Bio 169 Final Exam Questions For Review 2019 Dr. Frear Wtcc Flashcards
What are the characteristics of an endocrine gland?
-Composed of secretory endocrine cells derived from an epithelium that is supported by a connective tissue framework.-extensive blood supplyhttps://quizlet.com/6011405/general-characteristics-of-the-endocrine-system-flash-cards/
What is unique about thyroid hormone?
-it has a large concentration of iodide.-it is neither a protein or cholesterol based, they incorporate iodine as a active constituent-it has two forms (T3 (most active) & T4)The thyroid keeps your metabolism under control through the action of thyroid hormone, which it makes by extracting iodine from the blood and incorporating it into thyroid hormones. Thyroid cells are unique in that they are highly specialized to absorb and use iodine. Every other cell depends on the thyroid to manage its metabolism. The pituitary gland and hypothalamus both control the thyroid. When thyroid hormone levels drop too low, the hypothalamus secretes TSH Releasing Hormone (TRH), which alerts the pituitary to produce thyroid stimulating hormone (TSH). The thyroid responds to this chain of events by producing more hormones.
How do lipid-soluble hormones exert their impact on cells?
being lipophilic the diffuse across the plasma membrane-binds to intracellular receptor in cytosol to form hormone receptor complex (hrc)-hrc binds to a particular DNA sequence in regions of chromatin within nuc. called hormone response element (hre)-resulting in transcripting mRNA-this change in protein syn. results in wither altercation in cell structure or shift in cell activity.orLipid-soluble hormones (e.g., Steroid, calcitriol) are relatively small, nonpolar molecules that are lipohilic or lipid- loving. Unbound lipid- soluble hormones like steroids are able to diffuse across the plasma membrane. Upon entering the cell, the hormone binds to intrcellular receptors located in either the cytosol or nucleus to form a Hormone - receptor complex.1. The unbound hormone diffuses readily through the plasma membrane and binds with an intracellular receptor, either within the cytosol or the nucleus to form a hormone-receptor complex.2. The hormone - receptor complex binds with a specific DNA sequence called a Hormone Receptor Complex (HRE)3. Binding of the HRE stimulates mRNA synthesis.4. mRNA exits the nucleus and is translated by a ribosome in the cytosol. A new protein is synthesized.
What are the first and second messenger in the process of hormone signal transduction?
-First messenger is the ligand, (signaling hormone)-second messenger is any small, non-protein components (formation changed molecule from the 1st messeger docking.)ACTIVATION OF A G PROTEIN - 1. Hormone (first messenger) binds to receptor and induces shape change to activate the receptor. 2. G Protein binds to activated receptor. 3. GDP is "bumped off" and GTP binds to G protein; G protein is then activated.4. Activated G Protein (GTP) is released from the receptor and moves along the inside of the plasma membrane, which results in formation or availability of second messenger.
What is a G protein?
protein named based on ability to bind guanine nucleotide.GDP=inactiveGTP=activeG protein is also a GTPase enzyme.Both of the two common signal transduction pathways function through an internal plasma membrane protein complex called a G Protein. This Protein can bind Guanine Nucleotide. Guanine Diphosphate (GDP) is bound to G protein when it is in the inactive state. The binding of hormone to a plasma membrane receptor causes a change in G protein from its inactive form to its activated form.
How does viscosity change as a. ) RBC count changes.....b.) fluid amounts change...
A) Viscosity is inc. if the amnt of substanes (erythrocytes) inc. the amount of fluid dec. or bothB) (relative concentration of solutes) ->meaning the amount of proteins or ions determines whether fluids move into or out of the plasma by osmosis*hypertonic->too much *hypotonic-> not enough
What components separate out when blood is centrifuged?
Plasma 55%Buffy Coat (less than 1%)Erythrocytes 44%
What characteristics about leukocytes make them unique compared to the other formed elements?
they have a nucleus!
What are the characteristics of erythrocytes?
Contain hemoglobin to transport gases like oxygenDiscoidal cells with a biconcave shapeHave NO nucleus!
What antibodies and antigens are located in type O blood?
Has NEITHER A or B Antigens Has BOTH anti A & anti B antibodies.
Define intercalated discs?
connects cardiac muscle fibers to each other, prevent cardiac muscle fibers from being pulled apart during contraction and allows action potentials to travel rapidly across the muscle cells.
Where are intercalted discs located?
at cell-to-cell junctions
What are the functions of heart valves?
to prevent back flow of blood through the chambers
List the structures, in order, in which an electrical impulse travels across the heart.
