cardiovascular system

• 1 - a pump
• 2 - delivering Oxygen and Nutrients needed by cells, transporting hormones that help regulate body functions, delivering antibodies and inflammatory cells needed to protect the body and removing waste products from tissues

• Where the heart lies.
• The space between the two pleural cavities that contain the lungs
• AKA: interpleural space

• the outer layer of the heart
• the pericardium consists of 2 layers, 1 - an outer fibrous pericardium and an inner serous pericardium

• outer layer of the pericardium
• made of tough, fibrous connective tissue that protects the heart
• loosly attatches the heart to the diaghrapm

• inner layer of the pericardium
• this layer has 2 layers, 1 - inner visceral layer (epicardium), 2 - outer parietal layer, which lies between the epicardium and the fibrous pericardium

pertaining to the soft internal organs

pertaining to the wall of an organ or a cavity

the largest mass of the heart, thickest layer of heart tissue

a thin memberous lining between the myocardium and the chambers of the heart

• network of blood vessels
• supplying all cells of the body

blood supply that goes to the lungs so the blood can be OXYGENATED AND RID ITSELF OF CO2

• consists of a network of blood vesses
• 1-arteries
• 2-capillaries
• 3-veins

• tube like vessels that carry blood loaded with Oxygen, nutrients, water and elecrolytes (all deliver to cells of the body)
• they leave the cells carrying blood loaded with CO2, waste products, different mix of water and electrolytes

• from the outside -> in
• fibrous pericardium(outer layer of the pericardium, attatches heart to diapragm)
• serous pericardium(inner layer of the pericardium)
• pericardial space(pericardial fluid ->lubricated the heart for better function)
• serous pericardium(visceral layer)
• Myocardium layer (hearts largest mass)
• endocardium (layer of elastic epithelial tissue, lining the myocardium on the inside)

Located in the mediastinum

• cardiac muscle cells
• connected to each other by intecalated disks and desnosomes*allows the cells to work together in conducting electrical impulses and allowing the heart muscle cells to contract and relax together

• 2 atria - closer to the spine
• 2 ventricles - closer to the sternum

• smaller and less muscular
• dividing the atria is a wall of muscle called the INTERATRIAL SEPTUM
• dividing the ventricles is a similar wall called the INTERVENTRICULAR SEPTUM

cords of fibrous tissue that anchor the tips of the flaps of papillary muscles, which are finger like muscular projections of the myocardium into the lumen (interior) of the ventricle

3 flaps; TRICUSPID ->TRI

2 flaps; BICUSPID/MITRAL ->BI

2; control blood flow OUT of the heart

exits the RV, Valve -> Pulmonary Valve

Exits the LV; Valve - > Aortic valve

Ventricles

Atrium

• pumps against more resistance, needs to generate more pressure
• circle like look
• very thick, muscular wall

• Cresent shaped, wraps partially around the LV
• much thinner wall

pumps blood to the PULMONARY CIRCULATION

pumps blood to the SYSTEMIC CIRCULATION

• receives blood from the vein in the abdomen called the CAUDAL VENA CAVA
• receives blood from the head through a vein called the CRANIAL VENA CAVA

• Vena cava
• R Atrium
• Tricuspid Valve
• R Ventricle
• Pulmonary Valve
• Pulmonary Artery
• Pulmonary Circulation
• Pulmonary Vein
• L Artium
• Mirtal Valve/Bicuspid
• L Ventricle
• Aortic Valve
• Aorta
• Systemic Capillaries
• Systemic Veins

modified cardiac muscle cells within the heart muscle that form a network

conduct electrical impulses within cardiac muscle as a part of the cardiac conduction system

• a collection of cells within the R Atrium
• this is where the normal electrical impulses originate
• AKA = the pacemaker
• the cells generate an electrical current = self-excitement
• the cells of the SA node have different "channels" in the cell membrane that transport Sodium, Calcium, Potassium in or out of the cell
• such movements are dependable on the levels of Sodium, Potassium and calcium in the body

