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Anatomy Unit 7

Terms in this set (31)

What are the functions of the digestive system?
●Ingestion of food
●Digestion of food
-Large into small food molecules (mechanical digestion)
-Chemical break down of food (chemical digestion)
●Absorption of nutrients
●Elimination of wastes
Know Order of the Digestive Tract, - including sub-components of the Small & Large Intestine and the directional parts of the colon
1) Oral Cavity (Food--> Bolus)
2) Pharynx
3) Esophagus
4) Stomach (Bolus--> Chyme)
5) Small Intestine (duodenum, jejunum, ileum)
6) Large Intestine (cecum, colon [ascending, transverse, descending, sigmoid], rectum) (Chyme--> Feces)
7) Anus

(liver, pancreas, and gallbladder are not part of the digestive tract)
Functions of Digestive Organs
Stomach
●Break down and digest food
●Regulation: When ph ≥ 3.0 (increased secretions) and when ph ≤ 2.0 (decreased secretions)

Small Intestine
●Absorbs most nutrients

Large Intestine
●Feces production + water absorption
-Very little digestion happens here--> takes 18-24 hours to digest something

Pancreas
●Where most of digestion takes place
●Can break down all 4 organic compounds (proteins, lipids, carbs, nucleic acids)
Be able to match the major secretions and enzymes with the digestive organ that secretes them and also match them with their function within the digestive process
●Oral Cavity
-Salivary amylase

●Stomach
-Mucus
-HCl
-Pepsinogen
-Intrinsic Factor
-Gastrin

●Small Intestine
-Disaccharides
-Peptidases

●Liver
-Bile

●Pancreas
-Proteins: Trypsin/Chymotrypsin
-Lipids: Lipases
-Carbs: Amylase
-Nucleic Acids: Nucleases
-HCO3-
Oral Cavity Secretions
●Salivary Amylase: Breaks down complex carbs to simpler carbs.
Stomach Secretions
●Mucus: Coat inner lining of stomach and protect 2nd lining from HCl.
●HCl: Dissolves food and kills microorganisms.
●Pepsinogen: When added to HCl, it converts from pepsinogen into pepsin. This initiates protein digestion.
●Intrinsic Factor: Chemically binds with Vitamin B-12 and allows body to absorb it. Important in DNA synthesis + RBC production.
●Gastrin: Hormone that regulates all other secretions
Small Intestine Secretions
●Disaccharidases: Digest/break down carbs
●Peptidases: Finalize protein digestion of polypeptide (break the peptide bonds in proteins to form amino acids).
Liver Secretions
●Bile
-Helps to emulsify (break apart) fats--> assist in fat digestion
-Helps neutralize acidity of chyme--> raises pH
Pancreas Secretions
●Proteins: Trypsin/Chymotrypsin (digest proteins)
●Lipids: Lipases (break down lipids)
●Carbs: Amylase (break down carbs)
●Nucleic Acids: Nucleases (degrade DNA + RNA to their component nucleotides)
●HCO3- (bicarbonate ions): Neutralizes acidity of chyme--> raises pH
Describe the process of peristalsis.
Process by which esophageal contractions push bolus down the oral cavity.
Describe the location of the Cardiac and Pyloric region of the stomach.
●Cardiac region: esophagus attaches to stomach (right behind apex of heart)
●Pyloric region: duodenum attaches to stomach
List the 3 substances that are absorbed from the stomach straight to the bloodstream.
Aspirin, alcohol, honey
Explain what 3 structural modifications of the small intestine that increase inner surface area 600x and maximize nutrient absorption
●Circular Folds: A in picture.
●Villi: C in picture.
●Microvill: B in picture.
List and describe the 1 digestive and 4 non-digestive functions of the Liver.
●Digestive Functions:
-Produces and secretes bile--> secreted along common hepatic duct
*Emulsify fats + neutralize acidity of chyme
●Non-Digestive Functions:
-Remove and stores excess glucose in the form of glycogen
-Detoxifies harmful compounds: (EX: liver removes ammonia and converts it to urea which is eliminated in the urine)
-Produces/secretes blood proteins
-Involved in nutrient conversion

●Gallbladder: Stores and secretes bile--> secreted along cystic duct
Describe the duct system of the Liver and Gallbladder that distributes bile to the Duodenum.
Common hepatic duct from liver joins with cystic duct from gallbladder to form the common bile duct. Common bile duct empties bile into duodenum.
Tables/Figures To Know
●Table 16.1: Secretions/Enzymes
●Figure 16.23: Digestion of Carbs, Lipids, and Proteins
List the Components of the Urinary System
●2 Kidneys
●2 Ureters
●1 Urinary Bladder
●1 Urethra
List & Describe the 6 functions of the Kidney and discern among the Primary, Secondary and Non - Urinary Functions [FRQ]
●Primary Function: Filters wastes from blood and remove waste as urine.
●Secondary Functions
-Regulates blood volume / affects blood pressure
-Regulates ion concentration
-Regulates blood pH (secretes/reabsorbs H+) (High pH= low H+) (Low pH= high H+)
●Non Urinary Functions
-Regulate RBC production--- Erythropoietin
-Produce Vitamin D
Trace the pathway of Filtrate Production from Renal Corpuscle to when it becomes urine until it exits the body.
Nephron
●Renal corpuscle (filtrate is formed)
-Glomerulus
-Bowman's capsule
●Proximal Tubule
●Descending Limb of Loop of Henle
●Ascending Limb of Loop of Henle
●Distal Tubules

Then, filtrate becomes urine.

