module 7/8 exam 2

parasympathetic

• decrease HR

• ACh muscarinic

• SA node

• hyperpolarizing graded potential due to G-protein coupled reaction that creates an increased permeability to K, hyperpolarizing it

  • long time for SA node to reach threshold

sympathetic

• SA node, ventricular muscle, arterioles

• increases HR, stroke volume contractility, resistance (vasoconstriction) to increase BP

• depolarizes faster and reach threshold faster

beta-1 in SA node

• HR is faster

beta-1 in contractile cells

• increases Ca concentration

  • greater force of contraction = increased SV

beta-2

• on smooth muscle

• vasodilation

• decrease intracellular Ca

alpha

• vasoconstriction by increase intracellular Ca

• smooth muscle and arterioles

CO

HR x SV

MAP

CO x R = (HR x SV) x R

tidal volume

• 500 mL

• normal inspiration/expiration

expiratory reserve volume

• 1100 mL

• additional air that can be expired by forceful effort

inspiratory reserve volume

• 3000 mL

• max amount of additional air by forceful inspiration

residual volume

volume of air that’s left in alveoli

• 1200 mL

total lung capacity

5800 mL

vital capacity

• max volume in or out - 4.6 L

capacity

• sum of two or more

dead space

• volume of air remaining in conducting airways at the end of each expiration (150 mL)

• part of tidal volume

• mixes w fresh air

• diff from residual volume that’s always in alveoli

alveolar ventilation

(breath volume - dead space/150mL) x breaths per min

• increasing ventilation rate is much better than volume

pulmonary circulatory

to lungs

systemic circulation

to body

pulmonary capillaries

• O2 flows into the blood due to pressure gradient (blood PO2 < alveolar PO2)

• CO2 into alveoli

• blood leaving pulmonary/arterial is equal to alveolar

systemic capillaries

• O2 into the cells/interstitial fluid

• CO2 out of the cells into blood

• blood leaving systemic capillary/venous blood is equal to interstitial fluid

partial pressure of O2 is due to…

dissolved O2 in plasma (2%)

what effect do hydrogen ions have on conformation of hemoglobin

• decreases its affinity for oxygen

• thus, the P50 value will be larger as it takes more pressure of O2 in order to have 2 binding sites full

• decreasing pH, increases O2 release onto active tissue

what other factors create rightward shift in HbO2

• increase in temp

• high PCO2

myoglobin

• one binding site

• in muscle cells

• higher affinity for oxygen than hemoglobin

• at 20 mmHg, more than 80% saturated, which hemoglobin has given up most of its oxygen

• O2 reserve

cooperativity

• in hemoglobin, changes shape

• allows for subsequent O2 to bind easier on hemoglobin

CO2 in blood

• 7% dissolved in plasma (PCO2)

• bicarbonate (HCO3-) in plasma 70%

• most of H+ bound to hemoglobin

respiratory drive

• PCO2, PO2, pH (involuntary)

• conscious volition

controlling ventilation

medulla is the respiratory control centers and have chemoreceptors (chemical changes) that respond indirectly to CO2 lvls (main signal for respiratory)

• as CO2 lvls increase, orchestrate signals to respiratory muscles (diaphragm, external intercostals) and then relax

increase in plasma CO2

• dissolved in the plasma and goes thru BBB

• H+ can’t

• chemoreceptor in medulla detects acid/H+ concentration 

• neg feedback to increase ventilation

hyperventilation

• decrease PCO2

• increases pH of CSF/decrease H+

• decrease respiratory drive

hypoventilation

• hold your breath

• decreases pH, increase PCO2

Describe the general characteristics of asthmatic airways

• exaggerated immune response to triggers

  • inflammation of the conducting airways → mucus buildup

  • diameter for air decreases, increases resistance to airflow

  • smooth muscle that circles the airways, contracts - B2 adrenergic receptors

fluticasone

maintenance medicine

• dry powder inhalers (DPIs)

• the receptor determines the response in fluticasone (synthetic cortisol)

  • cytoplasmic receptor changes gene expression (anti-inflammatory genes expressed in response)

salmeterol and albuterol

• long-acting vs short-acting

• both beta2 adrenergic agonists

  • airway smooth muscle relaxation, so diameter increases = improves airflow