Cells and Tissue Function Flashcards
The ribosomes on the rough ER have
a strand of mRNA attached to them
The protein that the rough ER ribosomes synthesize are destined to be part of
the cell membrane or the creation of lysosomal enzymes
The smooth ER does not
synthesize proteins
The smooth ER syntehsizes
lipids, steroids
The Smooth ER is also involved with
detoxification and the regulation of intracellular calcium
The sarcoplasmic reticulum of cardiac and skeletal muscle is a form of
smooth ER
The smooth ER of the liver is involved in
glycogen storage and the metabolism of lipid soluble drugs
What does the Golgi Apparatus do
modifies substances transfered from the ER
All lysosomal enzymes are
acid hydrolases
lysosomes maintain a internal pH of
5.0
What is the appx. pH of the cytosol and other organelles
7.2
What are lysosomes made from
digestive vesicles called endosomes
What is the first step in the creation of lysosomes
multiple endosomes form together to create an early endosome
The early endosomes turn into late endosomes as they
recycle lipids, proteins, and other membrane components back to the plasma membrane
What do the early endosomes uses to recycle the membrane components
recycling vesicles
The late endosomes mature into lysosomes as they
collect lysosomal enzymes
How do the late endosomes get their enzymes?
the enzymes are produced in the rough ER, sent and packaged in the Golgi Apparatus, then sent to the late endosome
How is a autophagosome formed
the ER isolated these particles from the cytoplasmic matrix by engulfing it in ER membranes
What is a autophagolysosome
when a lysosome and autophagosome fuse together
What are materials that remain undigested in the lysosome called
residual bodies
What are some examples of residual bodies
lipofuscin granules in neurons and heart muscle cells, inhaled carbon, and tattoo pigment
Lysosomes can also be repositories where
accumulate abnoramal substances
What type of disease is Tay-Sachs disease
lysosomal storage disease
What happens in Tay-Sachs disease
it is an autosomal recessive disorder where hexosaminidase A, needed to digest GM2 ganglioside is missing. as a result GM2 ganglioside accumulates in tissues like the heart liver spleen but it causes the most damage to the nervous system and retina.
The complex shape that DNA is coiled into is called
chromatin
Each complex of DNA and a histone protein is called
nucleosome
Because DNA is coiled too tight in the chromatin, it needs to be induced to change shape so it is accessable. What is this called
chromatin remodeling
Only mutations in ______ cells can be inheirited
germ cells
What kind of enzyme repairs DNA
endonucleases
After the endonucleases cleaves the distorted part of the DNA, what creates a new piece to put back
DNA polymerase
What binds the newly synthesized piece to the old strand
DNA ligase
Besides the nucleus, where is DNA stored
the mitochondria
Mitochondrial DNA is inheirited by who
the mother
What is its structure
single stranded closed circle
What are three differences of RNA from DNA
single stranded vs double
the sugar on the nucleotides are ribose not deoxyribose
thymine is replaced with uracil
What are the principal leukocytes of acute imflammation
neutrophils
What are the principal leukocytes of chronic infection
macrophages, lymphocytes, eosinophils, and mast cells
How are endothelial cells involved in the imflammatory response?
They provide a semipermeable barrier for self and non-self, regulate leukocyte extravasation, release imflammatory mediators, and regulate immune cell proliferation by secreting hematopoietic colony-stimulating factors (CSF’s)
What do endothelial cells also participate in
the repair process that follows imflammation by producing growth factors for angiogenesis and extracellular matrix synthesis.
What leukocyte is arrives at the site of acute inflammation within 90 mins of injury
neutrophils
What method do neutrophils use to kill pathogens
phagocytosis
Besides its enzymes, what do neutrophils produce to aid in killing engulfed pathogens
they have oxygen-dependent metabolic pathways that generate toxic oxygen like hydorgen peroxide and nitric oxide
How do neutrophils die
apoptosis
How long does it take for neutrophils to dissappear after entering the site of inflammation
24-48 hours
What percentage are eosinophils
2-3
How long does it generally take for eosinophils to reach the site of inflammation
2-3 hours after the neutrophils
Why do eosinophils take longer to reach the site of inflammation
they have slower mobility and slower reaction to chemotactic stimuli
Inflammation is characterized as the
movement of fluid and leukocyte from vascular compartments into the extravascular tissue space
Acute inflammation is characterized by the
exudation of fluid and plasma proteins
Chronic inflammation is characterized by
angiogenesis, tissue necrosis, and fibrosis (scarring)
What is the first phase of acute inflammation and what happens
during the vascular phase the blood vessels momentarily constrict then rapidly dilate, and permeability increases and protein rich fluid pours into the extravascular space.
