Exam 3
What are the layers in the wall of the alimentary canal (esophagus through large intestine)?
Mucosa Submucosa Muscularis externa Serosa
What type of tissue makes up each layer in the alimentary canal?
Mucosa: innermost layer; made up of epithelium, lamina propria: loose connective tissue, muscularis mucosae (thin layer of smooth muscle) Submucosa: external to mucosa, contains blood and lymphatic vessels, nerve fibers Muscularis externa: external to the submucosa; two layers of smooth muscle (circrular muscularis and longitudinal muscularis) Serosa: outer most layer; simple squamos epithelium and thin connective tissue layer
In salivary glands, what is the function of serous cells and mucous cells? What is the relative abundance of serous and mucous cells in the three types of extrinsic salivary glands?
Mucous cells: secrete mucus Serous cells: secrete other products Parotid: only serous Submandibular: mixed serous and mucous Sublingual: mostly mucous (some serous units)
What cells make up gastric glands in the fundus and body of the stomach? What is the function of each of the cells?
Mucous neck cells: mucus Parietal cells: secrete gastric acid (hyrdrochloric acid) and instrinsic factor (allow absorption of vitamin B12) Chief cells: secrete pepsinogen
Where are the two main nerve plexuses in the wall of the alimentary canal located? What is the function of each plexus?
Myenteric nerve plexus: both parasympathetic and sympathetic- control contractions of muscularis externa Submucosal nerve plexus: both parasympathetic and sympathetic- control localized movement of muscularis mucosa and gland secretion
What is meant by the term capillary bed?
Network of capillaries running through tissues;
What are the three types of granulocytes?
Neutrophils Eosinophils Basophils
What is the function of each type of granulocyte?
Neutrophils- phagocytize bacteria Eosinophils-play role in allergic reactions and parasitic infections Basophils- function in inflammation mediation
What is the abundance of each type of granulocyte?
Neutrophils: most numerous Eosinophils: compose 1-4% of all WBCs Basophils: about 0.5%
When do papillary muscles contract?
Occur during contraction of ventricles
Which cells secrete dentine?
Odontoblasts
Describe oropharynx and laryngopharynx.
Oropharynx: posterior to oral cavity Nasopharynx: posterior to nasal cavity Laryngopharynx: posterior to larynx
What do megakaryocytes produce?
Platelets
What are hepatic sinusoids? How are they organized with respect to their location to the hepatocytes?
Present between the sheets/plates of hepatocytes; blood drains from portal traids through sinusoids toward central vein
What is the difference between red and yellow bone marrow?
Red marrow: actively generates new blood cells Yellow marrow: dormant; contains many fat cells
What are the two main functions of the spleen?
Removal of blood-borne antigens Removal and destruction of old/defective blood cells
What is the type of tissue that supports the developing bone cells in the bone marrow?
Reticular connective tissue
List the different heart valves.
Right AV valve (tricupsid) Left AV valve (mitral) Aortic valve Pulmonary valve
What are the two pacemakers of the heart and where are they located? Which one is the primary pacemaker?
SA node- upper right atrium; primary--sets rate of contraction AV node-between atria and ventricles
What is the type of epithelium found in the small intestine? What is the function of the absorptive cells?
Simple columnar epithelium absorptive cells uptake digested nutrients
What are splenic cords? Are they part of the white pulp or red pulp?
Splenic cords surround sinusoids; part of red pulp
How are the crypts in the large intestine different from the crypts in the small intestine?
Straight rectangular tubes; contain numerous goblet cells that produce mucus to lubricate passage of feces
What is red pulp? Which blood cells are found in the red pulp?
Surrounds white pulp; composed of sinusoids, splenic cords (surround sinusoids), reticular connective tissue, blood cells of all types found, including RBCs, many macrophages
How are T lymphocytes organized in lymphoid tissue?
T cells form clusters with no distinctive morphology
What are the two major classifications of lymphocytes and what do they do?
T cells- attack foreign cells B cells-multiply to become plasma cells and secrete antibodies
Where does stage 2 of T lymphocyte activation occur? Stage 2 for B lymphocyte activation?
