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Anatomy
Undergraduate 1
03/21/2013

Additional Anatomy Flashcards

 


 

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Term
Auricles
Definition
Small earlike projections on each atrium
Term
Atrioventricular sulcus
Definition
Deep groove on the surface of the heart, encircling it between atria and ventricles
Term
Anterior/Posterior interventriculuar sulci
Definition

-deep grooves that can be seen on the outer surface of the heart

 

-separate the right and left ventricles 

Term
Chordae Tendinae
Definition
strong fivrous strings attached to the cusps of the tricuspid and bicuspid valves
Term
papillary muscles
Definition

-small mounds of cardiac muscle tissue projecting inward from walls of ventricles

 

-pull on chordae tendinae to anchor valve flaps closed when contracted

Term
Pulmonary trunk
Definition
large artery that gives rise to smaller pulmonary arteries that carry blood to right and left lungs
Term
Cardiac Cycle
Definition
period of time between the start of one heartbeat and the beginning of the next.
Term
Phases of Cardiac cycle
Definition
-Systole
-diastole
Term
Systole
Definition

-contraction

 

-heart chambers contract and push blood into adjacent chambers or into arterial trunks 

Term
Diastole
Definition

-relaxation

-chambers relax and fill wth blood in preparation for next cycle

 

-when atria contract, ventricles relax
-when ventricles contrac, atria relax 

Term
Events of the cardiac cycle
Definition

1. atria relax and fill with blood (increase in fluid pressure)
2.bicuspd and tricuspid valves open and blood flows into the ventricles.
3. atria contract, ventricles completely fill with blood

4. Now there is increase in ventricle fluid pressure; ventricles contract atria relax
5.Bicuspid and tricuspid valves close; atria are fully relaxed and being to fill with blood again
6.ventricular contraction reaches it's peak; pulmonary valve and aortic valve open
7. blood leaves ventriles and goes into the arterial system, venricles relax and pulmonary and aortic valves close 

Term
Ventricular contraction is the ______ _____ of blood circulation
Definition
driving force
Term
______ contraction fills the _____ with blood
Definition
Atrial; ventricles
Term
What is the first heart sound?
Definition
lubb
Term
What is the second heart sound?
Definition
dupp
Term
What causes the first heart sound?
Definition
Occurs during ventricular systole when bicuspid and tricuspid valves close
Term
what causes second heart sound?
Definition
occurs during ventricular diastole when pulmonary and aortic valves close
Term
murmurs
Definition
irregular heart sounds
Term
valvular stenosis
Definition
-opening through valves becomes narrower
-can occur in any 4 valves
-dizziness, shorness of breath
-produces high pitched or "click" type sound.
Term
valvular insufficiency
Definition
- valve does not close tightly and blood leaks back through
-can occur in any four valves
-most commonly affected valve is the bicuspid or "mitral valve prolapse"
-swishing sound
Term
functional synctium
Definition
stimulation to any part of cardiac muscle network sends impulses throughout entire heart muscle and it contracts as a single unit
Term
Autorhythmicity
Definition
action potentials are conducted from cell to cell within the entire unit via ion passage through gap junctions linking adjacent cells
Term
2 syncytia of the heart
Definition
-atrial syncytium
-Ventricular syncytium
Term
ECG/EKG
Definition
-recording of electrical changes that occur in the myocardium during a cardiac cycle
-useful in determining how the heart is or is not conducting impulses
Term
P wave
Definition
Electrical charge produced When the S-A node triggers a cardiac impulse atrial fibers deplorize
Term
QRS complex
Definition
a larger electrical change than P wave, lasts longer caused when ventricles deploraize
Term
T wave
Definition
wave pattern caused by ventricles repolarizing
Term
Arrhythmias
Definition
irregular heart beats
Term
Atrial fibrillation
Definition

-Atria contract irregularly (P wave is gone)

-not life threatening, increased risk of stroke 

Term
Ventricular fibrillation
Definition
-ventricles contract irregularly
-life threatening since vital organs lack necessary blood
-heart muscle can seize (cardiac arrest)
Term
Tachycardia
Definition
-abnormally fast heart rate
-higher than 100 beats a minute
Term
Bradycardia
Definition
-slow heart rate
-lower than 60 beats a minute
Term
Atrial Flutter
Definition
-rapid rate of atrial depolarization
Term
Cardiac Conduction System (CCS)
Definition
-cells do not contract
-Initiate and distribute electrical impulses throughout the entire myocardium
-Cells coordinate the events of the cardiac cycle
Term
Components of the Cardiac Conduction System
Definition

