Mastering Flashcards
Cells may store carbohydrates in the form of these cellular inclusions:
glycogen granules
What is the function of cilia in human cells?
Cilia beat rhythmically to move substances across the surface of the ciliated cells.
The inclusions that destroy protein are called
proteasomes
Interstitial fluid is ? fluid outside the ? and the ?
extracellular/circulatory system/cells
What is the name of the hollow interior of an organ?
Lumen
Which two fluid compartments make up the extracellular fluid?
Plasma and interstitial fluid
Cell membranes are mainly constructed from ________.
lipids and proteins
Tay-Sachs disease, which results from accumulation of glycolipids that are normally broken down, is associated with malfunction of which cellular component(s)?
Lysosomes
What is the importance of having routine pap tests?
to screen for potentially cancerous cells
A rapid division and growth of cells that do not differentiate into specialized cells.
Cancer
Cancerous cells that originate in one tissue can escape from that tissue and spread to other organs through the circulatory system and the lymph vessels
metastasis
Cancer cells can usually be recognized by
large cells with big nuclei and a small amount of cytoplasm
Which tissues would likely have cells with the greatest number of gap junctions?
Cardiac muscle
Which tissue can generate electrical signals?
Smooth muscle
Undifferentiated cells in a tissue that can become specialized cells of that tissue, but not of other tissues, are ________ cells.
multipotent
During which phase of the cell cycle does DNA duplication, or replication, take place?
Interphase
When a double helix of DNA is replicated, two complete helices are formed. Together, these helices are called __________.
sister chromatids
During which phase of mitosis do sister chromatids line up at the center of the cell?
Metaphase
During which phase of mitosis do the sister chromatids move apart?
Anaphase
What is the name of the process by which the cytoplasm divides in two?
Cytokinesis
During which phase of mitosis do the nuclear envelope and nucleoli disappear?
Prophase
During which phase of mitosis do nuclear envelopes and the nucleoli reappear?
Telophase
Functions of the cell membrane include
physical isolation, regulation of exchange with the environment, communication between the cell and its environment, and Structural support
Functions of epithelia include
controlling permeability, producing specialized secretions, providing physical protection, movement
Glands that secrete hormones into the blood via tissue fluids are
endocrine glands
Groups of tissues that carry out related functions may form structures known as
organs
The term meaning programmed cell death is
apoptosis
Chondrocytes are to ? as osteocytes are to ?
cartilage/bone
How does the intracellular fluid compartment differ from the extracellular fluid compartment?
Potassium ions are more concentrated inside cells than in the extracellular space.
If a swimmer cuts his foot on a seashell while wading in the ocean and bleeds into the seawater, his red blood cells (erythrocytes) will shrink. What does this tell us about seawater?
The seawater is hypertonic to the erythrocytes.
How can a solution be hyperosmotic but hypotonic?
If the concentration of nonpenetrating solutes is less in the solution than in a cell
What is the most important distinction between the membrane transporters known as channel proteins and those known as carrier proteins?
Channel proteins create water-filled passages for small molecules that do not bind to the protein. Carrier proteins transport larger molecules by binding to them.
What properties must a molecule have to pass through a cell membrane by simple diffusion?
They must be small and/or lipophilic.
the relationship between intracellular fluid (ICF) and extracellular fluid (ECF)?
The types of solutes and their distribution between the ICF and ECF are not the same.
You have a total body concentration of 900 mosmol dissolved in 3 liters of solution. If you added 0.5 liters of a solution with 150 mosmol of NaCl to the body, what would the new total body concentration be?
300 mOsM
Channel proteins that can be opened or closed are called ____ channels.
gated
Membrane receptors are involved in various types of cell signaling. Some membrane receptors function as _____ channels.
chemically gated
Cell membranes are primarily made of _____ molecules.
phospholipid
What type of membrane transporter would be activated by an action potential?
A voltage-gated channel
What characteristic of transporters does the decrease in glucose transport in the presence of galactose demonstrate?
Competition
What will happen to the cells of a patient who is provided with an intravenous solution that is isosmotic to intracellular fluids?
The question cannot be answered with certainty without knowing the identity of the solutes present in the IV solution.
The membrane potential of most cells ________.
is negative, except when there is a change in membrane permeability to ions
What force causes the bulk flow of fluids (gases and liquids)?
Pressure gradient
Which neuron or groups of neurons are NOT considered to be a part of the efferent pathway?
sensory
Nerve cells in the central nervous system are primarily
interneurons
The cells that we are capable of controlling consciously are the _____ neurons.
somatic motor (somatic efferent)
Somatic motor neurons control
skeletal muscles
The part of the neuron that receives most of the incoming signals is the ________.
dendrite
The small space between the sending neuron and the receiving neuron is the
synaptic cleft
A molecule that carries information across a synaptic cleft is a
neurotransmitter
When calcium ions enter the synaptic terminal,
they cause vesicles containing neurotransmitter molecules to fuse to the plasma membrane of the sending neuron.
When neurotransmitter molecules bind to receptors in the plasma membrane of the receiving neuron,
ion channels in the plasma membrane of the receiving neuron open.
If a signal from a sending neuron makes the receiving neuron more negative inside, the receiving neuron is (less/more) likely to generate an action potential.
less
What would happen to the membrane potential if a cell suddenly becomes more permeable to Na+?
Depolarize
What happens if a graded stimulus is of sufficient strength to reach threshold at the trigger zone?
An action potential occurs.
Which two properties determine the conduction velocity in a mammalian neuron?
Axon diameter and the leak resistance of the membrane
Which type of receptor would bind acetylcholine and be found in skeletal muscle?
Nicotinic cholinergic
A stronger stimulus to a neuron results in ________.
larger voltage changes in graded potentials and greater frequency of action potentials produced in response
Which ion would NOT cause the membrane potential to change from –70 mV to +30 mV?
Potassium ions leaving the cell.
Where do most action potentials originate?
Initial segment
What opens first in response to a threshold stimulus?
Voltage-gated Na+ channels
What characterizes depolarization, the first phase of the action potential?
The membrane potential changes from a negative value to a positive value.
What characterizes repolarization, the second phase of the action potential?
Once the membrane depolarizes to a peak value of +30 mV, it repolarizes to its negative resting value of -70 mV.
What event triggers the generation of an action potential?
The membrane potential must depolarize from the resting voltage of -70 mV to a threshold value of -55 mV.
What is the first change to occur in response to a threshold stimulus?
Voltage-gated Na+ channels change shape, and their activation gates open.
The sympathetic and parasympathetic nervous systems are divisions of which system?
Autonomic nervous system
Which glial cell produces myelin in the central nervous system?
Oligodendrocytes
The multiple thin, branched structures on a neuron whose main function is to receive incoming signals are the
dendrites
Neurotransmitters are released from the
axon terminals
These glial cells act as scavengers.
microglia
The pattern of synaptic connectivity where a large number of presynaptic neurons provide input to a single postsynaptic neuron, is known as
convergence
The two varieties of adrenergic receptors are
alpha and beta.