SA node--->AV node--->AV bundle--->bundle branches--->Purkinje fibers
What waves of the EKG relate to atrial depolarization?
P Wave orginates at SA node
What waves of the EKG relate to atrial repolarization?
occurs at the same time as QRS complex, not usually evident
What waves of the EKG relate to ventricular depolarization?
the QRS complex; results in contraction of ventricles
What waves of the EKG relate to ventricular repolarization?
The T Wave. ~ The first wave produced after the QRS Complex. Has the following characteristics: The deflection produced by the ventricular repolarization. It is slighty asymmetric. No more than 5 mm in height.
What type of muscle is located in the 1) tunica media, 2) tunica externa,3) tunica intima
tunica media-->smooth muscle cells that are supported by elastic fibers.tunica externa--> areolar connective tissue that contains elastic and collagen fibers.tunica intima-->areolar connective tissue
What is unique about a portal system?
it is a circulatory pathway where blood can flow through two capillary beds,
What parameters impact peripheral resistance to blood flow?
viscosity, vessel length, vessel diameter
How does fluid intake impact blood viscosity and resistance to flow?
increased viscosity = greater resistance = decreased blood flow
What impact does age have on the thymus gland?
-Its most active during childhood, -The thymus initially increases in size and then decreases in size from adolescence through old age.
Compare Lymphatic Capillaries and Blood Capillaries.
-lymphatic capillaries are more permeable than blood capillaries close ended vessels that absorb interstitial fluid- they both have valves
Where do antibodies come from?
From plasma cells----> B Cells
Where do T cells become immunocompetent? Where do B cells become immunocompetent?
T cells - ThymusB Cells- Bone marrow
Compare lymph transport and blood transport.
- Mini flaps open and allow fluid to enter; 3. High permeability allows entrance of fluids, bacteria, viruses, and cancer cells; Accompany blood vessels; Contain more valves than veins do; Lymph fluid propelled by skeletal muscles
What are the symptoms of inflammation?
Redness-->> due to increased blood flowHeat-->> due to inc blood flow and inc metabolic activity within the areaSwelling-->>resulting from inc fluid loss from capillaries into the interstitial spacePain -->> caused be stimulation of pain recp. from compression due to accumulation of interstitial fluid, and chemical irritation by kinins, prostaglandins, and substances released by microbesLoss of function-->> may occur in more severe cases of inflammation due to pain and swelling.
What are the physiological causes of these symptoms?
1) The release of various chemicals. Damaged cells of injured tissue, basophils and mast cells, and infectious organisms release numerous chemicals, including histamine, leukotrienes, prostaglandins, and chemotactic factors. 2) The second step encompasses vascular changes. Released chemicals cause a variety of responses in local blood vessels, including vasodilation, increase in capillary permeability, and stimulation of the capillary endothelium to provide molecules for leukocyte adhesion (cell-adhesion molecules, or CAMs).3)The third step involves the recruitment of leukocytes. Leukocytes make their way from the blood to the infected tissue through the following processes:â¢Margination is the process by which CAMs on leukocytes adhere to CAMs on the endothelial cells of capillaries within the injured tissue. The result is similar to "cellular Velcro." Neutrophils are generally the first to arrive and are short-lived, followed later by the longer-lived macrophages.â¢Diapedesis is the process by which cells exit the blood by "squeezing out" between vessel wall cells, usually in the postcapillary venules, and then migrate to the site of infection.â¢Chemotaxis is migration of cells along a chemical gradient. Chemicals released from damaged cells, dead cells, or invading pathogens diffuse outward and create a chemical gradient that attracts immune cells. Recruited cells also participate in the inflammatory response through the release of specific cytokines, such as granulocyte-macrophage colony-stimulating factor (GM-CSF), that stimulate leukopoiesis. This helps account for the increase in leukocyte count that occurs during an active infection. Macrophages may also release pyrogens, such as interleukin 1 (IL-1), that induce a fever.
What are the different types of T cells?
Helper T cells Cytotoxic T cellsSuppressor
What are the functions of each type of T cell?
-Helper T cells: "help" activate B cells & other immune cells, and because they contain the CD4 plasma membrane protein and also considered CD4+ cells-Cytotoxic T cells: release chemicals that are toxic to cells, resulting in their destruction. Also, because they contain the plasma membrane protein CD8, they are also considered CD8+ cells.
