Exam 2 Flashcards
Cardiac muscle doesn’t require a nerve impulse beca
the heart uses an intrinsic method of conduction
Cardiac reserve
amount of extra blood that can be pushed through the heart when we need it to be
Stroke volume
amount of blood pushed out the heart during each beat
Stroke volume
end diastolic- end systolic
Cardiac output
SV x HR
Factors effecting stroke volume
stretch of cardiac muscle
Contraction strength
arterial pressure
Stretch of cardiac muscle
pre load
- the more blood in ventricles, more stretch, and stronger contraction
-causes ejection of more blood
-starling law of heart
Contraction strength
neither pre or post
-muscles can change its permeability to calcium which causes increase in strength of contraction
Arterial pressure
after load
-if there is increased pressure in the vessels, the heart cant’t push blood out because it has to go from high to low pressure
Cardiac output is what kind of variable?
homeostatic
If stroke volume increase, heart rate
slows down
Factors affecting heart rate
Parasympathetic nervous activation
Sympathetic nervous activation
Adrenal Medulla production of norepinephrine
Thyroxine
BP changes
Ionic balances
Age
Sex Exercise
Temperature
Parasympathetic nervous activation
releases acetlycholine, which causes hyperpolarization of the SA node. Makes it harder to create a pacemaker potential. slows it down
Sympathetic Nervous Activation
-releases norepinephrine, which causes the heart rate to increase.
-changes the sa node so it depolarizes faster
-increase in contractibility of the muscle
Adrenal Medulla production of norepinephrine
releases norepinephrine as a hormone
-increase in heart
Thyroxine
-increases cellular metabolic activity
BP changes
-detected by special receptors called baroreceptors
-if BP goes up, less blood can get out of the heart, so the heart needs to speed up
Ionic balances
-speed up or slow down heart rate depending on what we have
Age
-heart rate declines as you age->you wont be able to raise heart rate as high
Sex
females have a faster heart rate than males
Exercise
will go up, but if you continue long term aerobic exercise program, your resting heart rate will decrease
Temperature
heart rate goes up when you have a fever
Vagal escape
when heart starts racing when it shouldn’t be-> issue with vagal tone
Tachycardia
abnormally high resting heart rate >100BPM
Bradycardia
abnormally low resting rate <60BPM
Congestive Heart Failure
anything that causes abnormally low cardiac output
Coronary Atherosclerosis
coronary arteries: clogged from plague deposits
-stroke volume decreases, decreased amount of oxygen delivered to cardiac muscle-> can’t contract like it used to be
High Blood Pressure
Diastolic BP>90
-heart has to contract with greater force to eject the blood, decrease stroke volume and cardiac output
Myocardial Infarctions
Heart attack: oxygen supply to heart is eliminated temporarily-> loses contractibility bc lack of oxygen made it become fibrous connective tissue
-coronary arteries are blocked
Dilated cardiomyopathy
-too much blood in ventricles
-flappy ventricles
**What is the process called D-looping?
where the heart will flip upside down
-rightward bending of the heart
Where is the foramen ovale?
hole between right and left atria through the interatrial septum
Ductus Arteriosus locations
- connection between the pulmonary trunk and aorta, provides another shortcut in the embryo
- blood that didn’t take the shortcut to the foramen ovale, goes to right ventricle
- it is pumped into the pulmonary trunk where it goes through the connection of aorta
- Blood that would be going to the lungs, goes to the aorta itself
- seals after birth and becomes the ligamentum arteriosum
Age-related changes
valve sclerosis
decreased cardiac reserve
fibrosis of myocardium
Atheroscleroses
Valve sclerosis
deposits (calcium) accumulate on top of valve flaps, making them more rigid
-valves become less functional because it prevents them from closing all the way, so there is back flow of blood
-decreased cardiac out put
-offset by health diet, accumulates over time
Decreased cardiac reserve
as you age, you lose the ability to have a large cardiac reserve
-can be somewhat offset by exercise
Fibrosis of myocardium
-if you fail to use the myocardium, it will began atrophy and become non-contractible tissue
-prevent by staying active
Atherosclerosis
-accumulation of plague along inside of blood vessels
-reduces diameter of blood vessels, which changes blood pressure
Is are circulatory system open or closed?
