review Flashcards
1
Q
What zones does respiratory physiology consist of? Describe them
A
Respiratory zone–site of gas exchange, Conduction zone–gets air to the respiratory zone
1
Q
What does respiration include?
A
Ventilation, gas exchange between blood and lungs and between blood tissues, oxygen utilization by tissues to make ATP
2
Q
What is the difference between external and internal respiration?
A
External–ventilation and gas exchange in lungs. Internal–oxygen ventilation and gas exchange in tissues
2
Q
How does gas exchange occur in lungs?
A
Via diffusion. Oxygen concentration is higher in the lungs than in the blood, so oxygen diffuses into blood. CO2 concentration in the blood is higher than in the lungs, so CO2 diffuses out of blood
2
Q
Define the immune barrier
A
simple columnar epithelium with tight junctions prevents swallowed pathogens from entering body
3
Q
Describe the two kinds of alveolar cells
A
Type I–95-97% total surface area where surface gas exchange occurs. Type II–secrete pulmonary surfactant and reabsorb sodium and water, preventing fluid buildup
4
Q
Describe the conducting zone
A
Air travels down the nasal cavity –> pharynx –> larynx –> trachea –> right and left primary bronchi –> secondary bronchi –> tertiary bronchi –> more branching –> terminal bronchioles –> respiratory zone (respiratory bronchioles) –> terminal alveolar sacs
4
Q
What is atmospheric pressure?
A
Pressure of air outside the body
4
Q
Describe the parasympathetic division of GI tract regulation
A
Stimulates esophagus, stomach, small intestine, pancreas, gallbladder, and first part of large intestine via vagus nerve. Spinal nerves in sacral region stimulate lower large intestine
5
Q
What is intrapulmonary pressure?
A
Pressure in the lungs
5
Q
What is intrapleural pressure?
A
Pressure within the intrapleural space (between parietal and visceral pleura)
5
Q
Describe the stomach functions
A
Stores food, churns food to mix with gastric secretions. Begins protein digestion. Kills bacteria. Moves food into small intestine in the form of chyme.
6
Q
What is transpulmonary pressure?
A
The difference between the intrapulmonary and intrapleural pressure
7
Q
What is Boyle’s law
A
States that the pressure of a gas is inversely proportional to its volume. An increase in lung volume during inspiration decreases intrapulmonary pressure to subatmospheric levels–>air goes in. A decrease in lung volume during exhalation increases intrapulmonary pressure above atmospheric levels–>air goes out
7
Q
What is lung compliance
A
Lungs can expand when stretched. Defined as the change in volume per change in transpulmonary pressure. Reduced by infiltration of connective tissue proteins in pulmonary fibrosis.
8
Q
What is the law of laplace
A
Pressure is directly proportional to surface tension and inversely proportional to radius of alveolus. Small alveoli would be at greater risk of collapse without surfactant.
8
Q
What is surfactant? What is it secreted by, what is it made of, what is its function etc?
A
Secreted by type II alveolar cells. Consists of hydrophobic protein and phospholipids. Reduces surface tension between water molecules. More concentrated in smaller alveoli. Prevents collapse.
8
Q
What does the gallbladder do?
A
Stores and concentrates bile from liver
9
Q
How does surfactant affect premature babies?
A
Production begins late in fetal life, so premature babies have higher risk of alveolar collapse called respiratory distress syndrome.
10
Q
How does the diaphragm affect breathing?
A
It’s the most important muscle involved in breathing. Contracts in inspiration, relaxes in expiration
10
Q
What muscles are involved in inspiration?
A
External intercostals during normal breathing, add sternocleidomastoid, scalene, and parasternal intercostals if forced
10
Q
Describe HCl secretion
A
Primary active transport of H+/K+ ATPase pumps. Facilitated diffusion of Cl-. Stimulation: Gastrin–made in G cells; carried to parietal cells in blood. Also stimulates ECL cells to make histamine. Histamine: also stimulates parietal cells via H2 histamine receptors
11
Q
What muscles are involved in expiration?
A
Internal intercostals during normal breathing, add abdominal muscles and internal intercostals if forced
11
Q
Describe inspiration in terms of volume, volume direction, and direction of movement
A
Volume of thoracic cavity (and lungs) increases vertically when diaphram contracts (flattens) and horizontally when parasternal and external intercostals raise the ribs. Air moves from high to low pressure, moving inward
11
Describe when, where, and how bile secrections are regulated
The liver produces bile continuously, but the arrival of food into the duodenum stimulates increased production of bile. It happens when bile acids are returned to the liver after intestinal absorption via enterohepatic circulation. Secretin and CCK stimulate increased bicarbonate secretion into bile. CCK (in response to the presence of fat in chyme) stimulates gallbladder contraction.
