Unit 3 A&P

Be able to explain the differences between fat-soluble and water-soluble vitamins, provide examples of each type and what happens if we have too much or too little of a particular vitamin.

Fat Soluble: Vitamins A, D, E, and K, Absorbed by lipids too little vitamin A causes night blindness, too much- liver damage Water-Soluble: rapidly exchanged between fluid in digestive tract and circulating blood, Hypervitaminosis (too much of a vitamin) usually doesn't happen because Excesses are readily excreted in urine B1 too little- muscle weakness and heart disease, too much hypotension,

Describe the difference between catabolism and anabolism

Catabolism: Converts large molecules into smaller ones Breakdown of organic substrates releases energy used to synthesize ATP Anabolism: Converts small molecules into larger ones, Synthesis of new organic compounds is an"uphill" process that forms new chemical bonds NOTE: Catabolism makes ATP while Anabolism uses ATP

What causes a cavity? Be able to describe causes and treatment.

Caused by bacterial growth in your mouth and not cleaning your teeth well and eating/drinking sugary foods. Bacterial growth in your mouth which releases substances acidic waste products and makes enamel pH more acidic. To treat is a root canal where the tooth is opened and infected tissue is removed so the canal is cleaned and filled with gutta and then is sealed with fitting and new crown.

Describe histological differences along the length of the small intestines.

Few circular folds in the duodenum, Very prominent plicae & villi in the proximal half of the jejunum, Reduction in plicae & villi as you move to ileum, Distal portion of the ileum lacks plica, Has numerous Peyer's patches in lamina propria

Be able to define basal metabolic rate (BMR). How is it measured?

Is the minimum resting energy expenditure of an awake and alert person, measured by monitoring respiratory activity and energy utilization is proportional to oxygen consumption

Be able to compare ATP production by carbohydrate metabolism and lipid metabolism.

Lipid Metabolism: Cell can gain 120 ATP molecules from the breakdown of one 18-carbon fatty acid molecule, slowly creating ATP Carbohydrate Metabolism: Generates ATP and other high-energy compounds by breaking down carbohydrates, mostly glucose, one molecule gives 30-32 ATP molecules, can be aerobic or anaerobic

What causes ketone bodies to forms during the Postabsorptive State?

Lipid and Amino acid catabolism, generates acetyl-CoA causing ketone bodies to form

Be able to list functions of the oral cavity.

Sensory analysis: Analysis of materials ingested, Mechanical processing: Through actions of teeth, tongue, and palatal surfaces, Lubrication: Mixing with mucus and salivary gland secretions Limited digestion: Begins chemical digestion of carbs and lipids

intrinsic factor

a glycoprotein required for absorption of vitamin B12 in small intestine

hypothermia

abnormally low body temperature

lipolysis

breakdown of fat

glycogenolysis

breakdown of glycogen, occurs quickly, in single step

Describe the structure and the regions of the large intestine. Cite differences in the histology of the small & large intestines

large intestine has no villi, no lymphatic nodules in submucosa, no glands in submucosa while the small intestine does, the walls lack place

hepatocytes

liver cells

Explain what makes up a balanced diet and why such a diet is important.

need all nutrients for homeostasis, Digestive tract must absorb enough fluids, organic nutrients, minerals, and vitamins

What is the functional unit of the kidney?

nephron

Be able to follow the pathway that food would travel through the digestive system

oral cavity --> esophagus --> stomach --> small intestine --> large intestine --> rectum --> anus

colonoscopy

visual examination of the colon

hepatic portal system

the collection of veins carrying blood to the liver

lipogenesis

the metabolic formation of fat

deamination

the removal of an amino group and hydrogen from an amino acid to prepare for Citric acid cycle

masticate

to chew

Cite specific age-related changes in the digestive system

1. Division of epithelial stem cells declines, More susceptible to damage by abrasions, acids, & enzymes, Increased rate of ulcers 2. Smooth muscle tone and general motility decrease, Sphincters become less tight, Cause acid reflux & "heart burn"/GERD 3. Gradual loss of teeth from cavities &/or gingivitis, Accumulation of damage from toxins, Reduced liver function from cirrhosis or other types of liver disease 4. Rates of digestive cancers rise like colon cancer and stomach cancer

Distinguish between the primary energy reserves in the five different metabolic tissue types

1. Liver: Glycogen deposits 2. Adipose tissues: triglycerides 3. Skeletal muscle: Glycogen, glucose 4. Neural tissue: no reserves 5. Other peripheral tissues: no reserves

Describe the function of the tongue.

