unit 1

Diff between nervous and endocrine in terms of
mechanism:
area of effect:
signaling mol:
duration of effect:
target tissues:

Diff between nervous and endocrine in terms of
mechanism: nervous electrochemical, endocrine chemical secretion
area of effect: nervous local, endocrine broad
signaling mol: nervous neurotransmitters, endocrine hormones
duration of effect: nervous short, endocrine longer
target tissues: nervous neurons, muscle and glands. endocrine all body tissues

Craniosacral system is

parasympathetic

thoracolumbar system is

sympathetic

list the 3 effector cells of the autonomic nervous system

smooth muscle, cardiac muscle, gland cells

Describe the steps of the parasympathetic system and the neurotransmitters used

1. action potential in preganglionic

2. acetylcholine released

3. Ach binds to nicotinic type Ach receptor on postganglionic neuron

4. postganglionic neuron releases Ach on target

5. Ach binds to muscarinic type Ach receptor

BOTH NEURONS RELEASE ACH

4 main subtypes of adrenergic receptors and what pathway uses them

Alpha 1: smooth muscle contraction

Alpha 2: sympathetic postganglionic neurons, negative feedback

Beta 1: cardiac muscle cells

Beta 2: smooth muscle relaxation

USED IN SYMPATHETIC EFFECTORS

Describe the steps of the sympathetic system and the neurotransmitters used

1. AP in preganglionic

2. preganglionic releases ACh

3. Ach binds to nicotinic Ach receptor on postganglionic

4. postganglionic releases norepinephrine on target

5. NE binds adrenergic receptor

EXCEPTIONS TO THE SYMPATHETIC PATHWAY

1. sweat glands target receptor is muscarinic instead of adrenergic

2. adrenal medulla releases epi into the blood and then binds to adrenergic
   

2 ways to activate sympathetic system and 1 way to activate parasympathetic system

Sympathetic: CNS preganglionic, or release of epinepherine from adrenal medulla

parasympathetic: CNS preganglionic activation

5 functions of blood

transport,

defend,

regulate pH and ions,

clot

regulate temp

describe the composition of blood

Plasma, buffy coat middle layer, and formed elements

Describe the composition of plasma

mostly water, 8% proteins

describe the composition of formed elements

99.9% RBC/erythrocytes

Difference between hemopoiesis and erythropoiesis?

hemo is all blood cell, happens in red marrow, makes hemocytoblasts to form any blood cells. hemocytoblats can then go through erythropoiesis to form red blood cells.

what speeds up erythropoiesis?

erythropoietin (EPO)

why the structure of RBCs help with their function

biconcave disc create large surface to volume ratio

lack organelles , increases flexibility

How is hemoglobin recycled

heme is broken down to bilirubin and excreted

iron is reused

proteins broken down to AA and reused

Describe jaundice, anemia, myloid and lymphoid leukemia

jaundice: live cant break down RBC and bilirubin builds up

anemia: decrease in O carrying capacity of blood

myloid leukemia: abnormal granulocytes or marrow cells

lymphoid leukemia: abnormal lymphocytes

Describe the 3 granulocytes:

granules- nubs (NEBs)

neutophil: most of WBCs, phagocytic, first reponse to injurt. high levels indicate bacterial infection

eosinophil: attracted to foreign compounds that react w antibodies, phagocytic. high levels indicate allergy or parasite

basophil: release histamine and heparin in damaged tissue

Describe 2 agranulocytes:

lymphocyte: immune system cells

monocytes: leave circulation to become macrophage

Myloid stem cells go to

GRANULOCYTES (neut, eisino, baso) and MONOCYTES

lymphoid stem cells go to

lymphocytes and plasma cells

What does complete blood count measure

hematocrit and hemoglobin

platelet count

wbc count

what are platelets?

fragments of megakaryocytes, NOT CELLS

Describe the role of clotting

1. vascular spasm reduces diameter of vessel

2. platelets adhere, release chemicals that form positive feedback loop

3. thrombin catalyzes fibrinogen to fibrin

4. fibrin forms a mesh, clot forms

Thrombus vs embolus

thrombus: blood clot formed by platelets, often at disease site

embolus: piece of thrombus that travels and blocks another part of body

describe systemic circulation

aorta carries oxygenated blood to organs

systemic veins carry DEoxygenated blood from organs through superior and inferior venae cavae to pulmonary artery

describe pulmonary circulation

pulmonary artery carries DEoxygenated blood from heart to lungs

pulmonary veins carry oxygenated blood from lungs to aorta

Describe the 3 layered wall of a blood vessel

tunica intima: innermost, lined by endothelium

tunica media: middle, smooth muscle

tunica externa: outer, connective tissue

Difference between structure of artery vs vein

arteries have stronger thicker walls, and contain more smooth muscle and elastic fibers

