A&P2: Gastro Flashcards
Define Metabolism?
Use of nutrients gained from food to build, maintain and provide energy
Interactive set of chemical pathways to make life possible
After food is digested, molecules are placed into which part of the circulatory system?
Portal vascular system
Define assimilation
When nutrient molecules enter cells and undergo chemical changes
How is thermal heat released into the body and for what purpose?
Frequent, small bursts
Homeostatic body temps
What has to happen to chemical energy before it can be used?
Transferred into ATP
What is the difference between Micro and Macro nutrients and their ability to be absorbed?
Micro- absorbed in original form
Macro- need to be catabolized into smaller forms
What is the largest size a protein can be and still be absorbed?
AAs
Dipeptide
Tripeptides
All can be absorbed as is
What length/form do carbohydrates need to be in order to be absorbed?
Monosaccharide
Glucose, fructose, galactose
What form/length do lipids need to be in order to be absorbed?
Fatty acids
Monoglycerides
What are examples of Micronutrients?
Vitamins
Minerals
Needed in SMALL quantities
How many essential micronutrients are there?
28
What is the major source of biological energy used by organisms?
Carbs
Carbohydrates come in what 3 forms?
Mono
Di
Poly
Digestion of carbohydrates requires what type of enzymes?
Amylases
What is the absorbable form of carbohydrates?
Monosaccharides
Glucose
Fructose
Galactose
What are the nonabsorbable forms of disaccharides?
Sucrose- glucose + fructose
Lactose- Glucose + galactose
Maltose
Which disaccharide is a byproduct of starch digestion?
Maltose
What are the polysaccharide forms that are unable to be absorbed as is?
Starches
Glycogen
Cellulose
What combines to make starches?
Amylose + amylopectin
Where is glycogen placed for storage?
Liver
Muscles
Glial cells of brain
What is the chemical name for fiber?
Cellulose
Carbs can be classified within the diet under what two categories?
Simple- mono and disaccharides
Complex- polysaccharides
What is the most common form of lipid found in the diet and in the body?
Triglycerides (TAGs)
Define TAGs
High energy nutrient synthesized and stored in adipocytes and hepatocytes
TAGs are required in the body for absorption of ____?
Fat soluble vitamins
What provides constituent molecules for cellular membranes?
TAGs
What are the simple lipids?
Fatty acids: Sat/unsat/triacyglycerols
What compounds can join triacyglycerols to make compound lipids?
Phopholipds- FA+phosphorus+N
Glycolipids- FA+carbs+N
Lipoproteins
Where are functions of compound lipids?
Cell membrane
Nerve sheath
Helps w/ cellular recognition
Where are glycolipids found?
Cell membrane
Facilitate cell recognition
What are the types of Lipoproteins?
Chylomicrons
VLDL
LDL
HDL
Define Derived Lipid
Simple+compound lipid
What are examples of derived lipids?
Steroids- especially cholesterol
Terpenes
Fat soluble vitamins
Ketone bodies
Where are derived lipids synthesized?
Liver
Almost all cells including endothelial
What are the functions of Derived Lipids?
Plasma membranes
Vit D synthesis precursor
Androgen/sex hormone synth
In order to be absorbed at a cellular level, what has to happen to triglycerides first?
Hydrolyzed into FA/Monoglycerides by lipase enzymes
How are lipids transported?
Chylomicrons VLDL LDL HDL FFAs
During _____ state, blood can have so many chylomicrons that it can appear what color?
Absorbed
Turbid, yellow
During what state are chylomicrons going to be low or nonexistent?
Post-absorptive
What state are lipoproteins going to be most active?
Post-absorptive
Where are lipoproteins made?
What are they made from?
Liver
Lipids and proteins
What combine to make free fatty acids?
FA + albumin
During starvation state, what will free FA levels be?
Increased due to fat-catabolism
What is the largest/lowest density lipoprotein?
What is the smallest/heaviest density lipoprotein?
Largest- Chylomicron VLDL IDL (intermediate) LDL Smallest- HDL
Where are chylomicrons synthesized?
What is used to make them?
Enterocytes of small intestines
Fat and cholesterol from small intestine
How are chylomicrons transported so they can enter circulation?
Enter lacteals (lymphatic capillaries) -> thoracic duct -> circulation
Where are VLDLs synthesized?
What is used to make them?
Liver
Fats and cholesterol from portal circulation
How are LDLs made?
VLDLs are stripped of triglycerides, leftovers are remodeled into LDLs
What is the function of HDLs?
Reverse cholesterol transport, returns excess cholesterol to liver for recycling
Where are HDLs made?
Liver
Small Intestine
LIpogenesis/anabolism includes the formation of what lipids?
Triglycerides
Phospholipids
Cholesterol
Prostaglandins
What word means protein hydrolysis?
Proteases- pepsin, trypsin
20 total aa, of these there are _ essential, _ conditionally essential and _non-essential
9 essential
7 conditional- illness/inc stress
4 nonessential
Every cell synthesizes its own _____ proteins
Structural
Digestive system is closely associated with what other system? Why?
Cardiovascular
Due to vessels involved in digestive process
How does the Cardiovascular System impact the digestive system?
Supply organ with O2
Processes nutrients
How does the Endocrine System impact the digestive system?
Hormone regulate digestive system actions
How does the Integumentary System impact the digestive system?
Protects digestive organs
Vit D absorption
How does the Lymphatic System impact the digestive system?