closed
Arteries carry blood
away from heart
carry blood that is rich in oxygen
Exception: pulmonary artery
Elastic Arteries
-proximal to heart
-larger diameter
-have minimal resistance
-walls are rich in elastin which allows them to rebound to maintain the pressure in blood
EX: aorta or pulmonary artery
Muscular artery
-distal to heart
-smaller diameter
-branch of the pulmonary arteries and carry blood to our organs
-some elastin
Arterioles
-branches off of muscular arteries and lead to capillary beds
Capillaries
-compose of simple squamous epithelial tissue
-site of gaseous exchange
Veins
-return blood back to heart EX:vena cava
-carry blood that is poor oxygen
Exception: pulmonary veins
-more blood than anywhere else
-lowest pressure here
Lumen
opening in the middle of the vessel that contains the blood
Tunica interna
composed of simple squamous epithelium
-cells bind to create a flat surface that is as smooth as possible
Tunica media
middle layer, deep to tunica interna
-smooth muscle and elastin
-thick in arteries
-blood vessel diameter controlled subconsciously through sympathetic nervous system
Tunica Externa
-deepest
-made up of collagen and dense irregular
-anchors blood vessels in place
Vasa Vasorum
blood vessels for blood vessels; tiny blood vessels that feed into tunica externa, found in largest blood vessels
Capillaries
small enough that each blood cell has to go through single file
Continuous Capillaries
-most common
-epithelial cells, endothelium is very tightly joined, have intercellular clefts, must go through walls for exchange
-pinocytic vesicles
Located: skin, muscle, most places in the body
Fenestrated Capillaries
-has pores called fenestration that increase permeability across wall of capillary
Location: high absorption and filtration rates
EX: kidneys, endocrine organs, small intestines, digestive track
Sinusoidal capilaries
-bigger openings, leakiest, blood can pass through the walls.
Location: liver and bone (red bone marrow)
Terminal Arteriole
sends blood to capillary bed, can change blood flow by changing its..
Metarteriole
branches off terminal arteriole
Thoroughfare channel
becomes postcapillary venule, main middle channel
Postcapillary Venule
Thoroughfare channel empties into this and returns blood to the vein
Vascular Shunt
combo of metaartiole and thoroughfare channel, MUST always be open
True capillaries
branches off arterioles, where gas exchange occurs
Microcirculation
regulates the amount of blood going through capillary beds
Precapillary Sphincters
-helps open or close individual capillaries
-can be partially open to control amount of blood passing through->regulate micro-circulation within the body
Artery (walls, lumen, tunica media, blood volume, blood pressure, valves)
thick
small
thick
lower
higher
no valves
Veins (walls, lumen, tunica media, blood volume, blood pressure, valves)
thin
large
thinner
higher
lower
venous
How much percentage is in our veins?
65%
Blood in veins is under what pressure?
low
Muscular pump
-as we contract our muscles they change shape and push against the walls of the vessels
-pushes blood up in the direction of the heart
Respiratory pump
-as we breathe, we have a change in the pressure of our thoracic cavity
-as we inhale the blood can slip up to low pressure place close to the heart
Collateral channels
-multiply supply channels that connect to each other (called anastomosis)
-go to places that need greater blood supply
-if one channel got blocked there would still be a path to come through
**Our body tries to maintain what in blood flow
cardiac output
Blood flow is what proportional
directly proportional to differences in blood pressure
-the greater the pressure, greater amount
Blood flow is inversely proportional to what?
peripheral resistance
-due to friction
-flows more easily with less friction through a large vessel
Blood viscosity definition
change in slipperiness through the walls of vessels
-higher viscotiy, slower flow
EX:honey
Vessel length description
longer vessel=more resistant
larger people have longer vessels
Vessel diameter description
larger diameter has less friction so it is less resistant
**arterioles change the most
determines blood flow
Vessel diameter variability and degree of effect
-can change instantaneously
-largest effect
Pulse Pressure
difference between systolic and diastolic pressures of the blood
Systemic Blood Pressure
-blood pressure decreases continually as we move away from the heart
-lowest pressure found in the veins that are returning blood to the heart
Do capillaries or veins have higher pressure?
