a&p 2 test 2

Explain the changes in breathing that accompany exercise

Breathing depth increases as rate remains the same. Blood PO2 and PCO2 remains the same. There is an increase in cellular respiration compensated by deeper breathing with an increased cardiac output and greater blood flow

Explain the different reflexes that alter breathing rate and depth

Chemoreceptors alter breathing by sending signals to DRG which then are relayed to VRG. VRG triggers changes in rhythm and force of breathing. Rate changes by altering amount of time in inspiration and expiration. Depth changes by stimulation of accessory muscles

Distinguish the action of the muscularis mucosae from that of the muscularis tunic

Contractions of the muscularis mucosae facilitate release of secretions into lumen, whereas contractions of the muscularis tunic mix and propel contents within the GI tract.

Describe how breathing rate and depth affect venous return of blood and lymph

If someone is hyperventilating or breathing more than needed than there is an increase in venous return and lymph and hypoventilation decreases the venous return and to the lymph because of the lack of inspiration

Explain why the proteolytic enzymes of the stomach and pancreas are synthesized in inactive forms.

Inactive to prevent the enzymes from breaking down proteins in the cells that produce the enzymes

Describe inhalation. Describe all structures, muscles that contract

Inhalation or inspiration brings air into the lungs and expiration forces air out of the lungs. The diaphragm flattens when it contracts and the external intercostal muscles elevate the ribs. These muscles relax for expiration

Describe the innervation of lung structures by the autonomic nervous system

Innervates smooth muscles and glands of respiratory system

Explain the autonomic properties that keep the lungs inflated

Intrapleural pressure is low which makes the chest wall expand outward. Because the intrapulmonary pressure (in alveoli) is greater than intrapulmonary pressure the lungs remain inflated

Briefly describe the general process of absorption

Involves membrane transport of digested molecules, electrolytes, vitamins, and water across the epithelial lining of the GI tract into the blood or lymph; occurs primarily in the small intestine

Explain how pressure gradients and resistance determine airflow

It depends on the pressure gradient established between atmospheric pressure and intrapulmonary pressure. And the resistance that occurs due to conditions within the airways, lungs, and chest wall.

Name the two anatomic features of the respiratory membrane that contribute to efficient alveolar gas exchange

Large surface area and minimal thickness

Identify and briefly describe the numerous roles of the liver in metabolism

Liver responsible for carb metabolism, protein metabolism, lipid metabolism

Describe the anatomy of the small intestine

Long tube inferior to the stomach and located medially within the abdominal cavity; divided into duodenum, jejunum, ileum

Describe the bacterial action that takes place in the large intestine

Lots of indigenous microbiota that help in breakdown of macronutrients, produce CO2, H+, B vitamins, and vitamin K

Describe the location and general structure of the lung

Lungs are located on either side of the mediastinum. House the bronchial tree and all respiratory portions of respiratory system. Each lung has a conical shape. Has wide concave base and an apex points superiorly just behind clavicle

Explain the process of mastication

Mastication is chewing. It mechanically reduces bulk to facilitate swallowing, increases surface area to facilitate exposure to digestive enzymes, promotes salvation; it requires coordinated activities of teeth, lips, tongue, cheeks, and jaws; it's controlled by nuclei in medulla and pons, mastication center

Define metabolic rate

Measure of energy used in a defined period of time

Explain the function of the mesentery and describe the five individual mesenteries of the abdominopelvic cavity

Mesentery - double layer of peritoneum that supports, suspends, and stabilizes the intraperitoneal GI tract organs i. Greater omentum - "fatty apron" insulates the abdominal organs and stores fat ii. Lesser omentum - connects the superomedial surface of the stomach and the proximal end of the duodenum to the liver iii. Falciform ligament - attaches liver to the internal surface of the anterior abdominal wall iv. Mesentary proper - fan shaped fold of peritoneum that suspends most of the small intestine Mesocolon - fold of peritoneum that attaches the large intestine to the posterior abdominal wall

Identify the anatomic structures of the oral cavity

Mouth, vestibule, oral cavity proper, cheeks, lips, soft palate, hard palate, uvula, fauces, tongue

Describe the anatomic structures involved in regulating breathing

Muscles accompanied with regular or quiet breathing is the diaphragm and external intercostals. The diaphragm flattens when it contracts and the external intercostal muscles elevate ribs. They relax for expiration

Define partial pressure and the movement of gases relative to a partial pressure gradient

Partial pressure is a pressure exerted by each gas within a mixture of gases, measured in mmHg. Both types of gas exchange depends on gradients. - Alveolar gas exchange: between blood in pulmonary capillaries and alveoli. - Systematic gas exchange: between blood in systematic capillaries and systemic cells