1. Mechanical processing by compression, abrasion, and distortion 2. Manipulation to assist in chewing and to prepare material for swallowing 3. Sensory analysis by touch, temperature, and taste receptors 4. Secretion of mucins and enzymes 5. Helps to form some consonant sounds

Be able to list, identify, and define the four major layers of the digestive tract

1. Mucosa: It contains the glands that release digestive juices. 2. Submucosa: a thick layer of loose connective tissue that surrounds the mucosa. This layer also contains blood vessels, lymphatic vessels, and nerves 3. Muscularis externa: three-layered thick as outer longitudinal, middle circular and inner oblique layer 4. Serosa: It's the lining that wraps around the stomach to confine it, gives strength to digestive tract

Describe the factors that make protein catabolism impractical.

1. Proteins are more difficult to break apart than complex carbohydrates or lipids 2. A by-product (ammonium ion) is toxic to cells 3. Proteins form the most important structural and functional components of cells

Be able to provide examples of substances that are absorbed into the bloodstream from the stomach

Alcohol and Aspirin

Describe the Absorptive and Postabsorptive states.

Absorptive state: the period following a meal when nutrient absorption is under way, (about 4 hours long) Postabsorptive state: Period when nutrient absorption not under way, Body relies on internal energy reserves for energy demands

What is ketonemia and why is ketoacidosis so dangerous?

Appearance of ketone bodies in bloodstream, Lowers plasma pH, which must be controlled by buffers, Prolonged starvation leads to ketoacidosis—dangerous acidification of blood by ketone bodies, can cause body pH to fall below 7.05 which can cause coma, cardiac arrhythmias, and death

Know the phases of swallowing. What happens when the esophageal sphincter is open at the wrong times?

Buccal phase where bolcus is compressed against hard palate, so the tongue retracts and forces the bolus into the oropharynx and elevates soft palate which seals off the nasopharynx. After bolus enters oropharynx the reflex responses begin and bolus moves toward stomach Pharyngeal Phase: Bolus comes in contact with palatoglossal and palatopharyngeal arches and the posterior pharyngeal wall. Elevates larynx and folding of epiglottis direct the bolus past closed glottis. The uvula and soft palate block passage back to nasopharynx Esophageal phase: contraction of pharyngeal muscles make bolus go through the entrance of esophagus then the bolus is pushed to stomach by peristalsis Bolus Enters Stomach: The approach of the bolus trigger the opening of the lower esophageal sphincter. The bolus then continues into stomach If it stays open at the wrong time that means food and liquid can move back into the esophagus from stomach and can cause heartburn or acid reflux

Describe the regulation of gastric activity and be able to identify what happens in the three phases

Cephalic Phase: Sight, smell, taste, &/or thought of food cause CNS to prepare the stomach to receive food, Increase production of gastric secretions, Lasts only minutes Gastric Phase: Begins with the arrival of food into the stomach, Lasts 3-4hrs, Distension of the stomach walls stimulates mixing waves of muscle contractions, Also causes further stimulation of the stomach's secretory cells, Enzymes & acids work on the ingested materials, Production of chyme Intestinal Phase: Chyme enters the small intestines, Controls the rate of gastric emptying, Decreasing stretch of the stomach walls, lowering effect of gastric stretch receptors, Distention of the duodenum stimulates the enterogastric reflex, Inhibits secretory cells, Inhibits gastric contractions

cirrhosis

Chronic disease of the liver

Describe the pattern of muscle contractions that produce peristalsis. How is peristalsis controlled?

Controlled by pacesetter cells, Cells undergo spontaneous depolarization triggering a wave of contraction, and alternating contractions & relaxations produce peristalsis. 1. Circular muscles contract behind the bolus, circular muscles ahead of the bolus relax, 2. Longitudinal muscles ahead of the bolus contract which shortens that segment. 3. Wave of contraction in circular muscles force the bolus forward

What is the purpose of segmentation and how is it different from peristalsis?

