Cardiovascular System Flashcards
blood: general features/ function
specialised ct.
- transport, regulation, protection
- plasma (l) + erthrocytes (RBC) + leukocytes (WBC) + platelets
heart location:
in mediastinum, 2/3 left to midline, btw sternum, verterbral column, 1st rib, diaphragm and lungs
heart surfaces:
- base: posterior surface
- apex: directed anterior/ inferior to the left
- anterior surface: sternum and ribs
- inferior surface: diaphragm
pericardium: features/ function
anchors heart in place, with freedom to move
- fibrous (outer) layer: tough, inelastic, dense irregular ct
pericardial fluid in btw layers
- serous (inner) layer: parietal (outer), visceral (epicardium, inner)
- pericardial cavity filled with pericardial fluid
- reflected at the root of great vessels
heart wall layers:
epicardium: external, thin, visceral layer of serous pericardium
- mesothelium and ct.
myocardium: middle, cardiac muscle (95% of wall), thicker this layer = harder working
endocardium: inner, thin layer
- endothelium and ct.
chambers of the heart:
receiving chambers: (blood into heart)
L/R atrium, with auricles (pouches on anterior surface, increase V)
(blood away from heart)
pumping chambers: L/R ventricles
sulci: (grooves/ channel)
- coronary (atrioventricular) btw atria/ventricles
- anterior/posterior interventricular (btw ventricles)
Right atrium: features/ function
- deoxygenated blood from inferior/ superior vena cava (upper body) and coronary sinus (heart itself)
- posterior wall: smooth
- anterior wall: rough (muscular ridges, musculi pectinati, auricle)
- interatrial septium (btw atria)
- fossa ovalis (remnants from foramen ovale)
- right atrioventricular orifice closed by R atrioventricular valve (tricuspid) -> divides R atria/ventricle
- 3 parts, prevent backflow
Right ventricle: features/ function
- pumps deoxygenated blood to pulmonary trunk (artery), pulmonary (semilunar) valve
- thick outer muscular walls: interventricular septum
- inner wall/surface: muscular ridges- trabecular carne
- cusps of tricuspid valve connected to papillary muscles -> chordae tendineae (open and close valves)
Left atrium: features/ function
received oxygenated blood from four pulmonary veins
- smooth walls
- left atrioventricular orifice (hole) closed by L atrioventricular valve (bicuspid)
Left ventricle: features/ function
- blood passes to ascending aorta-> aortic (seminlunar) valve
- THICKEST wall
- trabeculae carne, papillary muscles, chordae tendineae
- ligamentum arteriosum (from foetal heart: ductus arteriosus) btw pulmonary trunk and aorta
list fibrous skeleton:
dense ct. connected to each other
- pulmonary fibrous ring
- aortic fibrous ring
- R atrioventricular fibrous ring
- L atrioventricular fibrous ring
cardiac conduction system:
systole: contraction
diastole: relaxation
autorhythmic fibres pacemaking, self excitable
- autonomic nervous system/ some hormones can modify timing/ strength of heartbeat
(SA) synoatrial node (near R atrium) –> (AV) atrioventricular node (btw R atrium/ ventricle) –> AV bundle (b. of His) (conduction from atria to ventricles) –> R/L bundle branches (intraventricular septum near apex) –> Purkinje fibres from apex across ventricles
list blood vessel types:
arteries: elastic, muscular, arterioles
capillaries
veins: large, medium, venules
list blood vessel layers:
tunica intima tunica media tunica externa (adventitia)
tunica intima:
innermost layer, thin mesothelium, basement membrane,
- internal elastic lamina (attaches to next layer)
- fenestra: openings for transport (esp. arteries)
tunica media:
middle layer, smooth muscle and elastic tissue (eg. elastic arteries
- external elastic lamina
tunica externa:
adventitia:
- outer layer, ct
- holds blood vessels in place
- vasa vasorum: blood supply for artery wall
- nervi vascularis: autonomic nerves for artery wall
general features of arteries and veins:
- both frequently travel together
- arteries: blood AWAY from heart, round shape, more smooth muscle/ elastic tissue than comparable veins
- veins: blood TOWARDS heart, irregular shape, may have valves, harder to see tunic layers, more veins than arteries (superficial and deep)
joining of blood vessels:
anastomose
elastic arteries: features/ function
conducting, large
- aorta and large branches
- well defined internal/external laminae
- intima relatively thick
- media thick, smooth m. separated by lamellae of elastic tissue
- externa: underdeveloped, thinner than media
muscular artieries: features/ function
distrubuting, medium
- more smooth m. less elastic fibres than elastic a.
- intima: relatively thin, prominent internal elastic lamina
- media: prominent smooth m. thin elastic lamina
- externa: thicker than media
arterioles: features/ function
- intima: unlikely internal elastic lamina
- media: very thin, 1-2 cell layers of smooth m.
- externa: thin, poorly defined ct.
capillaries: features/ function
smallest blood vessel diameter
- anastomose freely, interchange btw blood/tissues
- intima: endothelium and basal lamina, surrounded by pericytes, endothelial cells
continuous or fenestrated/discontinuous
- no media/externa
continuous/ fenestrated endothelium:
continuous capillary (most common) - no fenestrae, pynocytotic vesicle
fenestrated capillary:
- few locations: most endocrine glands, glomeruli in kidney, sinusoids of liver
- large fenestrae in walls, covered by diaphragm (thinner than cell membrane)
venules: features/ function
often with arterioles,
- intima: endothelium, basement membrane, pericytes
- media: from 0-2 layers of smooth muscle
- externa: none to limited loose ct. and elastic fibres
veins: features/ function
larger lumen, thinner walls than arteries
- no external/internal laminae, can’t sustain high pressure
- intima: thinner than arteries, may have valves, ct. rich in elastic fibres covered by endothelium
- media: thinner than arteries, smooth muscle, few elastic fibres/ collagen
- externa: ct. with elastic/ collagen fibres, thicker than media
varicose vein?
damaged tunica, leaking valves which cant close
list aorta parts:
ascending, arch, descending (divides into L/R common iliac) -> thoracic and abdominal
branches: ascending and arch of aorta
ascending (2): R/L coronary arteries (in sulcus)
arch (3):
brachiocephalic trunk–>
- R common carotid (R side of head/ neck)
- R subclavian artery (R upper limb)
- L common carotid artery (L side of head/neck)
- L subclavian artery (L upper limb)
descending branches:
thoracic aorta (7) abdominal aorta (8)
principal veins:
superior vena cava: begins at level of 1st costal cartilage (drains head, neck, chest and upper limbs)
- union of R brachiocephalic
inferior vena cava: 5th lumbar vetebra (drains abdomen, pelvis, lower limbs)
- union of L/R common iliac veins
brain:
internal carotid + vertebral aa. = cerebral arterial circle (circle of Willis)
venus dural sinuses:
- superior sagittal: initial drain of brain/skull blood
- inferior sagittal
- L/R transverse
- L/R sigmoid (internal jugular veins L/R)
upper limb:
subclavian, axillary (armpit), brachial, radial and ulnar
lower limb:
external iliac, femoral, popliteal, anterior/ posterior tibial, fibular
coronary arteries:
supply myocardium: branches of ascending aorta
- L coronary artery: anterior interventricular (ventricle walls), circumflex (L atrium/ventricle)
- R coronary artery: posterior interventricular (ventricle walls), marginal (R ventricle)
coronary veins:
coronary sinus: drains into R atrium
- great cardiac vein (drains into L/R ventricles and L atrium)
- middle cv. L/R ventricles
- small cv. R atrium and ventricle
- anterior cv. R ventricle
