Cardiovascular System Flashcards
Function of the system
What does it include
- pumps blood and contents to all cells for metabolite exchange and immune response
- cardiovascular and lymphatic
List the components of the cardiovascular system and what they do generally
1 heart - has 4 chambers to receive blood and pump blood
2 arteries - efferent to the blood. Transports blood away from heart
3 capillaries- responsible for metabolite exchange between tissue and blood
4 veins - afferent to blood and carries blood back to heart for pumping
List and describe the 2 major systems of the cardiovascular system
List the basic blood flow pattern
1 pulmonary - pumps deoxygenated blood to lungs for oxygenation
2 systematic- pumps oxygenated blood to the body
-right atrium / right ventricle / lungs / left atrium / left ventricle / body
What is internal surface of blood and lymph system lined with
And it’s function the lining
/simple squamous epithelium called endothelium
1 semi permeable for metabolite exchange
2 controls where exudate enters CT
3 antithryombogenic barrier
4 secret of factors for growth of other cells
Function of the heart and properties
What supplies heart with nutrients
- rhythmic contractions to pump blood into the cardiovascular vessels
- has 4 chambers
- is auto-rhythmic
-coronary arteries
List the 3 layers of the heart muscle
1 endocardium
2 myocardium
3 epicardium
Describe the endocardium structure , function
- thin inner layer of endothelium with CT.
- middle layer of smooth muscle called myoelastic
- subendocardial outer layer of CT which merges with myocardial layer
- subendocardial layer has modified cardiac fibers part of hearts impulse conducting system
Describe myocardial layer structure and function
- thickest middle layer of heart muscle
- around each chamber spirally
Why are ventricle myocardial thicker than atria ones
-a lot of force is required to pump blood as compared to receiving it
Describe epicardium structure and function
- outer layer of endothelium and CT with blood vessels and nerves for the Heart
- continuous with outer covering of heart called Pericardium
- it’s adipose cushions underlying structures during movement
- fluid of pericardial mesothelium prevent friction
List all parts of the heart
- atrium
- ventricle
- sinoatrial node
- internodal pathways
- atrioventricular node
- valve cusps
- papillary muscle
- atrioventricular bundle ( Bundle of His )
- interventricular septum
- purikinje fibers
- chordae tendinae
- valve flaps
Describe heart valves
How anchored In heart
Function of chordae tendinae
- flaps of CT anchored in the CT of the heart
- has chordae tendinae that extend from cusp to papillary muscle
-prevent valve from turning inside out during ventricle contraction
Describe impulse structures from AV node to apex of heart
- AV continuous with His bundle which gives rise to right and left bundles that run in interventricular septum
- run to apex of heart and divide into purkinje fibers
Describe structure and function of cardiac skeleton
-dense fibrous irregular CT which 1 makes interventricular septum
2 surrounds all valves and extend to valve cusp and chordae tendinae
3 provide insertion joint for cardiac muscle
4 provide electrical insulation between atria and ventricle
Describe structure, location and function of impulse system from SA nodes to purkinje fibers
—SA node is modified muscle fibers. Impulse initiated here and move along myocardial of both atria along internodal pathway
- stimuli reaches AV node and this propagates along His bundle to purkinje bundle
- purkinje have fewer myofibrills and much glycogen and stimulate both atrium and ventricles
What innervates the heart and it’s effects
Where are their ganglia found
- parasympathetic ( slows down )and sympathetic ( speeds up )system
- near SA and AV nodes
How does angina pectoris come about
-free afferent fibers between myocardium fibers register pain
What do walls of vasculature have
What determines the amount and arrangement
- endothelial and smooth muscle in veins and arteries
- only endothelial in capillaries
-mechanical and metabolic factors
Endothelial function
- semi permeable barrier facilitating exchange of metabolites between tissue and blood
- control where exudate is released ( immune roles )
- secrete factors which influence growth of other cells
- modulate blood flow by release of factors such as endothelin 1 , prostacyclin