Supressor T cells
Inhibit function of T cells and B cells to prevent them from attacking the body's own good cells-Inhibit function of T cells and B cells- decrease B-cell response after infection is gone and antibodies aren't needed- reduce the humoral response
How do B cells respond to a foreign antigen?
B lymphocytes see and respond to antigens outside of cells, The first stimulation occurs when intact antigen binds to the BCR, and the antigen cross-links BCRs. The stimulated B-lymphocyte engulfs, processes, and presents the antigen to the helper T-lymphocyte that recognizes that antigen.The second stimulation occurs when an activated helper T-lymphocyte releases IL-4 to stimulate the B-lymphocyte.Activation of B-lymphocytes causes the B-lymphocytes to proliferate and differentiate. Most of the activated B-lymphocytes differentiate into plasma cells that produce antibodies, and the remainder become memory B-lymphocytes that are activated upon reexposure of the same antigen. Memory B-lymphocytes differ from plasma cells in some respects: (1) The memory B-lymphocytes retain their BCRs, and (2) memory B-lymphocytes have a much longer life span (months to years) than plasma cells (typically 5 to 7 days). Note that B-lymphocytes can be stimulated by antigen without direct contact between a B-lymphocyte and helper T-lymphocyte under certain conditions. However, the production of memory B-lymphocytes and the various forms of antibodies requires helper T-lymphocyte participation during B-lymphocyte activation.
What is the relationship between air flow, pressure gradients and resistance?
----The pressure gradient (ÎP) is the difference between atmospheric pressure and intrapulmonary pressure (Patm â Palv). It can be changed by altering the volume of the thoracic cavity. The contraction of both the diaphragm and external intercostals during quiet breathing cause small volume changes that allow approximately 500 mL of air to enter into the lungs. The thoracic cavity volume is further increased if accessory muscles of forced inspiration are stimulated, causing a larger decrease in intrapulmonary pressure. ----Airflow into the lungs increases because a steeper pressure gradient is established between atmospheric pressure and intrapulmonary pressure.---Airflow is always opposed by resistance. Resistance includes all the factors that make it more difficult to move air from the atmosphere through the respiratory passageway into the alveoli. Resistance may be altered in three possible ways: (1) a decrease in elasticity of the chest wall and lungs, (2) a change in the bronchiole diameter or the size of the passageway through which air moves, and (3) the collapse of alveoli.
What muscles are involved in inspiration?
DiaphragmExternal Intercostal Muscles
What muscles are involved in expiration?
Internal Intercostal Muscles
dalton's law
the total pressure exerted by a mixture of gases is the sum of the pressures exerted independently by each gas in the mixture
bohr effect
uptake from CO2 from tissues facilitates release of O2
boyle's law
at constant temperature the pressure of a gas varies inversely with its volume (P1V1=P2V2)
all or none rule
all amino acids needed to make a specific protein must be present at the same time and in sufficient quantity to make a protein
henry's law
the amount of gas which dissolves in a liquid is proportional to the partial pressure and solubility of the gas
What is the relationship between pH and HBO2 bonds?
H+ binding to hemoglobin. H+ produced when CO2 enters erythrocytes (carbonic anhydrase reaction) binds to the globin protein in hemoglobin, causing a conformational change in hemoglobin and additional oxygen to be released. This H+-induced decrease in affinity of O2 for hemoglobin is known as the Bohr effect.Examination of the oxygen-hemoglobin saturation curve reveals the effects two of these variables (temperature and pH) have on oxygen release. If temperature decreases, hemoglobin saturation increases. Similar changes in hemoglobin saturation are observed with changes in pH. Factors that bring about a decrease in oxygen affinity to hemoglobin (e.g., increase in temperature, increase in H+) and the additional release of oxygen are said to cause a shift right in the saturation curve. In contrast, the variables that bring about an increase in oxygen affinity to hemoglobin (e.g., decrease in temperature, decrease in H+) result in release of less oxygen and are said to cause a shift left.
Hemoglobin and Oxygen Release.
(a) The most important variable that influences oxygen release from hemoglobin during systemic gas exchange is blood Po2. Other variables cause a conformational change in hemoglobin that increases the release of oxygen, including (b) an increase in temperature; (c) an increase in H+ (referred to as the Bohr effect); (d) the binding of 2,3-BPG; and (e) the binding of carbon dioxide. The influence of temperature and H+ levels (i.e., pH) on the oxygen-hemoglobin saturation curve is shown in figure (b) and figure (c), respectively.
What is the pathway that urine takes from the nephron to being released from the body?
