Mid term junior year 24-25 Flashcards
Explain Aerobic metabolism
When glucose crosses the cell membrane, it is broken down into pyruvic acid molecules. This process, known as glycolysis, occurs in the fluid portion of the cell (cytosol) and does not require oxygen. However, glycolysis releases only a small amount of (ATP). When oxygen is available, the reaction continues inside the mitochondria of the cell where the process releases a much larger amount of energy (ATP). all of the products of aerobic metabolism heat, carbon dioxide, and water are eliminated.
Explain Anaerobic metabolism
the breakdown of molecules in the cells without the presence of oxygen. Just as with aerobic metabolism, glucose crosses the cell membrane and normal glycolysis occurs with the production of pyruvic acid and the release of a small amount of ATP. Without the availability of oxygen, however, the pyruvic acid is not able to enter the next phase of metabolism and is converted to lactic acid. So, the by-products of anaerobic metabolism are lactic acid and a small amount of ATP.
Explain NA/K+ pump
Sodium (Na+) is a ion that is considered the primary extracellular ion. Potassium (K+) is considered the primary intracellular ion. Molecules naturally move from an area of greater concentration to an area of lesser concentration—moving “with the concentration gradient”. The molecules have to be actively pumped out against the concentration gradient. For the sodium-potassium pump to work, as with any other pump, energy is required. If ATP-energy production by cells is lacking, as found in poor perfusion states and anaerobic metabolism, the sodium-potassium pump may fail. This would allow sodium to collect on the inside of the cell which attracts water. As the water continues to accumulate, the cell swells and eventually ruptures and dies.
What is the epiglottis?
a flap of cartilaginous tissue that covers the opening of the larynx during swallowing. A jaw-thrust or chin-lift maneuver is designed to lift the epiglottis clear of the glottic opening.
What is ventilation and Boyle’s law?
Ventilation is a mechanical process that relies on changes in pressure inside the thorax to move air in and out of the lungs. Ventilation conforms to Boyle’s law can be quickly summarized as follows:
An increase in pressure (more positive) will decrease the volume of gas.
A decrease in pressure (more negative) will increase the volume of gas.
Explain the process of inhalation and exhalation.
By contracting the diaphragm (approximately 60 to 70 percent of the effort of inhalation) and the external intercostal muscles, the diaphragm moves slightly downward while the ribs are lifted upward and outward. This causes the thorax to increase in size, creating a negative pressure. Normal atmospheric pressure is 760 mmHg at sea level. With the expansion of the thorax immediately prior to inhalation, the pressure inside the chest drops to 758 mmHg. In accordance with Boyle’s law, this negative pressure causes the volume of air inside the chest to increase. Because energy must be expended to contract the muscles, inhalation is considered an active process. After inhalation, the diaphragm and external intercostal muscles relax, allowing the chest wall to move inward and downward and, assisted by the inward pull of the elastic lung tissue, decrease the size of the thoracic cavity. As the size of the thorax decreases, the pressure inside increases to about 761 mmHg which causes air to be forced out of the lungs. Because this process is brought about by the relaxation of muscles, with no energy expenditure, exhalation is considered a passive process.
What is pleural space and what would happen if you disturbed the space?
The potential space between the pleura maintains a negative pressure. If a break occurs in the continuity of either the parietal pleura from an open wound to the thorax or to the visceral pleura from an injury to the lung tissue, the negative pressure draws air into the pleural space. With each inhalation, the thorax increases its size and the pleural pressure becomes more negative. This draws even more air into the pleural space, increasing its volume and collapsing the lung. Therefore, occluding any open wound to the chest is done early in the primary assessment of a patient, as you will learn later.
What are central chemoreceptors?
The central chemoreceptors are located near the respiratory center in the medulla. These receptors are most sensitive to carbon dioxide and changes in the pH of the (CSF). The pH in CSF is a direct reflection of the carbon dioxide level of the arterial blood. Thus, you can consider the following association between CO2 and acid:
The greater the amount of CO2 in the blood, the greater the amount of acid.
The lesser the amount of CO2 in the blood, the lesser the amount of acid.
Summarize the relationship between CO2 in the blood, hydrogen ions and respiration?
An increase in arterial CO2 increases the number of hydrogen ions in the CSF, stimulating an increase in the rate and depth of respiration to blow off more CO2.
A decrease in arterial CO2 decreases the number of hydrogen ions in the CSF, causing a decrease in the rate and depth of respiration to blow off less CO2
What are peripheral chemoreceptors
The peripheral chemoreceptors are located in the aortic arch and the carotid bodies in the neck. The activity of the peripheral chemoreceptors can be summarized this way: A significant decrease in the arterial oxygen content causes an increase in the rate and depth of respiration to increase the content of oxygen in the blood.
O2 transportation
Oxygen is transported by the blood in two ways: dissolved in plasma and attached to hemoglobin. A small amount, only 1.5 to 3 percent, is dissolved in plasma. Most oxygen, approximately 97–98.5 percent, is attached to hemoglobin molecules. Hemoglobin has four iron sites for oxygen to bind to. Thus, one hemoglobin molecule could carry up to four oxygen molecules. three molecules 75 percent saturation. is hemoglobin has oxygen attached is oxyhemoglobin. A hemoglobin molecule that has no oxygen attached is referred to as deoxyhemoglobin.
