exam 4 flash cards

gastrointestinal tract and accessory organs

What does the digestive system consist of

Blastula

Stage of development where digestive system is made
- many cells fold in on itself
- fold gets bigger until it goes through it
- the hole is called an endoderm
- hole is surrounded by mesoderm

Protosome

Mouth is made first

Deuterostomes

Anus is made first
- humans
-Mouth made second

Peritoneum

Serous membrane that lines the abdominal cavity
- largest serous membrane in body
- simple squamous
- contains folds = mesenteries

Parietal peritoneum

Outer layer lining that touches wall

visceral peritoneum

Inner lining that covers organs

Mesentery

a fused double sheets of the peritoneal membrane
- stabilize position of organs & BV's
- provide attachment for BV's

Mesentery proper

binds jejunum and ileum to posterior abdominal wall
- holds small intestine to body wall

Mesocolon

binds transverse colon and sigmoid colon to posterior abdominal wall
- holds large intestine to body cavity

Greater Omentum

Drapes over transverse colon & small intestine
Largest mesentery
Fatty apron

lesser omentum

Connects the stomach and duodenum to the liver
- contains major blood vessels, bile & lymph structure
- hepatic portal vein

intraperitoneal

Digestive organs are completely surrounded by visceral peritoneum

Retroperitoneal

Organs lie against the posterior abdominal wall
- kidney

Mucosa

inner lining of digestive tract
- epithelium
- Lamina propria - only place inbody where this CT is found
- makes mucus

Submucosa

dense irregular connective tissue
Glands that secrete acid, BV & nerve plexus

Muscularis

smooth muscle that helps more food
-Inner circular layer & outer longitudinal layer

Serosa

visceral peritoneum - layer of serous membrane attached to organ.
- NOT FOUND IN: oral cavity, pharynx, esophagus, OR rectum

Inner circular

Pushing food along

outer longitudinal

Smooshing

processing food
Food → macros

What is the primary function of the digestive system

1. Ingestion - swallowing food
2. Digesting-Chem (enzymes cut food smaller) vs mech (teeth )
3. Absorption - large & small intestine absorbing nutrients
4. Elimination- waste leaving body

What are the steps of food processing

oral cavity

mouth
Cheeks form the lateral walls
- lined by stratified squamous epic
- lips - muscles

Start of mech & chem digestion
bolus forms when we swallow good
Bonus = food & saliva

Oral cavity primary function

soft and hard palate
uvula
tongue
mouth
cheeks
teeth
lips
muscles

What does the oral cavity consist of

Palate

roof of the mouth
Hard & soft

Uvula

CT from soft palate
- closes off nasopharynx while swallowing
- gag reflex

Tongue

Skeletal muscle, held down by the lingual frenulum

Chewing, gestation, and speech

Tongue primary function

Teeth

20 deciduous (baby) & 32 adult

Periodontal ligament

Anchors tooth to the bone

Incisors - scraping
Cuspids (canines)- hold food in place
Bicuspids (premolars) - transitional teeth both canines and molars
Molars- grinding of food

What are the types of teeth and function

Amylase

Enzyme in saliva that breaks down starches

parotid

Biggest gland over the masseter muscle

Submandibular

salivary gland under mandible

Sublingual

salivary gland under the tongue

Deglutition (swallowing)

Passing something from mouth the pharynx & into esophagus
Bonus moves through esophagus via peristalsis

Peristalsis

Rhythmic contract/relax of GI tract muscle
- moves food
- smooth muscle
- happens in esophagus, stomach, large/small intestine
-Slowly
- I secs from esophagus to stomach

Esophagus

Collapsible, muscular
Connects oral cavity to stomach
posterior to trachea
Start of peristalsis

gastroesophageal sphincter

Stomach & esophagus sphincter
- regulate and control the rate of food going into stomach

gastroesophageal reflux disease (GERD)

long term condition in which stomach acid goes into esophagus
● Acid in the back of the mouth, heartburn, bad breath, chest pain, regurgitation, breathing problems, and wearing away of the teeth
● Risk Factors: obesity, smoking, pregnancy, LES isn't functioning

stomach

Primary function - chem (cut protein) & mech digest
Secondary function- food storage, protein digestion (starts in mouth), hormone production that signals how full we are and for acid to be made
Tertiary function
Absorption
SOME H2O
SOME meds ex aspirin
Alcohol
Caffeine
mucosal layer has goblet cells

Chyme

Food (bolus) mixed with acid

Oblique

Innermost layer
- churns food inside stomach

cardia

Transition from esophagus to stomach

Fundus

most superior part of the stomach
Helps with expansion

Body

largest region of the stomach
Churning happens

Pylorus

Most inferior region of stomach

gastroesophageal sphincter

Controls rate of food entering body

Greater curvature

rugae of stomach

Expansion

pyloric sphincter

Between stomach and small intestine

slow and controlled
I tsp at a time
Empties in 2-6hrs

How fast does the stomach empty slow an

Acid + digestive juice, gastric glands

Stomach structures?

