vert phys FINAL

An increase in the membrane potential of a cell is known as

hyperpolarization

Which of the following hormones must have an extracellular receptor in order to exert an effect on the target cell?

peptides

T/F The action potential in a neuron is generated in the dendrites.

false

If you get your leg bitten off by a rabid rabbit, you will begin to lose a lot of blood resulting in a decrease in blood pressure. As a result, your heart will beat faster to pump more blood into the vascular system, but it will ultimately just result in more blood leaking out of your leg. As more and more blood leaks out of your leg, your heart rate continues to rise and rise. This is an example of ________, a normal physiological response, that will lead to cardiac shock.

a positive feedback loop

Which of the following scenarios represents a positive feedback loop?

Oxytocin increasing uterine contractions as a result of uterine pressure

What is the term for hormone action where multiple hormones enhance each other's effects?

synergism

Steroid hormones are synthesized from what molecule?

cholesterol

A plasma membrane protein that is embedded in the plasma membrane on the extracellular surface but not the intracellular surface is a _________ protein.

peripheral

Stimulus strength is conveyed by ________________.

frequency of action potentials

How does increasing levels of thyroid-stimulating hormone impact the circulating levels of thyroid hormone?

TSH increases T3 and T4

The insulin antagonist is ____________.

glucagon

What pathway does vasopressin use in the collecting ducts of the kidneys

cAMP

What effect does cortisol have on blood glucose levels?

increases levels via gluconeogensis

A cell, permeable to sodium, with an intracellular concentration of 150mM Na+ and a membrane potential of -55mV is in a solution of 150mM Na+. The equilibrium potential of Na+ in the system is +10mV and the cell has Na+ channels. In this example, sodium will ________________.

influx

Which signal transduction pathway is most likely involved if a hormone causes cell proliferation?

mapK

What distinguishes steroid hormones from peptide hormones?

Steroids bind intracellular receptors

What is the primary outcome of signal transduction pathways?

signal amplification

True of false: aldosterone increases water retention through direct upregulation of aquaporin channels.

false

Which of the following is a tropic hormone?

Thyroid stimulating hormone (TSH)

A post-synaptic excitable cell responds to a stimulus by opening Cl- channels and an influx of Cl-. This is an example of a ___________.

Inhibitory post-synaptic potential

Which of the following hormones causes the production of a competitive inhibitor for RANK on osteoclast precursors?

Calcitonin

Which portion of the neuron houses the nucleus?

cell body

The pars distalis (anterior pituitary) releases hormones as a response to _____________.

hormonal stimuli

If kinesin activity is inhibited, what process would be disrupted?

Vesicle transport towards the positive end of microtubules

A cell with a resting membrane potential of -70mV becomes permeable to sodium, which has an equilibrium potential of +80mV. Which direction will sodium flux?

Influx

Which hormone is synthesized by somatrotropic cells of the anterior pituitary?

growth hormone

If a cell lacks functional tyrosine kinase receptors, what process would be impaired?

Protein phosphorylation

What is the role of dynein in cellular transport?

Moves cargo towards the negative end of microtubules

Compare the actions of insulin and glucagon on blood glucose levels.

they are antagonists

What is treadmilling in microtubules?

Equal rates of growth and shrinkage

Chad's Cane Corso, Princess, has an abundance of parathyroid hormone due to the massive amounts of supplements Chad gives her. What is a possible outcome of this?

decreased bone density

Parathyroid hormone being released in response to low Ca2+ levels detected by calcium sensitivity receptors is an example of a ____________ stimulus.

humoral

How does up-regulation of hormone receptors affect sensitivity to ligands?

sensitivity increases

Which signal transduction pathway is shared by both vasopressin in the blood vessels and oxytocin in uterine contractions?

IP3

What is the Nernst equation used for?

Calculating the equilibrium potential for a single ion

What molecule acts as a carrier for steroid hormones in the bloodstream?

albumin

If the binding affinity of a hormone to a receptor increases, the percentage of hormones bound to a receptor _________.

reaches saturation quicker

If a cell needs long stable microtubules, which protein would be involved?

STOPS

How would a drug that blocks the phosphorylation of MAP kinases affect cell signaling?

It would inhibit the signaling pathway

T/F The DIRECT cause of insulin release is a high blood glucose level.

true

A cell with an osmolarity of 150mOsm is placed into a solution of 150mOsm urea. Assuming the intracellular compartment is devoid of urea and the cell is permeable to urea, the solution is ______________.

hypotonic

During the synthesis of peptide hormones, which of the following is packaged by the Golgi for exocytosis?

prohormone

The release of thyroid stimulating hormone is controlled by the level of thyroid hormone in the body. Increases in thyroid hormone cause a decrease in the release of thyroid hormone. This is an example of __________.

a negative feedback loop

Why might a drug that enhances cAMP degradation reduce hormone effects?

It inhibits protein kinase A

In the cyclic AMP signal transduction pathway, what molecule does the G-protein activate?

Adenyl cyclase

How does the concentration of tubulin affect microtubule growth?

High concentration promotes growth

In the inositol trisphosphate (IP3) signal transduction pathway, phosphatidyl inositol bisphosphate (PIP2) splits into inositol trisphosphate (IP3) and ____________.

diacylglycerol (DAG)

During the relative refractory period, the cell is in what stage?

hyperpolarization

Which feedback mechanism would be most effective for maintaining homeostasis?

