Module 4 - Blood Vessel Flashcards
Types of Blood Vessels
Types of Blood Vessels
Closed systems to carry blood to and from heart and body tissues
Main role is gas, nutrients, and waste exchange
Arteries
Arterioles
Capillaries
Venules
Veins
Lumen
Lumen – hollow passage for blood
Arteries – smaller lumen – more pressure
Veins – larger lumen – contains valves to combat less pressure & gravity
Nervi vasorum
Nervi vasorum – nerves controlling contraction and dilation
Vasa vasorum
Vasa vasorum – gas exchange to nourish vessels
3 tunics
Tunic intima (inner) – lining of connective and epithelial – endothelium, lining all to regulate exchange and flow – reduce friction for blood
Tunic media (middle) – smooth muscle cells
Tunic externa (outer) – connective tissue holding position – prevents movement – contains nervi and vasa vasorum – protects and reinforces
Arteries vs Veins Structure
Arteries vs Veins Structure
Lumen
Arteries – smaller lumen – more pressure
Veins – larger lumen – contains valves to combat less pressure & gravity
Walls
Arteries – thick walls
Veins – thin walls – less elastic tissue and smooth muscle
Both have 3 tunics
Tunic intima (inner)
Arteries – wavy endothelium
Larger arteries – internal elastic membrane/lamina – gives strength and allows stretch
Veins – smooth endothelium – no elastic – contains valves
Tunic media (middle)
Arteries – elastic & collagen fibers – thickest layer
Larger arteries – external elastic membrane/lamina – wavy lines – not as thick
Tunic externa (outer)
Arteries – thinner except in large – collagen & elastic fibers
Veins – thickest layer – collagen & smooth muscle fibers
Arteries
Arteries
carry blood from heart too tissue
branch into smaller arterioles
Elasticity
Contractility
Elasticity
Elasticity – accepts blood under pressure
Contractility
Contractility – smooth muscle in tunica media – increase and decrease lumen – limit bleed from wounds
Elastic artery
Elastic artery – conducting artery
Closer to heart – higher pressure
Thicker tunic media
More elastic tissue – stretchy for surge of blood from contraction – helps manage BP
Muscular artery
Muscular artery – distribution arteries
Further away from heart – less pressure
more smooth muscle – affects blood flow
Arterioles
Arterioles
smaller arteries – almost microscopic
3 tunics – thinner
deliver blood to capillaries
Sympathetic nerve system innervations
regulates blood flow – change size of lumen
neural and chemical changes
Vasoconstriction
Vasodilation
Vasoconstriction
Vasoconstriction – decrease size of lumen
Vasodilation
Vasodilation – increase size of lumen
Capillaries
Capillaries
Microcirculation – flow of blood in capillaries
Microscopic with massive surface area
Site of exchange for body tissue – nutrients and waste
Exchange into interstitial fluid
Single layer of endothelium and basement membrane
Regulate blood pressure
Role in thermoregulation – brings blood closer or further from surface to influence temp
Connected to venules
Capillary bed – Extensive network through tissue
Precapillary sphincters
Precapillary sphincters – regulate blood to capillaries – rings of smooth muscle on arterioles
Metarteriole
Metarteriole – connects arterioles to capillaries – control flow into capillary bed – can act as bypass – thicker vessels
Types of capillaries
Types of capillaries – determine substances passing and location
Continuous
Fenestrated
Sinusoid
Continuous Capillaries
Continuous – small pores for water, glucose, hormones, and gases – nervous system, skin, and lungs – average permeability
Fenestrated Capillaries
Fenestrated – large openings – fenestrae – allow nutrients and blood to pass fast – kidneys, small intestine, and endocrine glands – mid permeable
Sinusoid Capillaries
Sinusoid– large gaps allow more substances – liver, spleen, lymph nodes, bone marrow, and endocrine glands – most permeable
Capillary Exchange
Capillary Exchange
Blood comes in from arterial end – give cells oxygen and nutrients
Into capillary bed
Diffusion
Bulk flow – regulation of volume
Blood leaves from venous end – taking CO2 and waste
2 directions bring in and pushing out
Low blood pressure because it traveled so far from heart – lots of resistance
Hydrostatic blood pressure (CHP)
Osmotic pressure (BCOP)
Net filtration pressure – NFP
Arterial end – net outward push of 10mml
Venous end – net inward pull of – pulling in waste and CO2
Capillary Exchange - Diffusion
Diffusion – solute exchange between plasma and interstitial fluid
Capillary exchange - Bulk flow
Bulk flow – regulation of volume