• a collection of cells between the Atria and Ventricles
• functions as a gateway through which electrical impulses pass from the Atria to Ventricle

the changes in the electrical current across the SA nodal cell membranes generate an electrical current that then transmitted through artrial muscle fibers

• carry this signal throughout the R and L Atria
• carry the signal to the Atrioventricular (AV) node

• just ventral to the AV node
• cunducts the signal to the Ventricles

contraction phase of the heartbeat

Repolarization

• where the electrolytes differences across the cell membrane return to normal
• during repolarization, the cardiac muscle cells relax, and the chambers enlarge and fill with blood = diastole

• cardiac muscles relax
• chambers of the heart enlarge and fill with blood

affect the ability of the cardiac cells, especially the SA and AV node

blood vessels that carry blood away from the heart towards the cells of the body

• smaller branches off arteries that connect directly to capillaries
• smallest form of artery
• carry blood from the muscular arteries to the capillaries
• lack elastic fibers
• have only a few layers of smooth muscle cells in the tunica media
• the tunica adventita and tunica intima are very thin
• gradually decrease in size as they reach the capillary

• branch out from arterioles
• microscopic vessels that connect to arteries to veins
• allow exchange of gasses, nutrients and waste materials between the blood and the bodys cells
• tiny vessels that form a network to supply blood to the bodys tissues
• very thin walls
• lack tunica adventita and media

• slightly larger than capillaries
• they carry blood from capillaries to veins
• tunica media is thinner
• lumen of the vessel is larger

• blood vessels that carry blood from the bodys cells back to the heart
• tunica media is thinner
• lumen of the vessel is larger
• the venous system can hold more blood that the arterial system (although the pressure is lower)
• pumping action of the skeletal muscle compresses the veins that course through them, helping pump blood out of the veins

• Outer to Inner
• Tunica Adventita (connective tissue)
• Tunica Media (smooth muscle cells)
• Tunica Intima (epithelial cells = endothelium)

• Outer layer of the blood vessel
• composed of connective tissue
• in larger blood vessels, this layer contains small blood vessels that transport oxygen and nutrients to the cells of the vessel walls

• the middle layer of a blood vessel
• composed of smooth muscle cells that control the blood vessels diameter
• may also contain elastic connective tissue

• the inner most layer of a blood vessel
• composed of a thin layer of epithelial cells = endothelium

• carry blood from the heart to the cells of the body
• responsible for establishing the blood pressure within the circulatory systems

• elastic arteries
• muscular arteries

• contain a larger portion of elastic connective tissue within the tunica media
• most of the arteries closer to the heart are elastic (pulmonary, aorta, carotid)
• during SYSTOLE, the blood is pushed against the walls of the arteries, stretching the elastic fibers of the wall
• during DIASTOLE, the blood pressure against the arterial wall decreases and the elastic fibers in the tunica media go back to normal

• branches off the main elastic arteries that carry blood to various regions of the body
• have more muscle that elastic fibers in the tunica media
• more muscle allow finer control of blood vessel diameter

large capillaries located in certain areas of the liver, bone marrow and spleen

• the purpose of the pulmonary circulation is to carry oxygen to the lungs and carry oxygen away from the lungs
• the pulmonary artery brings dirty blood from the RV to the lungs
• capillaries line the walls of alveoli where gas exchange takes place, these capillaries then join together to form the PUKMONARY VENOUS SYSTEM, goes to the pulmonary vein, the pulmonary vein carries clean blood to the LA

carries clean blood to the LA

• take Oxygen and nutrient rich blood from the heart to the cells of the body
• then carry oxygen and nutrient poor blood from the bodys cells to the heart

