1. Respiratory System

2. Upper Respiratory Tract
Figure 21.3a

3. Superior, middle, and inferior nasal conchae
Covered with a mucous membrane.
Warm and moisten the air
Increase the turbulence in the flow of air through the nasal cavity
Sensory receptors to enhance the sense of smell.
When you have a cold and get extra fluid (edema)  runny nose.

4. Nasal Conchae
A cartilage nasal septum divides the right and left sides of the nose.
The nasal conchae contain blood vessels that can dilate, causing the tissue to swell, closing off one side of your nasal airway at a time. This allows the closed side to increase its moisture.
Then it will open again and the other side may close. These cycles occur every eight hours throughout the day.

5. What causes snoring?
When we are asleep the area at the back of the throat sometimes narrows. The same amount of air passing through this smaller opening can cause turbulence in the airflow and some vibration of the tissues in the nose and mouth. Different people who snore have different reasons for the narrowing. The narrowing can be in the nose, mouth, or throat.

6. Snoring
Some people cannot breathe through their noses because of obstruction of the nasal passages. This can be caused by a deviation of the nasal septum, allergies, sinus infections, swelling of the turbinates, or large adenoids (tonsils in the back of the throat). Many mouth breathers snore, because the flow of air through the mouth causes greater vibration of tissues.

7. Snoring
When we lie on our backs, gravity pulls the palate, tonsils, and tongue backwards. This often narrows the airway enough to cause turbulence in airflow, tissue vibration, and snoring. Frequently, if the snorer is gently reminded to roll onto his or her side, the tissues are no longer pulled backwards and the snoring lessens.
Some medications as well as alcohol can lead to enhanced relaxation of muscles during sleep. This will increase snoring.

8. Apnea
An apnea is a period of time during which breathing stops for 10+ seconds or the breath is 25% less than normal. Apnea is also a term for blood oxygen levels 4% less than normal.
These episodes often occur during sleep.
The two types of sleep apnea are Central Sleep Apnea and Obstructive Sleep Apnea.

9. Polyps
Nasal polyps are overgowths of the mucosal tissue in the nasal cavities.
Usually caused from chronic allergies
Can cause difficulty breathing through nose, loss of smell, headaches.
Treated with steroid sprays or surgery.

10. Sinuses
The nasal cavity is connected to PARANASAL SINUSES (ETHMOID, SPHENOID, FRONTAL, AND MAXILLARY SINUSES).
They are also lined with the same kind of mucosa.
When you have a cold, you get stuffed up, and the pressure can cause sinus headaches.
Some people with headaches and sinus pain assume they have a sinus headache, but the CT scan shows clear sinuses. They actually have a problem with cranial nerve V, causing referred pain to the sinuses. They need to see a neurologist.

11. The Paranasal Sinuses
Figure 7.11a, b

12. Fig. 23.2b(TE Art) Nasopharynx Oropharynx Laryngopharynx LARYNX
Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display.
Fig. 23.2b(TE Art)
Nasopharynx
Oropharynx
Laryngopharynx
LARYNX

13. Pharynx Separating the oropharanyx and the nasopharynx:
1. NASOPHARYNX: a continuation of the nasal cavity.
The EUSTACIAN TUBE is located here.
2. OROPHARYNX is the back of the mouth; visible when you open your mouth and look all the way back.
Separating the oropharanyx and the nasopharynx:
SOFT PALATE: feel it with your tongue
UVULA: located at the end of the soft palate
The function of the soft palate and uvula is to move upward when swallowing, to prevent food from going into nasal cavities. (They don’t close during vomiting)
3. LARYNGOPHARYNX: Can see the vocal cords here.

14. Pharynx
Figure 21.3a

15. LARYNX It has two functions: 1. Produce sounds (vocal cords)
2. Prevent food from entering lungs
Made up of nine separate cartilages:
EPIGLOTTIS
THYROID CARTILAGE
CRICOID CARTILAGE
(2) ARYTENOID CARTILAGES
(4) Smaller cartilages we’re not going to name

16. Anatomy of the Larynx
Figure 21.5a, b

18. GLOTTIS is the opening. It stays all the way open when you are breathing hard.
EPIGLOTTIS flaps over the glottis when you swallow so nothing will go into the trachea. When you get hiccoughs, it’s from a sudden movement of air into the lungs, so the epiglottis closes to prevent more air from going in. It’s unknown why you get hiccoughs. All the treatments you can try involve interrupting the normal breathing patterns.