Describe the function of the trachea

Passageway for air, moistens and warms it while it passes into the lungs, and protects the respiratory surface from foreign particles

Identify the six organs that make up the gastrointestinal (GI) tract

Pharynx, esophagus, stomach, small intestine, large intestine, and anus

Distinguish between the two types of blood circulation through the lungs

Pulmonary circulation and bronchial circulation. - Pulmonary circulation replenishes O2 and eliminates CO2. Pulmonary arteries carry deoxygenated blood to pulmonary capillaries where it is reoxygenated and then the blood enters pulmonary venules and veins and returns to left atrium. - Bronchial circulation transports oxygenated blood to tissued of lungs. Bronchial veins collect venous blood and some of it drains into pulmonary veins.

Distinguish between quiet and forced breathing

Quiet breathing is rhythmic breathing at rest and forced breathing is vigorous breathing accompanies with exercise

Describe the sources and functions of cholesterol

Required as component of plasma membrane, precursor for steroids and bile salts and vitamin D, comes from diet or liver

Explain the physiologic events associated with controlling quiet breathing

Respiration for normal, quiet breathing is eupnea. Average is 12-15 breaths/minute. Pontine respiratory center facilitates smooth transitions between inspiration and expiration. Sends signals to medullary respiratory center

Explain the structure of the respiratory membrane

Respiratory membrane is a thin barrier separating air into alveoli and blood in pulmonary capillaries. Consists of alveolar epithelium and its basement membrane, and capillary epithelium and its basement membrane. Two basement membranes are fused

Explain the processing in the oral cavity that initiates carb digestion

Salivary amylase breaks the bonds between glucose molecules in the oral cavity. It is inactivated within 20 minutes by the low pH of the stomach when the bolus is swallowed

List the accessory organs and structures involved in the digestive process

Salivary glands, liver, pancreas, teeth, tongue, and gallbladder.

Compare and contrast the right versus left lung

The right lung is larger with three lobes and the left lung has two lobes (because left side of body also houses the heart). Right lung has horizontal fissure and oblique fissure. Left lung has oblique fissure

Describe the components of the upper gastrointestinal tract

a. Oral cavity and salivary glands- mechanical digestion begins, saliva secreted from salivary glands contains salivary amylase, which is an enzyme initiating digestion of starch- mixed with ingested materials to form bolus b. Pharynx- bolus moved to pharynx during swallowing, mucus secreted to facilitate swallowing c. Esophagus- bolus transported from pharynx into stomach; lubricated by mucus secretions d. Stomach- bolus mixed with gastric secretions by smooth muscle contractions; secretions produced by epithelial cells of stomach; chyme formed from mixing e. Duodenum of small intestine for some reason

pathway of air during exhalation

alveoli > bronchioles > tertiary bronchi > secondary bronchi > primary bronchi > trachea > pharynx > nasal cavities

residual volume

amount of air left in the lungs after the most forceful expiration

tidal volume

amount of air per breath

lung capacity

maximum volume of air that the lungs can hold -Sum of all volumes including residual volume

pathway of air during inhalation

nasal cavities > pharynx > trachea > primary bronchi > secondary bronchi > tertiary bronchi > bronchioles > alveoli

vital capacity

total amount of air a person can exchange through forced breathing. -Tidal volume + inspiratory and expiratory reserve volumes

Describe the phases that regulate motility and secretion in the stomach.

· Cephalic phase: involves cephalic reflex, initiated by thought of food; nerve signals are sent to the hypothalamus, which relays nerve signals to medulla oblongata; increases vagal stimulation of stomach; causes increase in motility and secretory activity; stomach "growls" · Gastric phase: process following bolus reaching stomach; regulated via gastric reflex (baroreceptors detect stomach stretch) and release of gastrin hormone (presence of food, especially protein, in stomach causes release. Gastrin stimulates contractile activity and HCl release, also contracts pyloric sphincter to slow stomach emptying); chemoreceptors detect protein and increased pH; stimulates medulla oblongata -> increases stomach motility and secretion activity · Intestinal phase: processes following chyme reaching small intestine; involves intestinal reflex (opposes cephalic and gastric reflexes, chyme in duodenum signals to medulla oblongata causing decrease in motility and secretory activity of stomach) · Cholecystokinin (CCK) and secretin also decrease stomach motility and secretory activity

Explain how both basal metabolic rate and total metabolic rate are measured and the variables that influence each

