BIO 108: Digestive System

The __ absorbs material for building and replacing body tissues. __ is our only source of chemical energy.

digestive system, food

Digestive system functions:

__ - taking in food & liquid

Ingestion

Digestive system functions:

__ - mechanical (grinding) & chemical breakdown

Digestion

Digestive system functions:

__ - 7L per day of water, acid, buffers, and enzymes

Secretion

Digestive system functions:

__ - stomach absorbs some water, ions, short-chained fatty acids, alcohol, and some drugs. GI tract → blood or lymph

Absorption

Digestive system functions:

__ (motility) - altering contractions

Mixing/Propulsion

Digestive system functions:

__ - elimination of material

Defecation

Which layers of GI tract:

__ - inner lining of GI tract

Mucosa

Which layers of GI tract:

__ - irregular connective tissue, contains blood & lymph vessels, neurons

Submucosa

Which layers of GI tract:

__ - mostly smooth muscle, mixes and propels food thru tract

Muscularis

Which layers of GI tract:

__ - outer most layer, is serous membrane (aka adventitia) forms peritoneum

Serosa

What is the serous membrane of the abdomen?

Peritoneum

Peritoneal Folds:

__ - fatty apron that covers transverse colon & small intestine, beer belly

Greater Omentum

Peritoneal Folds:

__ - suspends stomach & duodenum from liver, contains lymph nodes

Lesser Omentum

Peritoneal Folds:

__ - attaches liver to anterior abdominal wall

Falciform Ligament

Peritoneal Folds:

The mesentery connects the __ intestine to the __ abdominal wall.

small, posterior

Peritoneal Folds:

The mesocolon connects the __ intestine to the __ abdominal wall.

large, posterior

The oral cavity consist of …

… cheeks, lips, hard palate, soft palate, uvula.

Major Salivary Glands:

__ - inferior and anterior to ears

Parotid glands & ducts

Major Salivary Glands:

__ - beneath base of tongue, posterior to floor of mouth

Submandibular glands & ducts

Major Salivary Glands:

__ - superior to submandibular gland

Sublingual glands & ducts

Major Salivary Glands:

__ = chewing (temporalis, masseter, internal pterygoid, external pterygoid)

Mastication

Major Salivary Glands:

__ is 99% water and ions

Salvia

Major Salivary Glands:

__ - breaks down starch

Salivary amylase

Major Salivary Glands:

__ - breaks down triglycerides

Lingual lipase

Which muscle of tongue:

__ - lateral, in & out

Extrinsic tongue muscles

Which muscle of tongue:

__ - speech & swallowing, alters shape and size

Intrinsic tongue muscles

Which muscle of tongue:

__ - receptors for taste (sweet, salty, sour, bitter)

Modified Papillae

What are the accessory digestive organs on mandible & maxillae?

Teeth

Which part of the teeth:

__ - visible portion above gums

Crown

Which part of the crown:

__ - outer surface, hardest substance in the body

Enamel

Which part of the crown:

__ - under enamel, calcified connective tissue, gives shape and support

Dentin

Which part of the crown:

__ - cavity underneath dentin

Pulp cavity

Which part of the crown:

__ - connective tissue in pulp cavity, contain nerves, blood & lymph vessels

Pulp

Which part of the teeth:

__ - narrowed junction between crown & root

Neck

Which part of the teeth neck:

__ - gums of the mouth

Gingiva

Which part of the teeth:

__ - embedded in the socket

Root

Which part of the root:

__ - channel for nerves & vessels

Root canal

Which part of the root:

__ - anchors teeth in position, acts as shock absorber.

Periodontal ligament

Which part of the root:

__ - bone-like substance that attaches tooth to periodontal ligament

Cementum

Which part of the root:

__ - opening at base of root canal

Apical foramen

Baby teeth appear after ___ and total of __.

6 months, 20 teeth.

Permanent teeth appear after __ and total of ___.

6 to 12 years, 32 teeth.

Which stage of swallowing:

__ - food passes from mouth to oropharynx

Voluntary stage

Which stage of swallowing:

__ - from pharynx to esophagus, epiglottis keeps material out of trachea

Pharyngeal stage (involuntary)

Which stage of swallowing:

__ - a constricting progression toward stomach

Esophageal stage (involuntary)

Esophagus has the following characteristics EXCEPT:

All choices are characteristics

What is the alternating muscle contractions (circular & longitudinal) occurring in esophagus to push bolus onward?

Peristalsis

The stomach performs the following functions EXCEPT:

HCl do not kill but repairs bacteria

Which stomach anatomy:

__ - surrounds superior opening of the stomach

Cardia

Which stomach anatomy:

__ - upper left, rounded part

Fundus

Which stomach anatomy:

__ - large central portion of stomach

Body

Which stomach anatomy:

__ - large folds of mucosa

Rugae

Which stomach anatomy:

__ - region that connects to duodenum

Pyloric

Which stomach anatomy:

__ - limits emptying of stomach into duodenum

Pyloric sphincter

Which stomach anatomy:

__ - concave medial border

Lesser curvature

Which stomach anatomy:

__ - convex lateral border

Greater curvature

Which stomach anatomy:

__ - consist of longitudinal, circular, oblique

Muscularis layers

What are the narrow channels that hold gastric glands?