19. Vocal Cords
Figure 21.6

20. VOCAL CORDS (vocal folds)
Vocal cords are attached to the ARYTENOID CARTILAGES. If these cartilages move, the vocal cords open. When they go back to normal, the glottis will close. The ability to vary the pitch of the voice results from varying the tension in the vocal folds.

21. Vocal Cords
For air to move through, muscles have to contract. If muscles here are paralyzed, the airway closes. In surgery, have to intubate. In an emergency, have to do a tracheotomy above the jugular notch.
The type of sounds you make depend on how far apart the vocal cords are.
Way open = no sound (like when breathing)
Mostly closed = sounds
Men: their thyroid cartilage is larger, so their vocal cords are longer = deeper voice.

22. Problems with vocal cords
LARYNGITIS: inflamed vocal cords
(↓ sound production)
Singers can get scar tissue nodules, requires surgery.

23. FUN FACTS What is the Adam's apple and what does it do?
It’s really a part of the larynx or voice box. When boys go through puberty, hormones cause the larynx to grow rapidly, deepening their voices and causing the bulge to form. Girls' voices also deepen with puberty, but since their larynxes don't tend to grow as much, they don't usually develop an "Eve's apple." The protrusion is actually composed of thyroid cartilage. Your larynx is surrounded by a skeleton of cartilage plates that prevents it from collapsing. Some folks undergo cosmetic surgery to make it less prominent.

24. FUN FACTS Definition of Adam's apple
Adam's apple: Enlargement of the Adam's apple is considered, like pubic hair growth, one of the secondary sexual characteristics.
Origin of the term: It is usually said that Adam's apple takes its name from the biblical story about Adam, Eve. The serpent and the apple. A piece of the forbidden fruit stuck in Adam's throat and created the anatomic Adam's apple. So the story goes. However, it may be wrong. Adam's apple in Latin is "pomum Adami." This may have been a mistranslation of the Hebrew "tappuach ha adam" which also means male bump. Between Latin and English there's many a slip.

25. FUN FACTS
Why does your voice sound funny after you inhale helium from a balloon?
A healthy 13-year-old boy suffered a cerebral gas embolism after inhaling helium from a pressurized tank at a party. A word to the wise: Pressurized, industrial tanks are not for human consumption! Repeated inhalation of helium can hinder your ability to breathe.
Helium is an inert gas that is lighter than air. Sound is produced by vibration, the movement of air around our vocal chords. Because helium gas is lighter than the usual oxygen/nitrogen blend, it changes the resonant frequency of the human vocal tract, causing a faster vibration and a higher-pitched, cartoon-character sound.

26. TRACHEA This is a tube that carries air from the larynx to the lungs.
It’s fairly rigid from about 16 rings of cartilage.
The purpose of the cartilage rings is to keep the trachea open. Otherwise, when you inhale, the trachea would collapse like when you suck hard on a straw. That’s why your vacuum cleaner has rings on the hose.

27. The Trachea
Figure 21.7a

28. Histology of the trachea
MUCOSA (Inner, most superficial layer)
EPITHELIUM (pseudostratisfied ciliated epithelium) and goblet cells. Function of goblet cells is to produce mucous to trap dirt. Cilia move dirt to larynx  swallowed.
LAMINA PROPRIA (loose connective tissue) with lots of elastic fibers to make the trachea flexible.
SUBMUCOSA (Deep to the mucosa) This is the serous portion to humidify the air.
ADVENTITIA (Deepest layer) This is dense connective tissue with hyaline cartilage.

30. BRONCHI
The trachea branches into the RIGHT and LEFT BRONCHUS (the primary bronchi).
These branch into the secondary bronchi, which branch into the tertiary bronchi.
The layers become thinner, and the hyaline cartilage no longer has nice rings; just bits.
The tertiary bronchi are microscopic. The distal part of the tertiary bronchi are called terminal bronchioles. These are the last parts of the respiratory tree that have smooth muscle and bits of hyaline cartilage. Beyond them are the respiratory bronchioles.

32. If you inadvertently inhale something, which lung does it go into
If you inadvertently inhale something, which lung does it go into? Right lung.
Lung cancer occurs slightly more frequently in the right lung than in the left lung (about 53% vs. 47% of the time). The most logical explanation for this is that the right primary bronchus is wider than the left one (and the right lung is larger than the left lung), so the right lung receives slightly more carcinogenic cigarette smoke with each puff.
The left lung has a cardiac notch; this is where the heart sits.
The left lung has TWO lobes, but the right lung has THREE lobes.

