Topic 12 Cardiovascular system Flashcards
Cardiovascular system is composed of? And what does it do?
Composed of the hear, blood vessels and blood
it transports and protects
Transports gases, nutrients, hormones, wastes and heat
proection from diseases, and fluid loss (clotting)
Describe the position of the heart in the thoracic cavity
The heart is in the area called the mediastinum which is the region between the lungs in the thoracic cavity
Mediastinum
region between lungs in the thoracic cavity/cage
this is where the heart is located
What is the coverings of the heart
coverings = pericardium
- double walled sac surrounding the heart and it has 3 layers
- a) fibrous pericardium
- b) serous pericardium
- 2 parts: parietal and visceral pericardium
- between seroud pericardial layers = pericardial cavity with serous fluid (lubricates)
identify and describe the location and structutre of the fibrous pericardium
Fibrous pericardium = wall of cavity
- outer most layer = dense irregular CT
- anchors to surrounding structures, e.g diaphragm, great vessels (aorta, vena cava etc)
identify and describe the location and structure of Parietal and visceral layers of serous pericardium
Parietal pericardium is fused to fibrous pericardium found in the serous pericardium (a layer of the heart)
- therefore fibrous + parietal pericardium = pericardial sac
**Visceral pericardium (or epicardium) **is fused to the heart surface = part of heart wall
- in the serous pericardium (a layer of the heart)
Identify and describe the location of the pericardial sac
fibrous + parietal pericardium = pericardial sac found in the serous pericardium
Idenfity and describe the location of the serous fluid and percardial cavity
Serous fluid helps with lubrication (so the walls dont stick) in the pericardial cavity between serous pericardial layers
Describe each layer of the heart wall
The heart wal has 3 parts
Epicardium
Myocardium
Endocardium
Epicardium
AKA visceral pericardium (fused to heart surface - part of heart wall)
- stratified squamous epithelium + CT (areolar)
Myocardium
Cardiac muscle
- arranged in spiral or circular patter, reinforced with CT (areolar)
Endocardium
Simple squamous epithelium + CT (areolar)
- epithelium named** endothelium **
- lines inner surface of heart and ALL blood vessles
Endothelium
The epithelium of the heart wall, Endocardium which is accompanied by Areolar CT
On the external surface of the heart, identify the 4 chambers, the anterior interventricular sulcus and the posterior interventricular sulcus
4 Chambers and assosciated blood vessels
1) right atrium
- inferior and superior vena cava
- coronary sinus (posterior)
2) left atrium
- 4 pulmonary veins
3) right ventricle
- pulmonary trunk - which then divides to form 2 pulmonary arteries
4) left ventricle
- aorta
Right atrium
inferior and superior vena cava
from upper and lower parts of body (abdominal)
coronary sinus (posterior) enlarged vein
coronary sinus
is an enlarged vein
apart of the right atrium and is posterior
left atrium contains
4 pulmonary veins
Right ventricle contains
pulmonary trunk which divides to form 2 pulmonary arteries (to rest of body)
Left ventricle contains
goes to lungs
contains the aorta
Arteries carry..?
carry blood away from the heart
veins carry..?
carry blood toward heart
What is the septa
it seperates chambers
2 types
Interatrial Septum and Interventricular septum (Interventricular sulcus)
Interatrial septum
seperates atria
Interventricular septum
Seperates ventricles
it is deep to interventricular sulcus (external), a shallow groove
interventricular sulcus
the interventricular septum is deep to the interventricular sulcus (external)
The interventricular sulcus is a shallow groove on the anterior surface of the heart
- marks the external boundary between the right and left ventricles on the anterior aspect of the heart
Sulcus
shallow groove
Identify and describe the structure and function of the primary internal strucutres of the heart including chambers, septa, valves, papillary muscles, chordae tendineae, fibrous skeleton, and venous and arterial openings
function of the chambers:
4 chambers (internal strucutres of the heart)
- 2 atriums bring blood to heart from blood vessels or veins
- 2 ventricles pump the blood from heart into arteries
Function of septa:
seperate chambers of the heart
1) interatrial septum: seperate atriums
2) interventricular septum: seperate ventricles
- the interventricular septum is deep to the interventricular suclus (shallow groove) on the anterior surface of the heart - marks external boundary between right and left ventricle
Function of valves:
includes atrioventricular valves and semilunar valves
1) atrioventricular (AV valves) invlude
- 1) biscuspid (mitral)
- left side, 2 cusps
- 2) tricuspid
- right side, 3 cusps (“its always right to tri!”)
