Final Exam Flashcards
Define Physiology
The branch of biology that concentrates on studying the normal function of a living organism and its parts.
What does a fertilized egg do?
Divides, those cells proliferate, differenciate and self assemble
What is the basic unit of the body?
A cell
How many cells do we have?
100 trillion
T/F Cells are specialized
True
What are cells organized into?
Tissues and Organs
What are cells held together by?
extra-cellular structures
What do cells require to live?
Water Oxygen Ions amino Acids Other nutrients
Where do cells obtain their input materials and release their output materials to?
Extra cellular fluid
How much of the human body is essentially water?
60%
How much of the water that makes up the human body is extracellular fluid?
1/3 of 60% water so about 20% of the water is ECF
How much intracellular fluid makes up the fluid in the body?
2/3
How is the volume and composition of the ECF controlled?
Homeostatic mechanisms
What is critical to maintain life in terms of ECF?
The compositon
Define Homeostasis
A state of equlibrium within living organisms characterized by the maintainence of nearly constant internal environmental conditions. All organs and tissues participate.
How many Liters of water in a 70 kg male?
42 Liters ( 60%)
What makes up the extracellular fluid?
Blood Plasma
Intersticial Fluid
Transcellular fluid
How much of the body is intracellular fluid?
60% of the water in the body or 25 liters
What mediates the constant mixing of ECF?
Blood Plasma
How much of the bodies water is in the blood plasma?
7% or 3 L
What is intersticial fluid?
fluid in spaces between cells in tissues (fluid inbetween the plama membrane and capillary endothelium)
What makes up intersticial fluid
Bulk intersticial (61.5%) Bone (7.6 %) Dense CT (23%)
How much of the bodies water is intersticial fluid?
31% (Mostly Bulk intersticial)
What is transcellular fluid?
Fluid in spaces surrounded by epithelia (Joint synvial fluid, CSF)
How much of the bodies water is transcellular fluid?
1 Liter or 2.38%
Why is there a difference in chemical composition of intracellular aand extracellular fluids?
Difference is due to control of transport of these substances accross the plasma membrane.
What do G cells secrete?
Gastrin into the blood stream
What do parietal cells secrete?
HCl and intrinsic factor
What do Mucus Neck cells secrete?
Mucus
What do chief cells secrete?
pepsinogen and gastric lipase
What do Enteroendochrine cells (G cells)
Secrete?
Gastrin
What lines the gastric pit?
Simple columner epithelium with Mucus suface cells
What type of cells are found in the gastric glands?
Parietal, Mucus Neck Chief and G cells
What does Submucosal Plexus control?
Secretion
What type of transport is used for HCl secretion
Active-Protons are pumped out of the cell in exchange for a potassium ion
What enzyme catalyzes the reaction in parietal cells?
Carbonic Anydrase-abundant?
How are chloride ions released into the gastric lumen?
Diffusion
T/F Choloride and Protons are released seperately into the gastric lumen
True!
How is HCl formed in the parietal cell?
Via the Carbonic Anyhydrase which is abundant in the pareietal cells
Where are H+ K+ ATPase located in the pareital cells?
Apical Membrane that faces the lumen
What provides energy for the outward transport of H+
ATPase
What is H+-K+ATPase inhibited by?
Omeprazole
What does omeprazole treat?
Gastric and duodenal ulcers
What provides energy for the active transport of Cl- across the pareital membrane?
The downhill movement of HCO3+
What is the function of HCl?
- Eliminates ingested bacteria
- Facilitates protein digestion
- Provides acidic environment essential for the activation and function of pepsin
What stimulates the secretion of gastric HCl?
Acetylcholine
Histamine
Gastrin
*through several second messenger systems
What inhibits gastric HCI secretion?
Somatostatin
Parasympathetic _____ induces _____ release
Parasympathetic Stimulattion induces ACh release
where are the G cells located?
The Antrum
What does gastrin do?
Stimulates HCl and pepsinogen secretion; and motility
What is released from the enterochrochromaffin like cells?
Histamine
What is the function of histamine?
- Direct stimulation of HCl
- Increase the secretion induced by ACh or gastrin
- It is a paracrine agent
What receptors does Histamine stimulate?
H2 receptors on the pareital Cells
What is the function of Cimetidine?
It inhibits acid secretion by blocking H2 receptors
What is the most important trigger for pepsinogen secretion?
