Quiz 6 Flashcards
What are the four phases of the male excitatory response? What nerve controls each one?
Stimulation: pudendal (somatic)
Erection: Pelvic splanchnic (parasympathetics)
Emission: Lumbar and sacral splanchnic (sympathetics)
Ejaculation: Pudendal nerve (somatic)
The pudendal nerve arises from where in the spinal cord?
S2-S4
The parasympathetics that cause erection arise from where?
Lateral horns of s2-s4.
The pelvic splanchnic nerves go through what plexi?
Pre-aortic and prostatic plexus
What causes vasodilation of the deep penile arteries? This causes blood to fill what erectile tissue?
NO
Corpus and spongy cavernousum
The pre-aortic plexus is also known as the…
Inferior hypogastric plexus
The urethra goes through what structure in the penis?
Corpus spongiosum
What is the only structure superficial to the deep penile fascia?
Superficial dorsal vein
The dilation of the corpus cavernousum causes what vein to pinch off?
Deep dorsal penile vein
The sympathetics that result in emission come from where?
Lateral horns of T10-L2
The lumbar and Sacral splanchnic nerves go to what plexi?
Inferior hypogastric plexus.. Which then go to the spermatic tubes
What does norepinephrine do in the male excitatory response?
Causes peristaltic contractions of the ductus deferens, seminal vesicles, prostatic smooth muscles, and constriction of internal urethral sphincter
The closing off of the urethral sphincter serves what purpose in the male excitatory response?
Prevents back flow into the bladder
In the ejaculation phase, what muscles are stimulated by the pudendal nerve to contract?
Bulbospongiosus and ischiocavernosus muscles contract
What 2 organs regulate metabolism?
Pancreas and Liver
What cells of the pancreas secrete insulin and glycogen?
Islet cells
What are the key regulators of metabolism?
Insulin, glucagon, epinephrine, glucose, ATP/AMP
What are the four fates for glucose?
Pyruvate (glycolysis)
Ribose 5 phosphate (pentose phosphate pathway)
Glycogen/starch (storage)
Synthesis of structural polysaccharides
Glycolysis and gluconeogenesis, glycogenesis and glycogenolysis, are exclusive. What does this mean?
Only one or the other can be performed in a cell at a time.
Gluconeogenesis can occur in all cells, but where does it primarily take place?
Liver
Where is excess glucose stored?
Liver or adipose. If not glycogen
What cells would contain the most glycogen?
Liver and muscle cells
How does glycogen play a role in osmolarity?
400 glucose molecules compared to 1 glycogen molecule. Less molecules = less concentrated solution.
Why is putting phosphates on glucose important?
It prevents the glucose from leaving the cell and allows energy to be transferred and used later
What enzyme is the point of regulation in glycogenesis?
Glycogen synthase
Does glycogen synthase add new UDP-glucose to the reducing or non reducing end?
Non reducing end
Glycogen phosphorylase. What is it? What end does it work on?
Removes glucose 1 phosphate molecules from glycogen from the non reducing end
Where would you find glucose-6-phosphatase?
Only in the liver (in the ER) It dephosphorylates glucose-6-phosphate so that the glucose molecules can exit the cell and into the bloodstream. Thus increasing blood sugar levels.
Glycogen synthase is activated by what factors?
Insulin, glucose 6 phosphate, glucose. Insulin also causes the inhibition of the deactivation of glycogen synthase a (active form)
What will prevent the activation of glycogen synthase?
Glucagon/epinephrine
Glycogen is allosterically regulated by… … Does this activate or deactivate glycogen synthase?
Phosphate. 3 phosphates deactivate glycogen synthase.
How does insulin prevent the deactivation of glycogen synthase?
Insulin inhibits glycogen synthase kinase 3.
Glycogen phosphorylase. Which is active, the phosphorylated or non phosphorylated form? What about glycogen synthase?
Glycogen phosphorylase is active when it is phosphorylated.
Oppositely, glycogen synthase is inactive in its phosphorylated form
What causes the activation of glycogen phosphorylase?
Glucagon, epinephrine
What are some things insulin does?
Activates GLUTs, hexokinase, glycogen synthase.
Also, it deactivates glycogen synthase kinase.
True or false… Glucagon and Epinephrine act on both liver and muscle cells.
False. Epinephrine acts on both but glucagon only acts on liver cells
What happens to the liver when it is affected by glucagon?
