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