Vagal Stimulation
When is pepsinogen active?
Only in a highly acid environment (1.8-3.5)
What is essential for protein digestion in the stomach?
HCl and Pepsin
What does pepsin do?
Breaks down peptide bonds found in proteins
What does intrinsic factor form a complex with?
Vitamin B-12
Once a complex forms from vitamin B-12 and Intrinsic facor, what does the complex do?
Binds to specific receptors in the ileum and then is absorbed via endocytosis
If someone has undergone abdominal surgery and are intrinsic factor deficient what are they vunerable to?
Iron deficiency anemia so they much eat frequently
What is dumping syndrome?
- develops following removal of part of the stomach
- Anastomosis of the jejunum to the stomach
- Rapid entry of hypertonic meals into intestine
What is the role of mucus in the stomach
Forms a gel like protective barrier butween glandular cells and lumen
Mucus is secreted by ______ and _____ in the ___ and _____ regions of the stomach
Mucus is secreted by Mucus Neck Cells and surface epithelial cells in the body and fundus regions of the stomach.
How often do epithelial cells get replaced?
every 3-6 days
What happens in the cephalic phase of digestive regulation?
- Somatostain inhibits gatrin secretion
2. Vagus nerve inhibits the release of Somatostatin
What kickstarts the cephalic phase?
Sight, smell, or presence of food in the mouth
What mediates the cephalic phase?
Vagus nerves originate in the medulla oblongota
What initiates the cephalic phase secretion?
Stimulation of the enteric neurons by vagal fibers
What directly stimulates the pareital,mucus, and chief cells during the cephalic phase?
the post ganglionic parasympathetic fibers
What do the post ganglioic parasympathetic indirectly stimulate during the cephalic phase?
G cells by inducing gastrin
What are the primary stimuli of the gastric phase?
Distention of the stomach
Gradual increase in the pH of gastric contents
Presence of protein breakdown products
What senses elevated pH during the gastric phase?
Chemoreceptors
What senses distention of the stomach during the gastric phase?
Stretch Receptors
Wat do the stretch receptors and chemoreceptors send the signal to?
Submucosal and Myenteric Plexuses
What occurs during the intestinal phase?
Enterogastric reflex
What elicits the intestinal phase?
Entry of acidic chyme into the duodenum
what is the purpose of the intestinal phase?
Control the rate of gastric emptying (enterogastric reflex)
What happens during the enterogastric reflex?
The duodenum sends inhibitory signals to the stomach by way of both the nervous and hormonal reflexes
what is acid, pepsin secretion and gastric motility inhibited by in the intestinal phase?
the presence of
fat, carbs, acid, etc. in the duodenum
What triggers the enterogastric reflex?
Distention of the stomach
What type of secretions are secreted during the intestinal phase for protection?
Mucus- from acid and enzymes
What inhibits gastric secretions in the stomach?
Duodenal secretion
CCK
GIP
Stomach emptying is ________ by the _____ _______,_______ and _____ in the duodenum.
Stomach emptying is inhibited by the enterogastric reflex, enterogastrones and fat in the duodenum.
What regulates gastric emptying?
Hormonal and Neuronal Reflexes
What do duodenal entero-endocrine cells secrete in the presence of fatty, hypertonic, acidic chyme in the duodenum?
Enterogastrones (CCK, Secretin, VIP)
What happens when enterogastrones (Hormones) such as Secretin, CCK and VIP are secreted?
Contractile force and rate of stomach emptying decline
What do chemoreceptors and stretch receptors target in the presence of fatty, hypertonic and acidic chyme in the duodenum?
Enteric neurons via short reflexes and CNS centers(SNS activity(kickstarted) and parasympathetic activity) via long reflexes
As a result of enterogastrone secretion, enteric neuron stimulation and CNS stimulation what happens in terms of the intestinal phase?
Contractile force and rate of gastric emptying decline
What activates the cephalic phase?
prior to food entry
What activates the gastric phase?
Food Enters the Stomach
What activates the intestinal phase?
Partially digested food enters the duodenum
What are the three phases of gastric secretion regulation?
Cephalic, Gastric and Intestinal
Myentric Plexus is located ______
1
G Cells are located mainly in the _____
1
Secretion of HCl is stimulated by the _____
1
The major inhibitory mechanism of HCl is ______
1
The stimuli for the cephalic phase include _____ and _____ & _____.
