Animal Biology Lab Quiz
Terms in this set (84)
What does it mean to say that a neuron is polarized at its resting potential?
Neuron is more positive on the outside of the cell membrane and is more negative on the inside.
When a neuron is at resting potential, which ion that we studied in lab is more concentrated on the outside of the cell? Which ion is more concentrated inside?
Na+ is high on the outside.
K+ is high on the inside.
If Na+ could suddenly move freely in either direction through the membrane, which direction would it go? Why? NOT SURE
It would want to go in because positive attracts negative.
If Na+ did move freely as described above, what effect would that have on the membrane potential?
It would become more positive.
If K+ could suddenly move freely in either direction through the membrane, which direction would it go? (1 Reason)
It would want to move to the outside of the cell.
If K+ did move freely as described above, what effect would that have on the membrane potential?
It would be more negative.
The resting potential of animal cells is a negative voltage. Considering your answers to the questions above, which ion (Na+ or K+) is the membrane more permeable to at rest? Which type of channel is responsible for this permeability?
More permeable to K+ at rest.
K+ Leakage Channels.
Which types of transport have a role in the system we study in this lab?
How specifically is each type of transport used?
-Active Transport: Requires energy to move substances across a cell membrane against a concentration gradient.
-Osmosis: Movement of molecules across a semi-permeable membrane from a less concentrated solution to a more concentrated solution, thus equalizing concentration.
-Facilitated Diffusion: Process of spontaneous passive transport (doesn't require energy) of molecules or ions across a cell's membrane via specific transmembrane integral proteins.
-Simple Diffusion: Process where a substance passes through a membrane without any aid. The force that drives the substance across the membrane is diffusion.
Which form of transport is more energetically expensive for the neuron - achieving and maintaining resting potential or the membrane voltage changes during an action potential?
Membrane voltage changes during an action potential. It's required to reach a certain threshold, where then it spikes upward using a lot of energy.
What different information is obtained from the conductance traces and the membrane potential trace?
-Conductance Traces: Tells you the permeability of the cell membrane to K+ and Na+ ions, and the change in conductance.
-Membrane Potential Trace: How negative or positive the membrane is.
How can you evaluate the relative rates of gates opening/closing?
-Na+ voltage gated channels open very quickly.
-Na+ voltage gated channels are inactivated more slowly than they open.
-K+ voltage gated channels open much slower than the Na+ channels.
-K+ voltage gated channels close very slowly compared to the Na+ channels.
-Relative rates of the opening and closing of K+ channels are different. Opening rate is quicker than closing rate.
Series of Events that Result in an Action Potential
1. The cell is resting at around -70 mv.
2. The cell is excited by a stimulus and some Na+ activation channels open. Na+ ions flow in via facilitated diffusion (NO ATP).
3. Once threshold is met, all voltage gated channels open though K+ opens very slowly. (Very few K+ ions cross membrane initially).
4. After a brief amount of time, Na+ voltage gated channels inactivate by closing gate on inside of cell.
5. As Na+ channels inactivate, K+ channels are finally wide open.
6. As the charge of the membrane drops due to K+ flowing out, the Na+ activation gates re-close.
7. Immediate recovery of resting membrane potential due to diffusion of ions that do NOT cross cell membranes.
What is threshold?
Set number that needs to be reached in order for an action potential to occur.
What occurs with the voltage gated channels if a stimulus reaches threshold?
The Na+ channels open fast and the Na+ travels into the membrane, then the gate slowly closes. Then the K+ channels open slowly and leaks out of the cell and then they close VERY slowly and the membrane potential spikes very low because too many K+ escape.
What occurs with the voltage gated ion channels if a stimulus is under threshold?
-The inactivation gate is open.
-The activation gate is closed.
What is meant by the "refractory period" of a neuron?
Time during which another stimulus is given to the neuron will not lead to another action potential no matter how strong. "Recovery"
Relative Refractory Period vs. Absolute Refractory Period
-Relative: Variable interval in which the capacity to start a second action potential depends on the amplitude of the stimulus.
-Absolute: Time in which it is impossible to stimulate a second action potential.
How do these relate to the gates of the voltage gated ion channel?
Why does the Na+ channel need an activation gate AND an inactivation gate, whereas the K+ channel only has one gate?
How does the neuron recover the ion gradient after an action potential?
Na+/K+ pump, K+ leak channel.