12
Describe expiration in terms of volume, volume direction, and direction of movement
Volume of thoracic cavity (and lungs) decreases vertically when diaphram relaxes (dome) and horizontally when parasternal and external intercostals lower the ribs in forced expiration. Air moves from high to low pressure, moving outward
12
What is tidal volume (TV)?
Amount of air expired or inspired in quick breathing
13
What is expiratory reserve volume (ERV)
Amount of air that can be forced out after tidal volume
14
What is inspiratory reserve volume? (IRV)
Amount of air that can be forced in after tidal volume
14
What is residual volume? (RV
Amount of air left in lungs after maximum expiration
14
What is pancreatic juice, what are its components and some examples?
Bicarbonate + 20 digestive enzymes. E.g. amylase--digests starch, trypsin--digestes protein, lipase--digests fat
15
What is vital capacity? (VC)
Maximum amount of air that can be forcefully exhaled after a maximum inhalation
15
What is total lung capacity (TLC)
Amount of gas in the lungs after a maximum inspiration
16
What is inspiratory capacity? (IC)
Amound of gas that can be inspired after a normal expiration
16
Describe the gastric phase of extrinsic gastric regulation
Triggered by arrival of food into stomach. Gastric secretion is stimulated by stomach distension (amount of food that enters) and amino acids in food. Positive feedback occurs; as more proteins are broken down, more secretions are released to break them down. There is also a negative-feedback system. As pH drops, somatostatin is released. this inhibits gastrin secretion. Lots of proteins buffer pH so secretion matches protein concentration.
17
What is functional residual capacity? (FRC)
amount of gas left in lungs after a normal expiration
17
How do you calculate VC?
VC = IRV + ERV + TV
18
How do you calculate FRC?
FRC = RV + ERV
18
How do you calculate total minute volume? (TMV)
TMV = tidal volume x breaths per minute
19
What are restrictive disorders?
Can't fully fill lungs with air or lungs are restricted from fully expanding. Results from condition causing stiffness in lungs, chest wall, weak muscles, or damaged nerves. Lung tissue is damaged. Vital capacity reduced but forced expiration is normal. E.g. pulmonary fibrosis, muscular dystrophy, ALS, scoliosis, obseity, hypoventilation syndrome
20
What are obstructive disorders?
Hard to exhale all air in lungs. Lung tissue is normal. Vital capacity is normal, but forced expiration is reduced. E.g. asthma, COPD (emphysema + chronic bronchitis), and cystic fibrosis
20
Describe the symptoms, causes, triggers, and treatments of asthma
Symptoms--dyspnea and wheezing. Caused by inflammation, mucus secretion and constriction of bronchioles. Often called airway hyperresponsiveness. Allergic asthmas: triggered by allergens stimulating T lymphocytes to secrete cytokines and recruit eosinophils and mast cells, which contribute to inflammation. Can also be triggered by cold or dry air. Reversible with bronchodilator like Albuterol.
20
Describe digestion and absorption of carbohydrates
Digestion: starch digestion begins in mouth with salivary amylase and continues in intestins with pancreatic amylase. Brush border enzymes finish breaking down resulting products and other disaccharides (maltose, sucrose, lactose). Absorption: monosaccharides are absorbed across the epithelium via secondary active transport with sodium and facilitated diffusion when glucose levels are high
21
Describe the symptoms, causes, statistcis, and treatments of COPD (Chronic obstructive pulmonary disorder)
Chronic inflammation, narrowing of the airways, and alveolar destruction. Includes emphysema and chronic obstructive bronchiolitis. Inflammation involves macrophages, neutrophils and cytotoxic T cells. Excessive mucus production and inflammation triggered by smoking. No cure. 5th leading cause of death. Most people with COPD smoke.
21
Describe emphysema
Destructions of alveoli. Reduces surface area for gas exchange. With fewer alveoli to put pressure on bronchioles they collapse during expiration.
22
Describe pulmonary fibrosis
Some people accumulate fibrous tissues in the lungs when alveoli are damaged. May be due to inhalation of small particles. E.g. black lung in miners.
