BIOL 102 FINAL EXAM STUDY GUIDE / BIOL102 FINAL EXAM STUDY GUIDE:LATEST-LIBERTY UNIVERSITY
3 views 0 purchase
Course
BIOL 102 (BIOL102)
Institution
Liberty University
BIOL 102 FINAL EXAM STUDY GUIDE / BIOL102 FINAL EXAM STUDY GUIDE:LATEST-LIBERTY UNIVERSITYBIOL 102 FINAL EXAM STUDY GUIDE / BIOL102 FINAL EXAM STUDY GUIDE:LATEST-LIBERTY UNIVERSITY
The Digestive System and Nutrition
Digestive System Brings Nutrients into the Body
The Digestive System includes:
o Gastrointestinal (GI) tract (Hollow tube)
Lumen: space within this tube
Includes mouth, pharynx, esophagus, stomach, small intestine, large intestine,
rectum, anus
o Accessory Organ
Salivary glands, liver, gallbladder, pancreas
Walls of the GI Tract are Composed of 4 Layers
Common layers throughout the system
o Mucosa: Innermost layer, mucous membrane in contact within the lumen
o Submucosa: Layer of connective tissue containing blood vessels, lymph vessels, nerves
o Muscularis: 2 or 3 layers of smooth muscle, responsible for movement, motility
o Serosa: Outermost layer
Sphincters: Thick muscular rings that separate some of the organs
Stomach has 3 layers, whereas everything else in the digestive tract has 2 layers.
5 Basic Processes Accomplish Digestive System Function
1. Mechanical Processing and Movement
Chewing and mixing
2. Secretion
Fluid
Digestive enzymes and hormones
Bile, acid, alkali, mucus
3. Digestion
Breaking down food to smallest absorbable units
Chemical and mechanical breakdown
4. Absorption
Through mucosa
Into blood or lymph vessels
5. Elimination
Undigested material eliminated
2 Types of Motility Aid Digestive Processes
, Motility enabled by smooth muscle in the muscularis layer
Peristalsis: propels food forward
Segmentation: Mixes food
The Mouth Processes Food for Swallowing
Teeth: Bite and chew food
o Types: Incisors, canines, premolars, molars
Children: 20 teeth
Adults: 32 Permanent Teeth
o Structure: Crown, root
Tongue: Positions and taste food
o Skeletal muscle
o Moves food in mouth
o Taste
o Important for speech
Saliva
o Salivary Glands
Parotid
Submandibular
Sublingual
o Composition
Mucin, salivary amylase, bicarbonate, lysozyme
Pharynx and Esophagus Deliver Food to the Stomach
Swallowing
o Voluntary phase: tongue pushes bolus of food into pharynx (throat)
o Involuntary phase: swallowing reflex
Pharynx: Common passageway for air and food
Epiglottis: Closes airway temporarily so food will not enter the trachea
Food moves through esophagus with the help of peristaltic contractions
Food passes through lower esophageal sphincter into the stomach
Stomach Functions
Food storage
Digestion of proteins
Regulation of delivery of partially digested food into the small intestine
Gastric Juice Breaks Down Proteins
Specific cells secrete gastric juice, which contains
Hydrochloric Acid
The benefits of buying summaries with Stuvia:
Guaranteed quality through customer reviews
Stuvia customers have reviewed more than 700,000 summaries. This how you know that you are buying the best documents.
Quick and easy check-out
You can quickly pay through credit card or Stuvia-credit for the summaries. There is no membership needed.
Focus on what matters
Your fellow students write the study notes themselves, which is why the documents are always reliable and up-to-date. This ensures you quickly get to the core!
Frequently asked questions
What do I get when I buy this document?
You get a PDF, available immediately after your purchase. The purchased document is accessible anytime, anywhere and indefinitely through your profile.
Satisfaction guarantee: how does it work?
Our satisfaction guarantee ensures that you always find a study document that suits you well. You fill out a form, and our customer service team takes care of the rest.
Who am I buying these notes from?
Stuvia is a marketplace, so you are not buying this document from us, but from seller ATIHUB. Stuvia facilitates payment to the seller.
Will I be stuck with a subscription?
No, you only buy these notes for $18.49. You're not tied to anything after your purchase.