• Basal - BMR - amount of energy used at rest; can be measured by a calorimeter or a respirometer • Decreases with age — 3% decrease each decade beginning at age 30; greater lead body mass - higher BMR; thyroid hormone increases BMR; greater body surface area, higher BMR • Total - TMR — BMR + metabolism associated with physical activity - Depends on amount of skeletal muscle used and its activity, food intake, and changing environmental conditions - Can be measured by calorimeter and respirometer - Increases if cold temperature, increases following ingestion of a meal

Explain how both blood and bile flow through the liver

• Blood - To the liver — hepatic portal vein - Blood transported through hepatic sinusoids, enter hepatocytes where macrophages clear harmful substances, then hepatic veins empty blood into inferior vena cava • Bile - Formed within hepatocytes and is released into bile ducts and then into the left or right hepatic duct and into the gallbladder

Name the three major regions of the large intestine and four segments of the colon of the large intestine

• Cecum - first portion • Colon - in order — ascending, transverse, descending, sigmoid • Rectum - Anal canal — last few centimeters of large intestine

Discuss the regulation of the accessory digestive structures associated with the small intestine

• Cholecystokinin (CCK) - Hormone released from small intestine in response to fatty chyme • Stimulates gallbladder to strongly contract and release bile, stimulates pancreas to release pancreatic juice, relaxes smooth muscle within hepatopancreatic ampulla which allows entry of bile and pancreatic juice into small intestine; inhibits stomach motility and release of gastric secretions • Secretin - Released from small intestine in response to increased chyme acidity; causes release of alkaline solution containing HCO2 from liver and ducts of pancreas to help neutralize acidic chyme; inhibits gastric secretions and motility

Explain the relationship of dietary intake of cholesterol and level of cholesterol synthesis in the liver

• Cholesterol synthesis — synthesized by hepatocytes by fatty acids that have been broken down into acetyl CoA - Acetyl CoA is synthesized into cholesterol by HMG-CoA reductase • Synthesis decreases with higher cholesterol intake and vice versa • Once formed, cholesterol is released into the blood in VLDL form or it is synthesized into bile salts

Difference between a complete or an incomplete protein

• Complete — contain all essential amino acids, general animal proteins • Incomplete - do not contain all essential amino acids, Generally plant proteins

Define core body temperature and explain why it must be maintained

• Core body temp — temperature of vital portions of body — head and torso • Must be maintained so those vital organs stay at a temperature that is optimal for performance — cells can't work if too cold or too hot

Describe where the following nutrient molecules enter the metabolic pathway of cellular respiration: glucose, the breakdown products of triglycerides, and amino acids

• Glucose — enters at glycolysis • Breakdown products of triglycerides — glycolysis if glycerol, fatty acids broken down into acetyl-CoA enters at citric acid cycle • Amino acids — depends on the specific amino acid where it enters

Describe the digestion of nucleic aids

• In small intestine — deoxyribonuclease and ribonuclease (Released by pancreas) break the phosphodiester bonds between nucleotides of DNA and RNA • Brush border enzymes in the small intestine • Phosphatase — breaks bonds holding phosphate • Nucleosidase — breaks bond between sugar and nitrogenous base • Components are then absorbed across epithelium of small intestine

Identify the enzyme that initiates protein digestion in the stomach and explain its activation and action

• In stomach — pepsin - The low pH caused by HCl released from parietal cells activates pepsinogen to form pepsin. Pepsin denatures proteins to facilitate their chemical breakdown.

List the glands found in the small intestine and their secretions

• Intestinal glands — secreted intestinal juice • Goblet cells - produce mucin • Unicellular gland cells - synthesize enteropeptidase • Enteroendocrine cells - release hormones such as CCK and secretin • Submucosal gland - produces alkaline mucus secretion protecting duodenum from chyme

Discuss the process by which lipids are absorbed

• Lipids are transported in micelles through the simple columnar epithelial lining. The micelles are absorbed into the cells and break apart. - The triglycerides reform. Sometimes they reform with cholesterol and other lipids and are wrapped with proteins. The triglycerides form chylomicrons which leave by exocytosis and enter the lacteals. The lacteals (lymphatic capillaries of small intestine) enter the blood and deliver lipids to liver and other tissues

Explain the role of bile salts in the mechanical digestion of lipids and the role of pancreatic lipase in the chemical digestion of triglycerides

• Lipids — bile salts are amphipathic and line up around lipid droplets creating a micelle - This emulsifies the lipid and allows greater access of pancreatic lipase to the triglyceride • The bile salt is recovered by active transport in the last portion of the ileum • Pancreatic lipase digests triglycerides into monoglyceride and two fatty acids