• the major artery leaving the heart
• largest blood vessel
• travels to the abdomen, ends in the pelvis, branching into several pairs fo arteries called iliac arteries

supply the legs and tail

• first artery to exit the aorta
• supplies blood to the heart and muscle

• branch off the aorta
• give rise to the carotid arteries which supply the blood to the head and neck

supplies blood to the stomach, spleen and liver

Supply blood to the intestines

supply blood to the kidneys

• branch off the iliac arteries
• traval distally along the medial thigh

carry blood from the head to the cranial vena cava, which empties into the RA

carries blood from the organs in the abdomen into the RA

multiple veins from the intestines, joined together to form the Portal Vein

• veins that have joined together from the intestines
• empties into the liver (blood is filtered and detoxified)
• blood from the liver is drained by the hepatic vein which then empites into the caudal vena cava

• blood from the liver is drained by this vein
• empties into the caudal vena cava

• the most important difference between fetal and mature circulation is that the fetal lungs are shrunken, collapsed and empty of air
• *DO NOT FUNCTION*
• the fetus relies on the placenta to act as the site of gas, nutrient and waste product exchange

• umbilical arteries to the placenta, where the fetal blood rids CO2 and wastes
• then picks up oxygen and nutrients

• umbilical vein through the liver and to the RA
• *the vessels to and from the placenta lie within the umbilical cord*
• because the lungs are non functional, the blood is pushed away from the lungs

• an opening in the ineratrial septum that connects the R and L Atrium
• as the RA contracts, part of the blood is pumped into the LA
• so it does not have to travel through the RV and the lungs

• an opening connecting the pulmonary artery and the aorta, so the blood pumped from the RV travels from the pulmonary artery into the aorta
• bypassing the lungs

• patent ductus arteriosus
• a fail in the closing fo the ductus arteriosus
• blood partially shunted away from the lungs (after birth)

• abnormalities in the protal vein
• portal vein doesn't deliver blood to the liver
• instead carries blood from the intestines to the caudal vena cava
• result = inability for the liver to detoxify substances absorbed through the intestines

• composed of
• 1 - fluid = plasma
• 2 - blood cells
• it is a transport medium
• blood provides an environment suitable for the survival of cells
• maintains the proper pH level, if not stable, many proteins can be damages ( >acidic, >alkaline)
• circulation maintains the body temp

made up of water, proteins, electrolyes, minerals, fats, sugar, acids and vitamins

• Erythrocytes = Red blood cells = RBC
• leukocytes = White blood cells = WBC
• thrombocytes = platelets

• liquid portion of the blood
• Depending on the species of the animal and the size of its RBC, plasma accounts for 45%-78% of a blood sample volume
• cats and goats have smaller RBC, hence more plasma
• dogs have larger RBC, hence less plasma
• substances dissolved or suspended in plasma include: albumin, globulins and fibrinogen; O2, CO2 and nitrogen; lipids, amino acids, metabolic wastes and electrolytes (Na, Cl, K, Ca, Magnessium, and bicarbonate)

• plasma with the clotting proteins removed
• still contains all the other proteins found in plasma
• the most important function is the transport of CO2, the wast gas produced by the bodys cells during normal metabolism
• CO2 enters the RBC (via diffusion), the CO2 reacts with a molecule of water to become CARBONIC ACID

carbonic acid breaks down to bicarbonate and a hydrogen ion, which then can diffuse back into plasma

the primary form of transport of CO2 in blood

• are primarily bicarbonate and phosphate
• they neutralize the acid to maintain the proper blood pH

• generated by the beating of the heart and the elasticity of the arteries
• force water out of the blood vessel and into the extracellular fluid or into the body cavities

• generated by the pressure of proteins *ALBUMIN*
• this pressure tends to retain water where theres a higher concentration of protein
• ex: Albumin levels are decreased, the colloidal pressuere are also decreased, and more fluid flows out of the capillary. this tends to excessive fluid building in the tissues = edema
• ex: fluid builds in the body cavitites such as the abdomen or pleural cavity = effusion

• transport oxygen and CO2 in the body
• produced in the bone marrow

• part of the immune system
• produced in the bone marrow

• blood clotting process
• produced in the bone marrow

• cells within the bone marrow
• divide rapidly, repeatedly and constantly
• giving rise to cells that continue dividing and changing until a mature cell of the appropriate type is made
• the mature cell is released