NephronGlomerulusbowmans capsuleproximal convoluted tubuleloop of henledistal convoluted tubulecollecting ductminor calyxmajor calyxrenal pelvisureterbladderurethra urethral oriface
Describe the anatomical location of the kidneys.
kidneys are located alond the posterior abdominal wall, lateral to the vertebral column. Left Kidney-->> between the level of the T12 and L3 vertebraeRight Kidney-->>is about 2 centimeters inferior to the left the to accommodate the size of the liver.
Describe the Location of the Renal Pyramid
Renal Medulla consists of striated, cone-shaped regions called renal pyramids (medullary pyramids), whose peaks, called renal papillae, face inward
Describe the Location of the Renal cortex
outer portion of the kidney between the renal capsule and the renal medulla.-it forms a continuous smooth outer zone with a number of projections (cortical columns) that extend down between the pyramids-contains the renal corpuscles and the renal tubules except for parts of the loop of Henle which descend into the renal medulla-contains blood vessels and cortical collecting ducts
Describe the location of the renal medulla,
Innermost part of the kidney -lies adjacent to the renal cortex. -consists of striated, cone-shaped regions called renal pyramids (medullary pyramids), whose peaks, called renal papillae, face inward-the unstriated regions between the renal pyramids are called renal columns
renal corpuscle
(the capsule that contains Bowman's capsule and a glomerulus at the expanded end of a nephron)
describe the location of the juxtamedullary nephron
(nephrons with well-developed loops of Henle that extend deeply into the renal medulla and have vasa recta)
describe the location of the Renal Pelvis
a structure shaped like a funnel in the outlet of the kidney into which urine is discharged before passing into the ureter
What are the two types of nephrons? How do they differ in function?
Cotrical nephronsare oriented with their renal corpuscle near the peripheral edge of the cortex and have a relatively short nephron look that barely penetrates the medulla. thus, the bulk of a cortical nephron resides within the cortex. approximately 85% of nephrons are cortical nephrons.Juxtamedullary nephronsthe remaining 15% of nephrons are juxtamedullary nephrons. their renal corpuscles lie adjacent to the corticomedullary junction, and they have relatively long nephron loops that extend deep into the medulla. juxtamedullary nephrons are important in establishing a salt concentration gradient within the interstitial space that lies outside of the nephron loop, the collecting tubules, and the collecting ducts allowing for the regulation of urine concentration by antidiuretic hormone (ADH).
What is the sequence of blood flow from the renal pelvis to the glomerulus through the vasa recta?
Renal Aretey---> Segmental Arteries-------> Interlobar Arteries --------> Arcuate Arteries -------> Interlobular Arteries---------> Afferent Arteriole------> Glomerular Capillaries------> Efferent Arterioles -------> Peritubular Capillaries-------> Interlobular Veins------> Arcuate Veins-----> Interlobar Veins----> Renal Vein
What are the characteristics of the filtration membrane? How does this membrane impact filtration rates?
a porous, thin, and negatively charged structure that is formed by the glomerulus and visceral layer of the glomerular capsule. it is composed of three sandwiched layers. for a substance in the blood to become part of the filtrate, it must be able to pass through these three layers of the "filter", from innermost (closest to the lumen) to outermost:1.endothelium of glomerulus2. basement membrane of glomerulus3. visceral layer of glomerular capsule.
How do changes in the systemic blood pressure impact the GFR?
Renal auto regulation maintains GFR by altering the size of the afferent artieriole in resp to changes in systemic bp.-the afferent arteriole vasoconstricts if sys. bp increases-vasodilates if sys. bp decreases
What is ANP? What is the function of ANP?
Atrial Natriuretic peptide(ANP) inhibits both the reabsorption of Na+ in the proximal convoluted tubule and collecting tubules and the release of aldosterone. consequently, more Na+ and water are excreted in urine. Recall that ANP increases GFR, a process that also increases urine output.
Where does tubular reabsorption occur? What is reabsorbed?
Proximal convoluted tubule.NA-->actively transported out of the tubule fluid and into the bloodglucose and a.a passively transported out of the tubule fluid by Na cotransport mechanismsCl, Phosphate, and bicarbonate -->passively move into blood because of an imbalance in electrical charge Water--> movement of Na and Cl into blood causes a osmotic imbalance, moving water passively into bloodUrea-->Approx half of urea passively moves out of the tubule with the remaining urea moving on to the Henle loop
What are the two major body fluid compartments? What percent of fluid is located in each compartment?
