Exam 4 Renal and Respiratory Study Guide

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Exam 4 Study Guide
Biol242 – Anatomy and Physiology II
Please bring a scantron!
Covers Lectures 6 and 7 – Urinary and Respiratory Systems
Total points: 75
 10 fill in the blank questions, terms drawn from the key terms list below. No
answer bank on the exam.
 8 fill in the blank labeling of urinary and respiratory structures
 35-40 matching questions, 1 point each
 3-4 short answer questions drawn from the topics below, 20-25 points total
Key Terms
Cortical nephrons:
 Short nephron loop, travels only very briefly through medulla
• Majority of nephrons
• Have peritubular capillaries
Juxtamedullary nephrons:
• Have much larger Loops of Henle
• Allows us to remove much more water and many more ions
• Long nephron loop, travels deep into medulla
• Minority of nephrons
• Have vasa recta
• Used to concentrate urine
Reabsorption: moving solutes from filtrate to interstitial fluid
• Movement from inside tubules into peritubular capillaries/vasa recta and
then systemic circulation
• Actually, movement occurs between tubules and interstitial fluid, but because
capillaries are fenestrated everything ends up in the capillaries in the end
Secretion: moving solutes from interstitial fluid to filtrate
Glomerulus glomerular capsule: is a tuft of fenestrated capillaries
Filtrate/Filtration membrane: superfine membrane that lets through only water,
salts, and very small nutrients (vitamins, single amino acids, ions)
• Blood plasma is strained through this filtration membrane
• Becomes filtrate when it enters the glomerular capsule space
Afferent arteriole/Efferent arteriole: are the main regulators of this hydrostatic
pressure
Glomerular filtration rate: rate of filtration through glomerulus
 Two major mechanisms for controlling GFR
• Intrinsic/renal autoregulation
- Maintains GFR, even at (small) cost to MAP
- Day to day, second to second regulation
- “Smooths out” spikes in MAP so GFR stays somewhat constant
- Involves both a myogenic and tubuloglomerular mechanism
• Extrinsic regulation
- Maintains MAP at a large cost to GFR
- Only used in extreme circumstances (hypovolemic shock, extreme
hypertension, etc.)
Proximal convoluted tubule: is a small tubular structure within the nephron of the
kidney. The PCT connects Bowman's capsule with the proximal straight tubule, and
it is essential for the reabsorption of water and solutes from filtrate within the
nephron.
Transport maximum: If we have too much of a substance in our blood, all of our
transporters are used and the excess stays in the filtrate
Facultative: is the reabsorption of water in the kidneys that is under the hormonal
control. The amount of water reabsorbed is dependent on how much the body needs
to reabsorb to maintain homeostasis and fluid balance.
- Antidiuretic hormone
• Causes production of aquaporins in epithelial cells of DCT/CD
• Increases urea reabsorption
• Effects: ↑ water reabsorption; ↓urine production; ↑blood volume
- Aldosterone
• Causes production of more Na+/K+ ATPase pumps
• Takes hours or days to have an effect
• Effects: ↑ Na+ reabsorption; ↓K+ reabsorption; ↑blood volume
– Indirect effects: ↑ water reabsorption, but only if ADH is also
present (which it usually is in small amounts)
- Atrial natriuretic peptide
• Prevents Na+ reabsorption
• Effects: ↓ Na+ reabsorption; ↓ blood volume
-Indirect effect: ↓ water reabsorption
Obligatory reabsorption of water: occurs in the kidneys. The reabsorption of
water is a part of the process that the kidneys perform of filtering and returning to
the bloodstream about 200 quarts of fluid within a 24-hour period
Renal clearance: the amount of plasma from which the kidneys completely remove
a particular substance in one minute
- Can measure several substances, but creatinine is the most common
- Creatinine is filtered out in the glomerulus into the filtrate, but not reabsorbed
or secreted
Creatinine clearance: clearance is the most common method used in the clinic to
determine renal function
- Creatinine is almost completely filtered by the glomerulus, and very little is
reabsorbed in the tubules
- Amount of creatinine in blood is compared to amount in urine to determine
rough GFR
- Normal creatinine clearance is 125mL/min, with some variance due to age or
biological sex
Pyelonephritis: inflammation of the kidneys
- Symptoms: Fever, tachycardia, abdominal pain
- Causes: Most often bacterial infection of urinary tract that spreads
- Treatment: corticosteroids, antibiotics
Chronic renal disease: GFR<60mL/min for 3+ months
- Symptoms: None at first, followed by anemia, ammonia-scented sweat,
abnormal blood electrolyte levels
- Causes: Diabetes, hypertension
- Treatment: kidney transplant, dialysis
Kidney stones:
- Symptoms: Excruciating flank and abdominal pain
- Causes: Excess calcium in filtrate, excess uric acid in filtrate, etc.