●Collecting Ducts
●Renal Calyx
●Renal Pelvis
●Ureter
●Urinary bladder
●Urethra
Be able to label the following on an illustration of the kidney: Renal Pyramids, Renal Calyx / Calyces, Renal Pelvis, Ureter, Renal Artery and Renal Vein
Renal Calyx /Calyces= Yellow tubes in picture
Be able to label the following on an illustration of the Nephron: Renal Corpuscle, Glomerulus, Bowman's Capsule, Proximal Tubule, Descending Limb of the Loop of Henle, Ascending Limb of the Loop of Henle, Distal Tubule, Collecting Duct and Peritubular Capillaries.
Renal Corpuscle= In (b), ball-shaped structure
Another picture of the nephron.
Name the three general processes involved in the production of urine.
●Filtration
●Reabsorption
●Secretion
Know where 100% of Filtration takes place along a Nephron; also where the filtrate is filtered from and what initially receives the filtrate
●Nephron= Basic functional part of a kidney
●100% of filtration takes place: renal corpuscle
-Filtrate is filtered from glomerulus
-Filtrate is captured by Bowman's capsule
Describe Reabsorption
●Movement of mostly water and other needed substances from the filtrate of the nephron tubule across the wall of the nephron back into the blood of the peritubular capillaries.

-About 99% of the original filtrate volume is reabsorbed and enters the peritubular capillaries (mostly water).
-Only 1% becomes urine.
Know what % of Reabsorption occurs along the Proximal Tubule, Desc Limb of LoH, Asc Limb of LoH, Distal Tubule / Collective Duct and what process is causing this reabsorption (and what controls Reabsorption from the Collecting Duct / Distal Tubule)
Process causing reabsorption: osmosis
●65% reabsorbed from proximal tubule
●15% reabsorbed from descending limb of LoH

●0% reabsorbed from ascending limb of LoH

Controls reabsorption: ADH + other hormones
●19% reabsorbed from distal tubule/collecting duct

Ions/Electrolytes: Active Transport
Describe Secretion (and why it needs to occur)
●Movement of toxic byproducts from the bloodstream of paritubular capillaries to the filtrate of the nephron tubule.
-Why: Helps the kidneys clean and filter the blood while producing urine.
Know whether a net secretion or net reabsorption of H+ occurs based on blood pH levels
Blood pH= 7.4
-If > 7.4--> Net H+ reabsorption
-If < 7.4--> Net H+ secretion
Know where K+ secretion occurs and where its reabsorption occurs
-Reabsorbed from proximal tubule
-Secreted into distal tubule
HQP
●Secretin
-Trigger: Low pH/high acidity of chyme
-Action in Stomach: Decreases gastric secretions
-Action in Pancreas: Increases HCO3- secretion
-Action in Liver: Increased bile production/secretion
-Action in Gallbladder: Nothing

●Cholecystokinin
-Trigger: High fatty acids and amino acids
-Action in Stomach: Decreases gastric secretions
-Action in Pancreas: Increases enzyme secretions (increased typsin, lipase, nuclease, amylase)
-Action in Liver: Nothing
-Action in Gallbladder: Increased gallbladder contraction which causes bile secretion

Both:
●Help regulate secretions of gallbladder, liver, and pancreas
●Regulate digestion
●Neutralize acidity of chyme
HQP 2
●Renin-Angiotensin-Aldosterone Mechanism
-Trigger: Low BP + low blood volume
-Source of Hormones/Secretions
*Renin: Kidney
*Angiotension: Liver
*Angiotensin II: ACE
-Target Organ + Effect
*Renin: Converts Angiotensiogen into Angiotensin I which is converted into Angiotensin II
*Angiotensin II: Adrenal Cortex to secrete Aldosterone
-Overall Effect: Aldosterone increases Reabsorption of Na+ via Active Transport, Cl- cotransports with Na+, water follows NaCl reabsorption

●ADH Mechanism
-Trigger: Hypothalamic Nerve Impulses (responding to high blood volume concentration) or baroreceptors
-Source of Hormones/Secretions: Posterior Pituitary
-Target Organ + Effect: Increased permeability of distal tubule/collecting ducts to water, causing more water to be reabsorbed
-Overall Effect: Small volume of concentrated urine or low BP--> increased ADH secretion / high BP--> decreased ADH secretion

●ANH Mechanism
-Trigger: High BP + high blood volume
-Source of Hormones/Secretions: Cardiac cells in right atrium
-Target Organ + Effect: Kidney to decrease Na+ reabsorption
-Overall Effect: Less water reabsorption~ lowers blood volume and BP
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