Cycles of contraction that churn and fragment the bolus, Mix contents with intestinal secretions, Unlike peristalsis it has no set pattern of contraction, Do not push the materials in one direction just mashes bolus

List the organs/structures of the digestive system and their general functions. Distinguish between structures of the digestive tract vs accessory organs.

Digestive tract or GI tract that goes from mouth to anus which includes Oral Cavity, Pharynx, Esophagus, Stomach, Small intestines, and Large intestines. Also accessory organs like Teeth, Tongue, Salivary glands, Pancreas, Liver, and Gall Bladder.

Locate and describe the 3 regions of the small intestine. Know the function of each region and which region is the site of most chemical digestion and nutrient absorption

Duodenum: closest to the stomach, Receives secretions from the pancreas and the liver, Main pancreatic duct & common bile duct enter, Functions: Receive chyme from stomach and Neutralize stomach acids so they do not damage the small intestine surface Jejunum: Middle section of the small intestines, Site of most chemical digestion & nutrient absorption Ileum: Final segment of the small intestine, Ends in the ileocecal valve

Describe villi structure, including differences in the nutrients absorbed by the capillary network compared to lacteals

Each villus has an extensive capillary network, Carry absorbed nutrients towards the hepatic portal circulation, Carry absorbed nutrients towards the hepatic portal circulation, Also a lymphatic capillary = a lacteal, Important to help absorb materials unable to easily enter the blood capillaries, Like large fatty-acids and other lipids, Lacteal refers to the milky color of the lymph from the high fat content

Describe the structure of the pancreas and the pancreatic enzymes that are secreted. Be able to list what substance each enzyme breaks down. What cells are in the endocrine portion versus in the exocrine portion and what do they produce?

Endocrine portion: islet cells that produce and release hormones into the bloodstream Exocrine portion: acinar cells that secrete digestive enzymes and act to digest food at their site of release Pancreatic Enzymes & Secretions: Carbohydrase - breaks down starches, Pancreatic lipase: Breaks down complex lipids Nucleases: Break down nucleic acids, Proteolytic enzymes: Proteases & peptidases Break down protein and amino acid chains (peptides) to amino acids

Define energetics and metabolism, including cellular metabolism.

Energetics: Study of the flow of energy and its change from one form to another Metabolism: Sum of all chemical and physical changes that occur in body tissues Cellular Metabolism: Includes all chemical reactions within cells, Provides energy to maintain homeostasis and perform essential functions

How is energy released by Adenosine Triphosphate (ATP)? What is the relationship between ATP and ADP?

Energy in glucose & lipids is converted into ATP, Energy for work is stored in ATP bonds, when 3rd phosphate is broken off then energy is released and ADP is left over

Calorie

Energy required to raise 1 g of water 1 degreeCelsius is a calorie (cal)

What are the 3 major functions of the urinary system?

Excretion: removal of organic wastes products from bodily fluid Elimination: discharge of these waste products Homeostatic regulation: regulation of the volume and solute concentration of the blood

Describe the structure and position of the liver. Be able to list functions of the liver

Function: Regulate composition of circulating blood, Nutrient metabolism, Waste product removal, Nutrient storage, Drug inactivation, and Regulate lipid digestion through production of bile

Describe the functions and structure of the stomach. List the secretory cells of the stomach and their secretions

Functions: 1. Storage of ingested food, 2. Mechanical breakdown of ingested food to produce chyme, 3. Disruption of chemical bonds in food material by acid and enzymes 4. Production of intrinsic factor Regions of the stomach: Cardia, Fundus, Body- most enzymes & acids secreted here, and Pylorus - links stomach to the duodenum at the pyloric sphincter

Be able to describe Carbohydrate Metabolism, including what it does, what it involves, and how the breakdown works.

Generates ATP by breaking down Glucose, Cellular respiration: Glucose + oxygen → carbon dioxide + water, Involves glycolysis, citric acid cycle, and ETC, One molecule of glucose provides a net gain of 30-32 molecules of ATP Glucose Breakdown: Occurs in small steps, Which release energy to convert ADP to ATP

What nutrient metabolism is used by neural tissue?

