Arterial System of Pigeon- Diagram, Questions & MCQs Explained

 Arterial system of pigeon- Explanation with Important QnA and MCQs

The Avian arterial system is remarkably similar to the arterial system of mammals, accept the right hand arching of the aorta.

( In birds, the embryonic aortic arch derives from the right half of the 4th gill arch.)

Arterial system of pigeon Diagram

Two main arteries leave the heart to form the arterial system in birds (pigeon) and supply blood throughout the body.

1. Aortic arch 

2. Pulmonary arch

I. Aortic arch in birds

The aortic arch originates from left ventricle and immediately gives of two small coronary arteries to the heart itself and after that in a short distance it gives rise to, 

1.  Right and left innominate arteries

The right and left innominate arteries branch into, 

• Anterior common carotid
• Lateral subclavian artery

2. Anterior common carotid:

Originates from: Brachiocephalic artery,

Supplies to         : Neck and head

(The carotid artery in birds show variance in accordance to the size of the neck of bird, for example, in American Woodcock and Great blue Heron, they may have large carotid artery in one side and small on the other. Some can have single carotid artery or some may even lack them.)

3. Lateral (right and left) subclavian artery:

Originates from: Brachiocephalic                                  artery 

Branches to and Supplies  

4. Pectoral artery: It supplies blood to pectoral muscles of the breast and also send an internal mammary artery to the central thoracic wall.

5. Brachial artery: To wings.

Branches to, 

• Ulnar artery 
• Radial artery 

6. Dorsal aorta (Descending aorta): 

Branches of descending aorta carries blood to the rest of the body.

Originates from:  Aortic arch

Supplies to         :  posterior body.

Dorsal aorta Branches to,

7. Coeliac artery: 

Originates from: Dorsal aorta

Supplies to         : It supplies blood to    proventriculus, gizzard , duodenum, liver and spleen.

Branches to        : 

Gastric and hepatic arteries.

8. Anterior mesenteric artery:

Originates from: Dorsal aorta 

Supplies to         : 

Greater part of small intestine and pancreas.

9. Renal artery: 

Originates from: Dorsal aorta 

Supplies to.        :

 Anterior, middle and posterior lobe of kidneys via anterior, middle and posterior renal arteries.

In male, each renal artery gives of a branch to testis, but in female, only the left renal artery gives of branch to the ovary. Finally branches of as capillaries to kidney.

10. Internal iliac artery:

It goes to hinder part of pelvis. 

Originates from: Dorsal aorta 

Supplies to  and to 

Branches to       : femoral, tibial and popliteal arteries of the leg.

11. Femoral artery:  

They are the paired arteries passing outwards dorsal to the anterior lobes of the kidney and supplies the pelvic muscles and outer muscles of the thigh.

12. Sciatic or ischiatic arteries: 

Originates from: between middle and posterior lobes of kidney.

Supplies to.        : 

Inner muscles of the thighs and legs.

13. Middle renal artery:

Originates from: Sciatic artery 

Supplies to.        : 

Middle lobe of kidney.

14. Posterior renal artery:

Originates from: Sciatic artery 

Supplies to.        : 

Posterior lobe of kidney.

15. Posterior mesenteric artery:

Originates from: Dorsal aorta 

Supplies to         : Rectum & cloaca

16. Internal iliac arteries: They are paired arteries going to hinder part of pelvis.

Originates from: Dorsal aorta 

Supplies to.        : Thigh and leg

Branches to       : 

It further branches to,

     Femoral, tibial, popliteal arteries of the leg.

17.Caudal artery: It is the last and single artery which make the terminal part of dorsal aorta.

 It supplies the tail region, muscles that control the tail.

II. Pulmonary Aorta:

The right ventricle gives of a single pulmonary aorta which passes ventral to the systemic arch and divides into two pulmonary arteries to each side, to the lungs.

Related Important Question Answers 

Question:

Write a short note on the aortic arch and its major branches in pigeon circulatory system.

Answer:

There is no left systemic arch only the single right aortic arch which arises from the left ventricle of the pigeons four chamber heart for the distribution of oxygenated blood to the body.

It immediately gives of paired innominate arteries which branch into common carotids to supply head and neck and subclavian to wings through the axillary and brachial arteries. The arch continues as dorsal aorta supplying the viscera via coeliac, intestine via anterior mesenteric and to the lobes of kidney via renal arteries. 

It continues as posterior mesenteric to rectum and cloaca, internal iliac to hinder parts of pelvis and as caudal artery to the tail.

Question:

Describe the pulmonary aorta and its significance in pigeons double circulation. 

Answer: 

The pulmonary aorta in pigeon is the large blood vessel that originates from right ventricle of the heart and splits into right and left pulmonary arteries carrying deoxygenated blood to the lungs.

Significance in double circulation 

Pigeon (Birds) exhibit complete double circulation such that the oxygenated and deoxygenated blood remain separate. 

Pulmonary aorta is the starting point of the pulmonary circuit in double circulation.

• Seperation of blood:The pulmonary aorta ensures that the deoxygenated blood from the body is sent exclusively to lungs to get oxygenated for supplying rest of the body.
• High metabolic efficiency:Pulmonary aorta helps in rapid gas exchange by providing a dedicated route to support pigeons incredibly high metabolic rate which is the necessity for energy intensive task of flight. 
• Temperature regulation:Pulmonary aorta supporting double circulation in pigeon (Bird) help maintain their constant body temperature (endothermy), allowing them to remain active and various environments.

Question:

Explain the arterial supply to flight muscles via pectoral and brachial arteries

.

Answer:

Pigeon's pectoral (or pectoralis) arteries arise from the subclavian artery which originates from dorsal aorta and supplies the massive flight muscles, pectoralis major and pectoralis minor 

Brachial arteries from subclavian artery further nourishes wing musculature and bones, supporting sustained flapping.

 This specialised supply reflects avian evolutionary adaptations for aerial efficiency over ground locomotion.

Multiple Choice Questions (MCQs)

Which arch rises from the left ventricle in pigeons to form the main systemic arch? 

a. Left aortic arch

b. Pulmonary arch

c. Right aortic arch 

d. Caudal arch

Answer: (c) right aortic arch

2. The innominate arteries from the right aortic arch primarily give rise to,

a. Pulmonary arteries 

b. Common carotid and subclavian arteries

c. Renal arteries 

d. Femoral arteries

Answer: (b) common carotid and subclavian arteries 

3. How many pair of renal arteries supply the lobes of kidney in pigeons?

a. One pair 

b. Two pairs 

c. Three pairs 

d. Four pairs

Answer: (c) three pairs 

4. What is the primary function of Pulmonary arch? 

a. Supply oxygenated blood to the body

b. carry deoxygenated blood to the lungs

c. supply the tail region

d. Drain blood from kidneys

Answer: (b) carry deoxygenated blood to the lungs.