33. Cardiac Notch
Cardiac Notch
Figure 21.8a

34. Fig. 23.9b(TE Art) Apex Superior lobe Pulmonary Secondary arteries
Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display.
Fig. 23.9b(TE Art)
Apex
Superior
lobe
Pulmonary
arteries
Secondary
bronchi
Pulmonary
veins
Hilum
Pulmonary
Ligament
Middle
lobe
Inferior
Lobe
Diaphragmatic
surface

35. BRONCHIOLES
(simple columnar epithelium, no cilia, no mucosa) Surrounding bronchioles are a smooth muscle layer, which functions to direct the flow of air to particular portions of the lungs.
Right now, only a small percentage of lungs are needed, compared to if you are running.
Since there are no cilia, any particle that gets down that far has to be eaten by macrophages or just stay there.
In allergic conditions, bronchioles will constrict, blocking air flow to the lungs = ASTHMA. Asthma can also be caused by irritants in the environment, especially by pollution in the city.

36. Respiratory Bronchioles
Distal to the terminal bronchioles, the branches of the respiratory tree are now called respiratory bronchioles.
These end in alveoli (air sacs)

37. ALVEOLI
Respiratory bronchioles branch into TERMINAL BRONCHIOLES (simple cuboidal), which empty into a sack = ALVEOLUS (simple squamous epithelium).
This sac is like a balloon surrounded by a capillary bed.
Within the alveoli are macrophages.

38. Structures of the Respiratory Zone
Figure 21.9a

39. Alveoli
Figure 21.10b

40. Alveoli
Figure 21.10c, d

41. Partial Pressure of Oxygen (pO2)
The air we breath is a mixture of gasses: primarily nitrogen, oxygen, & carbon dioxide. So, the air you blow into a balloon creates pressure that causes the balloon to expand.
However, the total pressure generated by the air is due in part to nitrogen, in part to oxygen, in part to carbon dioxide.
That part of the total pressure generated by oxygen is the 'partial pressure' of oxygen, while that generated by carbon dioxide is the 'partial pressure' of carbon dioxide. A gas's partial pressure, therefore, is a measure of how much of that gas is present (e.g., in the blood or alveoli).
The pO2 of blood therefore refers to the amount of dissolved oxygen in the blood plasma.

42. The Respiratory Tree
As the conducting tubes of the respiratory tree become smaller, the following changes occur
Cartilage rings are replaced by irregular plates of cartilage
Cartilage disappears in the bronchioles
The lining epithelium thins
Elastin remains in the walls

43. DIAPHRAGM
When the diaphragm muscle contracts, the size of the thoracic cavity increases and air rushes into the lungs.

44. Inspiration
The diaphragm and the external intercostals are the muscle group that produces inspiration.

45. FUN FACTS
Exactly what happens when you get the wind knocked out of you?
It’s all about your diaphragm. This dome-shaped muscle sits below your lungs, and it helps your windbags inhale and exhale. When you get hit in the abdomen, this can cause a pressure difference that makes your diaphragm spasm for a few seconds. You can't catch your breath until the spasm stops.

46. FUN FACTS
MYTH: Cover your head or catch a cold: Although 90% of the heat lost from the body is lost from the head, covering your head will not prevent this heat loss. The heat is lost from the warm air that you exhale.

47. Lung Damage
Smoking destroys cilia, and smoke of any kind is toxic. Particles in the lungs can’t clear.
Cigarettes contain tar, which is the same kind of tar used to pave roads.
When there is a thin lining of tar on the alveoli, there is no oxygen exchange to the lungs there. Large chunks of the lung become useless.
Damage to the lungs shows up several ways.

48. CHRONIC OBSTRUCTIVE PULMONARY DISEASE (COPD)
Number 5 killer in the USA.
It is a combination of two conditions:
CHRONIC BRONCHITIS: inflammation of the bronchi, produces mucous, the openings become smaller = obstructed.
EMPHYSEMA: scarring of elastic tissue on the bronchioles and alveoli, which collapse now during exhalation.
Characterized by a person with a large, “barrel” chest.

