Exam 1 Flashcards
Which of the following is a correct example of a physiological concept relating to the study of a mechanism?
Acid secretion in the stomach occurs when the parietal cells are activated
through both neural and hormonal stimuli
Which of the following organelles is the site of protein synthesis for proteins, such as hormones, that are secreted from the cell?
Ribosome
Which of the following is the major constituent of the animal cell membrane?
Phospholipid
Which of the following statements correctly identifies the difference between a channel and transporter
A transporter only sometimes requires ATP, whereas a channel never requires ATP
Which of the following is not an example of a cell receptor?
Voltage-gated
Which of the following correctly lists the key secretions in the non-ruminant stomach?
Hydrochloric acid, mucous, pepsinogen
What key role does bile play in the digestive process?
Makes dietary fat soluble so that it can interact with its digestive enzymes
If a bird had proventriculus that was not releasing adequate amounts of its secretions, the digestion of what nutrient would you expect to be the most impacted?
Protein
Which organ plays a critical role in water absorption in non-ruminants?
LI
The secretions of what organ are controlled entirely by hormones?
Gallbladder
Which of the following correctly describes the sequence of events that occur during microbial fermentation of cellulose in the rumen?
Microbes release cellulase → cellulose digested into glucose → microbes absorb
glucose and metabolize glucose to volatile fatty acids → microbes release the volatile fatty acids, which can be absorbed via diffusion or transport by the rumen papillae
Which of the following is a role of saliva that is common between ruminants and non- ruminants?
Moistening and lubrication of the ingested feed
Unlike ruminants,hindgut fermenters, such as the horse, are able to absorb __________________, but not ____________________.
Glucose from starch, amino acids from microbial protein
Which of the following correctly identifies the key substrates AND end products of aerobic ATP synthesis
Glucose, fatty acids, volatile fatty acids and amino acids; CO2 and H2O
When comparing a cat and a horse, the _____________ would have a higher whole-
animal metabolic rate and the ______________ would have a higher weight-specific metabolic rate
Horse, cat
Which of the following is an example of a strategy to increase heat dissipation via convection?
On a hot day, your dog lies in front of a fan
Which of the following statements about core thermoreceptors is false?
Core thermoreceptors communicate information about the core body
temperature to the skin thermoreceptors in order to adjust the ‘set point’
In a typical animal cell, an increase in the number of open sodium channels on the cell
membrane will result in a(n) _______in the rate of sodium diffusion across the
membrane.
Increase
In order to buffer the acid entering the duodenum from the stomach, the pancreas releases
______from its duct cells.
Bicarbonate
. In non-ruminants, _______ is the primary retentive motility pattern, whereas
______is the primary propulsive motility pattern.
segmentation, peristalsis
In ruminants, ______is the process where partially digested feed from the rumen is
returned to the mouth for rechewing, whereas ______ is the process where the
gases produced during fermentation are expelled from the rumen.
rumination, eructation
The__________ of an animal is its rate of energy expenditure (consumption)
determined under the standardized conditions of fasting, and being at rest in a thermoneutral environment.
Basal metabolic rate
true of false: Physiology is the study of animal structure
False
true of false: In animals that conform to their external environment, if environmental temperature changes, then their body temperature will change as well
True
true of false: Enterokinase is an enzyme produced by the small intestine that is necessary for the activation of pepsinogen to pepsin
False
true of false: The majority of the proteolytic (protein degrading) enzymes released by the pancreas are released in an inactive form and must be converted to an active form in the small intestine
True
true of false: Microbial fermentation slows down when the most digested feed particles are mixed with the least digested feed particles
False
true of false: Glucose is the only nutrient that can be used to make ATP using both aerobic and anaerobic pathways
True
Triggers an increase in stomach acid secretion
Gastrin
Causes gallbladder contraction
CCK
Cause an inhibition of stomach acid secretion (select 2 hormones)
CCK and Secretin
Primary hormone causing pancreatic enzyme release
CCK
Primary hormone causing bicarbonate secretion by the pancreas and gallbladder
Secretin
Explain why the pancreas is considered an essential component of the digestive processes occurring in both ruminants and non-ruminants but is not considered to be a part of the gastrointestinal tract
Releases enzymes and bicarbonate of the small intestine but the digesta does not actually pass through the pancreas
Both starch and cellulose are polymers of the same molecule.