Glucose

Be able to identify the building blocks (glucose, fatty acids, amino acids) and the nutrient reserves (glycogen, triglycerides) for each major organic nutrient (carbohydrates, lipids/fats, proteins)

Glycogen: Most abundant storage carbohydrate Triglycerides: Most abundant storage lipid, Primarily of fatty acids Proteins: Most abundant organic components in the body, Perform many vital cellular functions

What is glycolysis? Where does it take place? Can it occur without oxygen?

Glycolysis: Breaks down glucose in cytosol into smaller molecules used by mitochondria, Does not require oxygen, occurs in mitochondria

Describe the structure of a tooth. Be able to distinguish between the different types of teeth and what they are used for (also in the Digestive Anatomy Lab). Know the number of deciduous and permanent teeth.

Has crown, dentin (mineralized matrix similar to bone but has no cells) covered by enamel (calcium phosphate in a crystal form), has pulp cavity that receives blood vessels and nerves through root canal, neck, root. Types of teeth: inscisors, cuspids, bicuspids, molars. There are 20 deciduous teeth and 32 permanent teeth.

Fever

Is body temperature maintained at greater than 37.2C (99F) Occurs for many reasons, not always pathological, In young children, transient fevers can result from exercise in warm weather

Be able to list mechanisms for increasing heat-loss and for promoting heat gain to maintain body temperature.

Heat exchange with environment involves four processes 1. Radiation 2. Convection 3. Evaporation 4. Conduction To increase heat loss: It inhibits vasomotor center, causes vasodilation so warm blood goes to surface of body, sweat glands are stimulated to increase sweat output to evaporate heat, respiratory centers are stimulated to increase depth of respiration To promote heat gain: heat loss center is inhibited, heat gain center is activated, blood flow to skin is restricted and blood return from limbs is moved to deep veins to trap heat to body core, countercurrent exchange, shivering thermogenesis

What is the purpose of bile production?

Helps digest lipids

Explain the function of brown fat. At what age/where would it be found and how does it work?

Highly vascularized adipose tissue, stimulate lipolysis in adipocyte, energy released radiates into surrounding tissues as heat which warms blood and is distributed in body, its found at shoulder blades, around neck, and in upper body Found in infants

Describe the histology of the small intestine, including plicae, villi, and microvilli. What is the purpose of these structures?

Histology of the small intestines: Has circular folds called plicae, Are permanent - unlike rugae of the stomach, Do not disappear when the intestine fills Plicae and Villi: Plicae are covered in intestinal villi, A series of fingerlike projections in mucosa of small intestine, Covered by simple columnar epithelium and scattered goblet cells, and Covered with microvilli called the brush border

What is thermoregulation and why is it important?

Homeostatic mechanisms that keep body temperature within acceptable limits, Important because enzymes operate over arelatively narrow temperature range

Peyer's patches

Important lymph nodules Protect small intestine from bacteria in the large intestines

Shivering thermogenesis

Increased muscle tone increases energy consumption of skeletal muscle, which produces heat

List and describe the 6 functions of the digestive system.

Ingestion: Occurs when materials enter the digestive tract, its an active process Mechanical processing: Physical breakdown of ingested material includes, Makes ingested material easier to swallow and propel along digestive tract, and Increases surface area to make it easier for enzymes to work Digestion: Chemical breakdown of swallowed food into smaller fragments for absorption by digestive epithelium and primarily achieved by enzymatic action Secretion: Release of water, acids, enzymes, buffers, & salts and Done by epithelium of digestive tract and glandular organs Absorption: Movement of organic substrates, electrolytes, vitamins, and water across digestive epithelium Excretion: Removal of waste products from the body and wastes plus indigestible materials ejected through defecation

Describe control of the release of feces by the anal sphincters.

Internal anal sphincter: Circular muscle layer of muscularis externa and Smooth muscle, not under voluntary control External anal sphincter: Encircles distal portion of anal canal and A ring of skeletal muscle fibers, under voluntary control

Describe the functions of the major organs of the urinary system (fig 26.1 is helpful)

Kidneys — organs that produce urine Urinary tract — organs that eliminate urine Ureters (paired tubes) - transport urine Urinary bladder (muscular sac) - storage of urine Urethra (exit tube) - eliminate out of body

Where does digestion start for lipids, proteins, and carbs?

