Blood vessels

circulatory system functions

• carries blood back and forth between the heart and body

• exchange nutrients, wastes, gases

• transport hormones, enzymes, gases

• blood volume transported to maintain homeostasis

arteries

• thick muscular walls found beneath skin

• carry oxygenated blood from heart to tissues

arterioles

• small arteries that connect to capillaries, deliver blood to capillaries

• metarterioles: form branches into capillary bed connecting arterioles to capillaries

• tunica media contains few layers of smooth muscle (2-3 layers)

capillaries

• small blood vessels with thin walls

• site of substance exchange btwn blood and body tissues

veins

• thin walls; contains valves preventing backflow of blood

• closer to skin surfaces

• convey blood from tissues back to heart

venules

• Small veins collecting blood from capillaries

• connect capillaries to larger veins

• Tunica media contains only a few smooth muscle cells & scattered fibroblasts

vaso vasorum

• small blood vessels supplying blood to cells of the walls

  • tunica externa of the arteries and veins

tunica intima

• internal layer

• made of endothelial cells (simple squamous), basement membrane, and lamina propria made up of elastic membrane separating the intima from the media

tunica media

• middle layer

• made of smooth muscles, elastic and collagen fibers

• vasoconstriction decreases BV diameter and vasodilation increases BV diameter

tunica externa

• outside layer

• made of dense connective tissues, loose connective tissues

elastic arteries

• Large arteries with more elastic fibers and less smooth muscle (6-7 layers)

• receive blood under pressure and propel it onward

• aka conducting arteries: conduct blood from the heart to medium sized muscular arteries

muscular arteries

• Medium-sized arteries with more muscle than elastic fibers in tunica media

• Capable of greater vasoconstriction and vasodilation to adjust rate of flow

• aka distributing arteries: they direct blood flow

  • brachial and axillary

continuous capillaries

• Small intercellular clefts are gaps between neighboring cells

  • skeletal & smooth tissue and lungs

Fenestrated capillaries

• Mid size intercellular clefts

• Contain large fenestra allowing molecules to leave

• kidneys, small intestine, choroid plexuses, endocrine glands

Sinusoids

• very large gap (intercellular cleft)

• Allow for leakage of molecules

• liver, bone marrow, spleen, anterior pituitary gland, & parathyroid gland

pulmonary circulation

transports deoxygenated blood from the right side of the heart to the lungs for oxygenation

Systemic circulation

• Transport blood between the heart and other organs

• left side heart to body & back to heart

Fetal circulation

from fetal heart through umbilical cord to placenta & back

Coronary Circulation

Blood supply to and from the heart

pulmonary circulation steps

Starts off from right atrium (deoxygenated blood) → right ventricle → pulmonary trunk → left/right pulmonary arteries → lungs (alveoli) → out through pulmonary veins (oxygenated blood → exits each lungs; right and left → and into heart

aorta

supplying arms, head, lower limbs, and all viscera with O2 from the lungs

left and right external carotid arteries

• Supplies neck and face

  • tongue, mouth, thyroid gland, larynx, middle and inner ear, lower jaw, upper jaw, nose

left and right vertebral artery

supplies blood to the upper spinal cord, brain stem, cerebellum, posterior part of the brain, posterior neck, upper limbs