Describe vessels of arterial system:
elastic arteries:

muscular arteries:

arterioles vessel:

Describe vessels of arterial system:
elastic arteries: conducting arteries

muscular arteries: distributing arteries

arterioles: resistance vessel, few muscle layers

What are the only vessels that move materials through wall?

capillaries / exchange vessels

Describe vessels of venous system:
veins :

Describe vessels of venous system:
veins : capacitance vessel, just hold blood

What is a venous valve and how is it formed?

valves catch blood if they try to flow back, formed from tunica intima foldings

Describe the difference between

continuous capillaries

fenestrated capillaries

sinusoidal capillaries

Describe the difference between

continuous capillaries: tight endothelial layer, only water and lipid solutes pass through, creates BBB

fenestrated capillaries: pores in endothelial lining, exchange of water and larger solutes. Found in choroid plexus, endocrine organs, kidneys, GI

sinusoidal capillaries: large gaps between endothelial cells, free exchange of water and large proteins. Found in liver, spleen, bone marrow

Describe the pericardial sac

surrounds heart:
parietal pericardium is outer
pericardial cavity is fluid filled
visceral pericardium adheres to heart surface

What separates atrium and ventricle?

AV valves

left coronary artery branches into

circumflex artery and left anterior descending

3 layers of the heart wall

epicardium: outer, connective tissue, fat

myocardium: middle layer, cardiac muscle

endocardium: inner, endothelium

Explain the 2 sets of ACTIVE AV valves and AV valve anchors

Tricuspid: right, 3 flaps

Bicuspid/Mitral: left, 2 flaps

flaps anchored to papillary muscle by chordae tendineae

Explain the 2 sets of PASSIVE Semilunar valves and valve anchors

Pulmonary valve leaves the right vent

aortic valve leaves the left vent

anchored to inner wall. no muscles

What determines if a valve is open or closed?

pressure gradients

Explain the steps of blood flow through the right side of the body

1. blood from body through sup + inf venae enter right atrium

2. passes through tricuspid valve to right ventricle

3. passes through pulmonary valve to pulmonary trunk

4. trunk branches into right and left arteries to go to lungs

Explain the steps of blood flow through the left side of the body

1. blood returns from lungs through two right and left pulmonary veins into left atrium

2. passes through bicuspid/mitral to left ventricle

3. to aortic valve and aorta

4. aorta ascends to aortic arch

2 types of cardiac muscle cells and percentage of each

contractile cells- 99%

pacemaker cells- 1%
no contraction, initiate APs

Explain 3 steps of pacemaker APs

1. pacemaker potential, slow depolarization due to opening of Na and closing of K

2. Depolarization: Ca influx, reaches threshold

3. Repolarization: Ca inactivation, K opening

Sequence of conducting system

1. SA node

2. AV pause

3. AV bundle

4. Bundle branch

5. Purkinje fibers

Describe Ectopic pacemaker

high AP, disrupts contraction, poor blood ejection

Describe the structure of a contractile cell

single central nucleus

made up of sarcomeres arranged into myofibrils, surrounded by sarcoplasmic reticulum

intercalated discs connect cells

Explain steps of contractile cell APs

Depol: Na channels open, then close

Plateau: Ca channels open fast,K channels close

Repol: Ca channels close, K channels open

Resting potential

Difference between pacemaker and contractile APs?

contractile membrane potential gets stable, resting

Difference between cardiac contraction and skeletal muscle contraction APs?

cardiac APs cannot summate, and last as long as the contraction

muscles summate, and brief relative to contraction

what does an EKG measure

sum of electrical activity in myocardium., NOT A SINLE CELL

Describe P wave, QRS wave, and T wave

P: atria depolarize-

QRS: Ventricle depolarize

T: ventricle repolarize

Describe the 3 steps of the contractile cycle (6 stages <3)

1a. ventricular filling/ disastole: all chambers relaxed, ventricles fill passively

1b. P STEP: atrial contaction/systole: contraction moves blood to ventricles. AV valves open

2a. QRS STEP: FIRST HEART SOUND HEARD: isovolumetric contraction/ ventricle systole: AV valves close

2b. T STEP: ventricular ejection: SL + aortic valve open. blood moves to aorta and pulm art

3a. isovolumetric relaxation: SECOND HEART SOUND HEARD: SL and aortic valve close. blood flows into relaxed aorta

3b. back to ven diastole. all chambers relaxed, ven fill passively

Cardiac output definition + equation

volume of blood pumped by left ventricle in one minute

CO= HR x SV

CO = HR x (EDV-ESV)

Define EDV and ESV

end dias volume: volume just before contraction

end sys volume: volume after contraction

define SV

stroke volume: amount pumped out during systole

how is HR controlled through CV center in medulla?