49. Barrel Chest of Emphysema

50. Emphysema A person with emphysema is like this:
Inhale all the way, then exhale a little bit, and hold it. Now inhale and exhale to that same point.
They cannot exhale all the way. They start using their abdominal muscles, and get a large, barrel chest.
They have chronic acid-base balance problems, and the kidneys have to work harder. They usually develop kidney problems.

51. Smoking
If a person stops smoking after 10 years, damage will repair. Longer than 10 years may have some residual damage. It takes 7 years for lungs to repair.
Smoking right after exercise is worse because you are breathing more deeply.
Pollution in the air can also cause particles in the lungs, and the ozone can damage the lungs. Living in southern California is like smoking one pack a day.
A mother who smokes during pregnancy will give birth to a baby with a lower birth weight.

52. Smoking
Smoking also is associated with heart disease, cancer of the lung, bladder, and pancreas.
It also causes emphysema, pneumonia, and bronchitis.
Some people try to quit smoking by smoking less, trying not to inhale, or switching to chewing tobacco, but there is no safe way to use tobacco.

53. Pneumonia
An infectious illness that results in the accumulation of fluid in the alveoli.

54. Respiratory Disorders
Upper Respiratory Infection (URI)
Lungs are not involved
Usually caused by a cold virus or allergies
Usually not associated with a fever
Lower Respiratory Infection (LRI)
Lungs are involved
Usually caused by bacteria
Usually associated with a fever

55. Other Lung Conditions INFLUENZA LUNG CANCER
RESPIRATORY DISTRESS SYNDROME
SURFACTANT
PLEURISY
PNEUMOTHORAX

56. INFLUENZA This is the “flu” caused by a virus.
This is what you are vaccinated against when you get the flu vaccine.

57. LUNG CANCER
There are many types of lung cancers. About 150,000 die each year from them.
It is the #1 or #2 most deadly form of cancer.
85% of lung cancer is caused from smoking.

58. LUNG CANCER
The problem is that it starts as a hard nodule deep in the spongy tissue of the lung, where it has no symptoms until it presses against a structure. By then, it has also metastasized.
Surgery on a smoker won’t work because the lungs are too weak, and they can’t do without the lung tissue. There are no good screening procedures for lung cancer.
In lung cancer, the cancer cells usually arise from the epithelium lining a large bronchus.

59. RESPIRATORY DISTRESS SYNDROME
SURFACTANT is a detergent produced within the alveoli, which coats it.
It functions to help with lung inflation by keeping the walls of the alveoli from sticking together when they collapse during exhalation.
If you have two wet pieces of paper and stick them together, they are hard to pull apart without ripping. Put soapy water between them, and you can pull them apart.

60. RESPIRATORY DISTRESS SYNDROME
Surfactant is not produced in a fetus until the ninth month, so premature babies don’t have enough surfactant  RESPIRATORY DISTRESS SYNDROME, which is the #1 cause of death in premature babies.
You know how hard it is to blow up a brand new balloon? Imagine a baby having to do that with every single breath. You get tired.
The treatment is to spray artificial surfactant into the lungs, and put them on a respirator to push air in. The more distal regions are still collapsed, so there are problems.

61. Pleura Lining the thoracic cavity is PARIETAL PLEURA.
Lining the lungs is the VISCERAL PLEURA.
Both of these are made of 2 layers (simple squamous epi and loose fibrous ct), same as the pericardium. Between these pleura is a tiny space: PLEURA CAVITY.
The pleura lubricate the lungs so when the lungs move, it is smooth. They also form an airtight seal to allow the lungs to inflate.

62. Diagram of the Pleural Cavities
Figure 21.11

63. PLEURISY
The rubbing together of inflamed pleural membranes that produces a stabbing pain in the chest with every breath; it feels like a broken rib.
Usually the inflammation is caused from an infection.
It is fairly common.

64. Breathing
When the lungs inflate, the thoracic cavity expands for two reasons:
The diaphragm pulls down, increases volume
The rib cage expands, increases volume.
When the diaphragm contracts, the size of the thoracic cavity increases, the pressure inside the thoracic cavity drops, and air flows into the lungs.

65. Changes in Thoracic Volume
Figure 21.15d

66. PNEUMOTHORAX
If there is a hole in the pleura (injury from broken rib, knife), it’s like opening the stopper; air flows in through the hole, and the lungs don’t inflate = PNEUMOTHORAX (air in thorax)  COLLAPSED LUNG.

