Ahangari Physiology UCF Exam 4

Where does gas exchange occur in the lungs?

alveoli

What is the volume left in the lungs after normal expiration

Functional residual capacity

The sum of what adds up to Functional Residual Capacity (FRC)

residual volume (RV) and expiratory reserve volume (ERV)

Define Tidal Volume (TV)

Volume inspired and expired in a normal breath

Sum of what adds up to Inspiratory capacity

tidal volume (TV) and inspiratory reserve volume (IRV)

The sum of what adds up to Vital Capacity (VC) or Forced Vital Capacity (FVC)

tidal volume (TV), inspiratory reserve volume (IRV) and expiratory reserve volume (ERV)

How is most of the carbon dioxide in the blood carried?

bicarbonate

Where in the brain is breathing controlled?

medulla oblongata

Metabolic alkalosis includes the increase of bicarbonate concentration in the blood; true or false?

true

What is HCl secreted by?

parietal cells in the walls of fundus and corpus

What is pepsinogen secreted by?

chief cells of the stomach

Most GI reabsorption occurs in?

small intestine

What does intrinsic factor do?

Carries B12

Where is intrinsic factor secreted?

fundus of the stomach

Oral glucose causes what to be secreted?

GIP - glucose-dependent insulinotropic peptide (also known as gastric inhibitory polypeptide)

What does the drug Cimetidine do?

Blocks H receptors - H2 receptor antagonist. It works by blocking H2 receptors on the parietal cells in the stomach, which reduces the secretion of stomach acid.

Which Cranial Nerves control the swallowing reflex?

CN 9 and CN 10 -cranial nerves IX (the glossopharyngeal nerve) and X (the vagus nerve)

Phasic contraction locations

Esophagus, small intestine, and antrum of the stomach

What is the drug Loperamide used for?

Antidiarrheal medication. It works by slowing down gut movement

What is the drug Azathioprine used for?

immunosuppressant medication. It works by inhibiting the immune system

What is the drug Prednisone used for?

Anti-inflammatory medication It is often used to reduce inflammation

What is Hemochromatosis

Accumulation of iron in the body, causes liver damage

Cholelithiasis

Gall stones caused by buildup of bile salts

Which hormone contracts the gallbladder?

Acetylcholine (ACH) - It is released from the parasympathetic nervous system and causes the gallbladder to contract, releasing bile into the duodenum

Low levels of bicarbonate causes metabolic acidosis, true or false?

true

What stimulates the G cells to secrete?

vagus nerve

What does somatostatin do

Inhibits GI hormone release

Neonatal respiratory distress syndrome is cause by

lack of surfactant

Which type of cell releases surfactant?

Type 2

what is partial pressure of O2 and CO2 in dry inspired air?

O2= 160 ; CO2= 0

what is partial pressure of O2 and CO2 in the trachea?

O2= 150 ; CO2= 0

what is partial pressure of O2 and CO2 in the alveolus (alveoli)?

O2= 100 ; CO2= 40

what is partial pressure of O2 and CO2 in the pulmonary artery?

O2= 40 ; CO2= 46

what is partial pressure of O2 and CO2 in the pulmonary vein?

O2= 100 ; CO2= 40

Does Lung Diffusing Capacity (DL) increase or decrease with Emphysema?

DL decreases; Inflamed alveoli; decreased surface area

Does Lung Diffusing Capacity (DL) increase or decrease with Fibrosis/Pulmonary Edema?

DL decreases; increased alveolar membrane thickness; increased diffusing distance

Does Lung Diffusing Capacity (DL) increase or decrease with Anemia?

DL decreases; hemoglobin in RBCs is reduced; reduction of gas diffusion

Does Lung Diffusing Capacity (DL) increase or decrease with Exercise?

DL increases; additional capillaries perfused with blood; increased surface area

What is anatomical dead space

areas that cannot participate in gas diffusion:

Nasal cavity, trachea, primary, secondary, and tertiary bronchi

What is physiological dead space

anatomical dead space + alveoli that are saturated w/ gas exchange

What is inspiratory reserve volume

volume inspired above tidal volume, common during exercise

What is expiratory reserve volume

volume expired after tidal volume expiration

What is surfactant? Why is it important?What is it synthesized by?

Reduces surface tension → prevents alveoli from collapsing

Secreted by Type II cells

How does PNS change airway resistance?

negative effect -

Constricts airway, decreases radius, increases resistance to airflow

How does SNS change airway resistance?

positive effect by beta 2- Dilates airway, increases radius, decreases resistance to airflow

At rest, what does alveolar pressure equal?

atmospheric pressure

At rest, what does lung volume equal?

(functional residual capacity) FRC = ERV + RV

What is Dalton's law of partial pressure?

Partial pressure= Total pressure x Fractional gas concentration

At rest, what is intrapleural pressure?

negative

During inspiration, what happens to alveolar pressure?

Alveolar Pressure < atmospheric Pressure

During inspiration, what happens to intrapleural pressure?

more negative (than at rest)

During expiration, what happens to alveolar pressure?

Alveolar Pressure > atmospheric Pressure

During expiration, what happens to intrapleural pressure?

returns to resting value

During expiration, what does lung volume equal?