Sight, Smell and presence of food in the mouth
Gastrin Stimulates ____,_____, and ____.
1
Pareital Cells secrete _____ and _____.
1
Pancreas facilates the process of _____ and ______
Absorbtion and digestion
What are the two components that the exocrine juice consists of?
Aqueous and Enzyme component
What does the aqueous component of the exocrine juice consist of?
HCO-
What is the function of the aqueous part of the exocrine juice?
Facilitates neutralization of duodenal contents
what does secretin elicit?
bicarbonate secretion
What does the enzyme portion of exocrine juice consit of?
Enzymes that aid in digestion of proteins, carbs and fats
What promotes the secretion of the enzyme component of the exocrine juice?
CCK
Where is the endocrine portion located in the pancreas?
Islets of langerhans
What percent of total volume is the endocrine secretion in the pancreas?
Less than 2%
What hormones are secreted by the endocrine cells?
Insulin, Glucagon. somatostatin
What structures/Cells are found in the pancreas?
Acini (dark clusters)-99%
Islets of Langerhans (1%)-Pale Stain
What do the acini produce?
Pancreatic Juice
What do the islets of langerhan produce?
Hormones
What secretes the enzymic component of pancreatic juice?
Acini
Where does the duodenum fuse with the bile duct?
The hepatopancreatic ampulla
What controls the entry of pancreatic juice and bile?
Sphincter of Oddi (hepatopancreatic sphincter)
What is pancreatic juice made of?
water
Enzymes
Bicarbonate Ions
What releases bicarbonate ions in the pancreatic juice from the pancreas?
Small Ducts (make it alkaline —pH 8
What does Bile, intestinal and pancreatic secretion allow for?
neutralization of the acidic doudenal contents
What does the enzyme component of the pancreastic juice do?
Produces complete breakdown of food
What enzymes are found in the enzyme rrich portion of the pancretic juice?
Major proteases:
Trypsin
Chymotrypsin
Carboxypeptidase
What is enteropeptidase?
A brush border enzyme that is involved in the activation of trypsinogen
What does the trypsin inhibitor do?
prevents premature activation of proenzymes in the pancreatic ducts
What promotes the release of pancretic juice neurally?
Vagal stimulation during the cephalic and intestinal phases of gastric secretion
What does the CCK do?
- induces the secretion of enzyme rich pancreatic juice
- Stimulates gallbladder to release stored bile
What does secretin do?
- Causes secretion of bicarbonate rich pancreatic juice
- It also acts on the liver to secrete more bile
- Inhibits gastric motility and gastrin mediated effects on pareital cells
T/F secretion is rich in enzymes
False! It is poor in enzymes
What is secretin secreted by?
S Cells of the duodenum
What is secretin secreted in response to?
H+ and fatty acids in the lumen of the duodenum
What cells does secretin act on?
Ductal cells that then produces alkaline rich pancreatic juice
What is CCK secreted by?
I Cells in the duodenum
What is CCK released in response to?
Fatty Acids
Peptides
Amino Acids
What is the Function of CCK?
- Stimulation of the secretion of enzyme rich pancreatic juice
- Potentiates the stimulatory effects of secretin (secredtion of bicarb)
- Stimulates the gall bladder to releaase stored bile
Where is Gastrin Found?
Stomach
What stimulates the secretion of gastrin?
- Food in the Stomach
2. ACH released by nerve fibers
What is the action of gastrin?
- Stimulates the release of gastric juice
2. Stimulates Stomach Emptying
Where is intestinal gastrin found?
Duodenum
what is the stimulus for intestinal gastrin secretion?
Acidic food in the stomach
What is the action od intestinal gastrin?
Stimulates gastrin emptying and emptying
Where is Histamine Hormone found?
Stomach
What is the stimulus for histamine secretion?
Food in the stomach
What is the action of histamine?
Activates pareital cells to secrete HCl
Where is the hormone somatostatin found?
Stomach and Duodenum
What is the stimulus for Somatostatin secretion?
Food in the stomach stimulated by sympathetic nerve fibers
What is the action of somatostatin?
- Inhibits secretion of gastric and pancreatic juice
- Inhibits emptying of stomach and gallbladder
(Braking mechanism)
Where is Secretin,CCK
and Gastric Inhibitory peptide found?
Duodenum
What is the stimulus for secretin secretion?
Acidic chyme and partially digested foods in the duodenum
What is the action of secretin?