1- Extracellular Fluid 1/32- Intracellular Fluid 2/3
Intracellular Fluid
the fluid within our cells. The majority (approximately two-thirds) of the total fluid is within our cells. the barrier enclosing this fluid is the plasma membrane. the selectively permeable plasma membrane allows some, but not all, substances through it.
extracellular fluid
the fluid out side of the cell. Extracellular fluid includes both interstitial fluid and blood plasma. (984)
What portion of the body fluid does plasma form? Which of the two major body fluid compartments contains plasma?
1/3Extracellular Fluid
Compare the components of the fluid found in the two major body fluid compartments.
Intracellular fluid is the most distinct compartment; it contains more potassium (K+) and magnesium (Mg2+) cations, phosphate anion (PO4^3-), and negatively charged proteins than the extracellular fluid. (984)the two fluids composing the extracellular fluid-interstitial fluid and blood plasma- are both comically distinct from intracellular fluid and similar in chemical composition to one another. Both interstitial fluid and blood plasma have a high concentration of these ions: sodium (Na+) and calcium (Ca2+) cations, and both chloride (Cl-) and bicarbonate (HCO3-) anions. interstitial fluid and blood plasma exhibit one significant difference-namely, that protein is present in blood plasma, but very little protein is within the interstitial fluid. the similarity in ionic composition and the difference in protein composition reflect the relative permeability of the capillary wall: proteins are generally too large to move out of the blood through the openings in the capillary wall to enter the interstitial fluid, whereas fluids and ions move freely. During capillary exchange. blood plasma and all of its dissolved substances- except for most proteins- are filtered to become part of the interstitial fluid.
How does renal function impact body fluid volume? How would abnormal renal activity impact body fluid volume?
The higher pressure in the blood pushes more plasma out of the capillaries and into the glomerulus. The kidney maintains has to maintain the glomerulus filteration rate (blood filteration per minute). Higher bp results in the stretching of afferent arterioles which causes the glomerulus capillaries to constrict. Resulting in unchanged blood flow. Alcohol and caffeine inhibit the formation of Antiduiretic/ vasopressin harmones, which is secreted by the posterior pituitary gland to help the body retain water and stay hydrated. cell membranes are generally not that permeable to water but in the parts of the nephron that reabsorbed water like the descending limb of the loop of Henle water has to move easily through cells from the filtrate into the blood. This is possible because of special proteinchannels and the membranes called aquaporins, that are both on the apical or filtrate facing side and the basal or capillary facing side of the cells. Bycontrast the cells in the collecting duct only have aquaporins on the basal side so not a lot of reabsorption takesplace. ADH triggers those cells to move aquaporins, they havein storage over to the apical side which allows more water to leave the urine and since caffeine and alcohol inhibit ADH that means no moving aquaporins whichmeans very little water reabsorption and ultimately tons of peeing and dehydration.Lots of factors affect the production of urine but onceit's produced it doesn't just leave and has to be moved and storeduntil the time is right.
How does diabetes mellitus impact body fluid volume?
causes excessive urine output
What regulates thirst sensations?
timuli for activating the thirst center, which occurs when fluid intake is less than fluid output, includes:-decreased salivary secretion -increased blood osmolarity -decreased blood pressure
What impact does ADH have on the blood pressure?
Raises blood pressureADH is rleased in response to various stimuli, including angiotensionII, low blood vol, and high blood osmolarity. The effect of ADH on target organs is to raise blood vol, and blood press., and dec blood osmolarity to within homeostatic limits.
What organs are components of the GI tract? What organs are accessory organs for the GI tract? What are the general functions of these organs?
Oral Cavity-->>mechanical digestionPharnyx-->>bolus is moved here, mucus secreted by saliva helps with swallowingEsophagus-->> transportation to the stomachStomach-->> bolus is mixed with gastric secretions. Results in Chyme. Small In -->>(duodenum, jejunum, and ileum) receives chyme from stomach, chemical digestion and absorption occurs here!ACCESSORY ORGANS (liver, gallbladder, pancreas) secretions like bile and pancreatic juice. bile produced by liver released by GB . Pancreatic juice has many enzymes to help break down food.Large In-->>cont absorption mostly water, electrolytes and vitamins. Anus
What is the route for substances that move from the GI tract into the blood supply?