capillaries
Blood pressure in the capillaries is relatively
low
MAP
diastolic pressure + (pulse pressure/3)
Thrombopoietin
a hormone which stimulates production of platelets
Thromboembolism’s disorders (not enough clotting)
Thrombocytopenia
Hemophilia
Thrombocytopenia
not enough platelet production due tp pathology (sickness)
Hemophilia
genetic disorder-don’t have genes to produce clotting proteins
Antigen
markers from other peoples body
Agglutinations
markers in out body
how blood is determine
Antibodies
attackers from other people’s bodies
Agglutination
attackers from out body
What is the injection that suppresses production of anti-RH called?
rhogam
Fibrous pericardium
functions: protects and anchors heart to mediiastinum
Composed of : connective tissue
Parietal layer
covering cavity; parietal pericardium
Visceral layer
covering heart itself; epicardium
Pericardial cavity
space b/w parietal and visceral layers, fluid filled to dissapate heat and prevent fiction
Epicardium
composed epithelial tissue
Myocardium
composed of cardiac MT
Endocardium
composed of squamous epithelial tissue, antithrombic
Auricles
increase the surface area of the atria so they can hold more blood
Fossa Ovais
provides a passageway for the blood to bypass the right ventricle since the embryo wasn’t using its lungs to breathe
Vena Cava
attached to right atrium
-we have a superior (drains head and neck) and an inferior (drains rest of our body)
Coronary sinus
-empties into right atrium
-drains all of the blood that went to the heart muscle itself
Flow of blood
r atrium-> tricuspid valve->r ventricle->pulmonary valve(r semilunar valve)->pulmonary arteries->lungs->pulmonary veins-> l atrium->mitral valve->l ventricle->l semilunar valve->aorta->body->vena cava
Two-circuit syste,
oxygen-poor blood is completely separated from oxygen rich blood
Each of these circuits have gaseous exchange called capillary beds where
-in lungs where we pick up oxygen and leave waste
-in body tissue where we deliver the oxygen
Coronary arteries
-branch off aorta
-supply blood to the heart muscle itself
Cardiac veins
collect all the blood brought by the coronary arteries and return it to the heart chamber for recirculation
Coronary sinus
cardiac veins drain into this and into right atrium
Anatstome
connection of blood vessels
-allows blood from multiple sources to be delivered to a particular area
-if one gets damaged, we still have blood supply
Pulmonary circuit
-right from heart to lungs
-blood gets oxygen from lungs
Systemic circuit
left from heart to lungs
delivers blood and oxygen to body tissues;collects waste from body
When are atriventicular valves open?
when the pressure of blood in the atrium is higher than the pressure in the ventricule
Tricuspid valve
right AV valve
-b/w right atrium and r ventricle
-3 # of cusps
Bicuspid valve
left AV valve
-b/w left atrium and left ventricle
-2# of cusps
Cordae tendinae
string like structures that connect the flaps of the valves to the papillary muscles in the ventricle
Semilunar valves
valves that seperate the ventricles from the arteries that carry blood away
Leukemia
cancerous condition of WBC’s
Infectious mononucleosis
increase in agranulocytes
-caused by exposure to highly contagious Epstein-Barr virus
Leukopenia
decrease in WBC
immune system is compromised
Interleukins
chemical messengers usually released when we’re fighting an infection
-when a cell is attacked by a virus, it releases these to protect neigboring cells
Colony-stimulating factors
increase WBCs
Leukopoiesis (production of WBC’s)
hemocytoblast is stimulated and gives rise to two different stem cells
-Myeloid stem cells: give rise to->all granulocytes and monocytes
-Lymphoid stem cells:give rise to lymphocytes
Agranulocytes
lymphocytes
monocytes
Lymphocytes
function: immunity
characterictics: large nucleus which makes up most of the cell; in lymph tissue
-T and b cells
-25% of WBCS
T cells
attack virally infected cells or tumors
B cells
secrete antibodies
What are the functions of blood
-delivers oxygen and nutrients to tissues
-transports metabolic waste
-transports hormone
-maintains body temp
-maintains body pH
-maintains fluid volume
-prevents blood loss
-prevents infection
Transports metabolic waste ex
allows waste to be released into the blood stream and release if co2 breaks down proteins and gets rid of ammonia
Maintains body temperatures decription
temp of blood is higher than body temp
What does blood carry which regulates pH of blood?