- Increases Output of pancretic juice rich in bicarb ions
- Increases Bile Output by liver
- Inhibits gastric motility and gastric gland secretion
What is the stimulus for CCK secretion?
Fatty Chyme and partially digested proteins in the duodenum
What is the action of CCK?
- Increases Output of enzyme rich pancreatic juice
- Stimulates gallbladder to expel stored bile
- Releases Sphinctor of duodenal papilla to allow bile and pancreatic juice to enter the duodenum
What is the stimulus for Gastric Inhibitory peptide?
Fatty Chyme in the duodenum
What is an important brush border enzyme for carbohydrate digestion?
Na-Glucose Cotransporter (same direction)
What carbohydrate is transported via facilitated diffusion at the apical membrane in the small intestine?
Fructose
How do Glucose and Galactose get through the apical membrane in the small intestine?
A cotransporter (sodium glucose transporter) SGLT1
How do glucose, fructose and galactose all cross the basolateral membrane?
Facilitated Diffusion
What does pepsin do in the Stomach?
Hydrolyzes proteins into peptides
What two molecules digest proteins in the stomach?
HCl-denatures
Pepsin-Hydrolyzes
How are proteins digested in the pancreas?
Digestive Enzymes and Brush Border Enzymes
How do digestive enzymes digest protein?
Split peptide bonds between different amino acids
How do brush border enzymes digest proteins?
(Carboxypeptidase, aminopeptidase, dipeptidase) split off amino acid at amino end of molecule or split dipeptide
How are lipids digested?
Lipase and Colipse break down triglycerides into A monoglyceride and free fatty acid
What are the breakdown products of Lipases?
Monoglyceride and Free Fatty Acid
Explain the Mechanism of Lipid Digestion
- Large fat droplets from stomach are coated with bile salts from the liver and are emulsified
- Pancreatic lipse and colipase break down fats into momoglycerides and fatty acids stored in micelles
- Monoglycerides and fatty acids move out of micelles and enter cells by diffusion
What is a property of bile salts?
Ampiphic (hydrophobic and hydrophilic ) property
How do fatty acids and monoglycerides enter intestinal cells?
Diffusion
After fatty acids and monoglycerides enter the intestinal cell what are they combined with?
Triglycerides, cholesterol
proteins to form chylomichrons
How are chylomicrons extruded?
Exocytosis
After extrusion what happens to chlylomicrons?
They enter lacteals and are transported to the circulation via lymph
What are the functions of the female reproductive system?
- Production of the oocyte (Female Gamete-most important)
- Providing the environment for the acceptance of spermatozoa and for the fertilization of the ovum.
- Providing the environment for the growth and nutrition of the fetus.
- To give birth at the appropriate time
The reproductive tract of a female is a ______ system that starts with the ____ and ______ and ends at the ______
is a tubular system that starts with the ovary and infundibulum and ends at vulva
The Ovary produces and releases _____.
oocytes
The ovary is a Endocrine/exocrine gland that secretes ____ and _______.
Estrogen and progesterone
What is the infundibulum?
is a funnel-like ending of uterine tube that catches the oocyte that was released from ovary.
What captures the oocyte?
Oviduct (Fallopian Tube)
Where does fertilization occur in the female?
Ampulla of the oviduct
What is the uterine wall made of?
Endomeitrium and myometrium
What is the oviduct?
a tube that transports the egg to the uterus.
Where does fertization occur?
Oviduct-just past the infundibulum
The cervix is a _____
sphinctor
Entrance to the vagina is called the _____
Vestibule (Covered by the hymen)
Clitirous has ______
somatosensory innervation
What is the wall of the oviduct made of?
Walls contain smooth muscles, cells with cilia and secretory cells. These components assist the support and transport of sperm and egg.
What are the three parts of the uterus?
- Two horns
- Body
- Cervix
What happens in the body of the uterus?
Development of the fetus
What holds the uterus in place?
Broad ligament
What are the basic units of female reproduction?
Follicles
The medulla of the ovary is ____
highly vascular
Females are born with ovaries that contain a finite number of ______ _______.
Primordial follicles
What is contained within each primordial follicle?
primary oocyte
What cells secrete estrogen?
Granulosa cells
What hormone triggers ovulation?
A surge of lutenizing hormone
What does progesterone inhibit
GnRH and gonadotropins
What is an important function of progesterone?
inhibits ovulation
What are the two layers of the endomeitrium?