Explain how these two polymers differ structurally from each other
Glucose
Starch: α(1-4) linkages between glucose molecules Cellulose β(1- 4)linkages of glucose molecules
How does the digestion of starch and cellulose differ from each other in non-ruminant herbivores such as the horse
Starch: can be digested by the enzymes produced by the horse’s pancreas; primarily in small intestine
Cellulose: can only be digested with enzymes produced by the microbes; primarily in large intestine
Fiber
VFA is end product
LI are key organs for digestion
LI are key organs for absorption
Starch
Glucose is end product
Pancreas and SI are key organs for digestion
SI is key organ for absorption
Fat
Fatty acids are end product
Pancreas, Liver/gallbladder, and SI are key organs for digestion
SI is key organ for absorption
Protein
Amino acids are end product
Stomach, pancreas, and SI are organs for digestion
SI is key organ for absorption
What are the three organs that digest can go to from the reticulum?
Esophagus
Omasum
Rumen
What is the factor that determines where digesta goes?
Particle size
What happens to digesta in rumen?
Undergoes additional microbial fermentation
What happens to digesta in esophagus?
returns to the mouth via rumination for rechewing
What happens to digesta in omasum?
continues on to the omasum and the remainder of the ruminant GIT
Give an example of physiological mechanism that homeotherms apply to maintain core body temp. when its colder than their thermoneutral zones?
Shivering
Give an example of physiological mechanism that homeotherms apply to maintain core body temp. when its warmer than their thermoneutral zones?
Sweating, Panting or Gular fluttering
Give an example of physiological mechanism that homeotherms can do to maintain their core temp. as ambient temp. cools down within the thermoneutral zone?
Vasoconstriction
What is physiology?
The study of how the body works and why
What is internal environment?
Conditions inside the animal’s body
Some control
ie: body temp., hydration, ion concentration, pH of blood
What is external environment?
Conditions outside the animal’s body or factors animals cant control
ie: temp. wind, humidity, light
What is regulation?
Maintaining a constant internal environment despite changes in the external environment
Energetically costly, therefore it requires ATP
What is conformity?
Internal environment changes when external environment changes
Less energetically costly, therefore doesn’t require ATP
What is Homeostasis?
The tendency to maintain a constant internal environment
What are the 2 control systems of homeostasis?
Endocrine and Nervous system
What is plasma membrane?
Membrane that forms around animal cells that separates cells from each other
What is a phospholipid bilayer?
2 layers of phospholipids interacting with each other
What is the negative area of a phospholipid?
Phosphate
What is the positive area of a phospholipid?
Alcohol
A phospholipid has 2________ tails and a _____ head
Non-polar fatty acid, polar
Saturated
No double bonds
Packed tightly
Unsaturated
Double bonds
keep from packing tightly
What is hydrophobic?
Not water soluble
*water hating
What is hydrophilic?
Water soluble
*water loving
The polar head faces what 2 directions?
Into the cell and extracellular fluid
The non-polar tails face what direction?
The interior and cluster together
What are the cell membrane components?
Phospholipids- form bilayer
Cholesterol- non-polar forms rigid structure
Protein
Glycolipids and glycoproteins- facing outside the cell, identifies/differentiates or cell recognition, receptors
Structural properties of membrane proteins
Integral and peripheral
What is integral property?
Go through the bilayer and can’t be separated from the membrane without destroying it
What is peripheral property?
Associates with either intracellular or extracellular side of membrane and can’t be separated
What is the structural function?
Allows for interaction between cells and defines cells shape
What is transports function?
Movement of a solute across the plasma membrane
*solvent is usually H2O
What is a solute?
A dissolved substance in intercellular or extracellular fluids
*includes the plasma of blood
The plasma membrane is _______ permiable
Semi
____solutes can cross plasma membrane easily
Non-polar
What are some non-polar solutes?
CO2, O2, fatty acids (cholesterol), and vitamin A,D,E, and K
What are some polar solutes?
Ions, H2O soluble vitamins (B,C), glucose, and amino acids
What is membrane equilibrium?
Balance of competing forces(gradient) forces across the membrane
What is a gradient?