Define a lipoprotein, and provide a general overview of their function int he body

• Lipoprotein — lipids with a protein "wrap" to facilitate transport • Basically transport lipids to the peripheral tissues

Describe the accessory digestive organs associated with the small intestine and the contributions of each to digestive processes

• Liver — produces bile, which helps mechanically digest lipids • Pancreas - Endocrine function — produces and secretes insulin and glucagon - Exocrine function — ordures pancreatic juice to assist in digesting starch, triglycerides, proteins, and nucleic acids • Gallbladder — stores, concentrates, and moves bile produced in liver

Distinguish macronutrients from micronutrients and essential from nonessential nutrients

• Macro — must be consumed in large quantities, needed in daily amounts, carbs, lipids, proteins • Micro — must be consumed in small quantities, vitamins and minerals • Essential - must be obtained and absorbed via digestive system from diet • Nonessential - provided by biochemical processes of body - Not required in diet

Name three classes of carbohydrates

• Monosaccharides - glucose and fructose • Disaccharides — sucrose, maltose • Polysaccharides - starch and cellulose

Explain the distinguishing histologic features of the large intestine

• Mucosa lined by simple columnar epithelium, lots of goblet cells, no intestinal villi, many lymphatic nodules • Two layers of smooth muscle — outer longitudinal layer is discontinuous and forms teniae coli

Describe why protein is required in our diet and the amount that is needed

• Needed to replace worn out protein structures - General amount needed depends on age and sex

Explain the neural and hormonal controls of temperature regulation

• Neural — mediated by hypothalamus - Motor pathways to sweat glands, skeletal muscles, and peripheral blood vessels - Decrease in body temps — sweat glands inhibited, vasoconstriction of blood vessels, skeletal muscle contraction to generate heat (shivering) • Hormonal — mediated by multiple hormones — thyroid, epinephrine, norepinephrine, growth hormone, testosterone - Thyroid hormone most important — establishes metabolic rate Raises body temp by increasing metabolic rate of all cells

- Discuss nitrogen balance

• Nitrogen balance - Proteins are a source of nitrogen • Needed for synthesizing nitrogen containing molecules - DNA, RNA, porphyrin - Equilibrium can occur between dietary intake and loss - Positive nitrogen balance - absorbing more nitrogen than exerted • During growth, pregnancy, recovering from injury - Negative nitrogen balance - more nitrogen excreted than absorbed • During blood loss, malnutrition • Can be fatal

Define nutrition and nutrients

• Nutrition — study of how living organisms obtain and utilize nutrients needed to grow and sustain life • Nutrients - include most biological macromolecules, vitamins, and minerals that the body needs for development and growth, maintenance of anatomic structures and physiologic processes, and repair of damaged tissues

Describe the chemical digestion of carbs in the small intestine

• Pancreatic amylase, a component of pancreatic juice, continues digestion of starches. It breaks them down into shorter strands of glucose, maltose, and individual glucose. • The brush border completes starch breakdown using dextrinase and glucoamylase to break the bonds between glucose subunits of oligosaccharides - It also uses maltase to break bonds between two glucose molecules - Digestion of other disaccharides requires one enzyme each, named for the substrate it digests • Ex. Lactase digests lactose to glucose and galactose • Ex. Sucrase digests sucrose to glucose and fructose • Monosaccharides absorbed across lining — transported to liver where fructose and galactose are converted to glucose • CANNOT digest cellulose

- Identify the types and dietary sources of triglycerides and describe their function

• Saturated - No double bond, solid at room temp - Meat, milk, cheese, coconut oil, palm oil • Unsaturated - One double bond - Liquid at room temp - Nuts, canola oil, olive oil. Sunflower oil • Polyunsaturated - Two or more double bonds, liquid at room temp Soybean oil, corn oil, safflower oil

Explain motility within the small intestine

• Smooth muscle mixes chyme with gland secretions - Segmentation occurs (back and forth motion) - Peristalsis propels contents

Identify the categories that are dietary sources of carbs and give examples of each category

• Sugars - Monosaccharides — glucose, fructose, galactose - Disaccharides — sucrose, lactose, maltose (cereal) - Dextrose, brown sugar, honey, molasses • Starch - Polysaccharide polymer of glucose molecules found in tubers, grains, beans peas • Refined starches sometimes added as thickeners and stabilizers — ex. Cornstarch • Fiber - Include fibrous molecules of both plants and animals — cannot be digested and absorbed by human GI tract Lentils, peas, beans, whole grains, oatmeal, berries, nuts