- Treatment: Pain medication, ultrasonic destruction of kidney stone
Urinary tract infection:
- Symptoms: Pain when urinating, feeling of incomplete urination, itching, pain
- Causes: bacterial infection due to improper wiping or new sexual partner; far
more common in anatomical females
- Treatment: antibiotics
Valsalva maneuver: prevent air from escaping lungs and decreasing intraabdominal pressure
Trachea: AKA wind pipe (pseudostratified ciliated and hyaline cartilage)
- Structure: surrounded by flexible rings of hyaline cartilage that keep the
airway patent, or open
Bronchi:
Patent airway: flexible rings of hyaline cartilage that keep the airway patent, or
open
Heimlich maneuver: removes food stuck in the trachea
Type I alveolar cells: normal epithelial cells
Type II alveolar cells: secrete surfactant that breaks up surface tension inside
alveoli, allowing lungs to expand
Intrapulmonary pressure:
- Pressure inside the alveoli/lungs
- Rises and falls with breathing
Intrapleural pressure:
- Pressure in pleural cavity between visceral and parietal pleura
- Stays roughly constant
- Created as the two pleura stick to each other due to serous fluid
• Counteracted by elasticity of lungs and alveolar fluid surface tension.
Surfactant decreases this surface tension
Transpulmonary pressure:
- Equal to intrapulmonary minus intrapleural pressure, should always be
positive
- Positive transpulmonary pressure keeps lungs inflated
- If intrapleural pressure is > intrapulmonary pressure, lungs will collapse
• Only occurs due to puncture wounds (resulting in pneumothorax),
severely increased mucus production, etc.
Ventilation: the movement of air into and out of lungs
Inspiration: breathing in
1) Diaphragm contracts, moving downwards
– Increases lung volume
2) Simultaneously, intercostals contract
– Expands ribcage, increasing lung volume
3) Intrapulmonary pressure drops (due to increased volume)
4) Air rushes into lungs
– Air goes down pressure gradient
– About 500mL of air goes in
5) Additional muscles (pectoralis major, sternocleidomastoid) are used if needed
for deeper breathing
Expiration: breathing out
1) Diaphragm relaxes, moving upwards
– Decreases lung volume
2) Simultaneously, intercostals relax
– Compresses ribcage, decreasing lung volume
3) Elastic tissue in lungs recoils
– Actually the major contributor to volume decrease
4) Intrapulmonary pressure rises (due to decreased volume)
5) Air rushes out of lungs
– Air goes down pressure gradient
– About 500mL of air goes out
6) Additional muscles (pectoralis major, sternocleidomastoid) are used if needed
for deeper breathing
Tidal volume: Amount of air inhaled or exhaled with each breath under resting
conditions
Inspiratory reserve volume: Amount of air that can be forcefully inhaled after a
normal tidal volume inspiration
Expiratory reserve volume: Amount of air that can be forcefully exhaled after a
normal tidal volume expiration
Inspiratory capacity (IC): maximum amount of air that can be inspired after a
normal tidal volume expiration IC=TV+IRV
Forced vital capacity: total amount of air expelled during the deepest, most
forceful breath possible
Forced expiratory volume: the amount of air you can expel in one second
• Healthy lungs can expel 80% of their FVC in one second
Alveolar ventilation rate: amount of air that flows in and out of alveoli per minute
during quiet respiration
Dead space: The conducting zone doesn’t do gas exchange, and is referred to as the
dead space
Amount of dead space remains constant (150mL), so shallow breaths close to
150mL in volume only slightly get beyond dead space and enter respiratory zone
Perfusion, ventilation, V/Q coupling
- We have to match blood flow (perfusion) in the lungs to breathing rate
(ventilation)
- Decreased perfusion is the biggest health issue. What causes decreased
perfusion?