22
Describe pepcid ulcer
Erosions of mucosa of stomach or duodeum
23
Define absorption
Passing broken-down food into blood or lymph
24
Define storage and elimination
temporary storage and elimination of undigested food
26
Describe the order food travels through the digestive tract
Mouth-->pharynx-->esophagus-->stomach-->small intestines-->anus
27
Describe the layers of the GI tract
Mucosa--inner secretory and absorptive layer; may be folded to increase surface area. Submucosa--very vascular, to pick up nutrients; also has some glands. Muscularis--smooth muscle; responsible for peristalsis and segmentation. Serosa--outer binding and protective layer
29
Describe the sympathetic division of GI tract regulation
Inhibits peristalsis and secretion. Stimulates contraction of sphincters.
30
Describe the mouth functions
Mastication--chewing breaks down food into smaller pieces for delutition and mixes it with saliva. Saliva--contains mucus, antimicrobial agent, salivary amylase to start starch digestion. Deglutition--involves three parts: oral, pharyngeal, and esophageal.
30
Describe a male's sex chromosomes
Males have an X and a Y chromosome
31
Describe the small intestine functions
Complete digestion of carbohydrates, proteins and fats. Absorption of nutrients. Sugars, lipids, amino acids, calcium and iron absorbed in duodenum and jejunum. Bile salts, vitamin B12, water and electrolytes in ileum. Very rapid due to villi and microvilli
32
Describe the large intestine functions
Absorption of water, electrolytes, vitamin K and B. Production of vitamin K and B via microbial organisms. Storage of feces.
34
Describe the liver functions (accessory organ)
Detoxification of blood, carbohydrate metabolism, lipid metabolism, protein sythesis, bile synthesis
35
What does the pancreas do?
Has endocrine and exocrine functions. Endocrine--islet of Langerhans cells make insulin and glucagon. Exocrine--acini cells make pancreatic juice, which is delivered to duodenum via pancreatic duct.
36
Describe the secretory cells of the stomach
Gastric pits at base of folds lead to gastric glands with secretory cells. Mucus neck cells-mucus to help protect stomach lining from acid. Pariet cells--HCl acid and intrinsic factor. Chief cells--pepsinogen. Enterochromaffin-like (ECL) cells secrete histamine and serotinon (paracrine signals). G cells secrete gastrin. D cells secrete somatostatin.
38
Describe the function of HCl
Drops pH to 2. Proteins are denatured (also enzyme access), pepsinogen is converted to active pepsin (digests proteins). Serves as the optimal pH of pepsin activity
40
Describe bile production. How much is produced per day, by what organ, and what is bile composed of?
The liver makes 250-1500 mL of bile per day. Composed of bile pigments (bilirubin), bile salts, phospholipids (lecithin), cholesterol and inorganic ions
43
Where is bilirubin produced and what is it derived from? Is it directly filtered by kidneys or secreted into bile?
Produced in spleen, liver and bone marrow. Derived from heme [-iron] from hemoglobin. Not water-soluble, so not directly filtered by kidneys or secreted into bile.
45
How is bilirubin carried and secreted? Where does it travel?
Carried on albumin in the blood. Conjugated with glucoronic acid to make it water-soluble. Conjugated bilirubin is secreted into the bile, where it is taken to the small intestine. Bacteria there turn it into urobilinogen, which makes feces brown. 30-50% is absorbed by the intestines and taken back to the liver. Some is used to make bile and some remains in blood to be filtered by the kidneys.
46
Describe the uterus
Site of embryonic development. Endometrium, myometrim, perimetrium and cervis
47
How is blood detoxified by the liver?
The liver can remove hormones, drugs, and other substances in three ways: secreted into bile, phagocytized by Kupffer cells lining sinusoids, chemically altered by hepatocytes--ammonia is converted into urea, urea is returned to the blood to be filtered by the kidneys
50
Describe intrinsic regulation of the stomach
Motility and secretion are somewhat automatic. Contractions are stimulated spontaneously by pacesetter cells in greater curvature of stomach. Secretion of HCl and pepsinogen occurs when amino acids enter stomach. Inictiated/regulated by G cells (gastrin), D cells (somatostatin) and ECL cells
52
Name the three phases of gastric regulation
Cephalic phase, gastric phase, intestinal phase
54
Describe the cephalic phase of extrinsic gastric regulation
Stimulates ECL, chief cells, and parietal cells. Lasts for the fisrt 30 minutes of a meal. Control by brain via vagus nerve
57
Describe the intestinal phase of extrinsic gastric regulation
Inhibition of gastric activity when chyme enters the small intestine. Stretch when food enters the duodenum stimulates a neural reflex that inhibits gastric regulation via vagus nerve. The presence of fats stimulates the duodenum to make enterogastrone. Enterogastrone inhibits gastric secretions. Several specific hormones have been identified with enterogastrone activity (CCK, GIP, GLP-1)
59
What is a gastroileal reflex?