Gastric pits

Cells of Gastric Glands:

__ - secrete thick layer of mucus to protect stomach lining

Mucous neck

Cells of Gastric Glands:

__ - produce HCl, produce intrinsic factor to absorb vitamin B12

Parietal cells

Cells of Gastric Glands:

__ - secrete pepsinogen → (pepsin), and gastric lipase

Chief cells

Cells of Gastric Glands:

__ - is converted by HCl in the gastric lumen to pepsin (active enzyme that breaks peptide bonds - digests proteins)

Pepsinogen

Cells of Gastric Glands:

__ - secrete hormone gastrin into blood stream, triggered by amino acids, stimulates chief & parietal cells

G cells

Which phase of regulation:

__ - sight, smell, taste or thought of food initiates neural stimulation of gastric glands

• Pepsinogen, HCl, Mucus → into stomach

• Gastrin into blood

Cephalic phase

Which phase of regulation:

__ - neural and hormonal, stretch receptors monitor for distended stomach walls

• Chemoreceptors monitor for increase in pH

• Parasympathetic → gastrin → increase motility

Gastric phase

Which phase of regulation:

__ - slow exit of chyme from stomach to duodenum, triggers release of CCK (inhibits gastric emptying) & Secretin (decreases gastric juices)

Intestinal phase

What are Fad Diets/American Diet?

An eating plan that promises rapid weight loss or unrealistic health benefits, typically by using extreme, restrictive, or unbalanced rules.

What is the 40/30/30 diet?

A diet that balances daily caloric intake with 40% from carbs, 30% from protein, and 30% from fat.

Are eggs important in diet?

Yes, eggs are important because they contains about 70-80 calories, 6-7 grams of protein, and healthy fats.

What non-processed foods?

They are “whole foods” in their natural state with minimal chemical alteration.

Which is better for diet: whole foods vs supplements?

Whole foods are better because they’re primary source of nutrition while supplements address specific deficiencies.

The Pancreas has the following characteristics EXCEPT:

All choices are characteristics of Pancreas

Pancreatic juice buffers against low pH, and contains the following enzymes to digest EXCEPT:

All choices are enzymes within pancreatic juice

Pancreas:

__ → increase release of pancreatic juice (digestive enzymes)

CCK

Pancreas:

__ → increase release of pancreatic juice (bicarb ions) buffers duodenum from stomach acid

Secretin

The __ is a pear-shaped sac located posterior to the liver.

Gall Bladder

The function of the gall bladder is to __ and concentrate __ until needed.

store, bile

Gall Bladder:

__ - causes contraction of gall bladder, also relaxes sphincter at duodenal ampulla

CCK

Gall Bladder:

__ - cause liver to produce more bile

Secretin

What is the largest gland in the body (after skin)?

Liver

What is the role of bile (emulsification of fats) in liver?

Break down of large lipid globules, and assist in their absorption.

Blood Supply to Liver:

__ - oxygenated blood

Hepatic artery

Blood Supply to Liver:

__ - deoxygenated blood with newly absorbed nutrients, drugs, microbes, toxins from GI tract

Hepatic portal vein

Blood Supply to Liver:

__ - from central vein, out of liver to inferior vena cava

Hepatic vein

Functions of the Liver:

Carbohydrate metabolism - liver breaks __ into glucose, converts __ into glycogen & triglycerides.

glycogen, glucose

Functions of the Liver:

Lipid metabolism - breaks down fatty acids into __, makes lipoproteins for lipid transport, make __.

ATP, cholesterol.

Functions of the Liver:

__ metabolism - removes amino from amino acids for ATP, makes plasma proteins.

Protein

Functions of the Liver:

Processing __ - detoxifies alcohol & excretes drugs.

drugs & hormones

Functions of the Liver:

Excretion of __ - rids the body of heme from old RBCs → bilirubin

bilirubin

Functions of the Liver:

Produce __ - for emulsification & absorption of lipids.

bile salts

Functions of the Liver:

__ - for vitamins A, B12, D, E, K, iron, copper, & glycogen.

Storage

Functions of the Liver:

__ - kupffer cells phagocytize RBCs, WBCs, & some bacteria.

Phagocytosis

Functions of the Liver:

Activate __ - synthesizes active form of vitamin D

vitamin D

Which digestive organ has area of most digestion & absorption, and has diameter = 1” & length = 10’?

Small Intestine

Which section of small intestine:

__ - first 10 inches, follows pyloric sphincter

Duodenum

Which section of small intestine:

__ - next 3 feet after duodenum

Jejunum

Which section of small intestine:

__ - final 6 feet, ends with ileocecal valve

Ileum

Which small intestine anatomy:

__ - enhances absorption by increasing surface area, spirals chyme. (rifling in stomach)

Circular folds

Which small intestine anatomy:

__ - series of finger-like projections — vastly increases surface area.

Villi