1. Blood Vessels
Chapter 10
Section 10.1

2. Arteries and Arterioles
blood vessels that carry blood away from the heart
Arterioles
smaller arteries that carry blood into capillaries

3. Capillaries Capillaries
blood vessels composed of a single layer of cells
connect arterioles and venules
site of fluid and gas exchange between the blood and the body cells
easily destroyed due to their thin structure
when they burst bruising occurs

4. Veins and Venules Veins Venules
blood vessels that carry blood toward the heart
Venules
smaller veins that carry the blood between the capillaries and the veins

5. Arteries and Veins

6. Potential Blood Vessel Problems
Atherosclerosis
A degeneration of blood vessels caused by the accumulation of fat deposits in the inner wall
Fat Deposits

7. Potential Blood Vessel Problems Cont’d
Aneurysm
a bulge in the weakened wall of a blood vessel, usually an artery
can burst and cause severe problems
bursting of an aneurysm in the brain can lead to a stroke

8. Potential Blood Vessel Problems Cont’d
Varicose Veins
pooling of blood in the veins
caused by weakened valves that prevent the back flow of blood against gravity

9. The Heart
Chapter 10
Section 10.2

10. Introductory Video

11. Main Components of the Circulatory System
Blood
material to be transported
Blood Vessels
‘highways’ that transport the blood
Heart
pumps blood through vessels

12. The Heart Size: 1 fist Slightly left of the middle of chest
Pumps oxygen rich blood to the body
Pumps oxygen poor blood to the lungs

13. The Heart Walls of the heart are made up of CARDIAC MUSCLE.
This cardiac muscle contracts rhythmically and involuntarily to pump blood around our body.

14. Red vs. Blue Red = oxygenated blood
Blood just LEAVING lungs, full of oxygen to bring to cells.
Blue = deoxygenated blood
Blood just about to ENTER the lungs again, full of carbon dioxide ready to be exhaled.
NOT ACTUALLY BLUE

15. 2 Circulatory Systems
There are essentially two separate circulatory systems within our body.
1. Pulmonary Circulatory System – carries blood to and from the lungs
2. Systemic Circulatory System –
carries blood to and from the body

16. Heart Con’t Our heart has 4 chambers. Atria = top 2 chambers of heart
RECEIVE blood from lungs or body
Ventricles = bottom 2 chambers
PUMP blood to lungs or body
Septum = wall in heart that separates the ventricles
Thick & muscular

17. Vena Cavae Large blood vessels that open into the right atrium
Superior Vena Cava
collects oxygen-poor blood from upper body
Inferior Vena Cava
collects oxygen-poor blood from lower body

18. Pulmonary Arteries Arteries that open up into the right ventricle
Sends oxygen-poor blood to lungs to be oxygenated
ONLY artery in body that contains oxygen-poor blood

19. Pulmonary Veins
Sends oxygen-rich blood from the lungs back to the heart and into the LEFT atrium
ONLY veins in body that contain oxygen-rich blood

20. Aorta Connected to the LEFT ventricle Largest vessel in body
Sends oxygen-rich blood to entire body

21. Heart Valves
There are 4 valves that make blood flow in right direction.
Atrioventricular Valves
2 of them
Separates atria from ventricles
Right side: tricuspid (made from 3 flaps)
Left side: bicuspid (made from 2 flaps)
AKA mitral valve

22. Heart Valves Semilunar valves Name because of their half moon shape
Separates ventricles from blood vessels where they will be eventually pumping blood

25. Setting the Heart’s Tempo
The heart contains specialized muscle called myogenic muscle that contracts without external nerve stimulation.
The tempo or beat is set by the sinoatrial (SA) node.
The SA node is a small mass of tissue in the right atrium that originates the nerve impulses stimulating a heart beat.

26. The impulses are sent to a second node, the artioventricular (AV) node.
The AV node passes nerve impulses to the ventricles via two large fibres called the Purkinje fibres.
Once the nerve impulses reach the ventricles, the ventricles contract and blood is pumped.

28. Nervous System Input
The heart rate can also be influenced by external nerves impulses from the brain in specific situations.
The sympathetic nervous system – is a system that prepares your body for stress by increasing your heart rate.
Nerve impulses are sent to the SA node
The parasympathetic nervous system – is a system that returns the body to normal following a stressful situation by decreasing your heart rate.

29. Heart Sounds
The familiar heart sounds are caused by the closing of the heart valves.
The valves are closed when the heart is at rest or relaxating and the atria fill with blood.
This time period is known as diastole.
The valves are open when the heart is contracting and pushing blood out of the heart.
This period is known as systole.

30. Heart Sounds Cont’d The first beat is the closing of the AV valves.
The second beat is the closing of the semilunar valves.

31. Closure