L: Small intestine, some oral cavity P: stomach C: mouth, some in stomach and small intestine

Describe the differences between lipid metabolism, carbohydrate metabolism, and protein metabolism. When would cells use each type of metabolism? Which produces the most energy per gram?

Lipid metabolism: makes 120 ATP, harder to break down because its hydrophobic, stores energy Carbohydrate metabolism: makes 32 ATPs Protein metabolism: less likely to be broken into ATP because they are huge molecules, need amino acids for other processes so used less for energy

Which one is used more for energy storage and why?

Lipids because it takes longer to break down and can make more ATP

Be able to follow the flow of bile from the hepatocytes to the common bile duct.

Liver cells secrete bile into bile canaliculi then to bile ductules then to bile ducts and then to the right or left hepatic duct.

Describe the basis of a ketogenic diet and potential benefits and/or risks.

Low carb, high fat diet, Shifts metabolism from carbohydrates to fats and ketones, can help lose weight and lower risk factors for diseases, can cause ketonemia and ketoacidosis

Why are minerals and vitamins important nutrients?

Minerals: Inorganic ions released through dissociation of electrolytes, Are important for three reasons 1. Ions determine osmotic concentrations of body fluids 2. Ions play a major role in physiological processes 3. Ions are essential cofactors in many enzymatic reactions Vitamins: Essential organic nutrients that functions as coenzymes in vital enzymatic reactions,

Explain the difference between a nonessential amino acid and an essential amino acid

Nonessential can be made by the body Essential must be obtained from the diet

Name and locate the three salivary glands. Describe the composition and functions of saliva.

Parotid salivary glands, Sublingual salivary glands, and Submandibular salivary glands. Saliva is 99.4% water, and 0.6% of Electrolytes, Buffers, Glycoproteins (mucins), Antibodies, Enzymes, and Waste products. Functions: Lubricating the mouth, Moistening and lubricating materials in the mouth, dissolving chemicals that stimulate taste buds and provide sensory information, and Initiating digestion of complex carbohydrates by the enzyme salivary amylase

chyme

Partially digested, semiliquid food mixed with digestive enzymes and acids in the stomach.

Know where the juxtaglomerular complex is located and what it does.

Produces renin and erythropoietin, Renin: involved in regulating blood pressure, Erythropoietin: involved in erythrocyte production

Enzymes needed to break down carbs, proteins, and lipids?

Protein- peptides, Carbohydrates- salivary amylase, Lipids-lipase

Explain the relationship between digestion and metabolism

Purpose: Break food into useable molecules to create ATP, High calorie foods will produce more ATP molecules, Carbs most common to make ATP, Proteins less likely to be ATP

List functions of the large intestines. How are vitamins produced in the large intestine?

Reabsorption of water to compact intestinal contents into feces Reabsorption of bile salts Absorption of Vitamins K, B5, & biotin Storage of fecal material prior to defecation Diverse microbiome in the large intestine is important for our immune system

Describe the bile ducts associated with the liver and gall bladder. Describe the role of the gallbladder & CCK in the delivery of bile to the duodenum

Right & left hepatic duct unite to form the common hepatic duct that leaves the liver, Bile flows to: Common bile duct empties to the duodenum, OR Cystic duct empties to the gallbladder, gallbladder stores & concentrates bile prior to excretion to small intestine, Bile concentrates as water is absorbed, Releases bile to the duodenum under the stimulation of the intestinal hormone cholecystokinin (CCK), Without CCK, hepatopancreatic sphincter remains closed and bile from liver cannot enter duodenum through common bile duct

bolus

Rounded ball of digestive contents

What factors cause thermoregulatory problems for infants?

Temperature-regulating mechanisms are not fully functional, Lose heat quickly (due to small size), Body temperatures are less stable, Metabolic rates decline during sleep and rise after awakening, Infants cannot shiver

Describe the structure of the renal corpuscle and the filtration of the materials from the blood into the capsule. what's the role of the fenestrated capillaries and podocyte infiltration?