- basalis
2. Functionalis
What happens at Phase 0 of ventricular muscle action potential?
Depolarization)- Fast Na+ channels open, then slow Ca++ (Straight Line going up)
What happens at Phase 1 of ventricular muscle action potential?
(Slight Repolarization)- K+ channels open
Apex of Graph
What happens at Phase 2 of ventricular muscle action potential?
(Plateau)- Slow Ca++ channels open, decreased permeability to K+
What happens at Phase 3 of ventricular muscle action potential?
(Repolarization) K+ channels open
Straight line going down
What happens at Phase 4 of ventricular muscle action potential?
(Resting membrane potential- (-85 to -95 mV))
What are the Two Phases of the cardiac cycle?
Phase 1: Ventricular Systole (Contaction of the ventricle myocardium)
Phase 2: Diastole (Relaxation of ventricular myocardium)
What steps are in Phase 1 of the Cardiac Cycle?
- Isovolumic Contraction
2. Ventricular Ejection
What steps are in the Diastole Phase of the cardiac Cycle?
- Isovolumic Relaxion
- Rapid Inflow
- Diastasis
- Atrial Systole (Atrial Contraction)
What happens to ventricular pressure during Isovolumic Contraction?
Ventricular Pressure Rises Rapidly and AV valves close
What happens to ventricular Volume during Isovolumic Contraction?
There is not a change in volume (no emptying occurs
Are the valves open or closed during isovolumic contraction?
All 4 are CLOSED
What do you hear during isovolumic contraction?
The S1 sound (Lubb)
What makes the S1 sound?
AV valves snapping shut
What happens to left ventricular pressure during Ventricular Ejection in Phase 1 (Systole)?
When left ventricular pressure rises slightly above 80 mmhg the semilunar valves open and blood is ejected
What happens to right ventricular pressure during Ventricular Ejection?
Right ventricular pressure is less than pulmonary trunk
When does the T wave occur during the cardiac cycle?
During the Ventricular Ejection phase right before
What happens to right ventricular pressure during Ventricular Ejection in Phase 1 (Systole)?
When the right ventricular pressure rises slightly above 20 mmHG (book = 8 mmhg), the pulmonary semilunar valves open and blood is ejected.
During ventricular ejection, which volume can you measure?
End Systolic Volume (Volume of blood remaining in the ventricle after systole should be 50 ml)
What happens to aortic pressure during Ventricular Ejection in Phase 1 (Systole)?
Starts increasing during systole and aortic valve opens after that and then it begins to decrease
What happens to Atrial pressure during ventricular ejection?
c wave which is a slight backflow into the aorta
During the Isovolumic relaxion phase of diastole what happens to ventricular volume?
Does not change
During the Isovolumic relaxion phase of diastole, are any valves open?
No all are closed
When do we hear the S2 (Dupp) sound in the cardiac cycle?
During Isovolumic relaxation
What is the Dupp (S2) sound?
The semilunar valves closing
What causes the semilunar valves to close during isovolumic relaxation?
Pressure decrease in the ventricles and blood flow back into ventricles
During the Rapid Inflow phase of Diastole what happens to ventricular volume?
It increases
what is the verntricular pressure during the rapid inflow stage?
It is low
What happens during the rapid inflow stage of diastole?
- AV-Valves open and ventricles fill rapidly
1. Blood flows from great vein to atria (80% of it)
What happens to atrial pressure during rapid inflow of ventricles?
A v wave occurs at the end of ventricular contraction (isovolumic relaxtion phase) and atrial pressure does not change
What happens to aortic pressure during the rapid inflow stage of diastole?
After aortic valve closes an incirsura occurs because back flow stops suddenly toward the left ventricle
During diastole, what is happening to aortic pressure?
It decreases slowly due to elasticity of the aorta plus blood fllow to periphery
What wave occurs during diastasis?
P Wave
What happens during diastasis?
A small amount of blood passively flows into the ventricles
What occurson the ECG? during atrial systole
QRS complex
What happens to ventricular volume during atrial systole?
It increases by 20%
120 mL at end of diastole
What happens to ventricular pressure during atrial systole?
It increases slightly
what happens to atrial pressure during atrial systole?
- Atria contract causing a wave
- Ventricles fill by 20%
- Atria function as a primer pump and ventricles are 20% more effective
What happens to Aortic Pressure during atrial systole?
Decreases slightly