Why doesn’t endothelial clot
-due to release of anticoagulants such as heparin
What does VEGF do and how does it do it
- vascular endothelial growth factors stimulate vascular formation from mesoderm ( vasculogenensis )
- Maintain adult capillaries
- stimulate sprouting of already existing capillaries ( angiogenesis )
-endothelial recruits smooth muscle and fibroblasts to form vascular tissue
Where is smooth muscle present and it’s structure
Why do arteries have gap junctions
- in vessels larger than capillaries
- to modulate blood flow via vasoconstriction and vasodilation
Where elastic fibers present, why and in what structure
- in arteries to allow the vessels to expand under pressure
- as lamellae
What is tunics and. And them
-concentric layers of CT of vessels
1 initima
2 media
3 adventitia
Size of lumen and media of arteries and veins
- narrow and thick media
- large lumen and thin media
Describe the initima structure and function ( in veins and arteries )
- endothelial and thin subendocardial layer of CT
- arteries have internal elastic lamina which have holes to allow better diffusion from blood to deeper wall
Describe the media structure and function ( in veins and arteries )
-middle layer of concentric layers of smooth muscle which secrets ground substance , elastic reticular fibers
/thicker in arteries and has external elastic lamina
-thinner in veins and no lamina
Describe the adventitia structure and function ( in veins and arteries )
-CT of collagen 1 and elastic fibers continuous with and bound to stroma of organ wc it runs through
-has vaso vasorum
/has unmyelinated nerves ( vasomotor nerves )
-thicker in vein than artery
Function of vaso vasorum and why necessary
/supplies vessels with exchange of metabolites
-lumen blood isn’t enough for the vessels especially in veins with deoxygenated blood
Elastic arteries examples , alias , function and describe the structures of its media, adventitia and elastic lamina
- aortic and pulmonary artery and their branches
- conducting arteries
- carries blood to smaller arteries
- thick media of alternating smooth muscle and elastic lamellae
- adventitia thin
- internal lamina more developed than external
Function of internal lamina in elastic arteries
-to ensure uniform flow of blood
Describe state of elastic artery at systole and diastole
- ventricle contracts , blood forcefully moved into artery’s which stretch to limit of collagen
- pressure drops but elastic rebound is passive to maintain arterial pressure to continue flow of blood away from heart
Describe structure of carotid sinuses and where found
Function
State of tunic media and why
-slight dilations of the bilateral internal carotid where they branch from common carotid arteries
/baroreceptor for blood pressure
-tunice media thinner allowing greater swelling when pressure rises
Structure of adventitia of carotid sinuses
How do the sinuses control pressure
- has numerous nerve endings from nerve IX endings ( glossophranygeal nerve )
- brain vasomotors centers process afferent impulses from baroreceptors and adjust vasoconstriction controlling BP
Where does the Vegas nerve gets it signals from
What do chemoreceptors do. Where found
- baroreceptors from aortic arch
- monitor O2 and C02 and pH blood levels. Carotid bodies and aortic bodies
How do chemoreceptors work and the other structures aiding
-when there is acidosis, hypoxia or Hypercarpnia glomulus cells release neurotransmitters into nerve IX and signal brain to initiate adjustments
Function of muscular arteries
Where is external lamina found
Describe structure of tunics of muscular arteries
- distribute blood to organs
- modulate flow by contracting or relaxing smooth muscles
/in large arteries only
-thin subendocardial and prominent internal lamina. Adventitia has vaso vasorum which penetrates to base of media
What are arterioles
What do they indicate
Describe the structure of the media and adventitia and what they form
- branches of muscular arteries only 2-4 media cells thick
- beginning Of micro vasculature
/thin adventitia and media. Branch to form anastomose capillaries
Function of sphincters at ends of arterioles
Why are arterioles major sites of systematic blood pressure
- to Modulate flow into capillaries
- resistance to passive stretching keeps arterioles partially closed resisting blood flow making the vessels major determinants systematical blood pressure
