The Heart and CV system Flashcards
Functions of CV system
- Transport- delivery of O2, hormones and nutrients etc, waste removal
- Maintenance- body temp, pH, vasodilation, baroreceptors (dehydration)
- Protection- wbc delivery
name of two circuits
Systemic and Pulmonary
Pulmonary artery function
deoxygenated blood from heart to lungs
Systemic artery function
oxygenated blood from heart to body
systemic vein function
deoxygenated blood from body to heart
pulmonary vein function
oxygenated blood from lungs to heart
Pulmonary circuit carries blood…
to and from lungs
Systemic circuit carries blood…
to and from rest of the body
Factors influencing heart size
height, weight, age, sex, training status
Right side of heart used by
systemic circuit
pulmonary circuit uses which side of the heart
left side
blood route from S circuit
S circuit- RA, RV, P circuit
blood route from P circuit
P circuit- LA, LV, S circuit
Location of heart
Thoracic cavity anterior mediastinum, posterior to the sternum for protection. Between lungs.
Base of heart location
sits posterior to sternum at level of 3rd costal cartilage. average heart starts at 1st costal cartilage. Centre of base sits left of midline
Apex of heart location
average 5th intercostal space
Pericarditis symptoms
inflammation resulting in increased production of pericardial fluid causing cardiac tamponade
Cardiac Tamponade
restricted movement of heart due to increased fluid in pericardial cavity. Caused by trauma or pericarditis
Right atria receive blood from
S circuit via SVC and IVC
Left atria receive blood from
P circuit via 2 L and 2 R Pulmonary veins
What is special about the openings leading into the atria?
no valves
Characteristics of atria
thin walls, highly expandable
Expandable extension of atria
auricle
Anterior wall and inner auricle of atria contain
pectinate muscles
pectinate muscles
prominent muscular ridges on anterior wall and inner auricle of atria
R ventricle sends blood
P circuit
L ventricle sends blood
S circuit
How does RV differ from LV?
‘Moderator band’ and LV thicker muscular wall
Structural feature of ventricles
trabeculae carnae- series of muscular ridges
Function of moderator band
Delivers stimulus for contraction to pap muscles so can tense chordae tendinae before ventricle contracts.
What is the moderator band
muscular ridge extending horizontal from inferior interventricular septum, connect to anterior papillary muscle.
How does the LV contract?
apex closer to base, diameter decreases for max contraction to open SL valves
Function of septa
separate chambers
Septa of heart
Interatrial septum, interventricular septum
conus arteriosus
Superior R ventricle tapers into cone-shaped pouch which ends at pulmonary SL valve
Valve function
permit blood flow in one direction. Prevent backflow/ regurgitation.
Valve structure
Fold of fibrous tissue (cusps) extending btwn openings.
chordae tendinae
CT fibres that originate at papillary muscles. Free edge of cusps of valves attach to ch.t
Papillary muscles
conical muscular projections arising from inner surface of right ventricle
Function of papillary muscles
prevents inversion of AV valves by pulling closed during contraction
Valves of atria
Atrioventricular (tricuspid and mitral/ bicuspid)
Valves of ventricles
Semilunar (pulmonary and aortic)
Valvular Heart Disease
disfunctional valves following Carditis
Carditis
Inflammation of heart
Causes of Carditis
Strep infection result in rheumatic fever- inflamm autoimmune response
Passage of blood through aorta
Blood from LV through aortic SL valve into ascending aorta
Aortic sinuses
sac-like extension of base of asc aorta, adj to each cusp of valve
sac-like extension of base of asc aorta, adj to each cusp of valve
aortic sinuses
structures of aorta
asc aorta, aortic arch, desc aorta
fibrous band left over from fetal blood vessel once linking P and S circuits
Ligamentum Arteriorum
Ligamentum Arteriorum
fibrous band left over from fetal blood vessel once linking P and S circuits
Superior vena cava
- opens into posterior, superior portion of R atrium
* delivers blood from head, neck, upper limbs, chest
Inferior vena cava
- opens into posterior, inferior portion of R atrium
* blood from trunk, viscera, lower limbs
deep groove marking border of artia and ventricles
coronary sulcus