Villi in the Jejunum and ilium.Absorption is the process by which the end products of digestion are taken into bloodstream. It is carried out by passive active or facilitated transport mechanism. Diffusion monosaccharides like glucose amino acids of electrolytes like CL - are absorbed by simple diffusion.The passage of these substances into the blood depends upon the concentration gradients. Facilitated transport fructose and amino acids are absorbed with the help of carrier ions like Sodium, this mechanism is called facilitated transport. Active transport occurs against the concentration gradient and hence requires energy various nutrients like amino acids monosaccharides like glucose and electrolytes like Sodium are absorbed into the blood by this mechanism. Fatty acids and glycerol being insoluble cannot be absorbed into the blood they are incorporated into small droplets called micelles which move into the intestinal mucosa, they are reformed into very small protein coated fat globules call kilo microns which are transported into the lymph vessels in the villi. These new vessels ultimately release the absorbed substances into the bloodstream the absorbed substances finally reach the tissues which utilize them for their activities this process is called assimilation.
Compare absorption of amino acids to large lipid molecules.
Amino Acid/ Proteins - Enzymes used are Pepsin, peptidase, and trypsin. Pepsin in its non active form pepsinogen is present in the stomach. As soon as food comes in cells secrete hydrochloric acid. Pepsin = Hydrochloric Acid + pepsinogen. Peptidase and trypsin on the other hand come from the pancreatic juice and act in the duodenum. These enzymes digests protein from a long polypeptide into its simplest monomers which is the Amino Acid. Polypeptides are a chain of Amino acids held together by Peptide bonds. The amino acids will go into the Villi's Capillaries and then will be carried by blood to the hepatic portal vein. Hepatic portal vein goes straight to the liver where the protein will then be made into something else. The process is like breaking apart a pearl necklace and then building it back again. Uses - Structural (connective fibers, muscle proteins), Functional ( hemoglobin to carry Oxygen inside our blood), Antobodies (to fight off infection), enzyme, receptor, ATP, etc. Lipid Molecules - Are hydrophobic (water fearing). Bile is produced by the liver and stored by the gall bladder. Bile helps break down fat into smaller pieces with greater surface area. Which is known as Emulsification lipids and fats by Bile. Lipase helps helps in the digestion of lipids. Lipase is secreted by the pancreas (pancreatic juice) and performs its action in the duodenum. Fat is broken down into Glycerol and 3 fatty acids. Goes to two parts of the Villi - Lacteal (carried away into lymph) transport fatty acid and glycerol travels in the capillary bed to the hepatic portal vein (blood). When the reach the liver the lipids molecules are metabolized into Acidic Acid (most basic form). Uses Cell Membrane, myelin Sheath, Insulation/ cushion (subcutaneous fats), ATP.
What enzymes are found in saliva and pancreatic juice? What do these enzymes act upon?
Amylase digestive enzyme that breaks down starch (mostly amylose) and glycogen into oligosaccharides and glucose; found in saliva (salivary amylase) and pancreatic juice (pancreatic amylase)
What are the layers of the GI tract?
deep to superficial MucosaSubmucosaMuscularis ExternaSerosa (visceral periotneum)
What are the different secretory cells in the gastric glands? What do these different cells secrete?
mucus cellschief cells (peptic) ---pepsinogin--->digestive enxymesparietal cells (oxyntic)----Intrinsic Factor
Define villi and their function.
two inner layers of the mucosa into folds to form small fingerlike projections of the mucosa called villi. Villi are larger and most numerous in the jejunum. Each villus contains an arteriole, a rich capillary network, and a venule. The capillaries absorb most nutrients.
Where does carbohydrate, lipid and protein digestion occur?
Carbohydrate: Oral Cavity and Small Intestine Lipid: Stomach and Small IntestineProtein: Stomach and Small Intestine
How is pepsin activated?
Pepsin is formed from pepsinogen, an inactive precursor released by chief cells. Hydrochloric acid that is released from parietal cells causes a low pH within the stomach that both activates pepsinogen to pepsin and denatures proteins to facilitate their chemical breakdown
What are the different types of carbohydrates? What are the different types of lipids? What are the different categories of amino acids?
Carbohydrates: sugar, starch, fibersLipids: Triglycerides, CholesterolAmino Acids: Complete and Incomplete Proteins
List the vitamins and general function of each.