During the first phase of acute inflammation, what causes the cardinal signs like heat and redness
increased blood flow
What cause the swelling and pain during the first phase of acute inflammation
increased osmotic pressure in the extravascular space coupled with an increase in capillary pressure cause the outflow of fluid
How is the outflow and accumulation of fluid during the first phase of the acute inflammatory response beneficial
it helps localize any infectious pathogens
What is the second phase of acute inflammation
during the cellular phase leukocytes are moved to the site of injury
How is the second phase of acute inflammation broken down
margination, adhesion and trans migration, and chemotaxis
What is margination
free flowing leukocytes leave the central blood stream and interact with endothelial cells
What facilitates the adhesion and transmigration of leukocytes into the extravascular space
complemetary adhesion molecules like selectins and integrins
What is the process of the third phase of acute inflammation
Opsonization: complement factor C3b and antibodies facilitates recognition of the neutrophil by the C3b receptor and Fc antibody receptor
Intracellular signal and actin essembly: Activation triggers intracellular siganling and actin essembly, forming pseudopods to enclose the microbe within a phagosome.
Formation of phagolysosome and killing: the phagosome fuses with a lysosome and then uses the enzymes and oxygen radicals to kill the microbe.
Where are plasma derived mediators created
the liver
Plasma derived mediators are products of three major protein cascade systems called
kallikrein-kininogen
the coagulation system
the complement system
How do plasma derived proteins contribute to the inflammatory response
they cause vasodilation
increase vascular permeability
promote leukocyte adhesion, and chemotaxis
augment phagosytosis
Where are plasma derived mediators created
the liver
Plasma derived mediators are products of three major protein cascade systems called
kallikrein-kininogen
the coagulation system
the complement system
How do plasma derived proteins contribute to the inflammatory response
they cause vasodilation
increase vascular permeability
promote leukocyte adhesion, and chemotaxis
augment phagosytosis
What produce cell derived inflammatory mediators
tissue macrophages, mast cells, endothelial cells, platelets and leukocytes
Histamine and serotonin are clasified as
vasoactive amines
Histamine is derived from
histidine
Serotonin is derived from
tryptamine
What cell has the largest storage of histamine
mast cells adjacent to blood vessels
What does histamine do
its causes dilation of arterioles and increases permeability of venules by binding to the H1 receptor of endothelial cells
Where is serotonin primarily found
platelet granules
Arachidonic acid is found where
the phospholipids of the cell membrane
The release of what leads to the production of the eicosanoid family of inflammatory mediators
Arachidonic acid
What are some inflammatory mediators are in the eicosanoid family
prostaglandins and leukotrienes
Which two pathways does eicosanoid synthesis follow
cylcooxygenase pathway and lipoxygenase pathway
Which synthesis pathway creates prostaglandins
cylcooxygenase
Which synthesis pathway creates leukotrienes
lipoxygenase
How do antihistames work
they act to competetively antagonize the h1 receptors by binding to them instead of histamine
Which family of drugs blocks the inflammatory efffect of both the cyclooxygenase and lipoxygenase pathways
corticosteroids
How do corticosteroids block the inflammatory efffect of both the cylcooxygenase and lipoxygenase pathways
they inhibit phosphodiesterase thus preventing the release of arachidonic acid
Which prostaglandins induce inflammation and potentiate the effects of histamine and other mediators
PGD2, PGE2, PGF2alpha, PGI2
Which prostaglandin promotes platelet aggregation and vasoconstriction
Thromboxane A2
Which drugs effect the cyclooxygenase pathways
Aspirin and the NSAIDs
What does NSAID stand for
nonsteroidal anti-inflammatory drugs
How does aspirin and NSAIDs work
thhey inhibit the first enzyme in the cyclooxygenase pathway
Leukootrienes have a similar function to
histamine
Leukotrienes have been reported to affect the
permeability of venules,
adhesion properties of endothelial cells
and extravasation and chemotaxis of neutrophils, eosinophils, and monocytes
Leukotreine LTC4, LTD4, and LTE4 cause
slow and sustained constirction of the bronchioles
LTC4, LTD4, LTE4 are important inflammatory mediators in what conditions
bronchial asthma and anaphylaxis