left subclavian artery

transport blood to the upper limb

basilar artery

Supplies brain stem, cerebellum, thalamus, parietal lobes

internal thoracic artery

supplies thoracic and abdominal walls

Splenic artery

supplies spleen, pancreas, and stomach

Left gastric artery

supplies stomach

Common hepatic artery

supplies liver, gall bladder and small intestines

Superior mesenteric artery

supplies small intestines, cecum, ascending colon and transverse colon

Phrenic artery

supplies diaphragm

L/R suprarenal arteries

supplies adrenal glands

L/R renal artery

supplies kidneys

L/R gonadal artery

supplies ovaries and testes

lumbar artery

supplies back and abdominal wall

Inferior mesenteric

supplies descending colon, sigmoid colon, rectum

Right/Left external artery

• Common iliac artery

• supplies lower limb, anterior abdominal wall

Right/Left internal artery

• Common iliac artery

• supplies pelvic organ, genitalia and hip

circle of willis

• Anterior communicating Artery

• Anterior cerebral Artery

• Middle cerebral Artery

• Internal Carotid Artery

• Posterior communicating artery

• Posterior cerebral artery

Anterior communicating Artery

• Connect left/right cerebral hemispheres

• Supplies the fornix, optic chiasm, and hypothalamus

Anterior cerebral Artery

Supplies medial and superior portion of frontal lobe, anterior portion of parietal lobe, choroid plexus, lower portion of pons

Middle cerebral Artery

• Supplies frontal lobe, lateral side of temporal lobe, and parietal lobe

• motor portion of face, throat and hand

• largest branch of internal carotid artery

Internal Carotid Artery

Supplies blood to brain

Posterior communicating artery

• alternate supply in case the iCA is blocked

• Supplies thalamus, hypothalamus, optic chiasma

Posterior cerebral artery

supplies occipital lobe (visual area), inferior of temporal lobe, thalamus

superior vena cava

drains the head and upper extremities

inferior vena cava

drains the abdomen, pelvis & lower limbs

coronary sinus

large vein draining the heart muscle back into the heart

Cardiac Veins

transports blood from walls of the heart through the coronary sinus into the right atrium

Brachiocephalic vein

drains blood from the head, neck, arms back to the heart

L/R External jugular veins

Drain blood from posterior head and neck

L/R subclavian vein

drain right side of the limbs and into the brachiocephalic veins

L/R Internal jugular veins

• Drains blood from the anterior head, face and neck

• drain into the brachiocephalic veins

R/L internal thoracic vein

drain blood from thoracic and abdominal walls into the R/L brachiocephalic vein

axillary veins

blood from upper limbs, armpit towards the heart

Brachial veins

drains blood from upper arm, between elbow and shoulder

radial veins

drains blood from hand and forearm

ulnar veins

drains medial aspect of the forearm

median cubital vein

returns blood from the forearm

digital vein

carries blood from the fingers

gastric vein

drains blood from stomach

splenic vein

drains blood from spleen and pancreas

hepatic portal veins

drain blood from liver, gallbladder

Superior mesenteric vein

drains from Small intestines, cecum, ascending colon, transverse colon

Inferior mesenteric vein

drains from descending colon, sigmoid colon and upper rectum

L/R lumbar veins

drains posterior abdominal wall

L/R renal veins

drains kidneys

L/R suprarenal veins

drains adrenal medulla

L/R gonadal veins

drains ovaries and testes

L/R phrenic veins

drains diaphragm

L/R external iliac vein

drains lower limb, anterior abdominal wall

L/R internal iliac vein

drains pelvic organs, genitalia, and hip

hepatic portal circulation

collects blood from the veins of the pancreas, spleen, stomach, intestines, and gallbladder and directs it into the hepatic portal vein of the liver before it returns to the heart

laminar flow

• blood moving in a smooth streamlined fashion

• steady rate in a long smooth vessels

• silent sound

turbulent flow

• blood flow is irregular and a bit more chaotic

• causes murmurs

• ex: constriction of bv or an obstruction

blood pressure

the pressure exerted on the walls of a blood vessel

sphygmomanometer

used to measure blood pressure

systolic blood pressure

recorded during ventricular contraction

diastolic blood pressure

recorded during ventricular relaxation

normal blood pressure

120/80

elevated blood pressure

120-129/<80

stage 1 hypertension

130-139/80-89

stage 2 hypertension

≥140/≥90

hypertensive crisis

>180/>120

pulse points

1. brachial (upper arm)

2. temporal (temple)

3. carotid (neck)

4. radial (wrist)

5. femoral (inner groin area)

6. popliteal (back of knee)

7. axillary (armpit)