• Anything that thickens alveoli or capillary walls: edema, excess mucus,
emphysema, etc.
- Done by controlling arteriolar diameter
What causes V/Q mismatch?
- Severe pulmonary edema
- Tracheal obstruction (choking)
- Pulmonary embolism
- Severe COPD
- Emphysema (destruction of the alveoli walls)
What happens if there’s a V/Q mismatch?
- Hypoxia, which if left untreated leads to…
- Respiratory failure and/or tissue death
Arterial blood gasses: A measure of how much of each gas is carried in your
arterial blood
• Measured from blood taken from brachial, radial, or femoral artery
Normal measures:
- PO2: 75 to 100mmHg
- PCO2: 35 to 45mmHg
- pH: 7.35-7.42
- Bicarbonate: 22 to 28 mEq/L
- Oxygen saturation: 94 to 98%
Why take ABGs:
- Check for problems with V/Q coupling, asthma, cystic fibrosis, COPD, etc.
- Find out how well current treatments are working
- Measure acid-base level in people with kidney failure, diabetes, infections,
pneumonia, etc.
Carbonic acid-bicarbonate buffering system: One of the most important ways we
maintain our blood pH
Hyperventilation/Tachypnea: increase in breathing beyond normal need; may
result in hypocapnia
Hypocapnia: low CO2 levels and (therefore) higher pH
Hypoventilation/Bradypnea: decreasing in breathing below normal need; may
result in hypercapnia
Hypercapnia: high CO2 levels and (therefore) lower pH
Cyanosis: is the appearance of a blue or purple coloration of the skin or mucous
membranes due to the tissues near the skin surface having low oxygen saturation.
Hypoxia: deficiency in the amount of oxygen reaching the tissues.
Asthma:
- Symptoms: coughing, wheezing, dyspnea, chest tightness, anxiety
- Causes: Bronchospasm plus…
- Allergies: TH cells secrete cytokines that attract eosinophils and trigger edema,
magnifying any bronchospasm
- Exercise-induced: rapid ventilation doesn’t allow for proper warming and
humidifying of air, leading to dilated blood vessels in the lungs to warm the air
and edema (maybe?)
- Treatment: inhaled steroids (albuterol) and avoiding triggers
- Causes: Genetics, environment…?
Respiratory acidosis
Respiratory alkalosis
Metabolic acidosis
Metabolic alkalosis
Compensated and uncompensated acidosis and alkalosis
Short Answer Study Questions
Explain the two renal autoregulation mechanisms that control glomerular filtration rate
SLIDE: 22-23
Describe the movement of ions, water, and other solutes in the PCT
SLIDE: 25
Describe the movement of ions and water in the Loop of Henle
SLIDE: 28
Describe the movement of ions and water in the DCT and CD, including specifically the role of
ADH, aldosterone and ANP on water and ion reabsorption
SLIDE: 32-36
Describe the muscles involved, volume changes, and pressure changes that occur during
inspiration
SLIDE: 21-27
Describe how hemoglobin carries oxygen, and walk through hemoglobin’s oxygen-binding curve
SLIDE: 36-38
List then explain the three mechanisms carbon dioxide is transported through the blood
SLIDE: 39
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