Describe structure of thermoregulation vessels ( how formed ) and structures that aid in their function
- arterioels do not branch into capillaries but join direct to venues
- have thicker media and adventitia in the atrioventricular shunts and rich ANS nerves to control vasoconstriction
Describe portal veins and function
- blood flows thru 2 capillary beds separated by portal vein
- allows for metabolites absorbed in bed 1 are properly delivered to cells in bed 2 before going to heart for general distribution
Function of capillary beds
Function of metartioles where coming from and what connected to and how
-permit and regulate metabolic exchange between blood and tissue
- supply capillary beds, branching from arteriole
- connected to post capillary thru throughfare channel
How do capillaries from metarterioles
What encircles the capillaries after branching and its function and how it does it job
/branch from met-arterioles
-smooth muscle ( precapillary sphincter )
-control blood flow into capillary by cyclically causing blood to flow in a pulsatile manner
What happens when sphincter closed
Why is a few blood in capillary
How are capillaries specialized for their function
- blood flows direct to post capillary venule
- due to sphincters
- thin walls , extensive surface , pulsatile flow
Why endothelial nuclei curved
Listh the 3 types of capillaries
/to accommodate small tubular structure
1 continuous
2 fenestrations
3 sinusoids
Describe continuous capillary structure , function and where found
-numerous tight junctions
/overlapping cells for continuity
-for controlled exchange of metabolites via diffusion and transcytosis only
/muscle CT ,
Describe fenestrations capillary structure , function and where found
- sieve like structure on cells covered by thing glycoprotein coat
- allow more extensive exchange
- Basement membrane continuous
-kidney
Describe sinusoid capillary structure , function and where found
- permit maximal exchange
- large gaps on cells and no covering
- irregular cell clefts and discontinuous membrane
- large lumen so slow flow
-bone Marrow
Describe pericytes function , structure , where found and origin
- secrete ecm and BL wc fuses with endothelial
- have contractile apparatus to constrict and modulate flow
- proliferate and diff into vascular components during trauma
- long cyto processes
- surround continuous epi
- mesenchyme origins
Describe structure of post capillary Venule
Venule function
/similar to capillaries but larger lumen and has smooth muscle layers
- return blood to heart
- site of exudate diapedesis
How is muscular veins formed
Describe cell wall and lumen ratio
/joining of post capillary veins and aquire tunica
-large lumen compared to wall
How is blood moved through veins
Where are small and medium veins found
Describe tunice structure of small and medium veins
-smooth muscle Media and external muscle contractions
/parallel to muscular artery
-thin intima and media. Thick adventitia
Describe structure of large veins and where found
/parallel to elastic artery near heart
-thin media and thick adventitia
Which veins have valves. Their structure and function
- large and medium
- thin parallel folds of initima projecting into lumen
- ensure unidirectional flow of blood
Structure and function of lymphatic capillaries
Where isn’t lymphatic system found
/thin walled endothelial which collect excess interstitial fluid from tissue as lymph no blood
-transports of immune cells
-CNS and bone marrow
How is lymphatic vessels collapse prevented
Are tight junctions present
How is the basal membrane like
How does fluid enter lymph system
-anchoring fibrils extend to vessels and to CT
/no tight junction
-discontinuous
-Through diffusion and transcytosis
How are valves formed in lymph system
How is fluid propelled in lymphatic vessels
Tunics structure of lymphatic vessels
-some adjacent endothelial doesn’t have hemidesmosomes joining them to BL and so extend inward forming valves
/external tissue compressions
-no distinguish tunics
Where are lymph nodes found and function
- interposed in path of lymph vessels
- to process lymph by immune cells
What do lymph vessels eventually join into
-2 large trunks thoracic duct and right lymphatic duct
Where do the 2 lymph trunks join blood system
- thoracic at junction of the internal jugular vein with the left subclavian vein
- right lymphatic duct near confluence of right subclavian vein and internal jugular vein