• bioconcave disks
• cell membrane is quite flexible, allowing the RBC to squeeze through narrow capillaries
• the close proximity of the RBC membrane and the capillary endothelium improves gas exchange * decreased the distance across which gases must travel*
• Mature RBC do not have a nucleus
• Immature RBC in the marrow have a nucleus

• transport gases throughout the body
• O2 is carried from the lungs to the body
• CO2 is carried from the cells to the lungs
• RBC contain Hemoglobin

• a protien molecule with an iron molecule in the center
• binds with O2 and CO2 for transport
• is manufactured in the immature RBC(once matured, no nucleus, no enodplasmic reticulum present to manufacture more hemoglobin)

• passes through the capillary adjacent to the alveoli
• O2 diffuses form the air in the alveoli via alveoli wall
• through the capillary wall
• through the RBC wall
• once inside the RBC, the O2 molecule binds to hemoglobin

• the ability of hemoglobin to bind O2 is somewhat dependant on amount of O2, pH levles of blood, level of dissolved CO2 in blood, temp of blood
• when RBC reaches the capillary, O2 is released by the hemoglobin, then diffuses through the RBC membrane, through the capillary wall, then to the tissues

• fragments of cells formed in the bone marrow by budding off the cytoplasm of large cells called MegaKaryocytes
• the sole purpose is to contribute to the clotting process or coagulation ro hemostasis
• they adhere to small tears or leaks within blood vessels

• large amount of platelets
• larger areas of vessel wall damage require the formation of a blood clot or a fibrin plug

a larger and more complicated structure than the platelet plug

compossed of an interwoven mat of platelets, threads of fibrin

a blood protein

• 1st stage = hemostasis = controlling bleeding; stopping blood form leaking our of a vessel
• 2nd stage = involves the interaction of various clotting factors(ie: protiens synthesized in the liver) in the blood to eventually form a fibrin

• all are involved in the immune systems reactions to infection or some other disease that stimulate the immune response
• generally slightly larger than erythrocytes
• all posses a nucleus
• capable of normal protein synthesis

• Granulocytes
• Agranulocytes

• 3 types exist
• neutrophils
• eosinophils
• basophils
• they have granules in their cytoplasm and are named by how these granules stain using standard stains
• these cells are named based on the way the granules within the cytoplasm take up certain stains used to make the cells more visable
• Eosinophiles = red granules
• Basophils = blue granules
• Neutrophils = granules that stain neither blue nor red

• other WBC that don't have granules in their cytoplasm
• Monocytes
• Lymphocytes

• RBC carry O2 from the lungs to the cells and tissues of the body
• Thrombocytes help prevent leaks from damaged vessels
• Leukocytes include Neutrophils, Lymphocytes, monocytes, basophils and eosinophils

• production of all blood cells
• occurs primarilly in the Red Bone Marrow
• Fetal hematopoiesis occurs in the liver and spleen
• Neonatal hematopoiesis occurs in the red bone marrow
• Older animals = some red bone marrow is converted to inactive yellow marrow. yellow is composed of fat cells that have replaced some of the active red marrow
• Mature animals = most red marrow is found in the ends of long bones and in flat bones. *liver and spleen have limited capacity to participate in hematopoiesis*

• pluripotent
• can develop into any one of the blood cells
• depends on chemical or physiological stimuli
• involves numerous cell divisions

production of RBC

• a hormone released from cells in the kidney in response to hypoxia
• triggers stem cells to divide and differentiate
• multiple maturation steps

• approximately 65% water and 35% solid with hemoglobin being the primary solid
• round, anucluear bioconcave disks in most mammals(birds, fishes, amphibians, reptiles have elliptic RBC that are nucleated)
• variable in size
• use plasma glucose for energy

