BLOOD VESSELS AND CIRCULATION PPT (ALMO)

Blood vessels outside the heart are divided into two classes:

pulmonary vessels

systemic vessels

which transport blood from the right ventricle of the heart through the lungs and back to the left atrium

pulmonary vessels

which transport blood from the left ventricle of the heart through all parts of the body and back to the right atrium

systemic vessels

Blood Vessel Functions

Carry blood .

Exchange nutrients, waste products, gases within tissues

. Transport substances -.

Regulate blood pressure .

Direct blood flow to tissues

▪ Carry blood to the heart

▪ Walls are thinner

▪ contain less elastic tissue and fewer smooth muscle cells

Veins

▪ Carry blood away from the heart

▪ more elastic tissue than smooth muscle

Arteries

exchange of substances such as O2, nutrients, CO2, and other waste products occurs

Capillaries

Blood Flow

1. Blood flows from arteries into ___

2. Arterioles into ….

3. Capillaries into …..

4. Venules to …..

5. Veins return to ….

1. arterioles

2. capillaries

3. venules

4. small veins

5. heart

Blood Vessel Walls

innermost layer .

simple squamous

Tunica intima:

middle layer

smooth muscle with elastic and collagen

Tunica media:

outermost layer

connective tissue

Tunica adventitia:

Types of Arteries

⚫ largest in diameter

⚫ thickest walls

Example - aorta and pulmonary trunk

Elastic arteries:

medium to small size

⚫ thick in diameter

⚫ contain smooth muscle cells

can control blood flow to body regions

Muscular arteries:

• Blood flows from arterioles into capillaries

• Capillaries branch to form networks

• Blood flow is regulated by smooth muscle cells, precapillary sphincters

Capillaries

Walls consist of only a simple endothelium surrounded by delicate loose connective tissue.

Capillaries

Blood flows from capillaries into venules

Blood flows from venules into small veins

All 3 tunics are present in small veins

true

collect blood from small veins and deliver to large veins

Medium sized veins

contain valves

Large veins

Pulmonary Circulation Vessels

blood vessels that carry blood from right ventricle to lungs and back from left atrium of heart

Pulmonary circulation

⚫ blood pump from right ventricle towards lung

Pulmonary trunk:

exit lungs and carry 02 rich blood to left atrium

Pulmonary veins

carries blood from the left ventricle to the tissues of the body and back to the right atrium.

Systemic Circulation Vessels

Oxygenated blood from the pulmonary veins passes from the left atrium into the left ventricle and from the left ventricle into the aorta

. Arteries distribute blood from the aorta to all portions of the body

Systemic Circulation Vessels

Parts of the Aorta

passes superiorly from left ventricle

Ascending

3 major arteries which carry blood to head and upper limbs

Aortic arch

⚫ extends through thorax and abdomen to pelvis

Descending

part of descending aorta that extends through thorax to diaphragm

Thoracic

descending aorta that extends from diaphragm where it divides at the common iliac arteries

Abdominal

Branches of aortic arch:

brachiocephalic artery

left common carotid artery

• left subclavian

• first branch off aortic arch

• supplies blood to right side of head and neck

Brachiocephalic artery

• 2nd branch off aortic arch

• supplies blood to the left side of head and neck

Left common carotid artery

3rd branch off aortic arch

supplies blood to left upper limbs

Left subclavian artery

⚫ branches off brachiocephalic artery

• supplies blood to right side of head and neck

Right common carotid artery

branches off brachiocephalic artery

supplies blood to right upper limbs

Right subclavian artery

Arteries of the Upper Limbs,

1. Axillary arteries

2. Brachial arteries

• continuation of subclavian

• supply blood deep in clavicle

Axillary arteries

• continuation of axillary

• • where blood pressure measurements are taken

Brachial arteries

Arteries of the Upper Limbs

1. axillary arteris

2. brachial

3. ulnar

4. radial

branch of brachial artery

near elbow

Ulnar arteries

branch of brachial artery

⚫ supply blood to forearm and hand

pulse taken here

Radial arteries

supply blood to stomach, pancreas, spleen, liver, upper duodenum

Celiac trunk arteries:

. supply blood to small intestines and upper portion of colon

Superior mesenteric arteries

supply blood to colon

Inferior mesenteric arteries:

supply blood to stomach, pancreas, spleen, liver, upper duodenum

Celiac trunk arteries:

supply blood to small intestines and upper portion of colon

Superior mesenteric arteries:

supply blood to colon

Inferior mesenteric arteries:

Thoracic Aorta Branches

• Visceral arteries

• Parietal arteries

blood to thoracic organs: Esophagus trachea parietal pericardium part of the lung

Visceral arteries

blood to thoracic wall: Posterior intercostal a. Superior phrenic a.

