Unit 1 A&P 2 Written Q's

What does sympathetic stimulation do?

increases contractility

What does parasympathetic stimulation do?

reduces heart rate when a stressful situation has passed

What does thyroxine do?

increases metabolic rate, production of body heat, enhances epinephrine and norephrine, and causes a sustained increase in heart rate

What do low levels of calcium do?

depress the heart

What do high levels of potassium do?

causes heart block and cardiac arrest

Describe the generalized flow of blood through the heart in relation to the pulmonary and systemic circuits

blood from the systemic circuit, vena cava, right atrium, tricuspid valve, right ventricle, pulmonary valve, pulmonary trunk, pulmonary arteries, lungs, pulmonary veins, left atrium, bicuspid valve, left ventricle, aortic valve, aorta, blood to the systemic circuit

baroreceptor

pressure sensitive mechanoreceptors that respond to changes in arterial pressure and stretch; when stretched they send a rapid stream of impulses

pulse points

superficial temporal artery, facial artery, common carotid artery, brachial artery, radial artery, femoral artery, popliteal artery, posterior tibial artery, dorsalis pedis artery

Describe the general structure and functions of arteries, veins, and capillaries

Arteries take blood away from the heart, veins bring blood to the heart, and capillaries allow the exchange of blood and nutrients

Renal mechanisms influencing blood pressure

blood pressure is low, renin is released from the kidneys, angiotensin I is released, ACE is released and angiotensin II is created and has a multitude of effects

How the baroreceptor and chemoreceptor reflexes are involved with blood pressure regulation

1.low blood pressure occurs 2. baroreceptors in carotid sinuses and aortic arch are inhibited 3. low impulses from baroreceptors activate the cardioacceleratory center and stimulate the vasomotor center 4a. increase sympathetic impulses to the heart cause increased heart rate increased contractility and CO 4b.vasomotor fibers stimulate vasoconstriction causing an increase in R 5. increased CO and R return blood pressure to the homeostatic range

Describe a generalized capillary bed and the filtration processes occurring within them

diffusion through membrane, movement through intercellular clefts, movement through fenestrations, and transport via vesicle or caveolae

define blood pressure and peripheral resistance indication of the relationship

Anything that increases SV, HR, or R will also increase MAP ex. increase in vascular resistance, BV diameter, viscosity, vessel length, turbulence, cardiac output, or blood volume causes an increase in blood pressure

Hormones that affect blood pressure are

epinephrine and norepinephrine (Both hormones enhance the sympathetic response by increasing cardiac output and promoting generalized vasoconstriction), angiotensin II (which stimulates intense vasoconstriction, promoting a rapid rise in systemic blood pressure), atrial natriuretic peptide (ANP) (which leads to a reduction in blood volume blood pressure and vasodilation), antidiuretic hormone (ADH) (helps restore arterial pressure by causing intense vasoconstriction)

Define autoregulation and indicate where it occurs relative to blood flow

autoregulation is intrinsic control of local conditions that regulate blood flow independent of control by nerves or hormones; control is entirely within the tissue or organ. Changes in blood flow through individual organs are controlled intrinsically by modifying the diameter of local arterioles feeding the capillaries.

Explain the mechanisms leading to circulatory shock

any condition in which blood vessels are inadequately filled and blood cannot circulate normally. This can occur via hypovolemic shock

Describe neural controls regulating blood pressure including the roles of the vasomotor center and cardiac centers

vasomotor center controls the diameter of blood vessels, the cardioacceleratory center activates the sympathetic nervous system, which increases both heart rate and stroke volume, and the cardioinhibitory center

Describe the intrinsic cardiac conducting system structure and functions

1. the sinoatrial node (pacemaker) generates impulses (P wave) 2. impulses pause (0.1) at the atrioventricular node 3. the atrioventricular bundle connects the atria to the ventricles (QRS complex) 4. the bundle branches conduct the impulses through the interventricular septum 5. the subendocardial conducting network depolarizes the contractile cell of both ventricles

Describe the cardiac cycle integrating electrical activities, pressure, and volume changes with systolic and diastolic events in the atria and ventricle

1. atrioventricular valve close when the ventricular pressure exceeds the atrial pressure (ventricular filling phase) 2. semilunar valves open when ventricular pressure exceeds aortic pressure (the isovolumetric contraction phase) 3. semilunar valves close when ventricular pressure drops below aortic pressure (ventricular ejection phase) 4. atrioventricular valve open when ventricular pressure drops below atrial pressure (the isovolumetric relaxation phase)

Frank Starling law of heart

the higher the preload the higher the stroke volume (bully law)