- Chordae tendineae (CT) - attach AV valve cusps to papillary muscles (projections of the myocardium), prevent eversion of cusps (so cusps dont go into the wrong direction
2) semilunar valves (3 cusps each)
- 1) aortic - seperates left ventricle and aorta
- 2) pulmonary - seperates right ventricle and pulmonary trunk
Fibrous skeleton
contains CT fibres around muscle fibres + CT rings between atria and ventricles at the coronary sulcus (shallow groove)
- allow openings to remain open at all times (valves open and close)
- prvides electical insulation - prevents simultaneous contraction of atria and ventricles (makes sure theyre coordinated)
Fibrous skeleton contains
Connective tissue fibres that surround muscle fibres and Connective tissue rings between artia and ventricles at the coronary sulcus (shallow groove)
- allows opening to remain open at all times (valves open and close)
- provide electival insulation - prevents simultaneous contraction of the atria and ventricles
Differentiate the valves of the heart
Atrioventricular (AV) valves and semilunar valves
1) Atrioventricular valves
- 1) bicuspid (mitral): left side, 2 cusps
- 2) tricuspid: right side, 3 cusps
- Chordae tendineae (CT) - attach AV valve cusps to papillary muscles (projections of myocardium - part of heart wall; cardiac muscle), prevent eversion of cusps (so valve doesnt go in the wrong direction)
2) Semilunar valves
- 3 cusps each
- 1) aortic - seperates left ventricle and aorta
- 2) pulmonary - seperates right ventricle and pulmonary
DONT HAVE chordiae Tendineae
Chordae tendineae
CT which attach Atrioventricular valves (av) to papillary muscles (projections into the myocardium, cardiac muscle)
- prevent eversion of cusps
NOT IN SEMILUNAR VALVES
Papillary muscles
are projections of myocardium (cardiac muscle)
- the chordae tendineae attaches Av valve cusps to papillary muscles which prevents eversion of cusps
Atrioventricular valves
Has two types
Bicuspid and tricuspid
1) bicuspid: 2 valves, left side
2) tricuspid 3 valves, right side
Has Chordae Tendineae (CT) - attaches AV valve cusps to papillary muscles (projections of myocardium; cardiac muscle)
- prevents the eversion of cusps
Semilunar valves
Have 3 cusps each
two types
aortic and pulmonary
1) Aortic seperates left ventricle and aorta
2) Pulmonary seperates right ventricle and pulmonary trunks
Describe the properties of cardiac muscle fibres and compare their structure to that of skeletal muscle fibres
Forms BOTH contractile myocardium and conduction system
**Cardiac muscle cells **
modified/specialized conduction system
- generates electrical signals
- conduction of those signals
“normal” = myocardium
- contraction
Similarities to skeletal muscle
1) striated (myofibrils and sarcomeres)
2) has sarcoplasmic reticulum and T tubules
Differences:
1. Branched
2. uninucleated
3. intercalated discs = region where two fibres meet
- contain anchoring and gap junctions
What do cardiac muscle cells contain
cardiac muscle cells are a modified/specialized = conduction system
- generates electrical signals
- conduction of those signals
“Normal” = myocardium (what pumps blood)
- contraction
They are branched, uninucleated and have intercalated discs with anchoring and gap junctions
- also have striated (myofibrils and sarcomeres) (same as skeletal muscle fibres)
- sarcoplasmic reticiular and T tubule (same as skeletal muscle fibres)
Similarites of skeletal muscle to Cardiac muscle cells
- striated (myofibrils and sarcomeres)
- has sarcoplasmis reticulum and T tubules
Differences of skeletal muscle to cardiac muscle cells
- Branched
- uninucleated
- intercalated discs = region where two fibres meet
- contain anchoring and gap junctions
descibe the components of the cardiac conduction system
CARDIAC MUSCLE CELLS - modified to produc and conduct electrical impulses
- DO NOT CONTRACT
Components
sinoatrial (SA) node
- in right atrium at base of superior vena cava
- generates impulses the fastest
Atrioventricular (AV) node
- based of right atrium
Artioventricular (AV) bundle (bundle of His)
- superior part of interventricular septum
- electricallt connects atria to ventricles
AV bundle branches
- go to each ventricle
Purkinje fibres
- terminal fibres
- in ventricles only
NOTE: electical signal spreads from donuction system to contracile cardiac cells when they contract (signal saying go ahead and contract!)
