Circulation and Respiration

1
Circulation and Respiration

• Chapter 22

2
Circulatory Systems

• Blood flows through blood vessels
• Heart generates force to keep blood moving
• Closed system
• Blood is confined to vessels and heart
• Open system
• Blood mingles with fluid in tissues

3
Blood Cell Development

• Stem cells in bone marrow are unspecialized cells
  that retain the capacity to divide
• Some daughter cells of stem cells differentiate
  to form blood cells
• Body must continually replace blood cells

4
Human Heart Is a Double Pump

• Partition separates heart into left and right
  sides
• Each pumps blood through a different circuit

5
Pulmonary Circuit
right pulmonary artery
left pulmonary artery

• This loop oxygenates blood

capillary bed of left lung
capillary bed of right lung
pulmonary trunk
(to systemic circuit)
(from systemic circuit)
pulmonary veins
heart
lungs
6
Systemic Circuit
capillary beds of head and upper extremities
aorta
(to pulmonary circuit)
(from pulmonary circuit)

• Longer loop carries blood to and from body
  tissues

heart
capillary beds of other organs in thoracic cavity
capillary bed of liver
capillary beds of intestines
capillary beds of other abdominalorgans and
lower extremities
7
Four Chambers

• Each side has two chambers
• Upper atrium
• Lower ventricle
• Valves between atria and ventricles

8
In the human cardiovascular system, which blood
vessel carries the most oxygen?

• aorta
• vein
• pulmonary artery
• capillary

9
Heart Anatomy
arch of aorta
superior vena cava
trunk of pulmonary arteries
left semilunar valve
right semilunar valve
right pulmonary veins
left pulmonary veins
left atrium
right atrium
left AV valve
right AV valve
right ventricle
left ventricle
endothelium and connective tissue
inferior vena cava
inner layer of pericardium
septum
hearts apex
myocardium
10
The structure that divides the heart into two
halves is the _____.

• pericardium
• myocardium
• septum
• aorta

11
Conduction and Contraction
SA node

• SA node in right atrium is pacemaker
• Electrical signals cause contraction of atria
• Signal flows to AV node and down septum to
  ventricles

12
Blood Vessels

• Arteries carry blood away from the heart
• Arterioles diameter is adjusted to regulate
  blood flow
• Capillaries diffusion occurs across thin walls

13
Diffusion Zone

• Capillary beds are the site of exchange between
  blood and the surrounding cells.
• Capillary is a single sheet ofepithelial cells
• Flow is slow allows gasses to diffuse across
  membranes of blood cells and across endothelium

14
Blood

• Blood Transports
• A. nutrients
• B. waste products
• C. oxygen

15
Oxygen Transport

• Most oxygen is carried bound to hemoglobin in red
  blood cells