cardiovascular and lymphatic system

function of cardio vas system

• provides every cell in the body with necessary nutrients and gases

• remves harmful waste produts of metabolism

• protects the body via lymphatic system

artery

carries blood away form the heart

vein

carries blood to the heart

cappilary

smalled vessel site for exchange

right side circulation

heart recieves d o2 blood from the boyd and pumps it into the lungs were co2 is removed and oxygen is added ( pulmonary circut

left side circulation

heart recieves oxygenated blood from the lungs and pumps it out to the body

systemic circut

pericardial cavity

where the heart is located

pericardium

double walled sac

fibrous pericardium

outer walla loos fitting layer of dense ct

protects and anchors the heart

prevents the over filling of blood

serous pericardium

inner layer

epicardium

superficial visceral pericardium

myocardium

middle layer made of muscle and ct fibers

endo Cardium

deepest layer of endothelium and ct help the hearts electrical system

chordae tendinea

prevent the valaves from inverting during ventricular contraction

superior vena cava

returns de oxygenated blood form the body regions superior to the diaphragm and empties into the right atrium

inferiror vena cava

returns deoxygenated blood from body region inferior to the diaphagram and empties into the right atrium

blood circulation

svc/ivc- ra- tricuspid valave- right ventricle- pulmonary valve- lung- left atrium- bicuspid valave- left ventricle- aiortic semilunar valave- aorta- the rest of the body

3 circuts that blood flows through the body

1. pulmonary circut

2. systemic

3. coronary- supplies the heart

functions of blood

• transport

• homeostasis

• protection

transport

• delivery of oxygen and nutrients to the body for energy ise

• transport of metabloc waste to lungs and kidney

• transport of hormones from glands to target cells

homeostasis

body temperature

ph

fluid volume in cirulatory system

protection

• against infection via immune cells wbc

• against blood loss- blood clotting

matrix

• fluid matrix 90 percent water called plasma

• before centrifugation plasma is found on top

• cotains dissolved solutes- nutrients, gases, hormones, waste ion and plama proteins

• plasma protein play a key role in helping the blood carry out its functions

albumin

most abundant plasma protein

important buffer maintians blood ph

main contributer is osmotic pressure

osmotic pressure

pressure created by a solute in the blood

movement of msterial in and out of bv depends on water movement

maintain constant blood volume

prevents fluid leaking out

alpha and beta globuins

transport protein

gamma globulins

antibodies defense agaisnt invaders

fibrinogen

critical in forming the blood clot to prevent blood loss

rbc- erythrocytes

• most abdundant formed element

• bi concave shape

• no nucleus

• hemoglobin

• gives rbc its o2 and co2 carrying ability

wbs- leukocytes

granulocytes- neutrophol, eosinophill, basophill

agranulocytes- lymphocytes and monocytes

platelets- thrombocytes

critical role in hemostasis clotting

vascular phase of hemostasis

• injury to vessel wall invloves injury to the cells of the vessel wall

• injured cells release chemical factors causing contraction in the smooth muscle layer of the blood vessel

platelt phase- homeostasis

• chemical factors released also serve as a beacon for platelets

• platelets attracted to the chemicals start to gather at injury sits

• clump together

• make the platelet plug

coagulation phase

• reinforcement of the platelet plug with fibrin threads

• complex phase involiving 13 plama proteins- clotting factors

• end result is a blood clot that seals off the bessela nd allows for tissue repair to occur

hematopoeisis

• formation of the blood cells of the blood

• beings 3rd weel fo gestation with the migration of mesenchymal cells to the embryonic yolk sac

• differentiate into hemocyto blast

cardiac cycle

repeating pattern of contraction and relaxation

allowing chambers to fill and empty of blood

as chamber fill pressure rises volume decreases

as chamber empties presser decreases and volume increases

1. atrial systole

• in the beginning o the cardiac cycle all 4 chamberd are in diastole ventricles are 80 percent full

• as the atria contract pressure increases this empties all of the blood into the ventricles

2. atrial diastole

relaxation

pressure in atria falls

vemtric;es are full of blood which is the end of diastole volume

pressure in ventricles is rising

3. ventricular systole esrly

• ventricles begin to contract causing pressure to rise faster

• papillary muscles tug on chordae tendinaa causing av valves to snap shut= first lub sound