Sinoatrial (SA) node
in the right atrium at the base of the superior vena cava
- generates impulses the fastest (sets pace)
Atrioventricular (AV) node
Base of right atrium
Atrioventricular bundle
“bundle of his”
superior part of the interventricular septum (seperates ventricles)
- electrivally connects atria to ventricles
AV bundle branches
Go to each ventricle
Purkinje Fibres
Terminal fibres (end of the conduction system
LOCATED IN VENTRICLES ONLY
Define closed, double circulation
Closed, double circulation
- closed = blood confined to heart and blood vessules
- double = 2 routes (pulmonary (lungs) and systemic (all other organs))
Describe the adult pulmonary and systemic circulations
Pulmonary circulation (lungs)
- right ventricle to lings via pulmonary arteries (deoxygenated blood)
- pick up ozygen in lungs at capillaries
- lungs to left atrium vis pulmonary veins (oxygenated blood)
simplified
Right ventricle
pulm. ateries (deoxy blood)
capillaries in respiratory portion of lungs
Pulmonary veins (oxy blood)
left atrium
Systemic circulation (all other organs)
left ventricle to organs via aorta (oxygenated)
- organs remove oxygen at capillaries
- organs to right atrium via. superior and inferior vena cava (deoxygenated)
OVERALL ROUTE: left ventricle to right atrium = systemic circulation
simplified
left ventricle
aorta (to organs) - oxygenated
organs removed oxygen at capillaries
organs to superior and inferior vena cava
right atrium (deoxygenated)
Subdivisions/subroutes of systemic circulation
- cerebral = brain
- hepatic = liver
- coronary = heart
Subdivisions/subroutes of systemic circulation
cerebral = brain
hepatic = liver
coronary = heart
Identify the major arteries and veins of the systemic circulation
Major arteries:
Aorta (left ventricle) (oxy)
Veins:
Capillaries of upper and lower regions of body
Superior and inferior vena cava (deoxy)
Describe the blood flow to and from the heart wall (coronary circulation)
Include origin of:
* left and right coronary arteries
* left coronary artery and its major branches
* right coronary artery and its major branches
* cardiac veins
* coronary sinus
Coronary circulation is systemic
origin of left and right coronary arteries: Left ventricle -> Aorta
left coronary artery
2 Major branches
Right marinal artery
posterior interventricular artery
Right coronary artery
2 Major branches
Circumflex artery
Anterior interventricular artery
Next is vessels after arteries
Major branches from left and right coronary arteries go into arterioles (not the same arterioles)
Capillaries in myocardicum then
Venules (small veins)
Cardiac veins
Coronary sinus (a blood vessel) Large vein - right atrium
Lastly, Right atrium
Identify the major arteries and veins of the pulmonary circulation
Major arteries
(right ventricle) Pulmonary arteries
Major veins
Pulmonary veins (left atrium)
Describe fetal circulation
fetus gets O2, nutrients from and expels wastes from mothers blood at the placenta which is the site of exhchange (the blood supply of the fetus is close but not mixed with the mothers blood)
Describe the role of the placenta in fetal circulation
The exchange site of O2, nutrients from and expellation of wastes from mothers blood
- blood supplies is close together but don’t mix together because the baby is genetically different from the mom and it can kill the baby
Describe the role of umbilical vessels in fetal circulation
They go towards the fetals heart
- carries oxygenated blood from placenta to vena cava
Describe the role of umbilical arteries in fetal circulation
They go away from the fetals heart
- carries mixed blood (oxy and deoxy) from the heart to the placenta
