Cardiovascular System Part 2

Anatomy of Blood Vessels

Arteries

Vessels that carry oxygen poor blood away from the heart

Capillaries

Vessels that allow for exchange of materials

Veins

Vessels that carry oxygen rich blood back to the heart

Circulation of Blood

Pulmonary circulation

Carries blood from heart to lungs

Veins

Arteries

Oxygen rich

Oxygen poor

Systemic circulation

Carries blood out of heart to rest of the body

Tunica externa

Thinner than veins

Collagen & elastic fibers (connective tissue)

Protective

Gives strength

Anchor to surroundings

Tunica media

Smooth muscle

More than veins

Tunica intima

Internal elastic membrane

Endothelium

Simple squamous epithelium

Tunica intima

Endothelium

Basement membrane

Tunica externa

Thicker than arteries

Collagen & elastic fibers (connective tissue)

Protective

Gives strength

Anchor to surroundings

Tunica media

Smooth muscle

Less than arteries

Tunica intima

Endothelium

Types of Blood Vessels

Arteries

Elastic (conducting)

Largest blood vessel

Gets large amount of blood out quickly

Ex: aorta & major branches

Elastic fibers

Stretch & recoil

Muscular (distributing)

Goes to organs & parts of organs

Relatively more smooth muscle than other blood vessels

Contract/relax vessel

Decrease/increase blood flow distal to artery

Arterioles

Very small

Leads to capillary beds

1-2 layers of smooth muscle

Constrict/dialate

Changes diameter of lumen

More or less blood to capillaries

Capillaries

Absent in cornea, lens, epithelial tissue, & cartilage

Exchange vessels

Simple squamous epithelium

Oxygen & nutrients move out to tissues

Carbon dioxide & waste moves in

Continuous

Intercellular clefts

Small gaps between cells

Most common type of capillary

Least leaky

Most common in CNS, lungs, skin, connective tissues, & skeletal & smooth muscle

Fenestrated

Has windows/pores

More leaking

Located where there needs to be a high rate of exchange

Kidneys, choroid plexus, small intestine, & endocrine glands

Sinusoid

Most leaky

Wide & winding/curved

Very large pores

Entire cells & large molecules (proteins) can fit through

Located in liver, red bone marrow, & spleen

Venules

Small veins

Much like capillaries

1-2 layers of smooth muscle

Veins

Fewer elastic fibers

Medium sized veins

Valves

Primarily in lower extremities

Keeps blood flowing to the heart

Prevents back flow of blood

Blood flow to/from heart

Heart

Large sized veins

Elastic (conducting) arteries

Muscular (distributing) arteries

Arterioles

Capillaries

Venules

Medium sized veins

Large sized veins

Heart

Vasodilation

Vessel dialation

Smooth muscle relaxes

Vasoconstriction

Vessel constriction

Smooth muscle constricts

Anastomosis

Blood vessels interconnect/unite

Mostly veins around joints

"Detour possibilities"

Coronary circulation

Ex: circle of Willis

Blood flow to/from head & neck

Heart

Aortic arch

Brachiocephalic trunk

Subclavian arteries

Common carotid arteries

Vertebral arteries

Brain

External carotid arteries

Internal carotid arteries

Brain

Brachiocephalic veins

Vertebral veins

Internal jugular veins

External jugular veins

Blood flow to thorax

Heart

Aortic arch

Thoracic aorta

Anterior intercostal arteries

Subclavian arteries

Internal thoracic artery

Axial arteries

Posterior intercostal arteries

Brachial arteries

Radial arteries

Ulnar arteries

Blood flow to abdomen

Heart

Aortic arch

Thoracic aorta

Abdominal aorta

Gastric arteries

Celiac trunk

Hepatic artery (right)

Splenic artery (left)

Renal arteries

Superior mesenteric artery

Gonadal arteries

Inferior mesenteric arteries

Blood flow to lower limbs

Heart

Aortic arch

Thoracic aorta

Abdominal aorta

Common iliac arteries

External iliac arteries

Femoral arteries

Deep arteries of the thigh

Popliteal arteries

Anterior tibial arteries

Posterior tibial arteries

Fibular arteries

Blood

Connective tissue

Cells

Extracellular matrix

Proteins

Albumin

Helps to keep water inside blood vessels

Globulin

Antibodies

Transporters

Moves lipids, iron, & copper

Fibrinogen

Involved in blood clotting

Plasma

Makes up 55% of blood

Extracellular matrix of blood

Contains 90% water

Contains ions

Ex: sodium & chloride

Contains nutrients

Ex: proteins, sugars, lipids, & amino acids

Erythrocytes

Created in red bone marrow

Contains hemoglobin

Biconcave shape

More flexibility

Carries oxygen

Leukocytes

Plays role in immunity

Red blood cells

White blood cells

Platelets

Thrombocytes

Created in bone marrow

Not cells

Tiny pieces of a large cell

Involved in blood clotting