Describe the transport of lipids within the blood

• VLDLs take triglycerides from liver to peripheral tissue, once the lipid is released, they become LDLs • LDLs — high amount of cholesterol, deliver cholesterol to cells • HDLs take lipids from peripheral tissue back to the liver

Describe the absorption of water, electrolytes, and vitamins

• Water — small intestine absorbs almost all ingested water, large intestine absorbs some, rest passed in feces - Absorbed across epithelia and into blood vessels via osmosis • Electrolytes — small intestine absorbs almost all, unregulated and depends on diet BUT iron has controlled absorption - Iron — hepcidin, released by the liver, inhibits iron absorption. Levels are decreased when iron is low and vice versa. • Vitamins - Fat soluble • A, D, E, K — absorbed in small intestine along with lipids within micelles - Water soluble B, C - absorbed through diffusion and active transport

Explain the deamination of proteins

Amine group is removed within the liver hepatocytes, amine group is converted to urea

Define airflow

Amount of air moving in and out of lungs with each breath

Explain the meaning of recommended daily allowance.

Amount of each nutrient that must be obtained each day, established values for nutrients set by federal agencies

Explain the processes of bronchoconstriction and bronchodilation

- Bronchoconstriction= less air through bronchial tree (less entry of harmful substances). - Bronchodilation= more air through the bronchial tree

Describe the three ways carbon dioxide is transported in the blood

- CO2 can dissolve in plasma (7%) - CO2 attaches to anime group of globin portion of hemoglobin (23%) - CO2 as bicarbonate dissolved in plasma (70%)

Describe the general function of the enteric nervous system and autonomic nervous system in the regulation of the digestive system.

- Enteric nervous system: innervates smooth muscle and glands of GI tract; coordinates mixing and propulsion reflexes - Autonomic nervous system: parasympathetic innervation promotes GI tract activity; sympathetic innervation opposes it.

Explain how hyperventilation and hypoventilation influence the chemical composition of blood.

- Hyperventilation can cause the respiratory alkalosis. The breathing rate or depth is above the body's demand. The additional oxygen that is in the blood does not bind to hemoglobin because the body already has enough oxygen bound to hemoglobin (saturated). - Hypoventilation can cause the opposite. There is not enough breathing and oxygen in the body. The lower rate of oxygen causes too much CO2 in the body and can lead to hypoxia.

Distinguish between intraperitoneal and retroperitoneal organs

- Intraperitoneal organs: organs completely surrounded by visceral peritoneum; includes stomach, most of small intestine, and parts of the large intestine - Retroperitoneal organs: only anterolateral portions covered with peritoneum; they lie directly against posterior abdominal wall; includes most of duodenum, the pancreas, ascending and descending colon, and the rectum.

Explain the details of vitamin B 12 absorption

- Large, so absorbed by receptor-mediated endocytosis - Requires intrinsic factor formed by parietal cells in the stomach

Compare long reflexes and short reflexes that regulate the digestive system.

- Long reflexes: involve sensory input to CNS and autonomic motor output; coordinate GI tract mobility, secretions, and accessory digestive organs - Short reflexes: local reflexes, only involves ENS; coordinate small segments of GI tract

Name the three substances carried by hemoglobin

- Oxygen attached as iron - CO2 bound to the globin - Hydrogen ions bound to globin

Describe the structure of the serous membranes associated with the GI tract

- Parietal peritoneum lines the inner surface of the abdominal wall, visceral peritoneum covers the surface of internal organs within the abdominopelvic cavity. Between the two is a space called the peritoneal cavity which contains serous fluid - This serous fluid lubricates both the internal abdominal wall and the external organ surfaces - reduces friction

Describe the pleural membranes and the pleural cavity.

- Pleural membranes line the lung surface and thoracic wall. - The pleural cavity is considered extra space when the lungs are inflated

Differentiate between alveolar and systemic gas exchange

- Systemic gas exchange facilitates internal respiration. Oxygenated blood flows into the capillaries through the rest of the body. The blood diffuses oxygen into cells and absorbs carbon dioxide. - Alveolar gas exchange is where the oxygen moves from the lungs to the bloodstream. CO2 passes from the blood to the lungs

Explain ventilation-perfusion coupling and how it maximizes alveolar gas exchange

- Ventilation: perfusion coupling is the bronchioles ability to regulate airflow and arterioles to regulate blood flow (bronchoconstriction and bronchodilation). - Maximizes alveolar gas exchange because perfusion affects the flow of blood in the capillaries which is important for gas exchange which must be high enough to create a partial pressure gradient for oxygen in the alveoli

What are the functions of the respiratory system?