What are the differences from adult cirulation
Fetus has umbilical veins
lungs and liver are basically non-functional
(3 shunts to bypass the liver and lungs: ductus venosus, foramen ovale, ductus arteriosus)
fetus has umbilical arteries
Describe the role of ductus venosus in fetal circulation
Since the lungs and liver are basically non-functional there are 3 shunts to bypass (although some blood flows to these organs for nourishment/growth)
connects umbilical vein (oxy. blood) to inferior vena cava (deoxyblood) to bypass liver
- permits most of the oxygenated blood coming from the placenta to bypass the liver
- in vena cava, oxy and deoxy blood mixes
- mixed blood enters fetal heart via. inferior vena cava
Where is mixed blood found
Vena cava - oxy and deoxy blood mixes
- entering fetal heart (inferior vena cava)
And in the Umbilical arteries where mixed blood is carried to the fetals heart
Describe the role of foramen ovale in fetal circulation
hole in the interatrial septum (seperates both atriums)
- allows blood top move from right to left atrium (bypasses lungs)
Describe the role of ductus arteriosus in fetal circulation
Since the lungs and liver are basically non-functional there are 3 shunts to bypass (although some blood flows to these organs for nourishment/growth)
Connects pulm tunk and aorta (bypass lungs)
Trace the pathway of blood flow from the palcenta through the fetal heart and body and back to the placenta
The placenta is the sight of exchange where the fetus gets O2, nutrients and expels wastes to mothers blood
- however, the blood supplies are close together not mixed if mixed then the baby could die
The **umbilcal vein **has oxygenated blood from the placenta to the vena cava
The ductus venosus **connects the umbilical vein (oxy blood) to the inferior vena cava (deoxy blood) to bypass the liver
- blood mixes in the vena cava
- mixed blood enters the fetals heart via. inferior vena cava
**The foramen ovale **creates a hole in the interatrial septum - allows blood to pass from right atrium to left atrium
- bypasses lungs
The ductus arteriosus then connects the pulmonary trunk and aorta* (bypass lungs)*
Thereon the **umbilical arteries ** go away from the fetuses heart and returns mixed blood to the placenta
List the three tunics associated with blood vessel walls and describe the composition of each tunic
Three tunica for the general structure of blood vessels (except capillaries)
1) tunica externa (CT)
2) Tunica media
3) Tunica interna (=intima)
- endothelium - simple squamous epithelium
4) lumen - contains blood (not a layer! its a space(
Tunica externa
General strucutre of blood vessels
connective tissue
Tunia media
General strucutre of blood vessels
- middle layer
- smooth muscle
- elastic fibres
Tunia interna
General structure of blood vessels
= intima
endothelium - simple squamous epithelium
Lumen
General structure of blood vessels
contains blood (not a layer!)
Define the terms arteries and veins
Arterties carry blood away from heart (does NOT refer to oxy or deoxy)
- 2 types:
- 1) elastic
- elastic CT in all 3 tunics
- largest arteries (near heart)
- e.g aorta
- 2) Muscular: a lot of smooth muscle
- most arteries
- e.g coronary artery
Veins: contain large lumen
- valves prevent backflow of blood
- thin media - less smooth muscle, can collapse
Arteries
Move blood away from heart (does NOT refer to oxy or deoxy)
2 types elastic and muscular
1) elastic
- Elastic CT
- largest arteries near heart
2) Muscular
- a LOT of smooth CT
- most arteries
- e.g coronary arteries
Arterioles
little arteries
regulate blood flow and blood pressure
What do Capillaries contain?