The glomerular capsule Forms the outer wall of the renal corpuscle, and Encapsulates glomerular capillaries, podocytes wrap around glomerular capillaries with filtration slits between adjacent cells which filter materials out of capillaries that enter capsular space into the renal tubule, Fenestrated capillaries in glomerulus, have large pores which lets substances get pushed out of blood easier for filtration

How do hormones influence metabolic rate? Which hormones stimulate appetite and which hormones suppress appetite?

Thyroxine controls overall metabolism, Cholecystokinin (CCK) and adrenocorticotropic hormone (ACTH) suppress appetite, leptin decreases appetite and increases metabolism and is made by adipose cells, Ghrelin is made by stomach and triggers body to feel hungry

Why is the stomach acidic?

To activate enzyme pepsinogen to pepsin which is a protein digesting enzyme

Know where the blood that enters the hepatic portal system is coming from and what happens to blood composition in the liver

Venule & Arteriole, into sinusoids (capillary), to the central vein, to the hepatic vein. Hepatocytes manage these absorbed nutrients before the blood leaves the liver via the hepatic veins then sent to the inferior vena cava, Metabolic conversion of absorbed nutrients, Removal and storage of excess nutrients, Extraction of toxins/waste for excretion

amination

addition of an amino group

podocytes

cells in the glomerular capsule in the kidneys that wrap around capillaries of the glomerulus

Be able to describe the causes and treatments along with risk factors and prevention (if discussed) for the following diseases of the digestive system: gallstones, appendicitis, gastric ulcers, hemorrhoids, colon cancer

colon cancer: Risk factors/causes: 50+ y/o , African-Americans, family history, low-fiber, high fat diet, Prevention: colonoscopies, treatment: surgery or chemo Hemorrhoids: Prevention: eat high fiber, don't strain, drink fluids, exercise, don't sit too long, risk factors/causes: straining bowel movements, being pregnant, low fiber, heavy lifting Treatment: eat fiber, oral pain relievers Gastric Ulcers: Causes internal bleeding, destruction of stomach by acid, Caused by bacterial infection or some medication overuse, treatment: antibiotics and medication to reduce stomach acid secretions Risk factors: smoking, drinking, genetics Appendicitis: inflammation of infection caused by blockage of appendix by stool, cancer, or infection. treatment: remove appendix Gallstones: too much water is absorbed in gallbladder causing inflammation of ducts and blockage, treatment: wait and see or remove gallbladder, risk factors: obesity, age, diabetes, rapid weight loss, and estrogen

rugae

folds in the stomach

glucogenesis

formation of glycogen from glucose, occurs slowly, needs UTP

where does most of the nutrient absorption take place

ileum

cholecystitis

inflammation of the gallbladder and ducts leading to blockage

micturition

process of eliminating urine

Describe the greater omentum

provides location to store fat, is attached to greater curvature to stomach, protects abdominal organs

Explain the structure and function of the different regions of the renal tubule. For instance, why are microvilli present in the PCT and not in DCT?

proximal convoluted tubule (PCT) First segment of renal tubule, epithelial lining, has microvilli and functions in reabsorption of materials back into blood like ions, nutrients, and water, Loop of Henle: descending limb- fluid to renal pelvis, ascending limb- fluid to renal cortex, each limb has a thick segment and thin segment, Thick ascending limb pumps sodium and chloride ions out of tubular fluid, Thin segments are freely permeable to water but not to solutes, Water movement helps concentrate tubular fluid by reabsorbing water, Thick ascending limb Ends at a sharp angle distal convoluted tubule (DCT) Initial portion passes between the level of the afferent and efferent arterioles, smaller diameter than PCT, Epithelial cells lack microvilli, Functions: active secretion of ions and drugs/toxins, selective reabsorption of specific ions and water

Describe the overall anatomy of the nephron - what are the different regions and where are they located

site of urine formation, tubular structures in the cortex & medulla, contains renal corpuscle in cortex and renal tubule in medulla

deglutition

swallowing

Metabolic rate

the amount of energy used in a given unit of time, anabolic + catabolic processes in the body