NE release causes increase in HR

ACh release causes dec in HR

how is HR controlled through pacemaker cells/autonomic system

parasympathetic stim slows down depolarization

sympathetic stim speeds up depolarization

What changes EDV?

• fill time (inc fill time, inc HR)

• venous return (inc symp, inc vasocons, inc CO)

What changes ESV?

• preload (inc fill load, inc CO)

• contractility (inc contraction, inc CO)

• afterload (force to eject blood) (inc afterload DEC CO)

What is the ejection fraction and what does a lower ejection fraction indicate

percent of EDV pumped out in one beat

lower EF, weaker heart

define blood flow

difference in blood pressure divided by peripheral resistance

in terms of BP, hypertension is

140/90

in terms of BP, hypotension is

90/60

define MAP and give avg

mean arterial pressure: 1/3 pulse pressure + diastolic BP

Local and systemic factors that affect resistance

Vasodilation; inc blood flow
local: high CO2, H+ K+, low O2
systemic: low sympathetic activity

Vasoconstriction; dec blood flow
local: stretch and endothelins
systemic: increase hormones and sympathetic activity

Why are capillaries optimized for exchange?

high cross section decreases flow, and gives time for material exchange

3 forces at work in capillary exchange, and their pressures

Diffusion: lipids, gases, some ions

Filtration: driven by capillary hydrostatic pressure
35mmHg at arterial, 18 at venous

Reabsorption: water drawn back by blood colloid osmotic pressure (BCOP). constant 25mmHg

Net filtration pressure at each capillary ends

arterial: 10mmHg , fluid moves into interstitial

venous: -7mmHg, fluid moves into capillary

Dif between local and systemic edema

local is just extra interstitial fluid in inflammation, a process to dilute toxins.

systemic indicates cardiovascular problem

3 factors that influence CO and BP

1. autoregulation: immediate localized changes

2. neural mechs: responds quickly to changes at specific sites

3. endocrine mechs: slowest, direct long term changes

Describe autoregulation

LOCAL vasodilators (high CO, H, K, low O2) increase blood flow in busy or inflamed tissue

LOCAL vasoconstrictors decrease blood flow in quiet damaged tissue

If autoreg is ineffective, goes to neural or endo mechs. Describe the general baroreceptor reflex response in CV center (neural mechs)

1. baroreceptors in aortic arch and carotid sinus detect stretch in vessel wall

2. CV center in medulla receives info

3. alters symp/parasymp output to heart (from cardiac center)

4. alters symp output to blood vessels (vasomotor center)

more descriptive: describe the baroreceptor reflex for high blood pressure

• baroreceptor stimulated

  • vasomotor/sympathetic inhibited

  • cardioinhibitory/parasymp STIMULATED

  • cardioacceleratory/sympathetic inhibited

• vasodilation and dec CO

more descriptive: describe the baroreceptor reflex for low blood pressure

• baroreceptor stimulated

  • vasomotor/sympathetic STIMULATED

  • cardioinhibitory/parasympathetic inhibited

  • cardioacceleratory/symp STIMULATED

• vasoconstriction and increase CO

What happens when you stand up? How does baroreceptor response help?

• less blood to heart, BP CO SV decrease

• to compensate

  • baroreceptors detect low BP

  • CV center in medulla activates sympathetic, inactivates parasympathetic

  • sympathetic causes vasoconstriction

  • increases BP

What happens during light exercise

increase in autoregulation- metabolites causes vasodilatoin

increase in EDV increases stretch

What happens during strenuous exercise

same autoreg, but also SYMP activity

What happens during hemorrhage

elevation of BP through baroreceptors (neural)

hormonal activation (Endo)

Define atherosclerosis and describe how its caused

stiffening of wall due to fat deposits. reduces blood flow and increases peripheral resistance

1. high LDL attract WBCs

2. causes inflammation and thickening of wall (PLAQUE)

What causes coronary artery disease and 2 treatments

atherosclerosis

treat with coronary artery bypass or stent into blood vessels

difference between atrial and ventricular fibrillations

atrial: atrial wall quivers, blood clots may form, leads to stroke

ventricular: ventricle quivers, doesnt pump blood, cardiac arrest

Difference between heart failure and congestive heart failure

heart failure: cannot pump enough blood to organs

congestive hf: blood backs up on venous side. edema in tissue, lungs fill with fluid.

3 ways the CV system changes with age

blood: decrease hematocrit, increases clot liklihood

blood vessels: arteries lose elasticity, plaques, pooling of blood

within heart: conducting cells, reduce elasticity, atherosclerosis, scar tissue