4-Zoology-Organ-Circulation

circulation of blood

heart and blood vessels {circulation}.

cardiac as heart

heart {cardiac, heart}|.

cardiovascular

heart, arteries, and veins {cardiovascular}|.

vascular arteries

arteries and veins {vascular}|.

peripheral resistance

Most blood-flow resistance {peripheral resistance} is in capillaries.

4-Zoology-Organ-Circulation-Growth

angiogenesis

Blood vessels can grow {angiogenesis}.

vascular endothelial growth factor

Factors {vascular endothelial growth factor} (VEGF) can stimulate angiogenesis and guide blood cells to body regions by finding VEGF receptors. VEGF affects blood-vessel development. Perhaps, blood cells can evolve into blood vessels.

4-Zoology-Organ-Circulation-Pulse

pulse of blood

Heartbeats cause artery pressure pushes {pulse, blood}|.

blood pressure

Blood pulses cause pressure {blood pressure}. Blood pressure relates to heartbeat force, blood volume, and arteriole smooth-muscle constriction, which nerves, blood epinephrine, and blood carbon dioxide control. Inelastic and hardened arteries from cholesterol, scars, smoking, and kidney disease make high blood pressure.

systole

Pressure is highest {systole}| {systolic pressure}, 120 mm Hg, when blood pulses.

diastole

Pressure is lowest {diastole}| {diastolic pressure}, 75 mm Hg, between pulses.

4-Zoology-Organ-Circulation-Parts

rete circulation

Arteries and veins have networks {rête}|.

thoracic duct

Lymphatic system has a tube {thoracic duct}, from dilation {cisterna chyli} at second lumbar vertebra to left jugular and subclavian veins, that carries lymph into blood.

4-Zoology-Organ-Circulation-Parts-Artery

aorta

The first artery {aorta}| is the largest blood vessel.

artery

Blood leaves heart to go into tubes {artery}|. Arteries have inner endothelium-and-elastic-tissue layer, middle smooth-muscle layer, and outer connective-tissue layer.

coronary artery

Blood flow from aorta can go into heart arteries {coronary artery}|.

arteriole

Arteries have branches {arteriole}|.

capillary

Blood flows from arteries into tubes {capillary}|, where molecules diffuse between blood and tissue fluids. Capillaries have endothelial cell layers. Most peripheral resistance to blood flow is in capillaries.

4-Zoology-Organ-Circulation-Parts-Artery-Head

carotid artery

Head has neck arteries {carotid artery}| on sides.

vertebral artery

Head has arteries {vertebral artery} beside spine.

4-Zoology-Organ-Circulation-Parts-Vein

venation

Vein system has structure {venation}.

venous

about veins {venous}.

vein

From capillaries, blood goes into tubes {vein, circulation}| that have same layers as arteries but with thinner muscle layers. Valves prevent backward flow.

venule

The first veins {venule} are small tubes.

saphenous vein

Veins {saphenous vein}| drain leg surfaces.

varicose vein

Swollen veins {varicose vein}| can be in legs.

hepatic portal system

Veins {hepatic portal system}| can collect blood from spleen, stomach, pancreas, and intestines and take blood to liver.

vena cava

Blood reaches largest veins {vena cava}| to enter heart, from above {superior vena cava} and below {inferior vena cava}.

4-Zoology-Organ-Circulation-Parts-Vein-Head

jugular vein

Head has side neck veins {jugular vein}|.

vertebral vein

Head has neck veins {vertebral vein} by spine.

4-Zoology-Organ-Circulation-Parts-Heart

heart organ

Blood pumping organs {heart}| have auricles and ventricles. Skeletal muscles and breathing assist blood movement. Heart volume increases with regular exercise.

pericardium

Heart cavity has inside endothelium {pericardium}|.

4-Zoology-Organ-Circulation-Parts-Heart-Flow

auricle

Blood goes from vena cava into heart chamber {right atrium} {auricle}| {atrium, heart} at heart top right.

tricuspid valve

Right atrium pumps blood through valve {tricuspid valve}| to right ventricle.

ventricle in heart

Right atrium pumps blood through tricuspid valve to lower right chamber {right ventricle} {ventricle, heart}|.

semilunar valve

Right ventricle pumps blood through valve {semilunar valve}| into pulmonary artery.

pulmonary artery

Right ventricle pumps blood through semilunar valve into lung artery {pulmonary artery}|.

pulmonary vein

Blood goes from pulmonary artery to lung capillaries and then to lung vein {pulmonary vein}| back to left atrium.

bicuspid valve

Left atrium pumps blood through valve {bicuspid valve}| into left ventricle.

mitral valve

Left ventricle pumps blood through valve {mitral valve}| into aorta. Mitral valve gives high and short sound. Other valves and ventricle closures give low and long sound. Heart-sound change indicates valve damage. Syphilis and rheumatic fever weaken heart valves.

4-Zoology-Organ-Circulation-Parts-Heart-Node

sinoatrial node

Signals from specialized heart tissue {sinoatrial node} {pacemaker} initiate and regulate heartbeat. Heart fibers beat by themselves. Blood carbon dioxide, blood thyroxin, blood epinephrine, vagus-nerve stimulation, body temperature, fever, and muscle stretching affect heart rate.

atrioventricular node

Signals go from sinoatrial node to specialized heart tissue {atrioventricular node} and then to ventricles.

Related Topics in Table of Contents

4-Zoology-Organ

Drawings

Drawings

Contents and Indexes of Topics, Names, and Works

Outline of Knowledge Database Home Page

Contents

Glossary

Topic Index

Name Index

Works Index

Searching

Search Form

Database Information, Disclaimer, Privacy Statement, and Rights

Description of Outline of Knowledge Database

Notation

Disclaimer

Copyright Not Claimed

Privacy Statement

References and Bibliography

Consciousness Bibliography

Technical Information

Date Modified: 2022.0225