Increased gastric activity=increased ileum activity and movement of food through ileoceal valve
61
What is ileogastric reflex?
Distension of ileum=decrease in gastric motility
63
Intestino-intestinal reflex
Overdistension of one portion of the intestine causes relaxation of other portions
65
What Is CCK & Secretin
When chyme enters the duodenum, two hormones are produced. Secretin is produced in response to a drop in pH. Production stops with a rise in pH. Cholecystokinin (CCK) is produced in response to the presence of partially digested and fats in chyme. Production stops when food leaves small intestine
68
Describe the digestion and absorption of proteins
Digestion: begins in stomach with pepsin to produce short-chain polypeptides. Finishes in duodenum and jejunum with pancreatic trypsin, chymotrypsin, elastase, and carboxypeptidase and the brush border enzyme aminopeptidase. Absorption: free amino acids cotransported with sodium. Depeptides and tripeptides cross via secondary active transport using H+ gradient
70
Describe the digestion and absorption of fats
Digestion: fat digestion begins in duodenum when bile emulsifies the fat and pancreatic enzyme lipase breaks it down into fatty acids. Phospholipase A (from pancreas) digests phospholipids into fatty acids. Absorption: fatty acids and monoglycerides move into bile micells and are transported to brush border. Inside the epithelial cells, they are regenerated into triglycerides, cholesterol and phospholipids and combined with proteins to form chylomicrons. these enter the lacteals.
72
Describe heartburn
Acid refluxing back into esophagus
74
Describe gastritis
Inflammation of submucosa caused by eating at it
76
Describe lactose intolerance
Disorder of lactase enzyme
77
Describe diarrhea
Excessive fluid excretion in feces
78
Describe cirrhosis of liver
Liver lobules are destroyed due to inflammation and replaced with fibrous tissue
79
How many chromosomes do zygotes get from mom and dad
23 from mom, 23 from dad
80
How many pairs of homologous chromosomes get produced?
23 pairs
81
How many pairs of chromosomes are autosomal? What does autosomal mean? What is the las pair of chromosomes?
22 pairs. Have the same genes on them. The last pair are sex chromosomes
82
Describe a female's sex chromosomes
Two X chromosomes
84
Compare and contrast X and Y chromosomes
They look different and have different genes. X has 1,090 genes while Y only has 80 genes. The Y chromosome has many testis-specific genes.
85
Describe the formation of gonads
After fertilization, the gonads and associated structures are identical in males and females. Embryonic gonads can become either testis or ovaries. Signal that determines this--TDF (testis determining factor). Coded for by a gene on Y chromosome
86
Describe the formation of testes
Soon after the production of TDF in XY embryos, the seminiferous tubules form. Germinal cells and sertoli cells differentiate 45-50 days after fertilization. The Leydig cells (those that makes testosterone) appear around day 65. They begin making large amounts of testosterone about 8 weeks after fertilization. This stimulates the development of the rest of the male reproductive organs. As the testes develop, they descend into the scrotum
87
When do follicular cells appear?
The second trimester
88
Describe when and what systems of ducts that embryos develop
Between days 25 and 50, both male and female embryos have two systems of ducts. Wolffian ducts can become male tract. Mullerian ducts can become female tract.
89
Describe how the ducts play into the formation of accessory sex organs
Sertoli cells secrete Mullerian-inhibiting factor. This makes the Mullerian duct regress. Testosterone from the Leydif cells stimulates the development of the Wolffian duct. Without this inhibition and stimulation, the Mullerian ducts develop into fallopian tubes and a uterus.
90
Describe the formations of external genitalia
Identical in males and females for the first 6 weeks of life. Both sexes have a urogenital sinus, labioscrotal swelling, genital tubercule, and urethral fold. Testosterone musculinizes these into the scrotum, prostate gland and penis. Without testosterone, these become the labia and clitoris.
91
Describe the testes
Have two compartments. Seminiferous tubules: where spermatogenesis occurs, FSH receptors are found here, on Sertoli cells, FSH influences spermatogenesis. Interstitial tissue: where Leydig cells make testosterone; also filled with blood and lymphatic capillaries, LH receptors found here on Leydig cells, testosterone secreted in response to LH.
