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