Exercise 36

Blood vessels

The wall of the blood vessels Three distinct layers

Tunica intima• Lines the lumen• Simple squamous epithelium• endothelium and endocardium

Tunica media• Smooth muscle, • collagen and elastic fibers• Regulates the diameter of the

blood vessels

The wall of the blood vessels

Tunica externa or adventitia• Areolar or fibrous connective

tissue• Supports the vessel• Protects the vessel

The wall of the blood vessels

Arteries

Blood vessels that conduct blood away from the heart and toward tissues. In the pulmonary circulation, pulmonary arteries conduct deoxygenated blood to the lungs. In the systemic circulation, the aorta and its branches conduct oxygenated blood toward the systemic tissues

Arteries

Small arteries are called arterioles. Arterioles conduct blood into a network of even smaller vessels, or capillaries.

Arteries

Subject to pressure fluctuations Thick walls Contain more smooth muscle and

elastic tissues Narrower lumen than veins

Arteries

Can be classified as: Elastic

Closer to the heartLarge arteriesMore elastic fibers than smooth

muscle

Arteries

MuscularFarther from the heartSmaller arteriesMore smooth muscle than elastic

fibers

Veins

Blood vessels that conduct blood toward the heart. In the pulmonary circulation, the pulmonary veins return oxygenated blood from the lungs. In the systemic circulation the vena cava returns deoxygenated blood from the rest of the systemic loop. Venules are small veins.

Veins

Far from the heart Not subjected to pressure fluctuations Thin walls Larger lumen than arteries Presence of valves Skeletal muscle pump

Veins

Arteries and veins

Aorta

Ascending aorta – first portion Aortic arch Descending aorta – within the thorax Abdominal aorta – within the

abdomen

Aorta

Ascending aorta Right and left coronary arteries

originate from base of aortic sinus Aortic arch

Brachiocephalic trunk – first branch• Right common carotid• Right subclavian

Left common carotid – second branch

Left subclavian – third branch

Aorta

Descending aortaThoracic and abdominal aortas

Head and neck

Internal Carotid External carotid Vertebral Basilar – formed by the fusion of the

vertebral arteries

Head and neck

Head and neck

Circle of WillisPosterior cerebralPosterior communicatingMiddle cerebralAnterior cerebralAnterior communicating

Circle of Willis

Upper limb

Axillary – continuation of the subclavian

Brachial – continuation of the axillary Ulnar – branch of the brachial Radial – branch of the brachial

Upper limb

thoracic and abdominal regions

Intercostals Celiac trunk – to stomach, spleen, and

liver Superior mesenteric – to the small

intestine and proximal large intestine Suprarenal – to the adrenals Renal – to the kidneys

thoracic and abdominal regions

GonadalsTesticularOvarian

Inferior mesenteric – to the distal large intestine

Common iliac – branches from the inferior end of the abdominal aorta

thoracic and abdominal regions

Pelvis and lower limbs

Internal iliac – to pelvic structures External iliac- to the leg Femoral- to the thigh Popliteal – to popliteal region Anterior tibial – to the crural region Posterior tibial – to the sural region Fibular – to fibular region

Pelvis and lower limbs

Chapter 33

PART B

Veins – head and neck

Brachiocephalic – into sup.vena cava Subclavian – lateral branch of

brachiocephalic Internal jugular – medial branch into

the brachiocephalic vein External jugular – external vein of the

neck that returns blood to the subclavian

Head and neck

Head and neck

Sinuses – drain blood from the craniumSuperior sagittal Inferior sagittal sinusTransverse

Cranium

Upper limb and thorax

Axillary – it is a continuation of the subclavian

Basilic – medial and empties into the brachial

Brachial – continuation of axillary Cephalic – lateral and empties into the

axillary Medial cubital – connects basilic to

cephalic

Upper limb and thorax

Ulnar Median Radial Azygos – unpaired branch into the sup. Vena

cava. Drains the right side of the thorax. Hemiazygos, and accessory hemiazygos -2

sets of multiple veins that empty into the azygos and drain the left side of the thorax.

Intercostals

Upper limb and thorax

Abdominal veins

Hepatic Renal Gonadal – testicular or ovarian

Right side empties into inf. Vena cavaLeft side joins with left renal

Common iliac – two branches that fuse to become inf. Vena cava

Hepatic portal system

Portal circulation is a set of vessels that begins and ends with capillary networks.

It returns blood from the digestive system to the liver

From the liver the blood flows to the inf. Vena cava

Hepatic portal system

Hepatic portal vein – going to the liver Liver Hepatic vein - from the liver to inferior

vena cava

Hepatic portal system

Lower limbs

Internal iliac External iliac Femoral Great saphenous – medial; into the

femoral vein. Popliteal Small saphenous - lateral and

posterior; into the popliteal.

Lower limbs

Anterior tibial - branch into the popliteal

Posterior tibial – branch into the popliteal

Fibular

Lower limbs

Vessels on the Cat Thoracic Cavity and Arm

ArteriesAortaBrachiocephalic trunkCommon carotid- right and leftSubclavian – right and leftAxillaryBrachial

Vessels on the Cat Thoracic Cavity and Arm

VeinsBrachiocephalic trunksJugular –internal and externalSubclavianBrachial

Vessels on the Cat Abdominal Cavity and Leg

ArteriesAbdominal aortaCeliac trunkSuperior mesentericRenalInferior mesentericIliac – common, external and internalFemoral

Vessels on the Cat Abdominal Cavity and Leg

VeinsInferior vena cavaHepatic portal veinRenalIliac – common, internal and externalGreat saphenousFemoral