Diges, Bld, Exo, End

Description:	Histology Questions Digestive, Blood, Exo and Endocrine Glands
Category:	Histology
Created by:	Fleurdelis on 2009-04-19

Question	Answer
What is the overall function of the digest system?	Converts food into raw materials that help build and fuel our body's cells.
What are the two essential ingredients involved in metabolism?	1. Oxygen2. Organic Molecules
What are the components of the digestive system?	1. Alimentary Canal2. Accessory Organs (teeth, tongue, gallbladder, liver, salivary glands, pancreas)
List and describe the four basic layers of the alimentary canal.	1. Mucosa 2. Submucosa 3. Muscularis Externa4. Serosa
Mucosa	The epithelium that lines the alimentary canal, the deeper loose connective tissue called lamina propria, and the muscularis mucosae that surrounds the CT.
Submucosa	Dense, irregular fibroelastic CT surrounding the mucosa.
Muscularis Externa	Surrounds the submucosa. Thick muscular layer that is responsible for peristalsis. Smooth muscle.
Serosa	Surrounds muscularis externa and is made up of thin connective tissue.
List and describe six essential activities involved in digestion.	1. Ingestion 2. Propulsion 3. Mechanical Digestion 4. Chemical Digestion 5. Absorption 6. Defacation
Ingestion	Taking food into the digestive tract, usually via the mouth.
Propulsion	Process that moves food through the alimentary canal, includes swallowing and peristalsis.
Mechanical Digestion	Phsyically prepares food for chemical digestion by enzymes.
Chemical Digestion	Process in which food molecules are broken down into their monomers by enzymes secreted into the alimentary canal. Begins in the mouth and ends in the small intestines.
Absorption	When digested products pass from the GI tract to the blood and lymph system through active or passive transport. Most absorption takes place in the small intestines.
Defacation	Elimination of indigestable substances by the body via the anus in the form of feces.
What are the specific types of mucosa in the oral cavity?	1. masticatory mucosa 2. lining mucosa 3. specialized mucosa.
What are the three regions of the lips?	1. skin aspect 2. vermillion zone 3. mucous aspect
Dentin	Forms the bulk of the tooth; composed of 70% calcium hydroxyapatite and is the second hardest substance in the body.
Enamel	Overlies the dentin of the crown; composed of 96% calcium hydroxyapatite and is the hardest substance in the body.
Cementum	Overlies the dentin of the roots; composed of about 50% calcium hydroxyapatite and 50% organic matrix and bound water. It is approximately as hard as bone.
Periodontal Ligament	Holds teeth in the alveolus.
Alveolus	Bony socket in which the tooth is suspended via the periodontal ligament.
Gingiva	Gums
Where is the palate located and what composes it?	Separates the oral cavity from the nasal cavity and is composed of ulva and hard and soft palates.
What is the difference between lingual papillae and the taste buds?	The liqual papillae are located on the anterior portion of the tongue and the taste buds are located on the posterior portion of the tongue.
What are the taste sensations?	Sweet, salty, bitter, sour, umami.
What are the three mucosal layers of the esophagus?	1. epithelium 2. lamina propria 3. muscularis mucosa
Hiatal Hernia	The low pH of the gastric juice causes changes in the epithelium of the esophagus due to reflux.
Barrett's Syndrome	Constant reflux can cause a premalignant condition in which the stratified squamous epithelium changes to simple columnar.
What is Ghrelin?	Hormone that induces hunger sensation and modulates relaxtion of stomach muscles.
What is so damn special about the mucosal epithelium of the stomach?	Prevents stomach from autodigestion.
List the 6 cell types of the lamina propria.	1. Surface cells 2. Mucous neck cells 3. Regenerative cells 4. Parietal cells 5. Chief cells (zymogenic cells) 6. DNES
What is gastic juice?	water, HCL, enzymes, and mucous
What are the 3 phases of gastric production?	Cephalic (caused by psychological factors), Gastric (happens when food is introduced to the stomach), and Intestinal (secretion due to presence of food in sm. intestine.