Glycogenolysis increases
Glycolysis decreases
Gluconeogenesis increase
What happens to muscle cells when they are affected by epinephrine?
Glycogenolysis increases
Glycolysis increases
What is the input cost to produce one glucose molecule via the cori cycle?
4 ATP
2GTP
2 NADH
Where is the point of regulation in glycolysis and Gluconeogenesis?
Enzyme phosphofructokinase-1 (glycolysis)
Enzyme
Fructose 1-6 bisphosphatase - 1
Gluconeogenesis
How is phosphofructokinase 1 and fructose 1,6 bisphosphatase 1 regulated?
ADP and AMP will stimulate phosphofructokinase -1 to allow glycolysis to go. (AMP will also inhibit fructose 1,6 bisphosphatase1)
ATP and Citrate will inhibit phosphofructokinase 1 to prevent glycolysis from occurring.
What is AMPK?
Kinase that detects levels of intracellular levels of AMP. This will cause systemic changes such as less insulin secretion, less fatty acid synthesis, more fatty acid uptake in muscles and heart.
Electrons are being moved from glucose to other molecules. Thus glucose is being ____ while the other molecule is being _____
1) oxidized
2) reduced
The preparatory phase of glycolysis is ____ while the payoff phase is ___.
1) phosphorylation
2) REDOX
Fermentation is defined as…
The build up of NADH. Which must be restored back to NAD+
Cancer cells have a higher or lower rate of glycolysis?
Higher.
When does the glycolysis preparatory phase end?
Once glyceraldehyde 3 phosphate is formed
True or false… All dietary carbohydrates are converted into glucose before glycolysis?
False. Some directly feed into glycolysis at different steps
What are the three fates of glucose?
Stored as glycogen
Converted to pyruvate (glycolysis)
Can enter the pentose phosphate pathway.
What is the pentose phosphate pathway? What does it produce?
It produces NADPH.
turns glucose into ribose 5- phosphate (precursor for nucleotides, coenzymes)
What is NADPH? Functions?
It is necessary for reductive biosynthesis (creating fatty acids)
Free radical protection
How is the pentose phosphate pathway regulated?
Negative feedback.
Excess NADPH will shut off the pentose phosphate pathway
What is the electron acceptor for fermentation in humans?
Lactate
Where is lactate sent to be converted back to glucose?
The liver (Gluconeogenesis)
How are mitochondria involved in apoptosis?
Cytochrome C is located in the intermembrane space. When the permeability of the mitochondria increases, cytochrome C is released to cytosol.
How is cytochrome C involved in apoptosis (programmed cell death)?
Cytochrome C will activate Caspases which cause the cell to start destroying their own components.
First forms an apoptosome, activates caspase dimers, these in turn activate other caspases.
Is pyruvate actively or passively transported from the cytoplasm to the matrix of mitochondria?
Actively
5 vitamins are needed for pyruvate dehydrogenase complex to work. What are these?
Pantothenic acid
TPP
Lipoate
Uhhh that’s all I know!
Pyruvate is added to acetyl coA
Where is pyruvate added to coenzyme A to form acetyl coA?
Matrix of mitochondria
Why will the citric acid cycle halt in the absence of oxygen?
Due to the buildup of NADH and FADH2
The intermediate steps in the citric acid cycle are precursors for what?
Amino acids, lipids, etc.
Glycolysis and CAC are allosterically regulated by what?
The products themselves. (ATP, NADH). Excess ATP and NADH will shut it off while AMP and ADP and NAD+ will turn it on
Alpha ketogluterate is a precursor for what? Which in turn is a precursor what?
Glutamate. This is a precursor for purines and amino acids such as glutamine, proline, arginine.
Citrate can be converted into…
Fatty acids and sterols
Oxaloacetate is a precursor what? Which is a precursor for what?
Precursor for phosphopenolpyruvate. This is produced in the matrix of the mitochonrida but must be moved out of the mitochondria for it to be turned into… Amino acids or back to glucose
Oxaloacetate is also a precursor for other amino acids such as asparagine, which is a precursor for pyramidines
Where can pyruvate enter the citric acid cycle? 2 ways. What enzyme?
Either attached to co enzyme A to become acetyl coA (normal way)
Orrrrr pyruvate can be converted to malate by malic enzyme.