• pressure is not high enough to opem semi lunar valave so there is no chage in volume of the blood = isovolumetric contaction phase

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4. ventricle systole late

• main squeeze of complete ventricular contraction pressure is high

• open semilunar valves

• blood is ejected

• stroke volume- amount of blood that the heart pumps with every beat

5. ventricular diastole, early

• some blood remaining in the ventricles- end systolic volume

• pressire inside the ventricles falls rapidly, pressure in ventricle is lower than the pressure in the aorta/pulomnary trunk semi lunar valaves shut, causes second sound dub

• this is calles isovolumetric relaxation

• pressire in the atria has been falling all along when it gets below the pressure in the vena cava the atria begin to fill

6. ventricular diastole, late

• as the atria fills with blood, pressure inside the atria rises, av valves can open so the ventricles can being filling again

pacemaker cells

responsible for generating the electrical stimulus/ impulse to contract

• sa and av

contractile cells

responsible for spreading the electrical signal to the rest of the cardiac muscle fibers

contaction of skeletal miscles

• influx of NA+ causes depolarization in the sarcolema

• stimulus travels along sarcolemma and down t tubules

• triggers CA++ release from SR

• leads to the sliding of actin over myosin

cardiac twitch

AP in a cardiac pacemaker cell

pacemaker cells have different ion channels than other fibers

• no fast voltage gated NA++ channels only slow

• have voltage hated CA++ in the sarcolemma

1. pacemaker potential

slow depolarization opening of na++ chanells and closing of K chanells

2. depolarization

pacemaker potential reaches threshold depolarization due to CA++ through calcium chanells

3. repolarization

calcium inactivating and K channels opeing brings back to (-) voltage

contractile cells

have normal ion channels and have a sloe voltaged gated CA++ channels in the sarcolemma

depolarization of an adjacent muscle fiber causes that fast VG NA++ chanels to open close wuickly

VG K+ channels open slight repolarization

then the SVG CA++ channels open

extends the depolarization producing plateu

as long as Ca is entering cells continue to contract

svg CA channels close, repolarization

end diastolic volume

amount of blood in ventricle before ventricular systol end of diastole

end systolic volume

amount of blood in the ventricle after ventricular systole

stroke volume

the amount of blood that has left the heart per beat

sv= edv-esv

cardiac output

how efficient the heart is working to measure the amount of blood ejected by the heart in one minuete

CO= SVx heart rate

ANS regulation

parasympathetic- decreases HR, vagus nerve, cuases hyperpolarization by not opening NA and CA gates

sympathetic-increases HR, cardiac nerve, opens gate sooner, quicker repolarization, depolarization

reflex regulation

automatic response

brainbridge reflex (atrial reflex)- stimulus is the amount of blood returning to RA

mechanoreceptors are stimulated when to much blood returns

send signal to medulla oblongada

sends back to activate cardiac nerve to increase HR

reflux regulation

chemoreceptor reflex

monitor concentration of o2 and co2 in blood, ph

in the aortic and cartoid bodies

activated by- hypoxia, hypercapnia and changes in ph

3 ways to regulate stroke volume

preload, contractility, after load

preload

how much the heart muscle is stretched before contraction ( diastole)

due to EDV

amount of blood that is being recieved

as the ventricles fill with blood they will stretch

more stretch= more blood= more blood pumpled

contractility

fore of the hearts contraction during systole

after load

pressure that ventricles must over come to pump blood into pulmonary trunk and aorta

bp in these trunks remains constant

blood volume

• amount of solutes+ amount of water

• controlled by capillary exchange

capillary exchange

• process by which substances move from capillary into tissue and tissue into capillary

• capillaries are permeable to water

• substances must be dissolved in water to be able to move through

movement water

is what allows the exchange of blood gases, nutrients and waste between capillaries and body tissues

blood pressure

• hydrostatic pressure

• pressure created by the blood volume and the heart beat

• forces water out of the vessel

osmotic pressure

pressure created by the amount of solutes in the blood

pulls water into the vessel

capillary exchange

• bp is highest at the arterial end at 35mmhg, drops across capilary bed to 18mmhg