67. TUBERCULOSIS
An infection of a really bad bacteria that get in the lungs and make themselves a capsule to hide in, where antibiotics can’t reach. They set up shop in the lungs and reproduce. Soon, the lungs fill up with these hard nodes and make it difficult to breathe. It causes extreme coughing, and then lots of these bacteria break off and get spewed into the air, where someone else can inhale them. It is extremely contagious and very deadly.

68. TUBERCULOSIS
If a person gets TB, the State Health Department has to be notified.
If it is active TB, you must be hospitalized.
If it is not an active infection, you still need medicines.
They will show up at your house every morning for six months and stand there and watch you take your pills.
If you don’t accept this, they have the right to haul you away to a lock-up facility and force the medicine in you for six months.
There are only a few diseases where the State Health Department will step in like this: anthrax, typhoid fever, and bubonic plague are other diseases where you don’t get a choice; you are forced into isolation.
Diseases like TB and the plague have almost wiped out Europe!

69. TUBERCULOSIS
A TB test will be positive if you have been exposed to the organism at any point in your life.
Then you’ll have to go in for an x-ray to see if it is an active case of TB or not.
Once you recover from TB you will always have a positive TB test, so tell the nurse that in advance.
You may have to provide documentation that you have been treated for it already.
Most employers require TB tests before hiring. I had to take one to work here.

70. CYSTIC FIBROSIS
Cystic fibrosis is an inherited disease that causes thick, sticky mucus to build up in the lungs and digestive tract. It is one of the most common type of chronic lung disease in children and young adults, and may result in early death.

71. CYSTIC FIBROSIS
Millions of Americans carry the defective CF gene, but do not have any symptoms. That's because a person with CF must inherit two defective CF genes -- one from each parent. An estimated 1 in 29 Caucasian Americans have the CF gene. The disease is the most common, deadly, inherited disorder affecting Caucasians in the United States. It's more common among those of Northern or Central European descent.

72. CYSTIC FIBROSIS
Most children with CF are diagnosed by age 2. A small number, however, are not diagnosed until age 18 or older. These patients usually have a milder form of the disease.

73. RENAL SYSTEM

74. Organs of the Renal System
Kidneys
Ureters
Urinary bladder
Urethra
Not many structures, but very important!
Figure 23.1a

75. Functions of Urinary System
Regulate electrolytes (K, Na, etc)
Regulate pH in blood
Regulate blood pressure
Regulate blood volume (removes excess fluid)
Removing metabolic wastes
Urea, uric acid, and creatinine
This is the least important of the kidney’s functions. You can survive for a few weeks without excreting waste products in the urine, but hour by hour, the other functions are more important.

76. Relationship of the Kidneys to Vertebra and Ribs
They are retroperitoneal and are located in the abdominal cavity.
They are at the level of T12 to L3, so they are at the costal margin, and the ribs protect them a little.
Even though they are protected by thoracic ribs, they are NOT in the thoracic cavity because they are below the diaphragm.
Figure 23.1b

77. STRUCTURES WITHIN THE KIDNEY
The RENAL CAPSULE surrounds the kidney, dense fibrous connective tissue.
A layer of adipose tissue surrounds the capsule, called PARARENAL FAT (ADIPOSE). It cushions and protects.
Around that is a connective tissue layer = RENAL FASCIA, made of loose connective tissue. It anchors the kidney to the surrounding peritoneum and abdominal wall. Not very strong. Jumping up and down can cause tearing.

78. Position of the Kidneys with in the Posterior Abdominal Wall
Figure 23.2a

79. Gross Anatomy of the Kidneys
Renal cortex (Most superficial layer)
Renal medulla
Renal pyramids (drain into the calyx)
Renal pelvis
Calyx (drains into hylus  ureter)
Ureter

80. Renal fascia
Interlobar arteries
Interlobular arteries
Arcuate arteries

81. Internal Anatomy of the Kidneys
Interlobar artery
Figure 23.3b

82. Blood Supply to Kidney
AORTA  RENAL ARTERY  SEGMENTAL ARTERIES  INTERLOBAR ARTERIES  ARCUATE ARTERIES (form arcs)  INTERLOBULAR ARTERIES
INTERLOBULAR VEIN  ARCUATE VEIN  INTERLOBAR VEINS  SEGMENTAL VEINS  RENAL VEIN  INF. VENA CAVA

83. Summary of Blood Vessels Supplying the Kidney
Figure 23.10

84. Internal Anatomy of the Kidneys
Interlobar artery
Figure 23.3b

85. Microscopic Anatomy of the Kidneys
Just like the unit of function of the lungs is the alveolus, the unit of function of the kidney is the NEPHRON.
Each kidney has about 100,000 nephrons.
They carry out all of the various functions of the kidneys.