Parietal arteries

Abdominal Aorta Branches

• Renal arteries

• Hepatic arteries

• Testicular arteries

• Ovarian arteries

supply blood to kidneys

Renal arteries

supply blood to liver

Hepatic arteries

supply blood to testes

Testicular arteries

supply blood to ovaries

Ovarian arteries

supply blood to diaphragm

Inferior phrenic arteries:

supply blood to lumbar vertebra and back muscles

Lumbar arteries

Arteries of Pelvis

Common iliac arteries:

External iliac arteries:

Internal iliac arteries:

• branches from abdominal aorta .

• ⚫ divides into internal iliac arteries

Common iliac arteries:

. division of common iliac artery

⚫ supply blood to lower limbs

External iliac arteries:

division of common iliac

supply blood to pelvic area

Internal iliac arteries

Arteries of the Lower Limbs

• Femoral arteries:

• Popliteal arteries:

• Anterior and posterior arteries:

• Fibular arteries:

supply to thigh

Femoral arteries:

supply blood to knee

Popliteal arteries:

supply blood to leg and foot

Anterior and posterior arteries:

supply blood to lateral leg and foot

Fibular arteries:

• Veins return blood to the heart.

• In the systemic circulation, the blood returning to the heart is deoxygenated.

• In the pulmonary circulation, the blood returning to the heart in the pulmonary veins is Oxygenated.

Veins

• returns blood from head, neck, thorax, and right upper limbs

• empties into right atrium of heart

Veins

• returns blood from abdomen, pelvis, lower limbs.

• empties into right atrium of heart

Veins

Veins of the Head and Neck,

• External jugular vein:

• Internal jugular vein:

• Subclavian veins:

• Brachiocephalic veins:

• drain blood from head and neck

• empties into subclavian veins

External jugular vein

• drain blood from brain, face, neck

• empty into subclavian veins

Internal jugular vein:

⚫ forms brachiocephalic veins

Subclavian veins:

join to form superior vena cava

Brachiocephalic veins:

empty into axillary vein

Brachial veins:

empty into axillary vein and basilic vein

Cephalic veins:

connects to cephalic vein

near elbow

Median cubital veins:

Veins of the Thorax,

• Right and left brachiocephalic veins:

• Azygos veins:

• Internal thoracic veins:

• Posterior intercostal veins:

• Hemiazygos vein:

⚫ drain blood from thorax into superior vena cava

Right and left brachiocephalic veins:

⚫ drain blood from thorax into superior vena cava

Azygos veins:

empty into brachiocephalic veins

Internal thoracic veins:

⚫ drain blood from posterior thoracic wall

⚫ drains into azygos vein on right side

Posterior intercostal veins:

receives blood from azygos vein of left side

Hemiazygos vein:

Veins of the Abdomen and Pelvis,

• Common iliac vein:

• External iliac vein:

• Internal iliac vein:

• Renal vein:

• formed from external and internal iliacs

• empty into inferior vena cava

Common iliac vein:

• • drains blood from lower limbs

• empty into common iliac vein

External iliac vein

• drains blood from pelvic region

• empties into common iliac vein

Internal iliac vein

⚫ drains blood from kidneys

Renal vein

Liver is a major processing center for substances absorbed by intestinal tract

Hepatic Portal System

vascular system that begins with capillaries in viscera and ends with capillaries in liver

uses splenic vein and superior mesenteric vein

Portal system:

drain blood from thigh and empty into external iliac vein

Femoral veins

• drain from foot and empty into femoral vein

Great saphenous veins:

drain blood from knee and empty into femoral vein

Popliteal veins:

is the measure of force blood exerts against blood vessel walls.

Blood Pressure

contraction of heart

Systolic pressure

relaxation of heart

Diastolic pressure

Average Blood Pressure:

120/80

is the difference between systolic and diastolic blood pressures.

Pulse pressure