-Air passageway- air moves between atmosphere and alveoli as we breathe. -Exchange of oxygen and CO2 ) oxygen diffuses from alveoli into blood) and (CO2 diffuses from blood into alveoli) -Detection of odors -Sound production

Describe the structure and function of the components of the respiratory zone

-Conducting zone is passageways that transport or conduct air. Structures include the passageways from the nose to the end of the terminal bronchioles. - Components: Respiratory Bronchioles, Alveolar ducts, and Alveoli - Respiratory Bronchioles - S: subdivide to alveolar ducts and lined with simple cuboidal epithelium. - F: participate in gas exchange - Alveolar ducts/Alveoli - S: lead to alveolar sacs (clusters of alveoli), lined with simple squamous - F: participate in gas exchange

List and describe the six general functions of the digestive system

1. Ingestion- introduction of solid and liquid nutrients into the oral cavity; first step in process of digesting and absorbing nutrients. 2. Motility- voluntary and involuntary muscular contractions; mixing and moving materials through GI tract. 3. Secretion- process of producing and releasing fluid products facilitating digestion (e.g., digestive enzymes, acid, and bile). 4. Digestion- breakdown of ingested food into smaller structures. a. Mechanical digestion: material physically broken down by chewing and mixing. b. Chemical digestion: involves specific enzymes to break chemical bonds; changes large complex molecules into smaller molecules. 5. Absorption- transport of digested molecules, electrolytes, vitamins, and water; move from GI tract into blood or lymph. 6. Elimination- expulsion of indigestible components that are not absorbed.

List and describe the four tunics (layers) that make up the gastrointestinal wall.

1. Mucosa (innermost layer)- a. epithelium: simple columnar for secretion and absorption & nonkeratinized stratified squamous for portions that must withstand abrasion (esophagus, oral cavity). b. Underlying lamina propria: areolar tissue, small blood vessels, and nerves; absorption occurs when substances move into these vessels. c. Muscularis mucosae: smooth muscle deep to lamina propria; contractions facilitate release of secretions into lumen, increase contact of materials with mucosa. 2. Submucosa- a. Areolar and dense irregular connective tissue b. Blood vessels, lymph vessels, and nerves c. Submucosal nerve plexus: nerves and ganglia innervation smooth muscle and glands d. Houses mucosa-associated lymphatic tissue (MALT) which prevents ingested microbes from crossing GI tract wall e. Contains peyer patches- larger aggregates of lymphatic nodules in distal small intestine. 3. Muscularis- forms sphincters; functions in mixing and propulsion (using peristalsis- sequential contraction of muscularis) a. Inner circular layer of muscle- smooth muscle oriented circumferentially within GI tract; contraction constricts tube lumen b. Outer longitudinal layer- cells orients lengthwise along GI tract; contraction shortens tube c. Myenteric nerve plexus- axons and ganglia between layers control contractions d. Enteric nervous system- submucosal plexus and myenteric plexus; detects changes in tract wall and chemical makeup of lumen content 4. Adventitia (serosa) (outermost layer)- which one depends on organ location a. Adventitia- areolar connective tissue; found outside the peritoneal cavity b. Serosa- same composition as adventitia; completely covered by visceral peritoneum; found within peritoneal cavity

List three types of cells found in alveoli and describe the function of each

Alveolar Type I Cells, Alveolar Type II cells, and Alveolar macrophage - Type I: (squamous alveolar cells) most common of the two cell types making up alveolar wall. 95% of alveolar surface area. Form alveolar epithelium of respiratory membrane. - Type II: (septal cells) secrete oily pulmonary surfactant. Coats inside of alveolus and opposes collapse during expiration. - Alveolar Macrophage: (dust cells) leukocytes that engulf microorganisms. Either fixed in alveolar wall or free to migrate

Describe alveolar gas exchange and the partial pressure gradients responsible

Alveolar gas exchange is where the PO2 of oxygen is 04 mmHg and the PO2 of blood entering pulmonary capillaries is 40 mmHg. - The oxygen diffuses across respiratory membrane from alveoli from capillaries. This continues until the PO2 is equal to the alveoli. - The PCO2 in alveoli diffuses from blood to alveoli, and moves down the pressure gradient until blood levels equal alveoli levels.

Describe exhalation. Describe all structures, muscles that contract

During exhalation the diaphragm relaxes causing the thorax and lungs to recoil

Describe the differences between passive and active exhalation

Exhalation is normally passive because of the elastic properties of the lungs

Where does the exchange of oxygen and carbon dioxide take place?