ONLY IN tunica interna = endothelium (one cell layer) and basement membrane
- allows exchnage of gases and nutrients
- gaps allow limited fluid and solutes to leak out forming interstitial fluid (ISf)
- capillaries unite to form venules
Capillaries contain gaps that form?
gaps allow limited fluid and solutes to leak out forming interstital fluid
Capillaries unite to form..
venules
Venules
Interna, thin media, thin externa, bring blood toward heart
- goes into larger vessels (veins)
Describe the order of blood vessels (elastic arteries to veins) through which blood flows in the circulation
From heart and back to heart:
heart
Arteries
Elastic
Muscular
arterioles
capillaries
venules
veins
heart
Characteristics of blood
Blood is a connective tissue
characteristics
- higher viscosity than H2O
- 37 degrees
- PH 7.35-7.45
- 4-6 L in adults
Describe the general composition of blood
Plasma (matrix)
- fluid portion with solutes
Formed elements
- cellular portion
Describe the composition of plasma
Plasma is the matrix
= blood minus formed elements
Composed of H2O - 90%
proteins - 8%
- albumins
- fibrinogen
- globulins
- control tissue water valance
- clot foration
- antibodies
Other solutes
- nutrients
- hormones
- wastes
- electrolytes (ions)
- gases
Describe the morphological features and general functions of the formed elements
Formed elements contain RBC, WBC and Platelets
1) RBC erythrocytes
- hematocrit = % of blood volumne thats RBC (approx. 45%)
- biconcave disc shape
- anucleate when mature (indentation where the nucleus was)
- life span approx. 120 days
- destroyed in the liver and spleen
CONTAIN: hemoglobin - pigment protein
**2) WBC (leukocytes) **
- nucleated
- life span varies - days to years
- defend against disease
- 2 types:
- granulocytes (neutrophils, eosinophils and basophils) and agranulocytes/agranular leukocytes (lymphocytes and monocytes)
**3) Platelets **
- fragments of red bone marrow cells called, **megakaryocytes **
- involved in clotting (attract and stick together)
- life span is 2-10 days (constantly producing)
Megakaryocytes
A part of platelets which are fragments of red bone marrow cells
Define Hematocrit
= % of blood volumne that is RBC (45%)
Describe the structure and function of hemoglobin and its breakdown products
RBC CONTAIN: hemoglobin - pigment protein
1) heme = red pigment - contains iron (Fe)
- attaches and transports O2
2) globin - protein
- attaches and transports CO2
Hemoglobin is broken down to heme and globin
- heme is further broken down to bilirubin
- Fe^2 is recycled or stored (toxic, so always bound to a protein)
- globin to amino acids
List the 5 leukocytes in order fo their relative prevalence and describe their major functions
Granulocytes (granular leukocytes)
1. Neutrophils (≈60%): phagocytic (engulf and digest bacteria)
2. Eosinophils (≈3%): attack parasites (e.g worms)
3. Basophils (≈1%) release histamine (increase inflammation) and heparin (decrease local clotting)
Agranulocytes (Agranular leukocytes)
4. Lymphocytes (T and B lymphocytes) (≈35%): immunity
- 1) T lymphocytes - kill infected/disease cells directly
- 2) B lymphocytes - become plasma cells -> produce antioties
5. Monocytes (≈5%): enter tissue and enlarge to become macrophases (phagocytes -“big eaters”)
Describe hemopoeisis and where it takes place
Formation of blood cells
- ALL BLOOD CELLS arise indirectly from hemocytoblast (stem cells) in red bone marrow
Red bone marrow in an adult is located in
- axial skeleton
- pelvic and pectoral girdles
- proximal ends of humerus and femur
whereas in a child they have ALL red bone marrow
Where is red bone marrow located in an adult and child
Axial skeleton
pelvic and pectoral girdles
proximal ends of humerus and femur
a child has all red bone marrow