bicarbonate
What does maintaining fluid volume work with?
kidneys
All formed elements are in what marrow?
red bone marrow
Erythrocytes are what type of cell,nonliving or living, function, percentage of blood?
-red blood cells
-nonliving
-carry respiratory gas co2 and oxygen
-45%
Leukocytes are what type of cell, nonliving or living, function, percentage of blood?
-wbc
-living
-immunity
-less than 1%
Platelets are what type of cell ,nonliving or living, function, percentage of blood?
-fragments of cytoplasm
-nonliving
-clotting
-less than 1%
Blood Hematocrit
shows us the percentage of each component of our blood
Plasma water and solute
water: 90% of volume
Solute: proteins->albumin
-globulins
-nitrogenous waste
-nutrients
-electrocytes
Erythrocytes size, shape, nucleus, contain
size: small
shape: biconcave->packer on both sides
Nucleus: no nucleus
Contain: antioxidant enzymes-> free radical that accumulate and become toxic to body so get broken down by RBC
Hemoglobin
composed of globin protein bound to neme pigment
Heme pigment is what makes what?
blood red
Globin
a complex protein, which means it has more than one subunit
Heme pigment
-contains oxygen-binding iron
-each heme can bind to one oxygen molecule
Hemoglobin with oxygen bound
oxi-hemoglobin
-binding of oxygen to hemoglobin makes it bright red
Hemoglobin when oxygen is not bound
deoxi-hemoglobin
-lack of oxygen binding to hemoglobin makes it dark red
When is a patient struggling when their oxygen saturation is below
90%
Carbaminohemoglobin
-hemoglobin carries carbon dioxide
-20% of co2 carried in blood is bound to hemoglobin
-CO2 doesnt bind to heme, it binds to one of the amino acids on the globin part
Hematopoiesis
production of blood cells
-composition of blood cells will vary
EX: when exercising, we produce more RBC
-when fighting infection, we produce more WBC
Erytropoietin
-when our blood is low on oxygen, the kidneys start to produce this
-body monitors O2 level, not RBC count
-it is a hormone and has receptors on hematocytoblast and it initates their division process
Testosterone
-why men have more RBCs
-increase muscle mass results in an increased need for blood, more RBC
-works through the kidneys by stimulating them to release erythropoietin
B vitamins
-B12 and folic acid
-during pregnancy, a woman has to produce RBC to carry oxygen for both herself and the baby. Why needs supplement
Iron-
-need to create hemoglobin
-get in the food we ate
-if we don’t need it immediately, it is stored in cells as ferritin and nemosiderin
-when transported in the blood, called transferrin
Dietary nutrients
-if we’re making any sorts of cell, we have to have nutrients
EX: proteins, lipids, carbohydrates
Erythrocyte longevity
-last between 100-120 days
-cells start to get old, and macrophage consume them and break them apart. occurs in the spleen
Erythrocyte disorders
anemias
polycynthemia
Anemias
-either low number of or abnormal RBC that reduce the oxygen carrying capacity of the blood
Polycynthemia
-overproduction of RBC
-so many RBC that the blood has trouble moving through tiny capilaries
-blood is a sludge
Diapedesis
-some blood cells have the ability to leave blood vessels and enter interstitial fluid
-rbc cannot do this(if they die we bleed uncontrollable ), some WBC can
Neutrophils functions
-phagocytic cells which functions in inflammatory response
-multi-lobed nucleus
-50-70%
Basophils function
-granules full of histamine (vasodilator)
-stains very dark
-.5-1%
Esinophils functions
-attacks parasitic worms
-two lobed nucleus
-2-4%
Response: Alter blood distributions to respond to needs
-close precapillary spincters
-always go through vascular shunt, but if we need more, the sphincters will open up and more blood will pass through
-will increase Bp and decrease elsewhere
Response: Alter vessel diameter