Succinyl coA is a precursor for what?
Porphyrins and Hemes
In the electron transport chain… All complexes pump out hydrogen besides which complex?
Complex 2
What is significant about complex 2. What is its name?
Succinate dehydrogenase. It is also part of the citric acid cycle. Turns succinate into fumerate. This is where FADH2 is produced.
What complex is NADH added to? What about FADH2
Complex 1.
FADH2 = complex 2
What is the role of cytochrome C in the electron transport chain?
It is an electron carrier from 3 to 4
Where is ubiquninone found? What does it do?
It’s found within the membrane of the electron transport chain because it is lipid soluble and membrane mobile.
It carries electrons and protons between the complexes
True or false, fatty acids can enter the electron transport chain?
True
Where does complex 3 transfer its electrons?
To cytochrome c
How many ATP per NADH? What about FADH2?
NADH: 2.5 ATP
FADH2: 1.5 ATP
How is ATP moved out of mitochondria?
Adenine nucleotide translocase (anti porter)
Brings ADP in (down conc. Gradient) and ATP out (against conc. Gradient)
Moves out of inner membrane space by porins
What layer of the mitochonrida is impermeable to NADH?
Inner membrane
What is the malate-aspartate shuttle? Where is it located?
The malate aspartate shuttle is located in the liver, kidney, and heart. It functions to bring NADH from glycolysis into the matrix of the mitochondria. NADH attaches to oxaloacetate to form malate, which is transported into the matrix via malate-alpha ketogluterate transporter. Aspartate exits the matrix via glutamate aspartate transporter. This turns into oxaloacetate to allow this whole process to occur again
What is the glycerol-3-phosphate shuttle? Where is it located? Is it less effeciant or more efficient than the malate-aspartate shuttle?
Located in brain and skeletal muscle tissue. Less efficient than the malate-aspartate shuttle. Basically, the energy from NADH goes to FADH2
What causes the build up of reactive oxygen species?
Mitochondria not making ATP. Lack of O2/ lack of ADP. The buildup of reduced quinone will transfer its electrons to oxygen to early to form ROS. Also the build up of NADH can cause ROS
On the electron transport chain.. Where does the final electron acceptor accept electrons? Where is ATP produced?
O2 accepts electrons at complex 4. ATP is produced at ATP synthase
What inhibits hexokinase?
Glucose 6 phosphate
What activates the electron transport chain?
ADP. Thus the lack of ADP slows it down
What bones make up the neurocranium?
Frontal, sphenoid (excluding the pterygoid process), temporal (only the squamous and petrous parts), pareital, occipital, ethmoid (only the cribriform plate)
What is neurocranium vs viscerocranium
Neurocranium - bones that cradle the brain.
Viscerocranium - bones of the face. House sensory organs.
What is Desmocranium vs chondrocranium?
Desmocranium - top portion of the neurocranium… Directly ossifies
Chondrocranium - base portion of the neurocranium….develops from a cartilaginous state
Which bone makes up the superior portion of the orbit?
Frontal bone
What kind of joint are the sutures in the skull?
Synarthroses
True or false… The parietal bone is a weak part of the skull, prone to fracture.
False. The temporal bone is the weak point
The squamous suture separates what two bones?
Parietal and temporal
What bone(s) make up the anterior cranial fossa?
Frontal and sphenoid. And ethmoid
What bone(s) make up the medial cranial fossa?
Temporal
What is craniosynostosis?
Premature closure of sutures. Causes Brain to distort head shape. Serious cognitive defects
What embryonic feature forms the vicerocranium?
Neural crest cells
How many sinuses are in the skull? Name them
4... Frontal sinus Ethmoid cells (sinuses) Maxillary sinus Sphenoid sinus
Do sinuses get larger or smaller as we age?
Larger
True or false… All sinuses are connected to the nasal cavity
True
What is the strongest bone in the face?
Mandible
What bones make up the orbit?
Frontal, zygomatic, maxillary, sphenoid, ethmoid, palatine, lacrimal
What bones does the sphenoid bone touch?
Frontal, parietal, ethmoid, temporal, zygomatic, palatine, vomer, occipital
What bone is the inferior nasal concha a part of?
Maxilla
What sinuses drain into the middle meatus?
Frontal sinus, maxillary sinus, anterior ethmoid cells, middle ethmoid cells.
