exam 4 flash cards

gastrointestinal tract and accessory organs

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