-Sinoatrial Node (S-A node)

-Atrioventricular Node (A-V node)
-Atrioventricular Bundle (A-V Bundle)
-Purkinje Fibers 

Term
Cardiac Conduction System Pathway
(6)
Definition
1. Cells of S-A node reach action potential threshhold on their own
2. Initiates impulses that spread into myocardium & stimulate atrial cardiac muscle fibers to contract
3. S-A impulses slow down as they reach A-V node
4. cardiac muslces move rapidly through the A-V Bundle fibers
5. Purkinje Fibers stimulate mass of ventricular myocardium to contract as a single unit
6. Organiation of the muscle fibers causes the ventricles to twist during contraction which creates pressure and pushes blood from the ventricles into the appropriate arterial trunks 
Term
Sinoatrial Node (S-A node)
Definition

-found in the right atrium

-elongated mass of muscle fibers just beneath epicardium

-fibers are continuous with the atrial syncytium

-controls heart rate

Term
Atrioventricular Node (A-V Node)
Definition
-Found in inferior portion of interatrial septum; just beneath endocardium
 -serves as a elecrical bridge between the atrial and ventricular syncytia
Term
Atrioventricular Bundle (A-V bundle)
Definition
-found in upper portion of interventricular septum
-divides into left and right branches
Term
Purkinje fibers
Definition

-fored from the A-V bundle branches
-enlarged fibers that are located throughout distant regions of ventricular myocardium

-carry the cardiac impulse to all portions of ventricular syncytium 

Term
How does the autonomic nervous system regulate the cardiac cycle?
Definition
- Parasympathetic nerve fibers reach the S-A and A-V nodes
- Nerve impulse from the parasympathetic fibers causes acetylcholine to be released
- ACh decreases activity of S-A and A-V nodes, which will decrease the heart rate (act like a brake)
- Decrease in parasympathetic avtivity will cause an increase in heart rate
Symoathetic nerve fibers innervate the heart via accelerator nerves & innervate the S-A and A-V nodes
-nerve impuse from these fibers causes a release of norepinephrine
-norepinephrine increases heart rate and contraction force 
Term
Parasympathetic nerve fibers arise from
Definition
medulla oblongata
Term
Acetylcholine (ACh)
Definition
-neurotransmitter secreted by parasympathetic fibers
-decreases S-A and A-V node activity
-decrease heart rate
Term
Accelerator nerves
Definition

-belong to sympathetic nerve fibers

-secrete norepinephrine
-norepinephrine increases heart rate and contraction force 

Term
Cardiac control center
Definition
controls the balance between parasympathetic and spmpathetic activity on the heart
Term
Cardioinhibitor and cardioaccelterator reflex centers:

location:
function: 
recieve signals from what receptors:
Definition

-within the cardiac center

 

-receive sensory impulses from the circulator system

 

-baroreceptors

Term

baroreceptors
function: 

location:

Definition

-detect changes in blood pressure

 

-in the arch of the aorta and in the carotid arteries

Term
chemoreceptors
Definition

-sense changes in pH, oxygen and carbon dioxide

-if pH level is increased heart rate is decreased
-if pH level decreased heart rate is increased 

Term
Vena cavae
Definition
They are the veins that return deoxygenated blood from the body, into the heart.
Term
how is venous pressure effectively decreased?
Definition

-baroreceptors stretch and signal cardioaccelerator center

-cardioaccelerator center signals medulla oblongata
-medulla oblongata sends sympathetic signals to the heart which increase the heart rate and contraction force 

Term
how do temperature influence the rate of the cardiac cycle?
Definition

-body temperature increases, heart rate increases.

-if body temperature decreases heart rate decreases.

Term
how do potassium ions influence the cardiac cycle?
Definition
Potassium ions affect the electrical potential of the cardiac muscle cell membrane which will alter the ability of the cells to reach threshhold
-Increase/decrease potassium ion concentration causes decrease in heart rate
Term
how do calcium ions influence the cardiac cycle?
Definition

-Cacium ions affect the conductance of cardiac impulses
-increased calcium levels cause an increase in heart rate
Term
hypercalcemia
Definition
increased calcium ion levels
Term
Blood vessels
Definition
form a closed circuit of tubes that carry blood from the heart to body cells and back to the heart
Term
Arteries and Arterioles
Definition
Carry blood away from ventricles of heart and lead into capillaries
Term
3 layers of arterial/arteriole wall
Definition
Tunica Interna: innermost; made of endothelium
Tunica Media: forms bulk of wall (middle layer); made of smooth muscle  and elastic connective tissue
Tunica Externa: outermost layer; attatches artery/arteriole to surrounding tissues
Term
vasomotor fibers
function:
Definition