What are the regions of the small intestine?	Duodenum, jejunum, ileum.
What are the modifications found in these regions?	Pilicae circularis, villi, microvilli.
What are the surface absorbtive cells?	Tall cells that function in absorbtion of water and nutrients. Goblet Cells (mucous), DNES cells (paracrine and endocrine hormones), and M cells (phagocytic).
What are the parts of colon?	Secum, colon, rectum, anus.
How do epithelial cells form glands?	They leave the surface where they developed and penetrate into the underlying CT, these cells manufacture a basal lamina around themselves.
What are the two major groups of glands?	Endocrine (ductless) and Exocrine (ducts).
What are the methods of classifying exocrine glands?	1. Nature of scretion 2. Mode of secretion 3. Number of cells.
Mucous Glands	Produced by goblet cells. Certain salivary glands are mucous glands.
Serous Glands	Enzyme rich, watery fluid. Pancreas.
Mucous Mixed	Mucous and serous secretions.
What are the three methods of exocrine secretion?	1. Merocrin 2. Apocrine 3. Holocrine
Merocrine	Products are secreted via exocytosis.
Apocrine	Apical portion of the cell pinches off and is secreted.
Holocrine	Whole cell is secreted, disinegrates.
What are unicellular exocrine glands?	The simplest form of exocrine glands. Ex: Goblet Cell
What are multicellular exocrine glands?	Organized clusters of secretory cells. Simple: ducts do not branch. Compound: Ducts branch.
What are hormones?	Chemical messengers that are produced by the endocrine glands and are delivered by the blood to target cells.
How are hormones classified?	1. Protein - water soluable. 2. Protein based - mostly water soluable. 3. Steroid - Mostly lipid soluable.
What are the types of hormone receptors?	Membrane receptors and Intracellular receptors.
Where is the pituitary gland located?	Sits on the sella turcica of the sphenoid bone below the hypothalamus.
How is the pituitary gland divided?	1. Anterior Pituitary (Adenohypophysis) 2. Posterior Pituitary (Neurohypophysis)
What is the relationship of the hypothalamus and anterior pituitary?	The anterior pituitary is controlled by the hypothalamus.
What are the hormones of the anterior pituitary?	1. ACTH 2. TSH 3.FSH 4.LH 5.PRL 6.GH
ACTH	adrenocorticotropic hormone
TSH	thyroid stimulating hormone
FSH	follicle stimulating hormone
LH	luteinizing hormone
PRL	prolactin
GH	growth hormone or somatotropin
ACTH target	Adrenal cortex
TSH target	thyroid
FSH target	gonads
LH target	gonads
PRL target	mammary glands
GH target	bone, muscles, adipose tissue
Where are the adrenal glands located?	On the superior poles of the kidneys.
What are the hormones of the adrenal cortex?	1. Mineralocorticoids 3. Glucocorticoids 3. Androgens
Addison's Disease	Decreased secretion of ACTH and results in death if not treated by steroids.
Cushing's Disease	Small tumors in the anterior pituitary that lead to an increase of an output of ACTH = the overproduction of cortisol.
Where is the thyroid gland located?	Anterior portion of the neck.
What are the two types of thyroid cells?	Follicular and Parafollicular Cells.
Follicular Produces:	T3 and T4
Parafollicular Produces:	Calcitonin
What is the importance of T3 and T4?	They regulate the metabolism of carbohydrates, proteins, and lipids. They are also required for normal maturation of the nervous system.
What does a deficiency of thyroid hormone cause?	Hypothyroidism - Myxedema in adulthood and Cretenism in infancy.
What does an excess of thyroid hormone cause?	Graves' Disease
What does Iodine have to do with T3 and T4 production?	Iodine regulates the synthesis of T3 and T4?
What is a goiter?	Enlargement of the thyroid gland, due to insufficient intake of iodine.
Dicuss the effect of FSH and LH on the gonads.	LH causes secretion of sex steroids in both sexes and FSH stimulates the maturation of ovarian follicles and increases sperm production.
What affect does prolactin have on the mammary glands?	Promotes development of mammary glands during pregnancy and stimulates milk production after birth.