MALT defense against pathogens
Lacteals absorb lipids
How does the Nervous System impact the digestive system?
Sensory/motor neurons regulate secretions and GI tract contractions
How does the Respiratory System impact the digestive system?
Provides O2
Removes CO2
How does the Urinary System impact the digestive system?
Kidneys make calcitriol to aid w/ Ca+ absorption
How long is the GI tract in humans?
16-23 alive
23-29 dead
What are the accessory digestive organs?
Teeth Tongue Salivary Glands Liver Gallbladder Pancreas
What are the 6 processes of the digestive system?
Ingestion Secretion Mixing/propulsion Digestion Absorption Defecation
Define motility
Mix and movement of material along tract
What are examples of substances that can be absorbed w/out chemical digestions?
Vitamins
Ions
Essential FA
Water
What are the 4 layers of the GI tract?
Outer to Inner Serosa/Adventitia Muscularis Submucosa Mucosa
Adventitia layer of the GI tract starts and ends where?
Esophagus through proximal duodenum
What are the layers of the GI tract’s muscularis layer?
2-3 layers of smooth muscle
What structures are found in the GI tract’s submucosa layer?
CT
Glands
Vessels
Nerves
What are the layers of the GI tract’s mucosa layer?
Epithelium
Lamina propria
Muscularis mucosa
The serosa layer of the GI tract is AKA ?
Visceral periotneum
What parts of the GI tract’s muscularis layer is skeletal and smooth muscle?
Skeletal- mouth, pharynx, upper esophagus, external anal sphincter
Smooth- everywhere else
Where is the Myenteric Plexus located?
What is it AKA ?
Between circular and longitudinal muscle layers
Plexus of Auerbach
Where is the Submucosal Plexus located?
What is it AKA?
Submucosa layer of GI tract
Plexus of Meissner
What layer of the GI tract has the nerves and vessels?
Submucosa layer
The inner, mucosa layer of the GI tract is composed of that 3 layers?
Muscularis mucosae
Lamina Propria
Epithelium
What layer of the GI tract five the small intestine and stomach the folded appearance?
Mucosa, muscularis mucosae layer
Muscular movement within what layer of the GI tract ensured the absorption cells are fully exposed to the GI tract contents?
Mucosa muscularis mucosae
What layer of the GI tract contains the MALT defenses?
Lamina propria
Where is MALT tissue present in the GI tract?
Tonsils
Small intestine
Appendix
Large intestine
What layer of the GI tract is thicker and provides the tract protection from scraping/damage of passing contents?
Mucosa layer
What are the functions of the exocrine and enteroendocrine cells in the mucosa layer?
Exo- mucus/fluid/enzyme secretion
Entero- secrete hormones
What part of the NS innervates the GI tract?
Regulated by intrinsic (enteric NS) and extrinsic (ANS)
What is considered the “brain” of the guy?
Enteric NS
Where does the enteric NS exist in the GI tract?
Mouth to anus
The enteric NS is broken up into what two parts within the GI tract?
Both branches are composed of what structures?
Myenteric Plexus (Auerbach)- muscularis Submucosal Plexus (Meissner)- submucosa
Neurons, interneurons, sensory neurons
What is the function of the Myenteric plexus?
What is the function of the Submucosal plexus?
M= motor impulses to longitudinal/circular muscles of muscularis layer, GI tract motility (frequency/strength) S= secretory cells of mucosal epithelium
What structure connects the myenteric and submucosal plexuses?
Inerneurons
Sensory neurons supply which layer of the GI tract?
Some sensory neurons also act as what other function?
Mucosal epithelium
Chemo/baroreceptors
What is the Sympathetic NS and vagus nerve impact on the cardiovascular and GI system?
NS= Secretes NorEpi activating adrenergic receptors, stims cardiac activity; inhibits GI activity Vagus= secrete ACh activating cholinergic receptors, inihib cardiac and stim GI tract
What CN regulates the enteric NS?
CN10- supplies parasympathetic nerves to most of GI tract
Stimulation of the parasympathetic nerves that innervate the GI tract causes what result?
Increased GI secretions and motility by increasing enteric NS activity
How does the sympathetic nerves supplying the GI tract arise and connect?
From thoracic and lumbar regions of spinal cord
Stimulation of the sympathetic nerves in the GI tract causes what result?
Decreased GI secretion/motility by inhibiting enteric NS
What is the largest serous membrane in the body?
Peritoneum
What is the peritoneum divided into?
Parietal- wall of abdominopelvic cavity
Visceral- covers some of the organs
What is the space in between the two peritoneum layers called?
Peritoneal cavity, contains lubricating fluids
Organs in the retroperitoneal space are covered by the peritoneum on what surface?
What organs does this include?
Anterior Kidneys Ascending/Descending Colon Duodenum Pancreas
What are the 5 folds of the peritoneum?
Greater omentum Falciform ligament Lesser omentum Mesentery Mesocolon
What is the largest peritoneal fold?
What organs does it cover?
Where does it travel to/through?
Greater omentum
Transverse colon and small intestine
Attaches stomach and duodenum, anterior to small intestine, folds, extends to attachment on transverse colon
What part/fold of the peritoneum is a contributor to the term “beer belly”?
Greater Omentum
What part of the GI tract contains many lymph nodes that have macrophages and antibody producing cells to combat GI tract infections?
Greater omentum
The greater omentum is AKA what ligament?
Gastrocolic
What is the falciform ligaments function?
Attaches liver to ventral surface of abdominal wall