EXAM 4: RETAKE

When air is no longer moving through the respiratory tract and the airway is open to the environment, the pressure within the lung is equal to

the atmospheric pressure

The difference between what two pressures drives air into and out of the lungs?

atmospheric and intra-alveolar

Which of the following occurs when intra-alveolar pressure exceeds atmospheric pressure?

Air moves out of the lung

What does contraction of the diaphragm cause?

Increase in thoracic volume and a decrease in intra-alveolar pressure

What are the primary inspiratory muscles?

diaphragm and external intercostals

At rest, expiration is an process that involves _

passive; relaxation of the diaphragm and external intercostals

The compliance of the lung is determined by the elasticity of the lung and

surface tension

The surface tension of the alveolus is reduced by surfactants produced by what type of cells?

type II alveolar cells

A(n) is used clinically to measure lung volumes and rates of air flow.

spirometer

What is the volume of air moved into and out of the lungs in a single breath during unforced breathing called?

tidal volume

What is the term for the volume of air moved into the lungs every minute?

minute ventilation

What is the volume of the respiratory pathway that is NOT able to exchange gases (conducting pathway) called?

anatomical dead space

What is the primary determinant of airway resistance?

airway radius

Oxygenated blood is found in which of the following?

pulmonary vein

Movement of oxygen and carbon dioxide between alveoli and blood occurs by what process?

simple diffusion

In a mixture of gases, the driving force for the movement of an individual gas within that mixture is ultimately

partial pressure

What percentage of air is oxygen?

21%

What is an increase in alveolar ventilation to match the demands of increased metabolic activity in the cells called?

hyperpnea

Hyperventilation would lead to an within the systemic arteries

increase in PO2 and decrease in PCO2

The majority of oxygen present within the blood is

bound to hemoglobin in red blood cells

Which statement best describes why oxygen is unloaded in tissue that is highly active?

As temperature increases, the affinity of hemoglobin for oxygen decreases

What is the primary mechanism of carbon dioxide transport in blood?

as bicarbonate dissolved in the plasma

The is the respiratory center that appears to facilitate the transition between inspiration and expiration

pontine respiratory group

Central chemoreceptors are neurons in the medulla that respond directly to changes in

cerebrospinal fluid pH

As the food is broken into smaller pieces in the mouth, it is combined with that facilitates its movement down the esophagus.

saliva

The flow of chyme from the stomach to the small intestine is physically regulated by the

pyloric sphincter

What cells secrete pepsinogen into the lumen of the stomach?

chief cells

What cells function to secrete hydrogen ions into the lumen of the stomach?

parietal cells

What protects the stomach wall from the acidic lumenal contents?

gastric mucosal barrier

A lacteal is a located in ___

lymphatic vessel; villus

What enzymes, secreted by the exocrine pancreas, degrade fats?

lipases

What degradation by-product of hemoglobin is removed from the blood by the liver, conjugated, and then secreted into the bile?

bilirubin

The absorption of glucose involves across the apical membrane and _ across the basolateral membrane

secondary active transport; facilitated diffusion

The digestion of proteins begins in the with the activation of the enzyme

stomach; pepsinogen

In order to begin the process of fat digestion, the fat globules must be

emulsified by bile salts

Pancreatic lipase degrades triglycerides into a

monoglyceride and 2 free fatty acids

Lipids are absorbed as into

chylomicrons; lacteals

Vitamin B12 is absorbed in the

duodenum : cotransport with sodium

Many individual amino acids enter the epithelial cells that line the lumen of the digestive tract via what transport process?

sodium-linked secondary active transport

Gastric-phase control of gastrointestinal function refers to its site of origin, which is

the stomach

The secretion of cholecystokinin is predominantly regulated by

protein digestion products and fat presence in the duodenum

What does propelling food to the back of the mouth with the tongue initiate?

the swallowing reflex

What is the main job of the pharynx?

propulsion

Where does peristalsis occur?

esophagus, stomach, and small intestine

What is the function of segmentation in the small intestines?

mixing the chyme

What reflex protects the small intestine by inhibiting contractions while the intestines are injured or severely distended?

intestino-intestinal reflex

What stimulates the defecation reflex?

distention of the rectum

What is a mass movement?

a peristaltic-like wave in the large intestine that propels the contents toward the rectum

Which sphincter is composed of skeletal muscle between the anus and external environment?

external anal sphincter

Which of the following specifically describes the movement of air into and out of the lungs?

pulmonary ventilation