circulation and respiration. ii. circulatory systems a. circulatory system basics 1. fluid —...
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Circulation and Respiration
II. Circulatory systems
A. Circulatory system basics • 1. Fluid—blood • 2. Channels—vessels • 3. A pump—the heart
III. The III. The vertebrate circulatory circulatory system system
A. Functions • 1. Transport of O2 and CO2
• 2. Distribution of nutrients 3. Transport of waste • 4. Distribution of hormones • 5. Regulation of body temperature • 6. Protection of the body against blood
loss
The vertebrate circulatory system
B. The heart
1. Structure
a. Atria
b. Ventricles
aorta
superior vena cava
pulmonary artery (to right lung)
pulmonary veins (from right lung)
right atrium
atrioventricular valve
inferior vena cava
right ventricle
descending aorta (to lower body)
heart muscle
ventricular septum
left ventricle
semilunar valves
atrioventricular valve
pulmonary veins (from left lung)
left atrium
pulmonary artery (to left lung)
The vertebrate circulatory system
Function
• a. The cardiac cycle • 1) Systole—period of ventricle
contraction• 2) Diastole—relaxation of all the
chambers followed by contraction of the atria
• Blood Pressure:Systolic/Diastolic (ex. 120/80)
Oxygenated blood from lungs enters left ventricle.
Deoxygenated blood from body enters right ventricle.
(a) Atria contract, forcing blood into the ventricles.
Oxygenated blood is pumped to the body.
(b) Then the ventricles contract, forcing blood through arteries to the lungs and the rest of the body.
(c) The cycle ends as the heart relaxes.
Blood fills theatria and beginsto flow passivelyinto the ventricles.
Deoxygenated blood ispumped to the lungs.
Pathway of Blood Through the Heart
1. Vena Cava
2. Right Atrium
3. Tricuspid Valve
4. Right Ventricle
5. Pulmonary Artery (Pulmonary Valve)
6. Lungs
7. Pulmonary Vein
8. Left Atrium
9. Bicuspid Valve “Mitral Valve”
10. Left Ventrical
11. Aorta (Aortic Valve)
III. The vertebrate circulatory system
Function
• b. Coordination of heart activity
• 1) Atrioventricular and semilunar valves
• 2) The sinoatrial node (SA node)
• 3) The atrioventricular node (AV node)
aorta
superior vena cava
pulmonary artery (to right lung)
pulmonary veins (from right lung)
right atrium
atrioventricular valveTricuspid Valve
inferior vena cava
right ventricle
descending aorta (to lower body)
heart muscle
ventricular septum
left ventricle
semilunar valves
atrioventricular valveBicuspid Valve“Mitral Valve”
pulmonary veins (from left lung)
left atrium
pulmonary artery (to left lung)
Pathway of Blood Through the Heart
1. Vena Cava2. Right Atrium3. Tricuspid Valve4. Right Ventricle5. Pulmonary Artery
(Pulmonary Valve)
6. Lungs7. Pulmonary Vein8. Left Atrium9. Bicuspid Valve “Mitral Valve”10. Left Ventrical11. Aorta (Aortic Valve)
excitablefibers
sinoatrial(SA) node
atrioventricular(AV) node
The vertebrate circulatory system
. Coordination of heart activity
4) Influences on heart rate
a) Parasympathetic nervous system - decreases heart rate
b) Sympathetic nervous system - increases heart rate
c) Hormones
The vertebrate circulatory system
C. Blood
• 1. Functions • a. Transport of nutrients, gases,
hormones, wastes
• b. Immune response
The vertebrate circulatory system• 2. 2. Composition
• a. Plasma—55% to 60% • 1) 90% water • 2) Molecules of dissolved proteins, hormones,
nutrients, gases, ions, and urea as a waste
• b. Red blood cells—erythrocytes • 1) 99% of the total cellular component in the blood • 2) Carry oxygen bound to hemoglobin from the lungs
to the tissue and buffer CO2 carried from the tissues
• c. White blood cells—leukocytes • 1) 1% of the total cellular component of blood • 2) Five white blood cell types
• d. Platelets • 1) Cellular fragments from megakaryocyte in the bone
marrow • 2) Function in blood clotting
A white blood cell attacks bacteria
plateletstrapped redblood cell fibrin network
D. Blood vessels
• 1. Arteries and arterioles • a. Thick walls, smooth muscle with elastic tissue to
withstand high pressure • b. Carry blood away from the heart
• 2. Capillaries • a. Tiniest vessels; thin, single-cell thick for easy
diffusion • b. Exchange of materials between blood and body
cells
• 3. Venules and veins • a. One-way valves in thin-walled vessels surrounded
by thin layer of smooth muscle giving low resistance to blood flow, which is assisted by skeletal muscle
• b. Returns blood to the heart
The vertebrate circulatory system
arteriole
artery
endothelium(inner layer)
connective tissue
smooth muscle(middle layer)
connective tissue(external layer)
capillaryendothelium
venule
vein
capillaries
Red blood cells mustpass through capillariesin single file.