(functional residual capacity) FRC = ERV + RV

Asthma - What does it cause?

Obstructive or restrictive?

What is it characterized by?

-Inflamed airway

-Obstructive

-Decreased FEV/FVC (FEV greater decrease)

-Increased functional residual capacity (FRC)

-Excessive mucus

COPD- What is it a combination of?

Obstructive or restrictive?

What is it characterized by?

-Emphysema and Chronic Bronchitis

-Obstructive

-Decreased FEV/FVC

-Increased functional residual capacity (FRC)

Pink puffers (Emphysema) or Blue Bloat (Chronic Bronchitis)

What are Pink Puffers?

(primarily emphysema) have mild hypoxemia and normocapnia (normal PCO2)

What are Blue Bloaters?

(primarily bronchitis) have serve hypoxemia with cyanosis

- do not maintain alveolar ventilation, hypercapnia (increased PCO2).

-right ventricular failure and systemic edema.

Fibrosis- Obstructive or restrictive?

What is it characterized by?

-Restrictive

-FEV/FVC may be normal because there is a decrease in all lung volume

(FVC greater decrease)

How is O2 transport different for fetal life?

-Beta chains are replaced by gamma chains → 2 alpha, 2 gamma

-Higher O2 affinity - 2,3 DPG binds less avidity (releases O2 into cells)

Is PO2 (partial pressure of O2) higher in cells or tissues?

High in cells, low in tissues

How is the majority of CO2 transported?

HCO3- (bicarbonate)

How does pulmonary circulation pressure compare to systemic circulation pressure?

Pulmonary pressure is lower

Is resistance lower in pulmonary or systemic circulation?

lower in pulmonary circulation

What is blood flow and pressures (alveolar, arterial, and venous) in Zone 1

-lowest

-alveolar P > arterial P > venous P

What is blood flow and pressures (alveolar, arterial, and venous) in Zone 2

-medium

-arterial P > alveolar P > venous P

What is blood flow and pressures (alveolar, arterial, and venous) in Zone 3

-highest

-arterial P > venous P > alveolar P

Where is Apneustic Center located?What is it responsible for?

Lower pons

-Stimulates inspiration (gasp)

Where is Pneumotaxic Center located?

What is it responsible for?

upper pons

-Inhibits inspiration

Central control of Breathing is made up of?

Brainstem and cerebral cortex

Where is the Central control of Breathing located?

Reticular formation (medullary respiratory center)

In the lungs, what effect does hypoxia have?

vasoconstriction

Where are the central chemoreceptors for breathing located?

medulla oblongata

Where are peripheral chemoreceptors located?

carotid arteries and aortic bodies

Peripheral chemoreceptors respond to?

-Decreases in arterial PO2 (Oxygen levels)

-Increases in arterial PCO2 (Carbon dioxide levels)

-Increases in arterial H+ (Acid levels)

What is Ventral Respiratory Group responsible for? When is it activated?

-expiration

-Activated during exercise (not normal breathing)

-Ventral Respiratory Group (VRG) is a cluster of neurons in the medulla

GI Tract LUQ

stomach, spleen, pancreas

GI Tract RUQ

liver, gallbladder

What is the difference between sigmoid and rectum?

sigmoid has taenia coli ligament

What are the types of smooth muscle in the stomach?

THERE ARE 3

-oblique

-longitudinal

-circular

What are the types of smooth muscle in the small and large intestines?

THERE ARE 2

-longitudinal

-circular

Where does digestion occur?

lumen of GI tract - by enzymes

Where does absorption occur?

villi and capillaries

What are the 2 digestive system plexuses?

(parasympathetic)

1- Submucosal plexus of Meissner

2- Myenteric plexus of Auerbach

vagus nerve innervates esophagus=?

esophageal plexus

vagus nerve innervates stomach=?

gastric plexus

Tonic contraction locations

lower esophageal sphincter, orad stomach, ileocecal sphincter, internal anal sphincter

What makes up portal vein?

superior mesenteric

inferior mesenteric

left gastric vein

splenic vein

What happens during the depolarization and repolarization of a slow wave?

Depolarization- calcium Ca2+ enters cell

repolarization- potassium K+ leaves cell

does slow wave have action potential?

no, doesn't have action potential

when GI tract receives stimuli, slow wave becomes what?

spike wave

what voltage triggers spike waves?

-40mV; Resting membrane potential floats between -50 to -60 mV.

Depolarization of GI tract is stimulated by?

- Stretching

- Acetylcholine

- Parasympathetic stimulation

- Specific gastrointestinal hormones

Hyperpolarization of GI tract is stimulated by?

-Norepinephrine or epinephrine

- Sympathetic stimulation

in smooth muscle, calcium binds?

Calcium binds calmodulin, helps bind troponin C

what innervates dorsal respiratory group and subsequently phrenic nerve?

vagus nerve and glossopharyngeal nerve

phrenic nerve innervates?

Diaphragm muscle (causes contraction)

HCO3- leaves RBCs, and chloride ions enter via?

chloride shift (antiport)

(also called the Hamburger phenomenon)

Expiration muscles?

internal intercostal & abdominal muscles (pushes diaphragm up)

Any defect in Meissner's plexus causes?

malabsorption