What is the result of larger/longer stimuli?
More action potentials.
How can you relate this to the difference between having your alarm go off at soft vs. loud volume?
How does the presence of TTX affect the ability of a neuron to conduct an action potential?
Prevents action potential.
How does the presence of TEA affect the ability of a neuron to conduct an action potential?
What effect does temperature have on the sensitivity of a neuron to a stimulus?
Light pink cottage cheese gland in throat on either side of the thyroid.
Solid dark pink bean shaped gland in the middle of the throat.
Holds itself open with cartilage rings.
Esophagus (Food Tube)
Dorsal (back/behind) to the trachea.
Dorsal to the glottis, towards the backbone, opening to the esophagus.
Center of the chest.
Thin muscle between heart/lungs and stomach. Flexible.
Soft and light colored, on either side of the heart.
Light colored bean shaped organs at back wall.
Two lightly colored tubes leading from kidneys to bladder.
Sac-like structure attached from umbilical cord.
Opening on butt, Dorsal to everything.
Dorsal to trachea.
Light colored, underneath liver.
Big dark brown region in middle of abdomen.
Posterior surface of right central lobe of liver.
Behind stomach, light colored bean shaped wrinkly structure.
Leaf-like, ventro-lateral to stomach, dark brown, soft, thin.
Lightly colored coil. Small, thin, and rope-like.
Next to small intestine. Thicker and shorter.
Non-coiled part of the small intestine.
Bottom of the pig, leading to the anus.
Which of the four main tissue types is responsible for secreting digestive enzymes in the mouth?
Describe the difference between the glottis and epiglottis.
Glottis = Opening of the trachea.
Epiglottis = Flap covering the opening.
To what major organ does the esophagus lead?
To what major organ does the trachea lead?
What type of tissue primarily composes the esophagus?
What type of tissue primarily composes the trachea, forming distinct rings which keep it rigid and open all the time?
The stomach has a thick layer of smooth muscle that does what?
Involuntary movement. Churning of food.
Bile is produced by what organ?
Where is bile stored?
Through what duct does bile travel before entering the hepatopancreatic ampulla?
Common Bile Duct.
What is the function of bile?
What is the name of the duct that carries pancreatin from the pancreas to the hepatopancreatic ampulla?
What is the function of pancreatin?
Breaks down lipids, proteins, and carbohydrates.
Since bile and pancreatin travel via ducts, this tells you that they are secreted by endocrine or exocrine cells?
The pancreas is an organ that can produce many different proteins in its different clusters of cells. How can you explain this cell specialization?
Each cell has the same DNA, but different genes are transcribed and translated.
After leaving the duodenum, the chyme enters the __________ and __________.
Jejunum and ileum.
How do nutrients get from cells lining the small intestine to everywhere else in the body where they are needed to carry out basic cellular functions?
They are absorbed by the small intestine into the bloodstream.
What important role does the large intestine play in processing food and drinks?
Recovers water and helps to absorb ions.
What is the posterior portion of the large intestine called?
Through what muscular structure does solid waste exit the body?
What external features enable you to tell apart a male from a female pig?
Male = Scrotum
Female = Genital Papilla
In what maternal structure does the fetus spend most of its time growing and developing?
How do species like the sea urchin survive in the long term if such a high percentage of embryo die?
Pathway of oxygen from the air to a body tissue
Mouth or Nose > Glottis > Trachea > Bronchi > Alveoli > Pulmonary Capillaries > Left Atrium > Left Ventricle > Aorta > Systemic Arteries > Systemic Capillaries
The liquid waste filtered from the blood is converted into ___________ by the kidneys.
This liquid travels down the ____________ which are tubes connecting the kidneys to the bladder.
From the bladder, the liquid waste travels out of the body via the ___________.
For every ___ K+ ions pumped into the cell, ___ Na+ ions are pumped out of the cell.
Gates open in Rising
-K+ beginning to open very slowly.
Gates open in Latency
-Some Na+ open. (Some activation and inactivation open)
Gates open in Falling
-Na+ inactivated. (Activation open, inactivation closed).
-K+ wide open.
Gates open in Rest
-Na+ closed. (Activation closed, inactivation open).
Gates open in Hyperpolarization
-Na+ inactivated (Activation closed, inactivation opening).
Gates open in Recovery
-Voltage gated channels back to rest status.
-Na+/K+ Pump and diffusion from other parts restore it to rest.