Gas exchange takes place within the alveoli. Oxygen diffuses across respiratory membrane from alveoli into the capillaries.

List the major hormones that regulate the processes of digestion

Gastrin, secretin, cholecystokinin, motilin

Explain why hemoglobin is essential to oxygen transport

Hemoglobin is essential to oxygen transport because the iron in hemoglobin attaches to about 98% of O2 in blood and it is bound to hemoglobin

Explain the laws that govern gas solubility

Henry's Law: at a given temperature, the solubility of a gas in liquid is dependent upon the partial pressure of the gas in the air and solubility coefficient of the gas in the liquid

Explain the function of serous fluid in the pleural cavity

Serous fluid in the pleural cavity allows for pleural surfaces to slide by easily

Describe the three components of the lower GI tract

Small intestine, accessory digestive organs, large intestine

Describe the structural divisions of the bronchial tree

The bronchial tree is divided into 2 main parts, the primary bronchi and the secondary bronchi. The trachea splits into right and left main bronchi (primary) at level of sternal angle. It then enters into each lung on medial surface. The right bronchus is shorter, wider, and more vertically oriented. The bronchi then branches into lobar bronchi (secondary). Each extends into lobe of lung. From there they extend into smaller and smaller passageways known as bronchioles and terminal bronchioles (last part of conducting zone). This then leads to respiratory bronchioles (first part of respiratory zone).

Explain the significance of the oxygen-hemoglobin saturation curve for both alveolar and systemic gas exchange.

The oxygen-hemoglobin saturation curve is important for both alveolar and systematic gas exchange because if there is not enough oygen to bind to hemoglobin than it can affect the partial pressure gradients in a negative way. This is what can cause altitude sickness

Describe the physiological advantages of the ability to interconvert nutrient biomolecules

This way we don't need to only ingest one type of macronutrient and probably starve, we can ingest anything and use anything if we need to

Explain the structure and function of the tracheal cartilages

Tracheal cartilages support anterior and lateral walls. The C-shaped rings of hyaline cartilage ensure that the trachea is always open. These rings are made from perichondrium and dense fibrous membranes. The rings are connected to each other by annular ligaments.

Explain the partial pressure gradients between systemic cells and the blood in capillaries

When blood enters the systemic capillaries the blood will lose oxygen and gain CO2. This occurs because the pressure differences of the tissues and blood. The pressure gradient drives the diffusion of oxygen out of the capillaries and into tissue cells

Discuss the structure and development of the teeth

· Collectively known as the dentition; exposed crown and constricted neck; one or more roots, anchoring it to jaw, fit tightly int dental alveoli (sockets within alveolar processes; bound to processes by periodontal ligament; gomphosis joint: roots, dental alveoli, and periodontal ligament Made of: dentin (primary mass of tooth, harder than bone), enamel (on external surface of dentin, forms crown, calcium phosphate crystals), pulp cavity (center of tooth filled with CD and pulp), root canal (continuous with pulp cavity, opens to tissue around root, blood vessels and nerves passing through here), and cementum (hardened material ensheathing root) · 20 deciduous teeth (erupt between 6-30 months), replaced by 32 permanent teeth · Incisors- most anteriorly placed teeth; shaped like chisel for slicing food · Canines- posterolateral too incisors; pointed tip for puncturing and tearing food · Premolars- posterolateral to canines; flat crowns with prominent ridges (cusps) that crush and grind · Molars- most posteriorly placed teeth; large broad crowns and cusps; grinding and crushing materials · In each quadrant: 2 incisors, 1 canine, 2 premolars, 3 molars (3rd molars are wisdom teeth)

Explain the two general functional activities of the stomach.

· Gastric mixing: mechanical digestion- changes semidigested bolus into chyme · Gastric emptying: movement of acidic chyme from stomach into duodenum; pressure gradient moves contents towards pylorus, opening sphincter, a small amount of chyme enters then sphincter closes, with retropulsion (reverse flow of some contents back toward the stomach