• Composed of heme and globin
• Heme = is the pigment portion that is produced in the mitochondria, contains iron atoms(fe++), every heme group can carry one molecule of O2, four heme groups attatch to each globin molecule
• Globin = is the protein portion, produced by ribosomes

• HbE (Embryonic Hemoglobin)=found in developing fetuses
• HbF(fetal Hemoglobin)=found in fetal blood during mid to late gestation and up to a couple of months post birth
• HB(adult hemoglobin)=found in RBC of all animals beginning a couple of weeks to a couple of months post birth

• hemoglobin that is carrying O2
• *one O2 molecule is associated with each iron (Fe++) molecule

hemoglobin that has released its oxygen

• CO2 diffused into RBC and is transported into carbonic acid
• it then ionizes into hyrogen ions and bicarbonate ions
• H2O + CO2 = H3CO3 = H2 + HCO3
• deoxyhemoglobin accepts the hyrogen ion, bicarbonate diffuses into the plasma

• varies in species
• dogs ~ 110 days
• cats ~ 68 days
• horse and sheep ~ 150 days
• cow ~ 160 days
• mice ~ 20-30 days
• sensescence = process of aging, enzyme activity decreases, cell loses its deformability; becomes rounder;volume decreases

• results in decreased O2 carrying capacity of the blood
• caused by: low number of circulating mature RBC(blood loss, increased RBC destruction, decreased RBC production), insufficient hemoglobin production (ie: iron deficiency)

the heart lies between the 3rd and 7th ribs = cats and dogs, 2nd and 6th in cattle and horses

• Cardiac Rhythm = Lub-Dub
• Lub = S1
• Dub = S2
• S1 = associated with simultaneous closure of the mitral and tricuspid valves at the beginning of Ventricular systole
• Mitral Valve = Left Side
• Tricuspid Valve = Right side
• S2 = associated with the closure of the semilunar (aortic and pulmonary) valves at the beginning of Ventricular diastole.
• Aortic Valve = Left side
• Pulmonary Valve = Left side
• S3 and S4 = larger animals
• S3 = rapid ventricular filling
• S4 = conrtraction of the atria

the amount of blood that leaves the heart...determined by stroke volume and heart rate

the amount of blood ejected with each cardiac contraction

• how often the heart contracts
• CO(cardiac output) = SV(stroke Volume) X HR(heart rate)
• ex: the dog ejects 2ml of blood into the aorta with each Systolic contraction and the HR = 100
• CO=2ml/min(SV)X100 bpm(HR) = 200ml/min
• *larger animals have a larger stroke rate but a decreased heart rate*
• *larger heart to pump to larger areas of tissue*

blood pressure drops due to blood loss

• pressure drops due to the small blood vessels of the organs and tissues all dialate at the same time
• animals in shock tend to have rapid, weak pulses
• Pulses felt because of the pressure differences in blood vessels during systole and diastole

• electrocardiograph
• measures electrical current using metal electrodes attatched to the skin to produce = electrocardiogram = creating a record of depolarization and repolarization

P Wave

• QRS Complex
• ex: if the QRS is longer(takes more time) than normal = may be due to enlargement of the ventricles or poor conduction of the electrical impulses through the Purkinjie fibers in the ventricles
• ex: larger P waves(atrial depolarization) than QRS waves(ventricular depolarization) = suggests that not every electrical impulse generated by the SA node is being sucessfully transmitted through the AV node due to the Ventricle = HEART BLOCK

T Wave

are primarily bicarbonate and phosphate; they neutralize the acid to maintain the proper blood pH

• generated by the beating of the heart and the elasticity of the arteries
• force water out of the blood vessel and into the extracellular fluid or into the body cavities

• generated by the presence of proteins *ALBUMIN*
• this pressure tends to retain water where theres a higher concentration of protein
• ex: albumin level decreases, the colloidal pressure also decreases, and more fluid flows out of the capillary. this tends to excessive fluid building in the tissues = edema or body cavitites such as the abdomen or thorax = effusion