circulatory system

what are the two methods of blood circulation?

cardiovascular and lymphatic system

How does gas (O2) get to tissues?

blood

What is blood?

• a transport medium!

• transports

  • nutrients (diffuse across capillary walls)

  • signaling molecules (hormones from endocrine glands)

  • respiratory gases (O2 and CO2)

  • wastes (lactate and CO2

what are some other functions of blood?

stabilizes pH and electrolytes, prevents fluid loss (clotting), provides defense system (t-cells), thermoregulation (evaporation of sweat = cooling)

what is blood circulation powered by?

pumping action of the heart

what makes up blood composition?

• plasma

• Buffy coat

• erythrocytes

blood facts

• blood volume higher in males

• is cellular and liquid, specialized CT

  • blood cells- formed elements

  • plasma - liquid

what is hematocrit?

percent of blood volume with RBCs; higher in males (47% vs. 42%)

what is the Buffy coat?

portion with leukocytes (WBCs) and platelets, between the plasma and the RBCs

what is plasma?

• the sticky, fluid portion of blood

• around 90% water

what does plasma contain?

• ions: Na+ and Cl

• wastes: CO2, urea, ammonia

• nutrients: sugars, lipids, amino acids

• porteins

  • albumin- prevent H2O diffusion from blood vessel

  • globulins- antibodies and blood proteins that transport lipids, Fe, Cu

  • fibrinogen- in runs for blood clotting

erythrocytes (RBCs) facts

• packed w/ hemoglobin, oxygen carrying protein → LOVE OXYGEN

• most numerous cells

• pick up O2 @ lung capillaries (external respiration)

• release O2 across tissue capillaries (internal)

hemoglobin structure

• 4 chains of amino acids

• each amino acids bears Fe and 4 heme molecules which BIND to O2 molecule

• oxidation of Fe gives blood red color

leukocytes (WBCs) facts

• PROTECT body from infectious microorganisms

• function OUTSIDE bloodstream in loose CT

• 2 types

  • granulocytes: neutro/eosino/basophils

  • agranulocytes: lymph/monocytes

what is the mnemonic for relative abundance of lymphocytes (most → least)

Never Let Monkeys Eat Bananas

what is a open system? What is an closed system?

respiratory; circulatory

arterial circulation facts

• circulation carries blood away

• HIGH pressure

venous circulation facts

• circulation that carries blood towards heart

• LOW pressure

• “lazy river”

blood vessels in order from thick → thin

• arteries - highest pressure

• arterioles - small artery

• capillaries - smallest

• venues - receive from capillaries, tiny veins

• veins - receive from venues

what are the two types of arteries?

elastic and muscular

elastic arteries facts

• aka conducting

• largest arteries

• aorta and major branches

  • brachiocephalic trunk

  • left subclavian

  • left common carotid

• high elastin dampens pressure; rubber band

muscular arteries facts

• aka distributing because take from elastic arteries → body

• THICK tunica media

• in/external elastic membrane

• “muscle” so contract = increase pressure and dilate = decrease pressure

what are the three layers of blood vessels?

tunica intema, media and externa; lumen is the hole in the middle where blood goes

tunica intema facts

• innermost layer of the blood vessel

• aka endothelium

tunica media facts

• smooth muscle layer of the blood vessel

• middle layer

• allows for open/close

  • contraction: vasoconstriction

  • relaxation: vasodilation

tunica externa facts

• outermost layer of the blood vessel

• CT

arteries facts

• HIGH pressure

• small lumens, elastin, THICK

• arterioles: smallest artery

  • larger ones have all three tunics

  • diameter controlled by tissue and sympathetic nervous system

capillaries facts

• smallest blood vessel

• RBCs pass in a single file line

• site specific

  • lungs: O2 enter CO2 leave

  • s.intestine: receive digested nutrients

  • endocrine glands: pick up hormones

  • kidneys: remove waste

what are the different types of capillaries

continuous, fenestrated, sinusoid capillaries

continuous capillaries facts

• least permeable

• most common and @ most organs

• epithelial cells join by tight junctions

• intercellular clefts allows little permeability

what are intercellular clefts

gaps of unjoined membranes that allow small molecules in/out

fenestrated capillary facts

• medium amount of permeability

• epithelial cells join by tight junctions

• occurs at high rates of exchange

  • s.intestine, endocrine glands

• fenestrations aka PORES, intercellular clefts, and pinocytotic vesicles allow permeability

what are fenestrations?