The difference from one side of membrane to another
What are the 3 types of gradients?
Concentration, charge, and pressure
What is balance?
Forces drawing solute into the cell is equal to the forces pulling solute out of the cell
What is an uncharged molecule?
Equilibrium happens when equal amounts of solute are in both sides of the membrane
What are charged molecules?
Equilibrium when charge gradient and concentration gradient are in opposite directions
**Cl- and K+
What are the conditions of an animal cell?
Inside is more negative than the outside
Plasma membrane is semi-permeable
Ions need channels or transporters to cross the membrane
What is simple diffusion?
Towards equilibrium
No ATP needed
No proteins needed
Channels are polar
What is passive/facilitated transport/diffusion?
Towards equilibrium
No ATP needed
Always requires a transporter
What is active transport?
Away from equilibrium
ATP needed
Always requires a transporter
What is a channel?
An integral membrane that forms a pore in membrane
It’s solute specific
What is meant by solute specific?
Only certain solutes can go through
**K+, Na+, Cl-, Ca2+
What does a gated channel mean?
It is sometimes open and sometimes closed
What are the 4 categories of gated channels?
Voltage gated
Ligand gated
Phosphorylation gated
Stretch gated
What is voltage gated?
Opens when there is a certain charge gradient
What is ligand gated?
Opens when something other than the solute binds to it
What is phosphorylation gated?
Opens/closes based on a phosphorylation status
What is stretch gated?
Open/closes based on mechanical forces on membrane “pulled” open
What is a transporter?
Integral membrane proteins
Always binds the solute
Max. capacity depends on the # of transporters
What is simple diffusion?
It goes with the gradient until equilibrium (high-> low)
Two categories of active diffusion
Primary
Secondary
What is primary diffusion?
Transporter itself uses ATP
What is secondary diffusion?
Relies on gradient established by primary transporter
*almost always Na/K+ -ATPase
What is osmosis?
The movement of water across the membrane
Passive
Movement from high to low water concentration
infusing in solutions
NaCl and percentages
How does water directly cross membranes?
Through aquaporins, which make osmosis faster
Low osmolarity
Hypotonic or hypoosmotic
High osmolarity
Hypertonic or hyperosmotic
Water moves from ________ to _______
Hypotonic to hypertonic
What does it mean for something to be isotonic?
Equal on both sides
What is metabolism?
All of the reactions (chemical) happening in an animals body
Anabolism
Builds reactions
Small molecules-> complex molecules
(muscle growth, bone formation, fat storage)
Catabolism
Destructive reactions
Complex molecules->small molecules
(digestion,energy production)
What does it mean to catalyze?
Accelerates speed without the enzyme help
What is short-term regulation?
Seconds-> minutes Highly reversible Works with pre-existing enzyme Makes it more or less active ei: phosphorylation
What is long-term regulation?
Hours-> days
Change the amount of enzyme present
Takes time to make new enzyme and break down existing enzymes
ei: DNA->RNA->protein
What is cell signaling?
A way cells communicate with each other
Coordinates metabolism across the body
“Signals” neurotransmitters and hormones
What is the difference between anatomy and physiology?
Physiology is the study of animal function and anatomy is the study of animal form
The tendency of an animal to maintain a constant internal environment
Homeostasis
This part of the cell is necessary for the aerobic production of ATP (cellular energy)
Mitochondria
What is the arrangement of phospholipids to form the plasma membrane?
Phospholipids form a bilayer with the heads point towards the extracellular and intracellular fluid and the tails pointing towards the center of the membrane
true of false: Plasma membranes are reversible, meaning the identical molecules are present on the intracellular side as on the extracellular side.
False
A solute that can easily cross the plasma membrane, without requiring a channel or transporter?
Fatty acid
An animals charge gradient flows from _____ ions towards a ____charge
positive, negative
Define an electrochemical equilibrium
When the concentration and charge gradients for a given ion are approximately equal, but in opposite directions
In a normal animal cell at rest, what ions are close to electrochemical equilibrium?
Potassium and Chloride
What is a major difference between a channel and a transporter?
A transporter binds to the solute, whereas the channel does not bind to its solute
What type of gated channel opens in response to a change in charge gradient across the plasma membrane?