Water-soluble vitamins dissolve in water: They include both the B vitamins and vitamin C. These vitamins are easily absorbed into the blood from the digestive tract. B vitamins serve as coenzymes in various enzymatic chemical reactions. Vitamin C (or ascorbic acid) is required for the synthesis of collagen, which is an important protein in connective tissue.Fat-soluble vitamins dissolve in fat (not in water) and include vitamins A, D, E, and K. They are absorbed from the gastrointestinal tract within the lipid of micelles and ultimately enter into the lymphatic capillaries.-Vitamin A (retinol) is a precursor molecule for the formation of the visual pigment retinal.-Vitamin D (calciferol) is modified to form calcitriol: This is a hormone that increases calcium absorption from the gastrointestinal tract.-Vitamin E (tocopherol) helps stabilize and prevent damage to cell membranes -Vitamin K is required for synthesis of specific blood clotting proteins.
What are major vs trace minerals? Know examples of each.
Major Minerals: which are needed at levels greater than 100 milligrams (mg) per day (calcium, chloride, magnesium, phosphorus, potassium, sodium, and sulfur)Trace Minerals: which are required at less than 100 mg per day. (chromium, cobalt, copper, fluoride, iodine, iron, manganese, molybdenum, selenium, and zinc)
What is the metabolic rate?
The metabolic rate is the measure of energy used in a given period of time. There are two means of expressing metabolic rate: basal metabolic rate and total metabolic rate.Basal metabolic rate (BMR) is the amount of energy required when an individual is at rest (and not eating).Total metabolic rate (TMR) is the amount of energy used by the body, including energy needed for physical activity.
What are the characteristics/functions of gonads?
Both reproductive systems have elements in common, including the general processes that produce the gametes, the production of hormones, and the maturation of reproductive capability:Both females and males have primary reproductive organs called gonads: These are ovaries in females and testes in males. The gonads produce sex cells called gametes, which unite at fertilization to initiate the formation of a new individual.The gonads also produce relatively large amounts of sex hormones, which affect maturation, development, and changes in the activity of the reproductive system organs.Both sexes also exhibit accessory reproductive organs, including ducts to carry gametes away from the gonads toward the site of fertilization (in females) or to the outside of the body (in males).
What is spermatogenesis?
Spermatogenesis is the process of sperm development that occurs within the seminiferous tubule of the testis. Spermatogenesis does not begin until puberty, when significant levels of FSH and LH stimulate the testis to begin gamete development.The process of spermatogenesis: All sperm develop from primordial germ (stem) cells called spermatogonia. Spermatogonia are diploid cells (meaning they have 23 pairs of chromosomes for a total of 46). These cells lie near the base of the seminiferous tubule, surrounded by the cytoplasm of a sustentacular cell. To produce sperm, spermatogonia first divide by mitosis.
stages of spermatogenesis
1. Spermatogonia2. Primary spermatocyte3. Secondary spermatocyte4. Spermatid5. Spermatozoapg 1135 mcgraw
How is Chromosome number maintained within a species?
Meiosis is the reason why our chromosome number is kept constant. Upon gamete formation in parental organisms, meiosis occurs. And our chromosome number 46(2n) reduces to 23(n).Then upon fertilization, a male gamete with 23 chromosomes and female gamete with 23 chromosomes fuse together and form zygote of 46 chromosomes. So the total number is constant.
What is the function of meiosis?
Meiosis is sex cell division that starts off with a diploid parent cell and produces haploid daughter cells called gametes. Mitosis and meiosis (sex cell division) differ in the following ways:- Mitosis produces two daughter cells that are genetically identical to the parent cell. In contrast, meiosis produces four daughter cells that are genetically different from the parent cell.- Mitosis produces daughter cells that are diploid, whereas meiosis produces daughter cells that are haploid. - Meiosis includes a process called crossing over, whereby genetic material is exchanged between homologous chromosomes.
What is the ovarian cycle?
series of events in the ovaries that occur during and after the maturation of an oocyte.When a female reaches puberty, the hypothalamus increases its release of gonadotropin-releasing hormone (GnRH). GnRH stimulates the anterior pituitary to release follicle-stimulating hormone (FSH) and luteinizing hormone (LH). The levels of FSH and LH vary in a cyclical pattern and help produce a monthly sequence of events in follicle development called the ovarian cycle. The three phases of the ovarian cycle are the follicular phase, ovulation, and the luteal phase
What are the phases of this ovarian cycle? diagram
pg 1116 mcgraw hill AnP2
What are the phases of this ovarian cycle?
pg 1117 mcgraw AnP 2
What triggers ovulation?