Capillary walls are thin and permeable to gases, nutrients, and cellular wastes.
III. The vertebrate circulatory system
• 4. Distribution of blood flow
• a. Regulated by muscular walls of the arterioles
• b. Influenced by autonomic nerves, hormones, and other chemicals released from nearby tissues
aortasuperiorvena cava
inferiorvena cava
liver
femoral artery
femoral vein
intestine
kidney
heart
pulmonary artery
lung capillaries
carotid arteryjugular vein
The respiratory system
A. Functions of the respiratory system
• 1. Works in conjunction with the circulatory system
• 2. Provides oxygen for cellular respiration
Respiratory systems and gas exchange
A. Interrelated with circulatory system
B. Mechanisms of gas movement • 1. Bulk flow from areas of higher
pressure to areas of lower pressure
• 2. Simple diffusion at the tissue or lung level
1. Gases move in and out of the lungs by breathing.
2. O2 and CO2 are exchanged in the lungs by diffusion.
3. Gases dissolved in blood are transported by the circulatory system.
4. O2 and CO2 are exchanged in the tissues by diffusion.
alveoli (air sacs)
rightatrium
leftatrium
left ventricle
right ventricle
VII. Human respiratory system
A. The conducting portion
• 1. Carries air to the lungs
• 2. Warms and moistens air moving through it
• 3. Cilia that line the trachea, bronchi, and bronchioles filter dust particles
(a)
nasal cavity
pharynx
epiglottis
larynxesophagustracheabronchi
pulmonary veinpulmonary artery
bronchioles
branch of pulmonary artery
(b)
bronchiole
branch of pulmonary vein
alveoli
capillarynetwork
VII. Human respiratory system
B. Gas exchange portion • 1. The alveoli have an enormous
surface area • 2. Capillaries surround the alveoli • 3. The mechanism of gas exchange
and transport • a. Oxygen and hemoglobin • b. Carbon dioxide and bicarbonate
ions
interstitial fluid
fluid layer
alveolar cell
nucleus
air in alveolus
alveolarmembrane
capillarycell
nucleus
redbloodcell
plasma
capillary wall
capillary
VII. Human respiratory system
C. Mechanics of breathing • 1. Inspiration—active inhalation of air
• a. Diaphragm and rib muscles contract, making the chest cavity larger
• b. Chest expansion causes the lungs to expand; vacuum draws in air
• 2. Expiration—passive exhalation of air when muscles are relaxed
lungscompress
ribcage contracts
lungsexpand
ribcageexpandsribcageexpands lungs
expand
diaphragmcontracts downward
(a) Inhalation
ribcage contracts
diaphragmrelaxes upward
(b) Exhalation
lungscompresslungscompress
air moves in air moves out
VII. Human respiratory system
D. Control of respiration
• 1. Description of breathing • 2. Regulation of breathing by carbon
dioxide
1. Structure • a. Complex network of thin-walled
vessels
• b. In proximity to the capillary network
• c. Composed of cells with openings between them that act as one-way valves
Lymphatic system
(a)
superiorvena cava
lymph vessels
lymph nodes
valve prevents backflow
white blood cells
(b) lymph node
thoracic duct enters vein to vena cava
thymus
heart
spleen
thoracic duct
Lymph is transported into larger lymph vessels.
Blood capillaries leakfluid filtered fromblood plasma.
Interstitial fluid entersthrough valvelike openings betweenlymph capillary cells.
interstitialfluid
Lymphatic system
• 2. Functions • a. Removal of excess fluid • b. Transport of fats from the intestine • c. Cellular body defense