• op is constant 25mmhg

• where bp is higher movement of water out

• were op is higher movement of water in

dynamic center

the point in which bp and op are equeal

always shfted ot the right the venous end

blood pressure

force exerted on the blood vessel wall by the blood inside the vessel

Mean arterial pressure (MAP)

MAP= DP+ 1/3(SP-DP)

average arterial pressure during a single cardiac cycle

pulse pressure

SP-DP= PP

blood volume regulation

mainted by: capilary exchange in tissues

lymphatic system

kidneys

kidney function

resivoir, makes urine, filters through glomerus

returns good stuff into blood and holds onto excess water

hormones and body condition tell the kidney if it needs to make any adjustments

kidney can adjust water in accordance

antidiuretic hormone ADH

secretion is stumalted by an increase in plasma osmolarity solute in the blood

bp is detecte dby osmoreceptors in the hypthalamus

ht signal the pituitary gland to secrete adh

travel to thirst centers or travel to kidney increase bp and bv

aldosterone RAA

activated by : decrease in bp, detected by baroreceptors

decrease in sodium concentration detected by chemorecepors tells juxtaglomuar cells in kidney to secrete renin

angiotensinogen

renin acting on a plasma protein

angiotensein 2 effects

• activates thirst centers

• casuses vasocontraction

• enchances adh secretion

• travels to a gland on top of the kidneys

• adreal gland - secretes aldosterone

• tells the kidney to increase na resorbtion in blood

• na=h20=bv=bp

atrial natriuretic peptide (ANP)

• secreted in response to an increase in the amount of blood returning to the RA

• secreted by cells in the RA

effects of ANP

• causes vasodialation

• travel to the kidney and tells the kidney to excrete NA+

• increase na+ excretion

• water follows na, water loss

continupus capliarries

structure: tightly joined cells, basement membrane completly intact, with a few intercellular clefts

location: muscle, lungs, ct, CNS

Blood brain barrier

fenestrated capillaries

structure: cells that contain many small pores basement is intact

location: found where filtration occurs, kidneys, intestinonal villi, endocrine glands, plexus of the brain

sinusoidal cappilaries

structure: flattened irregular shapes with large gaps no basement membrane

location: massive molecular movement organs like the liver, bone marrow, spleen, anterior pituitary gland

function of the lymphatic system

• maintaining normal bv

• elimination of local variations in the interstitial fluid

• production maintenance and distribution of lymphocytes

• transports fats from the digestive system

lymph vessels

carry fluid from peripheeral tissues to the venous system similar to veins in structure

open ended

lymph is the name of the fluid

1. begins in the peripheal tissues- flow of lymph

fluid not returned to capillaries remains behind in tissue interstitial fluid

2. interstitial fluid drains into lymph capillaries- flow of lymph

• wider than blood capillaries

• endothelial cells overlap, forming mini valaves

• high osmotic pressure inside draws fluid in

3. lymph flows from lymph capillaries into lyphatics ( lyphatic vessels)

• very simialr to veins

• contains valaves

4. lymphatics drains into lymphatic trunks- flow of lymph

5 main lymphatic trunks

lumbar

subclavian

bronchomediastinal

jugular

intestinal

5. lymphatic trunks drain into one of two large collecting ducts

right duct- collects lymph from right side of head, neck , shoulder, arm

drains into the right subclavian vein

thoracic duct- collects lymph from ledt side of the head, neck, soulder, arm, chest, plus abdomen, hips, lower

drains into the left subclavian

lymphocytes

• warriors of the bodies defense system

• two main types b and t cells

• guard, defend, attack destroy

macrophages

eat foreign material

alert t cells

dendritic cells

• capture foreign material alert Tcells

reticular cells

• playa supporting role, create the framework for lymph tissue and organs

lymph tissue

• ct dominaated by lymphocytes

• loose arrangement of cells scattered= diffuse lymphoid tissue

• dense round mass of cells= lympphatic follice (nodule)

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function of lymph tissue and location

• surveillance

• clean up

• produce lymphocytes

• found in respiratoy, digestive, reproductive, and urinary tract

• this is bc the body has openings to the external environment

lymph organs

• differ from lymph tissue in size, structure, and function

• divided into two functional categories