What is hydrostatic pressure?
Hydrostatic pressure is the force inside the vessel or capillary bed generated by the contraction of the heart and the blood pressure. Hydrostatic pressure exerts a “push” inside the vessel or capillary. That is, it wants to push fluid out of the vessel or capillary, through the vessel wall, and into the interstitial space. A high hydrostatic pressure would force more fluid out of the vessel or capillary and promote edema, which is swelling from excess fluid outside the vessels.
What is plasma oncotic pressure?
also known as colloid oncotic pressure or oncotic pressure, is responsible for keeping fluid inside the vessels. Opposite to hydrostatic pressure, oncotic pressure exerts a “pull” inside the vessel. A high oncotic pressure would pull fluid from outside the vessel, through the vessel wall, and into the vessel. A balance between hydrostatic pressure and plasma oncotic pressure must be maintained for equilibrium of fluid balance.
The effects of high and low hydrostatic and oncotic pressures are summarized as follows:
- A high hydrostatic pressure pushes fluid out of a capillary and promotes edema.
- A low hydrostatic pressure pushes less fluid out of the vessel.
- A high oncotic pressure draws excessive amounts of fluid into the vessel or capillary and promotes blood volume overload.
- A low oncotic pressure does not exert an adequate pull effect to counteract the push of hydrostatic pressure and therefore promotes the loss of vascular volume and promotes edema.
What are baroreceptors?
Baroreceptors are stretch-sensitive receptors, located in the aortic arch and carotid sinuses, that detect changes in blood pressure. As the pressure inside the vessels changes, it decreases or increases the stretch of the fibers of the baroreceptors. The baroreceptors, having detected the change in blood pressure, send impulses to the cardioregulatory center in the medulla of the brainstem to make compensatory alterations in the blood pressure. The cardioregulatory center consists of the cardioexcitatory center and the cardioinhibitory center that control heart rate and force of cardiac contraction.
The baroreceptors response to an increase in bp?
An increase in BP increases baroreceptor stretch which increases impulses to medulla which increases PNS and decreases SNS which decreases HR which decreases contractility which decreases BP
The baroreceptors response to an decrease in bp?
An decrease in BP decreases baroreceptor stretch which decreases impulses to medulla which decreases PNS and increases SNS which increases HR which increases contractility which increases BP
What are the ovaries? what are they responsible for?
female gonads or sex glands, one on each side of the uterus. They are responsible for secreting the hormone estrogen and progesterone and for the development and release of the mature egg. The ovary that is released each month is referred to as the ovum.
Explain Ovulation?
During the first 7 days of the menstrual cycle, follicles grow. These follicles secrete estrogen into the bloodstream to prepare the uterus lining. On day 7 the follicles stop growing and degenerate except for one that continues to grow. One of the fallopian tubes surrounds the follicle. The follicle bursts open ejecting the egg. The fimbria (the tiny projections of the fallopian tube) sweep the egg inside the fallopian tubes. Contractions move the egg to the uterus.
What are the fallopian tubes?
Thin flexible structures that extend from the uterus to the ovaries. The end near the ovary is funnel shaped with fingerlike projections. This end is not directly connected to the ovary and is open to the abdomen. Fertilization occurs the distal third of the fallopian tube. The ovum, whether fertilized or not, is transported down the fallopian tube by peristalsis and into the uterus.
What is the Uterus and it’s three sections?
A pear-shaped organ that contains the developing fetus. The fundus (top), corpus (body), and the Isthmus (cervix).
What is the plug of mucus?
A plug that seals the uterine opening; preventing contamination from entering the uterus. The plug is discharged when the cervix begins to dilate. Signaling the first stage of labor, the “bloody show”.
What is the placenta and what does it do?
A temporary disk-shaped organ that provides fetal nourishment and waste removal; expelled after birth
What is true about the blood of the mother and the fetus?
They do not mix; unless during birth or miscarriage. btw the placenta is highly vascular.
What is and what causes hyperemesis gravidarum?
extreme morning sickness accompanied by severe nausea and vomiting due to Increased hormone levels.
When does hyperemesis gravidarum occur and peak?
Symptoms occur between 4 and 6 weeks and can peak between 9 and 13 weeks.
What is spontaneous abortion?
Delivery of the fetus and placenta before the fetus is viable (20 weeks of gestation) (miscarriage) (most often before 12 weeks)
What causes spontaneous abortion?
Genetics (50% of all cases), uterine abnormality, infection, drugs, or maternal disease.
S/S for spontaneous abortion? what is something you should do?
Cramplike lower abdominal pain, similar to labor
Moderate to severe vaginal bleeding, which may be bright or dark red
Passage of tissue or blood clots Any tissue that is retained within the uterus following a spontaneous abortion can lead to severe bleeding and infection.
Transport any patient with a suspected spontaneous abortion.
Provide emotional support to the mother and family.
What is ectopic pregnancy?