Negative feedback

The state at which the maximum number of molecules are moving across the cell membrane through channel mediated facilitated diffusion is called ______________.

saturation

T/F If the extracellular concentration of Na+ is 100mM and the intracellular concentration of Na+ is 50mM, Na+ will always passively influx

true

An action potential is generated after threshold is reached because at threshold________________.

activation gates on voltage gated Na+ channels open

What is the primary role of glucagon?

increase blood glucose levels

Which of the following is NOT a type of enzyme receptor?

Calmodulinase

A veterinary team administers a hypertonic saline solution to a patient to increase cardiac output. What immediate effect will this have on the cells?

Cells will shrink due to water loss.

In an experiment, a cell is placed in a solution with a higher osmolarity than its cytoplasm. Which conclusion can be drawn about the tonicity of the solution?

The solution is hypertonic

Hormonal clearing is calculated by determining the ___________ of the hormone in the blood.

half life

Which of the following interventions would NOT result in a decrease in a ligand-receptor signal?

Increasing ligand concentration

When cAMP levels rise in a cell, which enzyme is activated?

Protein kinase A

Which of the following hormone classes is derived from the plasma membrane fatty acid arachidonic acid?

Eicosanoids

How does the PIP2 pathway differ from the cAMP pathway?

PIP₂ produces IP₃ and DAG

How is prolactin release regulated by dopamine?

dopamine inhibits prolactin release

What structure organizes microtubules in cells?

Microtubule-organizing center

During the generation of an action potential, an increase in the graded potential is generated through subsequent activation of the same ligand gated channels multiple times. This is an example of _____________.

temporal summation

What happens when a ligand binds to a G-protein coupled receptor?

The G-protein is activated

T/F During homeostasis, ions are at equilibrium across the cell membrane.

false

If a person has a tumor secreting high levels of corticotropin-releasing hormone, which hormone will also likely be elevated?

Adrenocorticotropic hormone (ACTH)

What type of protein spans the entire membrane and can act as a channel or carrier?

transmembrane protein

Which type of transport requires ATP?

primary active transport

A patient is administered a hypotonic IV fluid. What effect would this have on their red blood cells?

The cells will swell and potentially burst

If blood calcium levels drop, which hormone would increase to restore homeostasis?

Parathyroid hormone

In a typical neuron at rest, the voltage gated Na+ channels are in what position?

Activation gate closed, inactivation gate open

A hormone binds to a receptor, activating adenylyl cyclase. What molecule is produced next?

cAMP

What is the major function of kinesin in cells?

Transports vesicles

Which statement best explains the relationship between membrane potential and ion permeability?

Changes in ion permeability can alter the membrane potential

What is the primary role of cytokines?

Function in paracrine signaling

Which type of receptor is involved in phosphorylation cascades?

Receptor enzymes

T/F Dopamine released from the hypothalamus triggers the release of prolactin.

false

What type of stimulus regulates the release of parathyroid hormone

Humoral

If a mutation prevents G-proteins from dissociating from their receptors, what would be the likely outcome?

Decreased signal transduction

The resting membrane potential of the cell is established by which of the following:

leak channels

Which of the following best explains why a hypertonic solution causes a cell to shrink?

Water moves out of the cell due to higher external solute concentration

Which of the following signaling molecules acts on different cells, but within the same tissue from which it is released?

paracrines

Myelin increases the rate of action potential propagation by ________________.

Letting the action potential jump from Node of Ranvier to Node of Ranvier

T/F A suprathreshold potential caused by the ligand gated channels in the dendrites will always lead to activation of voltage gated channels.

true

The Na+/K+ ATPase is an example of a/an ______________ channel.

antiport

A patient suffers from chronic muscle spasms and a doctor recommends a drug that decreases circulating levels of parathyroid hormone. Why would this be a recommended treatment?

To decrease blood calcium levels used in muscle contraction

How would an increase in gonadotropin-releasing hormone affect luteinizing hormone levels?

Increase LH levels

Which of the following glands is considered the master endocrine gland?

pituitary

Which of the following processes is least dependent on membrane proteins?

simple diffusion

What is the smallest structural and functional unit of life

cell

What happens when a membrane channel reaches saturation?

Transport continues at a fixed rate despite increasing solute concentration

A patient shows signs of dehydration, and lab tests reveal elevated plasma osmolarity. What IV solution would you recommend?

Hypotonic solution

In a traditional action potential, which event follows the opening of the inactivation gate on a voltage gated Na+ channel? (hint read carefully)

nothing

Given that steroid hormones are lipid-soluble, how would they typically enter a target cell?

By passive diffusion

Thyroid hormone _____________ metabolism

increases

T/F A patient presents with dehydation and your veterinary intern suggest giving them an isoosmotic solution of dextrose, a penetrating substance, as this will promote water uptake by the cells. Is this true or false?

true

How does actin contribute to intracellular trafficking?

By interacting with motor proteins

In facilitated diffusion, how do molecules move across the membrane?

Along the concentration gradient through a channel or carrier

Without a change in permeability, an increase in extracellular potassium concentration would cause the resting membrane potential to become:

Less negative