86. Microscopic Anatomy of the Nephron
GLOMERUS WITH A CAPSULE
PROXIMAL CONVOLUTED TUBULE
LOOP OF HENLE
DESCENDING LIMB
Thick portion
Thin portion
ASCENDING LIMB
DISTAL CONVOLUTED TUBULE
COLLECTING DUCT

87. Nephron

88. Position of Nephron in Kidney
Figure 23.4a

89. Glomerulus of a Nephron

90. JUXTAGLOMERULAR APPARATUS
The juxtaglomerular apparatus (JGA) consists of cells located in and around the glomerulus and the glomerular capsule.
The glomerulus is the first part of the nephron, where the filtration occurs.
The glomeruli are located only in the renal cortex.
A glomerulus (“ball of yarn”) is a tuft of capillaries surrounded by a glomerular capsule (Bowman’s capsule) made of simple squamous epithelium. The glomerulus fits in the capsule like a fist punched into an underinflated balloon.
The capsule collects the plasma from the arterioles and drains it into the convoluted tubules, which empty into a collecting duct, which exits the body.
The plasma is further filtered along the way.

91. Glomerulus of a Nephron

92. Normally at the end of the capillary bed you have venuoles
Normally at the end of the capillary bed you have venuoles. But this is the only part of the body that is different: here we have another arteriole, called the EFFERENT ARTERIOLE, which takes blood away from the glomerulus.
The efferent arteriole drops down straight, next to the Loop of Henle. While it is straight, it is called VASA RECTA (straight capillaries).
There are capillaries that come off the efferent arteriole which surround the loop of Henle. Here, they are called peritubular capillaries. They then leave the area to become the interlobular vein, which leaves the kidney.

93. Nephron

94. Efferent arteriole
Afferent arteriole
Glomerulus

95. FUNCTION OF THE NEPHRON
Blood comes in from the AFFERENT ARTERIOLES.
Plasma leaks out and enters the glomerular capsule. The plasma contains nutrients, waste products, etc. As the plasma moves through the proximal convoluted tubule, all of the nutrients, and most of the water, and most of the ions are absorbed back out of the nephrons and into the blood.
In the Loop of Henle, almost all of the rest of the water and salt are removed  blood.
Everything that is not reabsorbed (the waste products) goes into the collecting duct and is excreted as urine. This is also how the water-salt balance is maintained, as well as the acid-base balance.

96. Nephron

97. FUNCTION OF THE NEPHRON
In the distal convoluted tubule, the rest of the water and salt are removed.
The rest of the liquid goes into the collecting duct.
The distal convoluted tubule and the collecting duct fine-tune the water and salt absorption and excretion. If you are well hydrated, the water will be allowed to leave  urine.
If you are thirsty, the water will be absorbed. The purpose of the capillary bed is to absorb these things from the nephron into the blood.

98. Figure 23.5

99. Renal Corpuscle and the Filtration Membrane
Figure 23.6c

100. Diuretics
Diuretics are medicines that increase the amount of urine that is produced.
People who have high blood pressure might be prescribed diuretics to decrease the blood volume.
Alcohol is a diuretic and this is what contributes to the symptoms of a hangover. The best way to prevent a hangover after drinking is to consume a lot of water before you go to bed.
Caffeine is also a diuretic, so coffee and regular Coca-cola are diuretics.

101. HISTOLOGY OF THE NEPHRON
PROXIMAL AND DISTAL CONVOLUTED TUBULES
This area absorbs nutrients, water, and salt. Only about 1% of the fluid filtered by the kidney actually becomes urine.
LOOP OF HENLE
This is where you get diffusion of water. It is located in the renal medulla.

102. Urine Production
Filtration – filtrate of blood leaves kidney capillaries
Reabsorption – most nutrients, water, and essential ions reclaimed
Secretion – active process of removing undesirable molecules

103. Figure 23.9a

104. Collecting Duct (tubule)
Receives urine from distal convoluted tubules, empties into ureter.
Figure 23.4a

105. Kidney Problems
Things can happen to the kidney: infection, excess proteins, pH change, blood pressure drops, and can lead to kidney failure.
Treatment is DIALYSIS, which removes blood, send it through a filter, and return it without the wastes. Done three times a week. Ideally, need a kidney transplant because the kidney has other functions as well.
The brain, heart, and kidney are the only three organs in the body that have to get oxygen to sustain life.