Hydrostatic blood pressure (CHP)
Hydrostatic blood pressure (CHP) – outward pushing force on capillaries – capillary BP
pushing out nutrients, O2, electrolytes
Holes and exchanging changes the pressure – reducing as it travels towards venous
Osmotic pressure (BCOP)
Osmotic pressure (BCOP) – Inward pulling force
Created by cells and structures inside are too big to move out – WBCs, proteins, RBCs, and platelets – attract water
Stays same because substances don’t leave
Net filtration pressure
Net filtration pressure – NFP – force that drives fluid out of capillaries into surrounding tissue space
Difference between CHP and BCOP
Venules
Venules
Small vessels connected to veins
drain blood from capillaries into veins
union with capillaries
Veins
Veins
3 layer tunics
Thinner than arteries – less elastic tissue and smooth muscle
Valves
More compliant – expend to hold more blood
Venoconstriction
Pressure generated by contraction of left ventricle – creating movement, new blood is pushing old blood forward
Skeletal muscle pump
Respiratory pump
Valves
Valves to prevent back flow – thin flaps endothelium
Venoconstriction
Venoconstriction – stiffening of veins to promote blood flow
Carry blood back to heart
Skeletal muscle pump
Skeletal muscle pump – contraction of muscle during movement compresses the veins to propel blood towards the heart – valves prevent back flow
Respiratory pump
Respiratory pump – opening and closing of chest during inhale and exhale increases and decreases pressure allows blood to move and be pushed towards heart
Regulation of Blood Flow
Regulation of Blood Flow
Volume of blood flowing through any tissue at any time
Determined by blood pressure and resistance
Blood flows from higher to lower pressure – high resistance = low blood flow
Pressure decreases as blood moves further from left ventricle
3 factors of vascular resistance
Size of blood vessel lumen
Blood viscosity
Blood vessel length
Vascular Resistance - Size of lumen
Size of blood vessel lumen – changes easily with vasodilation and vasoconstriction – neural and chemical signals – vascular tone – contractile state of smooth muscle in vessel – determines resistance and flow
Vascular Resistance - Blood viscosity
Blood viscosity – formed elements and plasma proteins – thicker = less flow – directly proportional to resistance and inversely proportional to flow
Vascular Resistance - Blood vessel length
Blood vessel length – proportional to resistance – longer = greater resistance and lower flow – increase of surface area will impede blood flow
Baroreceptors
Baroreceptors – sensitive to stretch – ends of afferent nerves are the receptors – channels open to allow ions to depolarize the neuron – stims neuron
Carotid artery – carotid sinus – stretch due to blood pressure
Pulmonary artery – stretching w/ blood volume
Aortic arch – stretch due to blood pressure
Right atria – stretching w/ blood volume
Chemoreceptors
Chemoreceptors – chemical composition of blood – O2, CO2, H – atrial blood
Carotid bodies – glomus cells – measure the O2 and CO2
Aortic bodies
Afferent nerves
Afferent nerves – info travels
Vagus nerve – receptors on heart
Glossopharyngeal nerve – receptors from carotid sinus and bodies
Cardiovascular control centers
Cardiovascular control centers – medulla
Cardioaccelerator – increase HR
Cardioinhibitory – decrease HR
Vasomotor – control vessel tone
Efferent nerves
Efferent nerves – take instructions
Inhibitory – sympathetic
Stim – parasympathetic
Hormones
Hormones effect blood pressure and blow by altering cardiac output, adjusting volume, and changing vascular resistance
Sympathetic impulses
Sympathetic impulses increase HR & contractility
Vasomotor tone – moderate state of tonic contraction or vasoconstriction – continues firing of impulses at low rate during resting state – partial constriction
Autoregulation
Autoregulation – tissue adjust its own blood flow to match demand for O2 and nutrients
Pulse
Pulse – alternate expansion and elastic recoil of artery wall with each heartbeat – HR - #/1 min
Normal resting – 70-80bpm
Tachycardia
Tachycardia – rapid pulse - >100bpm
Bradycardia
Bradycardia – slow pulse - <60bpm
Blood Pressure
Blood Pressure – pressure on wall of an artery based on left ventricle systole and diastole
Sphygmomanometer used to measure on brachial arteries – when you hear first and last pump on meter
Normal BP
young adult male – 120/80mm Hg
8-10mm Hg less for female
Systolic BP
Systolic BP – force of blood at ventricle contraction – first pump - higher