Describe the gross anatomy of the stomach

· Gross anatomy: muscular J-shaped organ - Greater curvature- larger convex inferolateral surface - Lesser curvature- smaller concave superomedial surface - 4 regions of stomach: 1. Cardia: superior entryway into stomach lumen from esophagus; cardiac orifice (where cardia meets esophagus) 2. Fundus: dome-shaped region superior and lateral to esophageal connection 3. Body: largest region of stomach, inferior to cardiac orifice and extends to pylorus 4. Pylorus: funnel-shaped pouch forming terminal region; opening into duodenum, of small intestine (pyloric orifice); pyloric sphincter (ring of circular smooth muscle surrounding orifice) regulates entry of material into duodenum - Gastric folds (rugae): found on internal stomach lining when stomach is empty; allows stomach to expand greatly when it fills with food; returns to normal when empty

describe the histology of the stomach

· Histology: lined by simple columnar epithelium supported by lamina propria - Lining indented by depressions called gastric pits - Gastric glands: extend deep into mucosa from base of each gastric pit; partially surrounded by muscularis mucosae; helps expel gastric secretions - Muscularis of stomach: 3 smooth muscle layers (compared to the 2 layers of thee rest of GI tract)- inner oblique, middle circular, and outer longitudinal; 3rd layer helps with churring and blending; thickens as progresses from body to pylorus -Visceral peritoneum (a serosa) is the outermost layer of the stomach wall

Discuss the anatomy of the pharynx and esophagus and their complementary activities in the process of swallowing

· Pharynx: funnel-shaped muscular passageway for air and food; formed by 3 skeletal muscle pairs (superior, middle, and inferior pharyngeal constrictors); lined with nonkeratinized stratified squamous epithelial (to protect against abrasion) · Esophagus: normally collapsed, tubular passageway; begins at level or cricoid cartilage; directly anterior to vertebral bodies; inferior region connecting to the stomach; passes through opened in diaphragm (esophageal hiatus) -Superior esophageal sphincter: contracted ring of circular skeletal muscle at superior end; area where esophagus and pharynx meet; closed during inhalation of air - Inferior esophageal sphincter: contracted ring of circular skeletal muscle at inferior end; not strong enough by itself to stop stomach contents from regurgitating, diaphragm muscles help · Swallowing (deglutition): first voluntary phase, then bolus goes into oropharynx. - pharyngeal phase is an involuntary reflex; initiate sensory input to swallowing center in medulla oblongata and signals sent to effectors - Elevation of soft palate and uvula to block passageway between oropharynx and nasopharynx; elevation of larynx by extrinsic muscles; move epiglottis to cover laryngeal opening; nerve signals sent to medulla oblongata to ensure breath not taken during swallowing. - Bolus moves to esophagus: esophageal phase is involuntary, bolus passes through esophagus; bolus stimulates sequential waves of muscular contraction; esophageal sphincters closed at rest, relax when bolus is swallowed, contract again afterwards, preventing reflux of materials

1. Describe the structure and function of salivary glands and how the release of saliva is regulated.

· Structure of salivary glands: Mucous cells secrete mucin, forming mucus upon hydration; serous cells secrete watery fluid containing electrolytes and salivary amylase. · Functions of saliva: moisten ingested food to help become bolus, salivary amylase initiates chemical breakdown of starch, food molecules dissolved here so taste receptors stimulated, cleanses oral cavity structures, antibacterial substances inhibit bacterial growth (lysozyme, lgA antibodies). · Regulation of salivary secretions: regulated by salivary nuclei within brainstem; basal level of salivation in response to parasympathetic stimulation; receptors detect stimuli (especially acids) in oral cavity and stomach; sympathetic stimulation results in a more viscous saliva. · Two types of salivary glands: a. Intrinsic salivary glands (within oral cavity)- continuously release secretions independent of food; contains lingual lipase- enzyme that begins digestion b. Extrinsic salivary glands (outside of oral cavity)- produce most saliva i. Parotid salivary glands (largest salivary glands)- anterior and inferior to ear; 25-30% of saliva; saliva conducted through parotid duct to oral cavity; infection causes mumps ii. Submandibular salivary glands- inferior to oral cavity floor and media to mandible body; 60-70% saliva; submandibular duct opens from each gland to floor of cavity iii. Sublingual salivary gland- inferior to tongue and medial and anterior too submandibular glands; extends tiny ducts into inferior surface of cavity; 3-5% saliva

Describe the chemical digestion of proteins that occurs in the small intestine

• 3 enzymes released from pancreas — trypsinogen, chymotrypsinogen, procarboxypeptidase - Enteropeptidase (synthesized in small intestine) activates trypsinogen to trypsin - Trypsin activates more trypsinogen, chymotrypsinogen to chymotrypsin, and procarboxypeptidase to carboxypeptidase - Trypsin and chymotrypsin break bonds between specific amino acids and produce smaller strands of peptides - Carboxypeptidase breaks bonds between amino acids on carboxyl end and the remaining protein • Dipeptidase - Breaks final bond between two amino acids • Aminopeptidase generates free amino acids - Able to be absorbed across small intestine epithelial lining • Proteins can be used as building blocks for new proteins or can be transported to liver to make glucose