when they contract to move the body, they also squeeze the veins and push the blood along the vessels.
The CAPILLARY
the wall of a capillaryis only one cell thick
Basement membrane and endothel
The exchange of materials between the blood and the body can only occur through capillaries.
artery vein
capillariesbody cell
The CAPILLARYA collection of capillaries is known as a capillary bed.
The semi-permeable membrane (basement
membrane) of capillary walls allows
nutrients, oxygen, and water
to diffuse from the blood to the tissues.
Waste products, like
carbon dioxide, diffuse from the tissues
into the blood.
Subclavian vein
Superior vena cava
Pulmonary artery
Inferior vena cava
Renal vein
Iliac vein
Femoral vein
Carotid arteries
Subclavian artery
Pulmonary vein
Aorta
Renal artery
Iliac artery
Femoral artery
The aorta is
the largest
artery in the
body
This portion of the systemic circulation is known as
the hepatic portal system.
The gastric vein (stomach), splenic vein (spleen),
pancreatic vein (pancreas), and mesenteric veins
(small intestines) empty into the portal vein that
carries the blood to the liver.
The hepatic vein carries blood to the inferior (caudal)
vena cava.
The lymphatic system is part of the immune system and acts as a
secondary (accessory) circulatory system.
•return water and proteins to blood
• remove excess fluids from body tissues,
• absorb fatty acid and transport fat to circulatory
system, and
• produce immune cells (lymphocytes, monocytes,
and plasma cells).
Flow of Blood & Lymph Within Tissue
As the collecting lymph vessel accumulates lymph from
more and more lymph capillaries in its course, it becomes
larger and is called the afferent lymph vessel as
it enters a lymph node. Here the lymph percolates through
the lymph node tissue and is removed by the efferent
lymph vessel. An efferent lymph vessel may directly
drain into one of the (right or thoracic) lymph ducts
Both
the lymph ducts
return the lymph to the
blood stream by
emptying into the
subclavian veins
Lymph nodes filter foreign substances, such as
bacteria and cancer cells, before it is re-entered into
the blood system through the larger veins.
Lymph nodes act as the body’s first defense against
infection.
Lymph node
Photo from U. S. Federal Government courtesy of Wikipedia.
Lymph node has a fibrous outer covering (capsule), a cortex, and a medulla
Lymphoid tissue:
spleen, thymus,
bone marrow and the
lymphoid tissue
associated with the
digestive system.
www.worldofteaching.com
Campbell, Neil A., Reece, Jane B., Cain Michael L., Jackson, Robert B., Minorsky, Peter V., Biology, Benjamin-Cummings Publishing Company, 1996 –2010. chapter 42
Thank you for your attention
Recommended