pores

sinusoid capillaries facts

• MOST PERMEABLE

• wide, leaky, in some organs

  • liver, bone marrow, spleen

• large diameter and twisted

• some fenestration, WIDE intercellular clefts allow permeability

what are capillary beds?

network of capillaries running thru tissues

capillary beds facts

• precapillary sphincters: smooth muscle that regulates the flow of blood to tissue

• tendons and ligaments: poorly vascularized

• epithelia and cartilage: avascular; receive nutrients from CT

what vessel takes blood from the capillaries back to the heart?

veins

veins facts

• LOW pressure

• venules: small veins, post capillary

• RBCs single file line

• large lumens (65% of blood in veins)

• externa thicker, less elastin, thin walls

what are some mechanisms to counteract VENOUS low pressure?

• valves, only in veins

  • prevent back flow

  • in limbs

• skeletal muscle pump: muscles press against thin-walled veins

what is anastomosis?

vessels branching to then interconnect to nearby vessels

vascular anastomosis facts

• organs receive more than one arterial source of blood

• neighboring arteries form

• veins anastomose way more because arteries are too thick and high pressure

pulmonary circulation

systemic arteries facts

• branch in/directly from the aorta

• carries O2 blood away from heart

• HIGH pressure

• major arteries run deep in neck and limbs so bones and muscles protect

greater vessels that exit and enter the heart!!!

• ascending aorta

• aortic arch

  • brachiocephalic trunk

  • left common carotid

  • left subclavian

aorta facts!!!

• ascending - highest pressure, from left ventricle

  • branches right and left coronary artery @ beginning of the arch end of ascending

• arch - posterior to manubrium

  • branches L common carotid/cubclavian and brachiocephalic

• descending → thoracic and abdominal

• R/L common iliac arteries

what does “common” mean?

the first branch off of the MAIN branch

major arteries of the upper limb

• L/R subclavian arteries

• axillary

• brachial

• radial and ulnar

• internal thoracic

arteries of upper limb from the aortic arch

subclavian → axillary → brachial → radial and ulnar

major arteries of the head

• common carotid

  • internal carotid: to the brain

  • external: face and scalp

arteries of the lower limbs

• from the abdominal aorta → common iliac

  • internal - into pelvis

  • external → femoral → popliteal(back of knee) → anterior and postural tibial

systemic veins facts

• run along the arteries, have similar names

• LOW pressure

• empty into the vena cava and coronary sinus (O2 poor from myocardium)

• superficial and deep

• TEMP CONTROL

vena cava facts

• superior

  • head, upper limbs, thorax

  • anything above diaphragm

• inferior

  • abdomen, liver, pelvis, lower limbs

veins of the head

• internal jugular: from the brain

• external jugular: from the face and scalp

veins of the upper limb

• deep veins follow path of arteries

• superficial: visible beneath skin

  • cephalic

  • basilic

  • median cubital

  • median vein (forearm)

veins of the abdomen

• lumbar

• gonadal

• renal

• suprarenal

• hepatic

what is the venous system with draining capillary veins in the intestine that then get filtered at the liver capillary vein?

the hepatic portal system

what does the hepatic portal system do?

takes everything you have eaten and transferred to blood to the liver to then clean and go back to the heart

hepatic portal system facts

• takes contents of the intestines to the liver to filter → systemic circulation

  • proteins, fats, alcohol, toxins

• one way the liver FILTERS blood

veins of the pelvis and lower limb

• deep veins share name of accompanying artery

• superficial

  • great saphenous - empties into the femoral vein

  • small saphenous - empties into the popliteal