-contrict-> increase pressure
-vasomotor system
-vasomoter tone
Vasomotor system
in the medulla oblongata there is collection of sympathetic nerve cells called vasomotor system- these attach to walls of the blood vessels and cause vasoconstriction
Vasomotor tone
constant signals coming from vasomotor system, causing slight constriction in our blood vessels, called vasomotor tone (important bc if they weren’t always slightly constricted, they wouldn’t be able to dilate)
Neural reflex arcs
baroreceptors are sensory receptors which monitor blood pressure
-detect when it goes up and down
Side effects of activating baroreceptors
venus return reduced
cardiac output reduced
heart rate reduced
contractible force reduced
MAP declines
Venus return reduced
baroreceptors signal causes reduced amount of blood in the heart
Cardiac output reduced
cause less blood out (bc less blood coming to heart)
Heart rate reduced
slows down to maintain cardiac output
Contractible force reduced
less pressure less contraction force
MAP declines
less contraction force makes further reduction in BP
Results of side effects of activating baroreceptors
reduced MAP intiates vasocontriction
-responds to low blood pressure by constricting in an attempt to put blood pressure back up
increase cardiac output
-bc heart rat slowed down in response to baroreceptor activation, allows heart to fill more before each contraction
blood pressure rises
Chemoreceptors
monitor the composition of blood
-detect concentrations of oxygen, ph, and CO2 in the blood
Epinephrine and norepinephrine released by what, action, effect on BP?
released by: adrenal medulla
Action: fight/flight- increases CO and HR and causes vasoconstriction short term
Increase BP
Atrial natriuretic peptide released by what, action, effect on BP?
released by: heart
Action: production is stimulated when BP is high, effects the kidneys by increasing filtration by vasodilation: decreases blood volume bc more lost to urine
reduce BP
ADH released by what, action, effect on BP?
stored in post pituitary
rarely is a vasoconstriction
Usually: promotes water conserve and increase blood volume
Increase BP
Angiotensin 2 released by what, action, effect on BP?
released by live
vasocontriction + angiotensin activated by renin into angiotensin 2 causes kidneys to reabsorb more water
increase BP
Endothelium -derived factors released by what, action, effect on BP?
released by blood vessels
vasoconstrict or vasodilate: self regulate
inc or dec BP
Inflammatory chemicals released by what, action, effect on BP?
Ex: histamine
Acts in two ways
1.Making blood vessel larger
2.More permeable
reduce BP
Alcohol released by what, action, effect on BP?
Affects BP
1.Inhibits ADH
2.Promotes dilation
3.Inhibits vasomotor center
reduce BP
Nicotine released by what, action, effect on BP?
has same effects as norepinephrine’s and epinephrine-> causes constriction
increase BP
Renal regulation
-only long term regulation of blood pressure
Works by:
altering blood volume
increased blood pressure causes the kidneys to eliminate more water and produce more urine
Direct renal mechanism
direct bc only affecting kidneys
-site of blood filtration
-filtration rate may be increased by blood pressure, blood volume, amount of blood delivered by blood vessels
Pulse
as blood is circulating through there are waves of pressure
Blood pressur
related to flow of blood through vessel pushing on its wall
1st Korotkoff sound=systolic
Perfusion
the flow of blood through tissues of the body
As blood is flowing through the tissues it
delivers O2 and nutrients and removes waste CO2
As blood passes through the the lungs it
exchanges gases
Metabolic
low levels of oxygen or nutrients cause vasodilation as well as relaxation of the precapillary sphincters so that blood will flow through them