LH surgeFollicle-stimulating hormone (FSH) stimulates development of ovarian follicles during the follicular phase of the ovarian cycle. Estrogen (secreted from ovarian follicles) stimulates the proliferative phase in the uterine cycle, whereas a peak in luteinizing hormone (LH) promotes ovulation and the development of the corpus luteum, which produces both progesterone and estrogen to promote uterine lining growth.Long answer:Ovulation occurs on day 14 of a 28-day ovarian cycle and is defined as the release of the secondary oocyte from a mature follicle. Typically, only one ovary ovulates each month. Ovulation is induced only when there is a peak in LH secretion. As the time of ovulation approaches, the granulosa cells of the mature follicle increase their rate of fluid secretion into the antrum, forming a larger antrum and causing further swelling within the follicle. The edge of the follicle that continues to expand at the ovarian surface becomes quite thin and eventually ruptures, expelling the secondary oocyte.
What is the myometrium?
smooth muscle wall underlying the endometrium.The myometrium is the thick, middle tunic of the uterine wall formed from three intertwining layers of smooth muscle.
What is the endometrium?
inner lining of the uterus.The innermost tunic of the uterus, called the endometrium, is an intricate mucosa composed of a simple columnar epithelium and an underlying lamina propria. The lamina propria is filled with compound tubular glands (also called uterine glands), which enlarge during the uterine cycle.
70. How do estrogen levels vary during the ovarian and uterine cycles? How do progesterone levels vary during the ovarian and uterine cycles?/ Regulation of the Ovarian Cycle in Depth
A stepwise description of these hormonal effects in the ovarian cycle are listed here and shown in:1) The hypothalamus initiates the ovarian cycle by secreting GnRH, which stimulates the anterior pituitary to secrete FSH and LH.2) FSH and LH target the ovaries and help stimulate follicular development. Along with molecular signals from the oocyte and follicle cells, FSH and LH cause maturation of follicles, as described earlier, and both hormones also affect the ovarian follicle's secretion of other hormones.3) The maturing ovarian follicles secrete inhibin and estrogen. These hormones have a negative feedback effect on the hypothalamus and anterior pituitary. Specifically, inhibin helps inhibit FSH release by the anterior pituitary; low levels of estrogen inhibit production of GnRH, FSH, and LH.4) Estrogen also assists with the development of the dominant (mature) ovarian follicle. An antral follicle matures into a mature follicle under the influence of estrogen.5) The mature follicle, once it develops, produces a larger threshold amount of estrogen. Paradoxically, higher levels of estrogen have a stimulatory effect on the hypothalamus and anterior pituitary, and thus a positive feedback loop is initiated.6) The positive feedback loop results in an LH surge from the anterior pituitary, which induces ovulation. Without this surge in LH, the mature follicle would not ovulate (expel its secondary oocyte). Most oral contraceptives regulate estrogen and progesterone levels, which in turn prevent this LH surge. Estrogen levels decline slightly right after ovulation, presumably because ovulation damaged some of the estrogen-secreting granulosa cells in the mature follicle.7) A corpus luteum forms from the ovulated follicle. After ovulation, LH induces the remaining granulosa cells in the ovary to develop into the corpus luteumâhence the name "luteinizing."8) The corpus luteum secretes large amounts of progesterone, estrogen, and inhibin. This combination inhibits both the hypothalamus and anterior pituitary and builds the uterine lining. The corpus luteum degenerates in 10 to 13 days (if the oocyte is not fertilized), which results in decreases in some hormone levels.9) The ovarian cycle repeats. Unless the oocyte is fertilized, the negative feedback events described in step 8 serve to reduce LH levels, resulting in the degeneration of the corpus luteum. Consequently, the levels of progesterone, estrogen, and inhibin drop, and the hypothalamus again is able to secrete GnRH to initiate the cycle.In short
Regulation of the Ovarian Cycle in Depth
The ovarian cycle is initiated when the hypothalamus secretes gonadotropin-releasing hormone (GnRH), which stimulates the anterior pituitary to secrete follicle-stimulating hormone (FSH) and luteinizing hormone (LH). The cascade of events that occur during the cycle is illustrated.
What is the function of the interstitial cells?
Function of the interstitial cells in Testes - produce testosterone, which acts on sustentacular cells and promotes spermatogenesis. The spaces surrounding the seminiferous tubules are called interstitial spaces. Within these spaces reside the interstitial cells (or Leydig cells). Luteinizing hormone stimulates the interstitial cells to produce hormones called androgens. There are several types of androgens; the most common one is testosterone. Although the adrenal cortex secretes a small amount of androgens in both sexes, the vast majority of androgen release is via the interstitial cells in the testis in males, beginning at puberty.