-Sympathetic nervous system fibers

 

-innervate the smooth muscle of the tunica media

-when stimulated cause vasoconstriction
-when inhibited, cause vasodilation 

Term
Capilarries
function:
Definition

-smallest diameter blood

 

-Carry out the exchange of substances between the blood and tissue cells

Term

precapillary sphincters

 

function:

Definition

-muscle that encircles the true capillary entrances

 

-regulates distribution of blood through capillaries

Term
Osmosis
Definition
exchange of substances through capillaries by water moving from areas of high concentration to areas of low concentration
Term
Diffusion
Definition
exchange of substances through capillaries by movement of solutes from areas of high concentration to areas of low concentration
-most important
Term
Filtration

forces:
Definition
exchange of substances through capillaries by movement of large olecules like sugars and salts carried out by active forces pushing fluid across capillary wall.

Osmotic pressure: pulls fluid into capilarries
Blood pressure: tends to push fluids out of capillaries
Term
ultrafiltration
Definition
arterial end of capillar higher hydrostatic pressure so fluid moves out
Term
reabsorption
Definition
venous end of capillary has higher osmotic pressure so fluid moves in
Term
Venules and Veins
Definition
Carry blood back to Atria of the heart
Term
_____ are smaller diameter vessels which connect to the ________ end of capillaries and then merge to form _________
Definition
venules; venous; veins
Term
3 layers of vein walls
Definition
Tunica externa: outermost composed of thick connective tissue
Tunica Media: Middle layer
Tunica interna: innermost layer; composed of endothelial tissue
Term
venous vasoconstriction
Definition
helps return more blood to the heart; which helps maintain blood pressure
Term
larger veins have valves that originate from the ______ ______; project inward and prevent ______ of blood
Definition
tunica interna; back-flow
Term
Blood pressure:
Definition
force that exerts against the inner awlls of blood vessels
Term
systolic pressure:
Definition
maximum arterial pressure due to ventricles contracting; blood is forced into pulmonary trunk and aorta.
-sharp rise in blood pressure
Term
Dastolic pressure:
Definition
minimum arterial pressure and is caused by venricular relaxation
Term
Factors influencing Blood Pressure
Definition
-Heart action
-blood volume
-peripheral resistance
-viscosity
Term
Heart action
Definition
how much blood enters the arterial system with each ventricular contraction will influence BP
Term
Stroke volume
Definition
volume of blood discharged from the ventricles with each contraction
Term
Cardiac output
Definition
volume of blood discharged/minute
Term
if the heart rate or stroke volume ______________ the CO ________________ this causes an increase in ________
Definition
increases, BP
Term
If the heart rate or stroke volume ___, the CO _____. This causes a decrease in _____.
Definition
decrease, BP
Term
Blood Volume
Definition

Sum of formed elements (cells and platelets) and plasma volume.

 

-BP is directly proportional to blood volume

- if blood volume +, BP +

-if blood volume -, Bp- 

Term
Peripheral resistance
Definition
force produced by friction between blood and walls of blood vessels.

-hinders blood flow
Term
vasoconstriction:
Definition
increase peripheral resistance and increases BP
Term
vasodilation
Definition
decreases peripheral resistance and decreases BP
Term
Viscosity
Definition

how thick something is; how easily a fluid's molecules flow past one another


+ in viscosity, + in BP 

Term
hypertension
Definition
high blood pressure
Term
Vasomotor Center
location:
Definition
-located in medulla oblongata

-controls blood vessel diameter
Term
Nervous system regulation

4 things
Definition
-Vasomotor center
-Baroreceptors
-chemoreceptors
-higher brain centers
Term
Baroreceptors (bp control)
Definition

Elevated BP causess baroreceptor stimulation

casodilation occurs

Term
chemoreceptors (bp control)
Definition
increase in co2 levels or o2 levels will stimlate chemoreceptors

sympathetic fibers stimlated

vasoconstriction occurs
Term
cerebral cortex (Bp control)
Definition
in times of high stress or anxiety will send signals that cause an increase in Bp
Term
Hyothalamus (bp control)
Definition
mediatesfight or flight response
Term
kidneys control BP by
Definition
controlling how much aldosterone is secreted by adrenal cortex
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