Cardiovascular System Flashcards
functions of cv system
transport - o2, co2, waste, nutrients, hormones
homeostasis - temp, pressure/volume, pH
protection - white bcs
main structures of CV system
blood - fluid connective tissue
heart - muscular organ
blood vessels - arteries (away from heart)
capillaries, (exchange of gases, nutrients. waste between blood and tissues)
veins (towards heart)
what is the pulmonary circuit
deoxy blood to lungs
oxygenated from lungs back to heart
systemic circuit
oxygenated good from left side of heart being pushed out throughout rest of body
coming back from body as deoxy blood to heart
location of heart in body
in mediastinum cavity between lungs anterior to thoracic vertebrae 8
behind lower half of sternum offset to the left
function of pericardium
maintain heart position by being attached to diaphragm and prevent it from overfilling
two layers of pericardium and two layers of the inner layer
inner layer is serous (fluid producing)
outer is fibrous
inner has additional parietal (towards the wall, stuck to fibrous layer) and visceral (towards the organ)
gap between two serous layers is called pericardial cavity and its filled with fluid
3 layers of heart
endocardium - inner smooth layer to minimise friction of blood flow
myocardium - cardiac muscle layer forms majority of heart wall
epicardium - outer layer = visceral pericardium
what separates heart chambers
septa (like septum) wall between chambers
name of inner muscular lining of ventricles vs atrium
trabecular carneae
pectinate muscles
(same structure just different chambers)
what are papillary muscles
ones that outgrow from the inner cardiac wall
and connect to chordae tendineae which connect to valves
two types of valves and purpose of valves
prevent back flow of blood ensure its unidirectional
atrioventricular - mitral and tricuspid
semilunar - pulmonary and aortic
what do chordae tendineae do
prevent the valves from everting backwards
THEY DO NOT OPEN AND CLOSE THE VALVE
what happens during ventricular systole vs diastole
SYSTOLE - ventricles contact, AV valves close, semilunar valves open
DIASTOLE - ventricles relaxed, fill up passively as AV valves are open and semilunar ones are closed
3 stages of cardiac cycle
- atrial systole - atrium contracts to push last quarter of blood volume into ventricles
- ventricular systole - ventricles contract and force AV shut, press built opens semilunar valves, blood is ejected. Lubb (first heart beat) of blood hitting ventricles
- relocation period - all four chambers in diastole, with low pressure in ventricles. blood flows backwards in aorta to fill the heart about 75%, and pulmonary trunk semilunar valve shuts Dubb (second heart beat) of blood flowing from atria to ventricles and passively filling and hitting the AV
what is autorhythmicity
ability of heart to make itself beat
what structures allow autorhythmicity
though clusters of specialised cardiac muscle cells that can make themselves contract
location of specialised cardiac muscle cell clusters in right atrium
sinoatrial node towards opening of superior vena cava (natural pacemaker- since it beats the fastest) 60 X min
more towards inferior vena cava is AV (atrioventricular) node at 40x min contraction
what stops ventricles from contracting at same time as atrium
AV node delays impulse being sent to ventricles
eventually travels to AV bundle and split into interventricluar septum where one travels to left and other to right ventricle
connect to purkinje (large specialised cardiac muscle cells) fibres in apex
which make ventricle cells all contract at sam time
anatomical similarities between arteries and veins
hint layers
3 layers - tunica externa (outermost), tunica media and intima
anatomical differences between arteries and veins
arteries have thicker tunica media (more muscle in walls) and smaller lumen (opening through which blood flows)
veins have thicker tunica externa and are flatter. have a larger lumen
some small and medium veins have valves in systemic circuit
difference between arteries/veins and capillaries
capillaries don’t have outer layers only have tunica intima (allows them to be permeable for gas exchange)
basement membrane and inner endothelial cells
which circuit is low and which high pressure and why
pulmonary low due to delicate avioli
systemic high pressure to reach whole body
four regions of aorta and corresponding names
ascending aorta, arctic arch, descended thoracic aorta, descending abdominal aorta
what are the only branches of the AORTA
2 coronary arteries branch off at base of aorta (due to this location that’s close to the aortic semilunar valve (just above it) when there is aortic back flow of blood it goes into these arteries
to supply actual HEART with blood
what are the branches of the AORTIC ARCH
3 arteries - brachiocephalic trunk - branches into right common carotid artery & right subclavian arteries. Supplies upper limbs, head and neck
left common carotid artery - also head and neck
left subclavian artery - left upper limb
branches of thoracic aorta
small branches that supply organs within thoracic region eg.
pericardium
lungs and bronchi
oesophagus
NOT THE HEART - 2 coronary arteries supply it
branches of abdominal aorta
3 paired supply two organs -
Renal - kidneys,
Suprarenal - adrenal glands
Gonadal - testes & ovaries
3 unpaired supply gastrointestinal tract and spleen -
celiac trunk that splits into
superior and inferior mesenteric arteries
abdominal aorta end by dividing into 2 common iliac arteries, which further divide at L5 and S1 into
internal iliac arteries - pelvic organs and perineum
external IA - lower limbs
exception of vein names
deep veins accompany arteries and share their name
exceptions are deep - external and internal jugular vein (left and right brachiocephalic ins formed by joining of subclavian, external and internal jugular veins) these join to form superior vena cava
superficial are usually exceptions - cephalic and basilic at bend hind elbow both join into auxiliary vein (brachial plexus)
Great (inner thigh from ground to foot) saphenous and small saphenous (back of knee to foot on posterior leg)
what veins drain what parts of the body
superior vena cave - above diaphragm
inferior - below
coronary sinus - heart
what is a portal system and an example one
where blood goes form one capillary system to another
eg. hepatic portal system - its veins carry deoxy blood from GI tract and spleen to the liver before it returns to heart via the inferior VC
three parts - capillaries of GI organs, hepatic portal vein and sinusoids of liver (store/convert/excrete)
the liver has two blood supplies
and the artery version of this system is called hepatic artery proper
function of lymphatic system in relation to cardiovascular
return excess interstitial fluid from capillary beds to circulation
transport dietary lipids and lipid soluble vitamins from GI tract to blood
immune system - plays a roles in carrying producing and ageing immune cells