106. Ureters
These are long tubes that connect the renal pelvis to the urinary bladder
MUCOSA
TRANSITIONAL EPITHELIUM (for expansion)
LAMINA PROPRIA (has elastic tissue to recoil)
MUSCULAR LAYER (smooth muscle)
INNER CIRCULAR
OUTER LONGITUDINAL
ADVENTITIA
Provides protection, strength for organs, and attaches ureters to surrounding structures

107. URINARY BLADDER
The structure is identical to ureter except mucosal layer has folds = RUGAE which allow for expansion.
The mucosal folds in the bladder (rugae) have the same basic function as transitional epithelium—accommodating stretch as the bladder fills.
You can hold up to one liter of urine, although at 500ml, you’ll be dancing.

108. Urinary Bladder Rugae: allows for expansion
-A full bladder is roughly the size of a soft ball
Figure 23.14

109. URINARY BLADDER
At the base of the urinary bladder, the muscle layer is thicker and is called the DETRUSOR MUSCLE, which allows emptying of the urinary bladder.
The function of the urinary bladder is just to store urine.

110. Detrusor Muscle

111. URETER entrance to BLADDER
The URETER comes in at the base of the urinary bladder, not the top.
As the bladder fills, it presses down on the ureters to prevent urine from backing up into the kidneys.

112. BLADDER
The TRIGONE is a triangular area where the ureters come in and the urethra goes out.
Between the urethra and the urinary bladder are two sphincters:
INTERNAL URETHRAL SPHINCTER: smooth muscle
EXTERNAL URETHRAL SPHINCTER: skeletal muscle. Although it is primarily under voluntary control, it will contract if the urine volume is too much.
If the patient is in a coma or under anesthesia for a long time, the internal sphincter will be closed, like when you are asleep, so a catheter is needed to open it to drain the urine out.

114. Urethra Drains the urine to the outside.
Its histology is the same as the ureter
Females: 4cm
Males 20 cm (varies with mood)
Therefore, women (esp. little girls) are more susceptible to UTI.

115. Problems URETHRITIS = infection and inflammation of the urethra
CYSTITIS = infection of the urinary bladder.

116. UREA Urea is a waste product of amino acid metabolism.
Remember, proteins are made of amino acids, so when you break down proteins, you break down amino acids, and the waste product left over is urea.
This is the main waste product in urine.

117. COLOR OF URINE
When you urinate, it should be mostly clear with almost no yellow color.
The more yellow the urine is, the more dehydrated you are.
If the urine is very dark yellow, you are burning too much protein (as in food deprivation). This is often seen in diabetes.

118. Problems KIDNEY STONES Develop in the renal pelvis
Stones are made out of a variety of things: uric acid, calcium, etc.
They keep growing.

119. KIDNEY STONES
They can block the ureter, causing the kidney to enlarge. As the kidney stretches, the capsule stretches, causing excruciating pain in cycles of hours. As pressure builds up around the stone, urine can pass, and the kidney stone moves down the urethra slowly.
Symptomatic kidney stones are pea sized or larger (up to 1 ½ inches).
They get stuck in three places:
Renal pelvis
In the ureter as it bends over the common iliac artery
In the urinary bladder at the trigone.

120. Kidney stones get stuck in three places:
Renal pelvis
In the ureter as it bends over the common iliac artery
In the urinary bladder at the trigone.

121. Where kidney stones get stuck
Renal pelvis
Ureter
Common iliac artery
Urinary bladder trigone

122. KIDNEY STONES TREATMENT
ULTRASOUND LITHOTRIPSY
Put a powerful speaker on the outside of the kidney, sends a shock wave which the tissues absorb, but the stones shatter so the pieces can pass easier.
STENT
(1 ½ foot long tube) in to keep the ureter open along its entire length. Insert under general anesthetic, remove without.
To help prevent kidney stones, drink enough fluid so your urine stays clear and light colored.

123. Other Kidney Problems
Pyelitis: infection of the renal pelvis and calyces
Nephritis: inflammation of the nephrons.
Hydronephritis: excess fluid in the nephron.
Cystitis: inflammation of the urinary bladder.
Glucose in the urine: indicates diabetes.