Warm-Up 4/291. What is the function of the sinoatrial node?2. What does the QRS complex of an EKG represent?3. What two vessels are the semi-lunar valves located
in?
External Parts
• Enclosed by membrane called pericardium
• Double layered sac • Contains pericardial
fluid to reduce the friction of the beating heart
Pericardium Layers
• Visceral pericardium – Inner membrane– Surrounds heart– Attached to myocardium
• Parietal pericardium– Outer membrane – Anchors heart to sternum and
diaphragm
Parietal pericardium
Layers of heart walls
Pericardium – outer layer of fibrous tissue
Myocardium – middle layer of thick muscle
Endocardium – inner layer of epithelial cells
Three-layered wall
Chordae tendineae
• “heart strings”
• Attach to AV valves
• Anchor flaps on valves in closed position when needed
Fibrous skeleton
Mitral valve
Posterior
Opening ofleft coronaryartery
Aorticvalve
Tricuspidvalve
Pulmonary valve
6
The Blood Vessels
• The cardiovascular system has three types of blood vessels:
• Arteries (and arterioles) – carry blood away from the heart
• Capillaries – where nutrient and gas exchange occur
• Veins (and venules) – carry blood toward the heart.
The Arteries• Thick strong wall (three layers or tunics)
– Endothelial lining– Middle layer of smooth muscle and elastic tissue– Outer layer of connective tissue
• The largest artery is the aorta. • The smooth muscle of the middle layer can constrict to regulate
blood flow and blood pressure. • Arterioles are smaller than arteries have have a thinner middle and
outer layers• Arterioles can constrict or dilate, changing blood pressure and flow
into capillaries.
Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display.
Arteriole
Capillary
Endothelium
Smoothmuscle cell
Precapillarysphincter
9
The Capillaries• Capillaries have walls only one cell thick to
allow exchange of gases and nutrients with tissue fluid.
Anatomy of a capillary bed
13
Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display.
Arteriole
Capillary
Venule
© Don. W. Fawcett/Visuals Unlimited
The Veins• Venules drain blood from capillaries, then
join to form veins that take blood to the heart.
• Veins often have valves that prevent the backward flow of blood when closed.
Blood vessels
Towardheart
Varicose veins
What causes varicose veins?High blood pressure inside your superficial leg veins causes varicose veins.Factors that can increase your risk for varicose veins include having a family history of varicose veins, being overweight, not exercising enough, smoking, standing or sitting for long periods of time
Treatment often involves destroying the vein
VIDEOS!
TODAY!1. If you have not finished labeling the events on each image
of your flip book you need to complete that. 2. Once you have completed that show that to Mr. Baker and
he will give you the first portion of the case study. 3. Once you are done with that check with Mr. Baker and
show him the work and he will give you the second portion.4. Complete the second portion and show it to Mr. Baker and
he will give you the third portion of the case study.
THE THIRD PORTION OF THE CASE STUDY IS DUE TO Mr. BAKER BY END OF CLASS THURSDAY!
No Warm-Up!Get into groups of 4-5
Using your group members and any available props, you will act out the journey of a drop of blood through the
circulatory system.
On this journey you will need to describe the events of the cardiac cycle as they happen.
This may be a skit, a dance, mime, anything as long as it is some physically active and accurate representation.Include all events we’ve discussed, including arteries,
arterioles, capillaries, venules and veins in your presentation as well.
You will have 45min to create. Then you will present to the class.
In your groups you will be acting out the path of a drop of blood through the body.
You must create and perform a skit, dance, mime, some physically active representation of the path of a drop of blood through the body
and the events of the cardiac cycle.Include all events on your 1-22 slips of paper,
but include arteries, arterioles, capillaries, venules and veins in your presentation as well.
You will have 1 hour to create. Then you will present to the class.