Gastric glands

Inside of mucosa gastric pits
Make mucus or acid
Secretory cells

Vomiting

involuntary & forceful expulsion of the contents of the stomach
● Mouth or nose :(
burns bc or acid
● Risk factors: Motion sickness, head trauma, food poisoning, overeating, gastritis, drugs, stress
● Treatment: Medication, waiting it out, staying hydrated

Small intestine

Between stomach & large intestine
18-20 ft
- 1.5 - 2.5in diameter
- feeds with villi that contain microvilli
- nutrients absorbed by touching

Digestion & absorption of nutrients

Primary function of small intestine

SI absorption

BVs for sugars & amino acids
- lacteals for large macros
- eventually back general circulation

duodenum, jejunum, ileum

What are the 3 parts of the small intestine

Duodenum

first 10-13in segment of small intestine
● Chyme from stomach + digestive secretions
● Common bile & pancreatic duct open into duodenum○ Hepatopancreatic ampulla sphincter
-breaking down

Receive chyme from stomach
Neutralize acids
HCO3 - +H+ → H2O + CO2

Duodenum functions

jejunum

Middle segment of small intestine
Approx. 8ft
Chem digestion
Nutrient absorption

Ileum

The final segment of the small intestine
Approx. 12ft
ileocecal valve
cleaning

Segmentation
si digestion

Mixing of food stuffs+ digestive secretions
No net movement
-Pushes back and forth to mix then pushes → with peristalisis

Liver

largest organ of the body
Located under diaphragm
Can regenerate
Primary function: detox

Falciform ligament

Attaches liver to anterior abdominal wall & diaphragm

hepatic portal system

connects the digestive tract and liver
- specialized venous blood pathway
- from GI tract → liver → heart
- nutrient rich / O2 poor
- stomach, small intestine, pancreas, and spleen blood get together to form hepatic portal vein to dump blood into liver

Lobules

functional units of the liver

hepatocytes

liver cells
Break down parasites
A lot of rough/smooth ER and ribosomes

Kupffer cells

Immune system cells

hepatic artery, hepatic portal vein, small bile duct

What makes up the portal triad

Hepatic sinusoid

Holds kupffer cells

Storage of Fe, vit: A, D, E, K, & BI2
Production of glycerol & amino acids→ glucose when hangry
Cholesterol
Bile - cuts down fat increases sa

Liver secondary function

Gallbladder

Primary function: store bile
Located under liver

gall stones

a stone formed within the gallbladder/bile duct
● Cholesterol / ↓ bile salts = stone
● Crampy pain in the right upper part of the abdomen, fever, yellowish skin, vomiting, or tea-colored urine
● Other acc. organs to become inflamed
● Risk Factors: estrogen + 40 years, weight, and diet hormonal birth control too
● Treatment: Diet change, Surgery or shock waves

Pancreas

Primary functions
endo: make insulin and glucagon
exo=pancreatic juices
Located behind stomach

Lipase- lipids /fats
Pancreatic amylase-starch
Pancreatic trypsin -protein

What are the enzymes for all macros

Pancreatic juices

Contains sodium bicarb
Bicarb protect small intestine from stomach acid b/c no mucus

Large intestine

Primary function:
Last chance absorption & storage
Located around the small intestine
4-5 ft long
Approx 3in in diameter
Absorb H2O and vitamins made by proks (B complex and K)
K- help with blood clots I made by our E. coli

Feces

When it enter iliocecal value it becomes feces for 1st time
3/4 h20 & 1/4 undigested solids+ coliforms
bilirubin processing+ oxidized iron = brown poop

Cecum

transitionary pouch that connects small to large intestine

Appendix

Lymph tissue

appendicitis

inflammation of the appendix
●Caused by blockage
● Right/lower abdominal pain, nausea, vomiting, & decreased appetite
● Sepsis- infection could happen by fecal matter getting stuck
● Treatment: Removal

Colon

Largest portion of LI

Ascend

Fecal matter goes up

Trans

Fecal matter goes on transverse plane

Descend

Fecal matter goes down

Sigmoid

S-shaped
Leads feces into rectum

Haustra

Pouches for expansion - helps with abs and storage

taeniae coli

longitudinal bands of smooth muscle
Helps with peristalsis of each pouch

Rectum

Last 20 cm of LI
Storage area
Internal sphincter = involuntary
External sphincter = voluntary
Both control the rate of fecal exiting body

Anal canal

Site of defecation
Voluntary

lactose intolerance

- Only supposed to drink milk as babies
inability to digest milk sugars (lactose)
● If no lactase enzyme = can't digest lactose
● Bacteria breakdown lactose anaerobically, producing gas, bloating, diarrhea
● Cheese & yogurt OK, heavy cream & butter too! (more milk fat=less milk sugar)
● Risk Factors: being an adult
● Treatment: Diet & lactase supplement

Excrete waste from proteins
Urea & ammonium from AAs

Urinary system primary function

Water/salt (blood pressure) homeostasis
BP measured in salt

Urinary system secondary function

Aldosterone

regulates salt and stress homeostasis
increases blood vol and blood pressure
-stimulated by low sodium concentration (after exercise), blood loss (low blood volume), or low blood pressure
kidney reabsorption of Na+ & excretion of K+
NOT controlled by anterior pituitary

RAAS

renin-angiotensin-aldosterone system

Renin -> RAAS hormone complex

Made from juxtaglomerular apparatus
kidneys: constrict bvs = increased blood pressure
Tells Adrenal glands to make: Aldo = increased salt retention

Non urinary function: blood ph

If pH low/acidic = too many H ions & secretion of buffers (bicarb ion) increase
If pH high / too alkaline= increase excretions of buffers (bicarb ion) & secretion of H ion increase