vein
a blood vessel that carries blood from the capillaries toward the heart
Research draft, second pass
A second pass drafted this model: the structure a model of this thing needs, and what is known about it in the world. The line under this one says how the second half was obtained - researched against sources, or recalled without web access, in which case nothing here was read anywhere and every claim is a lead to verify. Unreviewed either way.
written by Claude from model knowledge without web access - no source was read, every claim is a lead to verify
Researched by: Claude
Purpose and description
Let an agent explain veins and their structure and function, relay major named veins and clinical relevance in general terms from anatomical sources, distinguish veins from arteries and lymphatics, and route personal concerns to clinicians.
A blood vessel that carries blood from the capillaries toward the heart, usually deoxygenated blood in the systemic circulation and oxygenated blood in the pulmonary veins, with thinner walls and lower pressure than arteries, valves in the limbs to prevent backflow, and named vessels such as the cephalic, accessory cephalic, hemiazygos, accessory hemiazygos and vertebral veins; veins are sites of thrombosis, varicosities and venous access for injections and sampling.
What it is for: Returning blood to the heart.
It can be explain structure and function; relay named veins; relay clinical relevance; route personal concerns.
Distinguishing features
Low pressure
Valves in limbs
Capacitance role
Venous access site
What it looks like
Thin-walled vessels, often visible as blue lines under the skin.
Physical character
share of blood volume in veins: about 60-70 percent - at rest
largest veins: superior and inferior vena cava vessels
How it is recognised
Blood vessel returning blood to the heart
Superficial, deep, systemic, pulmonary and portal veins; named veins such as cephalic and hemiazygos
Arteries carry blood away from the heart; lymphatic vessels carry lymph
Related models
is a kind of - in registry terms
is contrasted with - which carries blood away from the heart
drains - beds
returns blood to - through the venae cavae
In practice
Families and kinds
superficial veins such as the cephalic and accessory cephalic
deep veins of the limbs
venae cavae and azygos system including the hemiazygos and accessory hemiazygos
vertebral and accessory vertebral veins
pulmonary veins
portal venous system
venules
Identifiers
TA2 vena Terminologia Anatomica
MeSH D014680 veins
Standards and regulation
Terminologia Anatomica nomenclature
Clinical guidelines on venous thromboembolism and venous access
Failure modes and hazards
Deep vein thrombosis
Varicose veins and venous insufficiency
Agents giving personal medical advice
Confusing veins and arteries
Analytical facets
- substance
- living
- origin
- natural
- agency
- inert
- mobility
- not-applicable
- scale
- not-applicable
- affordances
- observable
Also called
+313
Where this came from
oewn:2024 · CC BY 4.0
Drafted structure
Bundle to layer to finding to question, as the second pass will find it: 4 bundles · 8 layers · 8 findings · 16 questions.
Understand What a vein is.
Science.
Definition
Structure and function.
Definition
Definition.
- What is a vein, how is its wall built, and how do valves and muscle pumps return blood? definition
- Is the question about veins, arteries or lymphatics? boundary
Named
Named veins.
Named
Named.
- What are the major named veins, such as the cephalic, hemiazygos and vertebral veins? definition
- Which entry fits the specific vein? action
Clinical Clinical relevance.
Clinical.
Conditions
Venous conditions.
Conditions
Conditions.
- What conditions such as thrombosis and varicose veins affect veins, in general terms? provenance
- Is the user describing symptoms such as leg swelling or pain, which need a clinician? boundary
Access
Venous access.
Access
Access.
- How are veins used for blood sampling, injections and lines? provenance
- Which references are standard? provenance
Physiology Physiology.
Science.
Return
Venous return.
Return
Return.
- How does venous return work, and how does it respond to posture and exercise? provenance
- Which sources are cited? provenance
Systems
Portal and pulmonary systems.
Systems
Systems.
- How do the portal and pulmonary venous systems differ from systemic veins? provenance
- Which entry fits hepatic portal system? action
Context Comparative and history.
Context.
Comparative
Other animals.
Comparative
Comparative.
- How do venous systems differ across vertebrates? provenance
- Which entry fits comparative anatomy? action
History
History.
History
History.
- How did Harvey and others discover venous valves and circulation? provenance
- Which entry fits the history of physiology? action
What the second pass must settle
- Should the major named veins be separate entries?
- How should anatomical references be linked?
- The registry entry has merged aliases naming specific veins; should they be split off?