Voltage-gated
true of false: In primary active transport, the transport protein directly uses ATP
True
What are the macronutrients
Carbs
Fats
Proteins
In a chicken, the end-product(s) of starch digestion is/are _____________.
Glucose
In pigs, the end product(s) of lipid digestion is/are primarily _____________.
FA
In mammals and birds, cellulose is digested _____________ and results in _______________ as the end-product(s) that is available for absorptio
microbially, VFA’s
Soybean meal is an important source of _________ in the diets of chickens and pigs. The digestive end product of this nutrient is _________.
Protein, AA
true of false: Enzymes are uniformly distributed across tissues.
False
true of false: Some examples of secondary messengers are hormones and neurotransmitters.
False
In which segment of the gastrointestinal tract do we see the most variation in the organs present when comparing different classes of domestic animals (ie. birds vs. ruminants vs. non-ruminants)?
Foregut
true of false: Digesta may pass through the accessory organs if needed
False
Facts about accessory organs
They are the salivary glands, pancreas and liver/gallbladder
Contribute secretions to the lumen of the gastrointestinal tract that are necessary for optimal digestion
Accessory organs are not part of the continuous tube between the animals mouth and anus (or cloaca in birds)
Facts about mastication
Results in a reduction in particle size
Results in bolus formation
In mammals, the shape of the molars (cheek teeth) determine how the animal is able to chew its feed
What are the three portions included in the serous portion of saliva?
Digestive enzymes
Ions
Water
Salivary amylase (is or is not) in the saliva of all non-ruminant animals
Is not
Which regulatory system controls the process of salivation?
Nervous system only
What is the name of the structure that ensures that digesta does not enter the airways during swallowing in mammals?
Epiglottis
true of false: In most mammalian species, the non-glandular region makes up the majority of the stomach and is responsible for acid, enzyme and mucus secretion.
False
In which component of the avian (bird) foregut is the gastric secretion released?
Proventriculus
Role of HCl in gastric secretion
Activates pepsinogen to pepsin
Unfolds protein chains
Ensures both the digesta and pepsinogen are in the form needed for the digestive processes in the stomach
What is the role of the bicarbonate in the pancreatic secretion?
Neutralizes the digesta pH
Pancreatic secretion regulations
Stomach distension triggers pancreatic secretion
The hormone CCK increases the release of enzymes into the pancreatic secretion
The hormone secretin increases the release of bicarbonate into the pancreatic secretion
What enzyme is needed to start the activation of the pancreatic zymogens and where is it located?
Enterokinase, brush border enzyme
The the process of starch digestion in the small intestine
Amylase released from the pancreas cleaves starch into 2-3 units of glucose; the brush border enzyme, maltase, then cleaves these in single units of glucose
In animals with a gallbladder, the release of what hormone increases bile secretion by relaxing the Sphincter of Oddi and causing the gallbladder to contract?
CCK
The enterocytes in the small intestine are arranged to form __________, which increases the surface area available for brush border (membrane-bound) enzymes and for absorption to occur.
Villi
The process of absorbing glucose from the gastrointestinal lumen
Transport across the apical membrane into the enterocyte, and then transport across the basolateral membrane into the portal vein
Major processes occurring in the LI
Absorption of H2O
Microbial fermentation
Storage of the feces prior to defecation
In the intestinal wall, when the circular muscles contract, the intestinal circumference gets _______________ and when the longitudinal muscles contract the intestinal length gets _______________.
smaller, shorter
What is the purpose of peristalsis?
To move digesta along the length of the gastrointestinal tract
The major motility patterns in the small intestine during digestion
Peristalsis and segmentation
Which of the following is a unique feature of ruminant saliva?
Contains high amounts of HCO3-
What is the process of cellulose digestion in a ruminant?
Certain ruminant microbes produce cellulase, cellulose is digested to glucose with the microbe then uses as an energy source; volatile fatty acids are made as a byproduct and released back into the rumen contents
true of false: The proportions of the various different volatile fatty acids produced in the rumen is influenced by the animal’s diet composition.
True
What is poikilotherms?
Body temp. changes with environment temperature
cold-blooded
What is homeotherms?
Maintain constant body temp. using physiological means