Oxytocin vs. Prolactin	Prolactin stimulates the milk production and oxytocin aids in ejection.
What tissues/organs does GH target?	Bone, muscles, and adipose.
Gigantism	Excessive GH causing extensive growth of long bones during childhood.
Acromegaly	Excessive GH causes extensive growth of body parts that never stop growing in adults like hands, feet, nose, chin, ears.
What happens with deficiency of GH?	Growth failure.
What are the hormones of the posterior pituitary?	Oxytocin and ADH
What are the targets for oxytocin and ADH?	Oxytocin targets the cervix and mammary glands. ADH targets the collecting tubules of the kidneys.
What are the functions of the blood?	Transport of dissolved gases, nutrients, and hormones. Maintain body temperature.
How is blood classified?	Specialized connective tissue that is bright to dark red, viscous, slightly alkaline, and accounts for 7% of total body weight.
What are the two major components of blood?	Plasma and formed elements.
What are the three types of formed elements?	RBCs, WBCs, and Platelets.
What are the three types of plasma proteins?	Albumins - 60%, Globulins - 35%, Fibrinogens - 4%.
Where are most of the plamsa proteins produced?	Liver.
What is hematopoiesis?	The formation of all blood cells.
What is hemoglobin?	A large protein composed of four polypeptide chains each of which is covalently bound to a heme group.
What is hematocrit?	The total red blood cell volume.
How is hematocrit used to detect problems?	Increases with dehydration because plasma levels decrease. Decreases with internal bleeding.
Explain the functions of the unusual shape of RBCs.	1. Increase surface area. 2. Flexible. 3. Stack neatly.
Why can't RBC undergo cell division and why do they have a short life span?	Because they have no nucleus and no mitochondria.
Why would it be a negative thing for RBCs to contain mitochondria?	Because the mitochondria would use the oxygen to produce ATP.
What makes up a molecule of hemoglobin?	2 alpha chains, 2 beta chains, and 4 HPC's (heme groups)
How many molecules of hemoglobin are found in a single RBC?	280 million in each RBC.
What is the role of heme?	Critical in the transportation of oxygen because the iron in heme binds to the oxygen to transport it.
What happens when heme interacts with oxygen?	Binds to oxygen.
Why must the bond between heme and oxygen be reversible?	So that the RBCs can release oxygen to the body.
What is deoxyhemoglobin?	Hemoglobin without oxygen.
What happens to old red blood cells?	They are phagocytosed and reeassimilated by the body.
What is erythropoiesis?	The formation of RBCs.
Where does erythropoiesus occur?	Bone marrow.
What are the two categories of WBCs?	Granulocytes and Agranulocytes
What is the significance of these categories?	The presence or absence of granules based on how they stain.
What role do WBCs serve?	Form a defense system.
What are the types of WBCs?	Neutrophils, lymphocytes, monocytes, eosinophils, and basophils.
What are antigens?	Any substance that stimulates an immune response by the body.
Where are they located?	On the outside of the cell.
What are antibodies?	Any of a large variety of proteins that are normally present in the body or produced in response to an antigen.
What is agglutination?	What antibodies lock into an antigen and the cell membrane lysis and clumping appears.
Explain the maturation process of RBCs.	Iron gets used up > Biliverdin > Bilirubin > Released into blood stream > Bilirubin binds to albumin > transported to liver for excretion in bile.
How is erythropoiesis regulated?	By production of erythropoietin by the kidneys.
What is erythropoietin?	A glycoprotein secreted by the kidneys that stimulates the production of RBCs.
When is erythropoietin released?	If circulating RBC level is low.
What are the two major effects of releaseing erythropoietin?	Pre curser cells of RBCs are produced.
WBCs vs. RBCs	WBCs - nucleus, bigger, function in immunity, less abundant. RBCs - no nuclei, more abundant, small, supply oxygen.
Leukopenia	Inadequate amout of WBCs.
Leukocytosis	Too many WBCs.
How do you determine a person's blood type?	By what antigens are present: A,B,Rh, or none.