Diastolic BP
Diastolic BP – force of blood during ventricular relaxation – last pump – lower
Systemic Circulation
Systemic Circulation
Largest route – closed-loop supply O2 and nutrients
Arteries – Delivery O2 blood from heart – left ventricle
Aorta – divided to supply whole body
Ascending aorta
Arch of the aorta
Descending Aorta
Veins – Returns CO2 blood to heart – right atrium
R & L coronary arteries
R & L coronary arteries – O2 blood to heart
Brachiocephalic
Brachiocephalic – supplies RIGHT side
Right subclavian artery – arm, chest, shoulders, back, and CNS
Right common carotid artery
External – blood to face, neck, esophagus, and larynx, outer parts of brain
Internal – blood to brain – circle of Willis
Left common carotid artery
Left common carotid artery – LEFT side
External – blood to face, neck, esophagus, larynx, and outer parts of brain
Internal – blood to brain – circle of Willis
Left subclavian
Left subclavian – LEFT – upper body
Descending Aorta
Descending Aorta
Thoracic – supplies above diaphragm
Abdominal – supplied below diaphragm
Systemic Circulation - Veins
Veins – Returns CO2 blood to heart – right atrium
Superior vena cava – CO2 blood from upper body
Inferior vena cava – CO2 blood from lower body
Coronary sinus – CO2 blood from heart
Pulmonary Circulation
Pulmonary Circulation
Smaller circuit
Takes deoxygenated blood from heart into lungs for gas exchange
Oxygenation of blood within lungs
CO2 blood comes into Right Atrium to Ventricle and pumped towards heart
O2 blood from lungs drains into Left Atrium to be pumped to body tissue
Lungs
Pulmonary veins
Left Atrium
Low resistance – less pressure needed
Path of Pulmonary Circulation
CO2 blood comes into Right Atrium to Ventricle and pumped towards heart
Right Ventricle
Pulmonary trunk – divided left and right
Left Pulmonary arteries – left lung
Right Pulmonary arteries – right lung
Branch to pulmonary capillaries – gas exchange with lung alveoli
Pulmonary arteries
Pulmonary arteries – larger diameter, thinner walls, and less elastic tissue
Coronary sinus
Coronary sinus – drains into right atrium with CO2 blood from heart
Hepatic Portal Circulation
Hepatic Portal Circulation
Abdominal aorta brings blood to GI structures - branch off to organs
Process of sending blood to liver via hepatic portal vein – all blood drains into liver – nutrient rich, O2 poor blood
2 capillary networks
Liver – gets O2 blood from hepatic artery from coeliac
GI Tract
Hepatic Circulation Abdominal Aorta - 3 main arteries
Abdominal aorta brings blood to GI structures – 3 main arteries – branch off to organs
Coeliac – liver (hepatic artery), spleen, stomach
Superior mesenteric – pancreas, sm. intestine, colon
Inferior mesenteric – colon
Enables nutrient utilization and blood detox
Hepatic circulation - Liver function
Liver – filters and processes blood
Storage area for nutrients
Removes harmful substances
Returns nutrient dense blood
Hepatic portal vein
Hepatic portal vein – blood to liver from organs
Hepatic veins
Hepatic veins – blood from liver to inferior vena cava
Fetal Circulation
Fetal Circulation
Placenta – site of gas exchange for fetus
Two umbilical arteries
One umbilic vein
Fetal lungs are nonfunctional – placenta replaces
Ducts close at birth – lungs become functional on their own – change of pressure – therefore heart starts pumping normally
Dustus Venosus
Foramen ovale
Ductus arteriosus
Placenta Function
Placenta – site of gas exchange for fetus
Organ supply O2 and nutrients to a fetus
Removes waste
Two umbilical arteries
Two umbilical arteries – CO2 blood out – become medial umbilical ligaments
One umbilic vein
One umbilic vein – O2 blood in – becomes ligamentum tere
Dustus Venosus
Dustus Venosus – liver bypass – nutrients from mom – becomes ligamentum venosum
Foramen ovale
Foramen ovale – R ventricle bypass – O2 blood from R atrium goes to L atrium – becomes fossa ovalis
Ductus arteriosus
Ductus arteriosus – lung bypass – becomes ligamentum arteriosum
Fetal Circulation - Pathway
Blood travels
Placenta via umbilical vein
Liver – dustus venosus
Inferior vena cava
Right atrium
Foramen ovale
Left atrium
Left Ventricle
Aorta
Body tissue
Superior vena cava
Right ventricle
Ductus arteriosus – skips lungs
Umbilical artery
Placenta
Hypertension
Hypertension
Persistent high blood pressure
Hypertension - Prehypertension
b/w
Systolic 120-140mm Hg
Diastolic 80-90mm Hg
Hypertension - stage 1
b/w
Systolic 140-160mm Hg
Diastolic 90-100mm Hg
Hypertension - Stage 2
Systolic >160mm Hg
Diastolic >100mm Hg