A fertilized ovum is implanted outside the uterus, usually in a fallopian tube.
What happens to the tissue surrounding the embryo during ectopic pregnancy?
It ruptures.
What causes ectopic pregnancy?
Previous ectopic pregnancies, pelvic inflammatory disease, adhesions from surgery, tubal surgery including elective tubal ligation, or intrauterine device (IUD).
S/S for ectopic pregnancy?
Dull, aching pain that is poorly localized and becomes sharp, and localized to one lower quadrant.
Shoulder pain
Vaginal bleeding
Tender, bloated abdomen
Palpable mass in the abdomen
Decreased blood pressure Increased pulse rate
Signs of shock
Discoloration around the umbilicus
Urge to defecate
What is placenta previa?
A misplaced placenta near or over the cervix. Normally implanted in the fundus (top).
Why does the placenta prematurely tear?
When the fetus changes position in the uterus, or the cervix begins to efface (thin) and dilate.
What is abruptio placentae?
Abnormal separation of the placenta from the uterine walls.
Patho of abruptio placentae?
Small arteries located in the lining between placenta and uterus are prone to rupture. When this happens, the accumulating blood begins to separate the placenta from the uterus in till it tears away disrupting the function of the placenta.
what does fetal abruptio placentae cause?
A reduction in fetal blood flow causes fetal hypoxia, inadequate nutrient delivery, and poor elimination of carbon dioxide and other waste products
What does maternal abruptio placentae cause?
Severe hemorrhage and hypovolemic shock.
predispositions for abruptio placentae?
Hypertension, use of cocaine, preeclampsia, multiparity, previous abruption, smoking, short umbilical cord, premature rupture of the amniotic sac, diabetes, and trauma involving the abdomen during pregnancy.
The two types of abruptio placentae? (also what is the morality rate)
Complete: the placenta completely separates from the uterine wall. 100% mortality rate.
Partial: the placenta is torn from the uterine wall and it has a 30-60% mortality rate.
Patho of a ruptured uterus?
As the uterus enlarges during pregnancy, the uterine wall becomes extremely thin, especially around the cervix. possibly allowing the fetus into the abdominal cavity. causes severe maternal hemorrhage and fetal distress.
Name all stages of labor.
- Dilation
- Expulsion
- Placental delivery
How long does dilation last for a 1st time mother vs a women who has had a child before?
1st time mother: 8-10 hours
Para I+ mothers: 5-7 hours
At the end of stage 1 describe the frequency/duration/intensity of contractions.
contractions are at regular 3- to 4-minute intervals, last at least 60 seconds each, and feel very intense.
describe what marks the first stage of labor.
The first stage of labor is from the beginning of true labor (contractions) to complete cervical dilation and 100 percent effacement (cervix stretches and gets thinner). During this first and longest stage, the cervix becomes fully dilated at 10cm.
What are Braxton Hicks?
Contractions that feel like pregnancy contractions but do not indicate labor.
What occurs during stage two?
the infant moves through the vagina and is born.
What is the frequency and duration of contractions during expulsion?
Contractions are less than 2 minutes apart and last 60 to 90 seconds each.
What does crowning/vertex presentation indicate?
The baby is coming, imminent birth.
How long does the expulsion phase last for 1st time mothers? (para 0 soon to be para 1)
50-60 minutes
How long does it take for the placenta to be delivered following birth?
5-20 minutes
signs that the delivery of the placenta is imminent are…?
There is a sudden increase in bleeding from the vagina.
The uterus becomes smaller in size.
The umbilical cord begins to lengthen.
The mother has an urge to push.
What should you NEVER do during placental delivery and why?
Pulling or tugging on the umbilical cord to deliver the placenta can cause the uterus to invert. If inverted, the uterus cannot contract and tone up effectively. The exposed uterine vessels continue to bleed and lead to serious hemorrhaging and hypovolemia.
What questions should you ask to determine if delivery is imminent?
Has crowning occurred?
Are contractions less than 2 minutes apart?
Do they last 60-90 seconds?
Does the patient have the urge to defecate?
Does the patient has a strong urge to push?
How to manage a nuchal cord?
A nuchal cord is when the umbilical cord is around the baby’s neck. A nuchal cord must be managed immediately when it is found. Use two fingers to slip the cord over the baby’s shoulders or head. If you cannot move the cord, place two clamps 2 to 3 inches apart and cut between the clamps using scissors.
when and how to suction?
Suction the mouth first and nostrils second of the newborn immediately following birth, only when secretions or other substances are present that obstruct spontaneous breathing. A bulb syringe may be used.
What is a prolapsed cord?
The umbilical cord is presenting itself with or before the baby during birth. The cord may be compressed, cutting off oxygen to the infant.
What do you do when a prolapsed cord occurs?
Instruct the mother not to push.
Administer high-concentration oxygen.
Put patient in a knee-chest position.
Keep the mother warm
Do not push the cord back
wrap cord in sterile moist towel
transport mother to hospital, continuing pressure on baby’s head
What is a breech birth?
Buttocks/lower extremities are presenting during birth.
how should you transport a breech birth?
Transport in a supine, head-down position.