92
Describe spermatogenesis
Diploid spermatogenesis first go through mitosis. One of the daughter cells (the primary spermatocyte) continues through meiosis). After meiosis I-->2 secondary spermatocytes. After meiosis II-->4 spermatids
93
Describe spermiogenesis
Maturation of spermatids into functioning spermatozoa. Mature spermatozoa have a flagellum, head, midpiece and acrosome cap.
94
Describe the ovaries
Female gonads; site of oocyte and sex steroid production
95
Describe fallopian tubes
have fimbriae that wrap around the ovaries and "catch" the oocyte after ovulation. Most common site of fertilization.
97
Describe the ovarian cycle
Involves growth, maturation, and release of oocytes from ovary every month. LH surge triggers ovulation
98
How many oocytes does a girl have as a newborn? By puberty? How many will be ovulated in her life time?
Newborn-2 million primary oocytes. By puberty, this number is cut to about 400,000. Only about 400 of these will be ovulated in her lifetime.
99
Describe the menstrual cycle
Describes the 28-day cycle of endometrial buildup and sloughing in response to ovarian hormones. Three phases: menstural, proliferative and secretory. Changes in the endometrium follow changes in the follicles of the ovaries
100
How many sperm enter the female at ejaculation? How many live to enter fallopian tube?
Over 300 million enter the female. Only about 100 live to enter fallopian tube
101
What must happen in order to fertilize ovum? How do sperm make it to oocyte?
Sperm must be capacitated. Sperm follow chemical and thermal signals toward oocyte.
102
Where does fertilization occur?
Fallopian tubes
103
What stimulates the release of acrosomal enzymes? What do those enzymes do?
The association between the acrosome cap and zona pellucida cells stimulates the release of acrosomal enzymes. These enzymes allow the sperm to "digest" its way into the oocyte.
104
What happens when the sperm enters the oocyte?
Calcium is released from the endoplasmic reticulum. The calcium prevents other sperm from entering the oocyte and activates the oocyte to finish meiosis to become a haploid ovum. 12 hours after the sperm enters, the nuclear envelope around the ovum disappears and chromosomes join to form diploid zygote.
105
Describe embryonic stem cells
Cells of early cleavage are totipotent and will divide to become every cell in the body. Embryoblast cells cultured in vitro are called embryonic stem cells and are pluripotent = able to become any type of cell in the body except for trophoblast. Inner cell mass from blastocyte. These cells might be used therapeutically to treat diabetes type I, Parkinson disease, or spinal cord injury.
106
Describe placenta formation
As the blastocyst develops, the endometrium also changes to form the dicidua basalis. This joins with the chorion frondosum to form the placenta. By the end of the second trimester, the spiral arteries of the endometrium have become tubes lined in cytotrophoblast.
107
Describe amniotic sac formation
Part of the chorion envelops the growing embryo. The fluid-filled space between becomes the amniotic sac. This fluid comes from isotonic secretion, urine from the fetus, and sloughed cells.
108
Describe how mammary glands change during pregancy
Cortisol, thyroxine, and insulin make mammary glands more sensitive to rising progesterone and estrogen levels. Progesterone stimulates alveoli growth. Estrogen stimulates tubule and duct growth.
109
Describe lactation
Prolactin from the pituitary gland stimulates the production of milk proteins, casein and lactalbumin. Prolactin is inhibited by PIH from the pituitary gland. PIH is stimulated by estrogen secretion. When the placenta is shed at birth, estrogen levels drop, lifting inhibition of prolactin. Nursing maintains high levels of prolactin secretion via neuroendocrine reflex that inhibits PIH secretion. Nursing also stimulates oxytocin secretion, which stimulates contraction of the lactiferous ducts for milk flow.
110
Describe the contraceptive pill
Includes synthetic estrogen and progesterone. Acts like a prolonged luteal phase. Produces negative-feeback inhibition of GnRH so ovulation never occurs. The endometrium still proliferates. Placebo pills are taken for 1 week to allow menstruation.
111
Describe menopause
Characterized by cessation of ovarian activity and menses. Due to changes in ovaries not to decrease in FSH and LH. FSH and LH levels are elevated due to lack of negative feedback. Usually occurs after age 50. Symptoms are due to loss of estrogen. Hot flashes are produced by vasomotor disturbances. The walls of the urethra and vagina atrophy, and vaginal glands no longer produce lubrication. After menopause, risk for atherosclerosis and osteoporosis increases.
112
Describe the vagina
tubular organ leading to external opening of vulva