T lymphocyte activation occurs in the thymus gland B lymphocyte activation occurs in bone marrow
What is the hormone produced by each of these types of cell?
alpha cells secrete glucagon--increase blood glucose levels beta cells secrete insulin --- decrease blood gluocse levels
Where is lymph returned to the blood circulation?
carry fluid to great veins in neck
Describe the circular folds (plicae circularis) and villi in the small intestine? What are their functions?
circular folds: transverse ridges of mucosa and submucosa villi: finger-like projections of the mucosa; covered with simple columnar epithelium; contain blood vessels and lacteals both modifications for absorption; all increase surface area
What is diapedesis?
circulating leukocytes leave the capillaries by squeezing between endothelial cells
What are chordae tendinae? Where do they attach?
connective tissue strands that connect AV valves to small muscles extending from ventricle walls
What is the function of papillary muscles?
contraction pulls chordae tendinae tight; prevent eversion of AV valves into atria
What is an antigen? How many different antigens can an individual T or B lymphocyte recognize?
recognize specific foreign molecules and produces antibodies; at least one lymphocyte can recognize any possible antigen configuration because there is hundreds of millions of unique lymphocytes
What are intestinal crypts (Crypts of Leiberkuhn)? Where are they located? What do their cells secrete?
epithelial cells secrete "intestinal juice"; watery fluid that mixes with chyme basal cells divide to replace old/defective epithelial cells--push up cells from base of crypts toward tip of villi where old cells slough off located in small intestine
What is lymph and where does it come from?
fluid that circulates throughout the lymphatic system, helps collect unwanted materials for removal from body; collected from loose connective tissue
Describe the organization of a hepatic lobule.
hexagonal shaped collections of hepatocytes; hepatocytes are arranged into plates/sheets; central vein at the center of each lobule; portal triad at each of the sides
Where is the oral cavity?
internal to teeth, contains anterior 2/3 of tongue
What is meant by retroperitoneal?
no mesentery present (lost during embryonic development); behind peritoneum
How is the exocrine portion of the pancreas organized?
numerous compound acinar glands; acini contain secretory cells; small ducts leave each acinus and converge on main pancreatic duct; main pancreatic duct enters duodenum
What are the major functions of the liver, as presented in class?
processing and storage of nutrients; secretion of most plasma proteins (blood coagulation proteins); detoxify/metabolize many toxic substances; digestive function-bile production
What are pre-capillary sphincters?
regulate the flow of blood to tissues
How are bile canaliculi formed? What is their function?
run in between hepatocytes; drain bile toward bile ducts at the triads; formed from fused (tight junctions) plasma membranes of adjacent hepatocytes; bile travels from center of lobule toward periphery
What are goblet cells and what do they secrete? Why are there large numbers in the stomach?
secrete mucus that lubricates chyme
What are enteroendocrine cells? Where are the cells that secrete gastrin located? What is the function of gastrin?
secrete various hormones that influence many digestive processes; scattered along lining of alimentary canal; also present in gastric glands in pyloric region of stomach: gastric glands contain enteroendocrine cells called G cells that secrete the hormone gastrin gastrin stimulates gastric acid secretion
What makes up a portal triad?
segment of hepatic portal veinule segment of arteriole from hepatic artery segment of bile duct
Describe the anatomy of lymph capillaries. What makes them so leaky?
simple squamos endothelium; closed at ends (minivalve flaps open and allow fluid to enter); high permeability allows uptake of tissue fluid
Which type of tissue makes up the muscularis externa of the esophagus? Is it the same throughout the esophagus?
skeletal muscle first third of length; smooth muscle remainder
What is the pathway for exocrine secretions from the pancreas to the duodenum?
small ducts leave each acinus and converge on main pancreatic duct; main pancreatic duct enters duodenum
What is the function of dendritic cells?
specialized macrophages; phagocytose foreign invaders and insert antigens into their membranes
Describe the embryonic gut rotation and how this influences the positions of the adult stomach, small intestine, and large intestine in the abdominal cavity.
stomach rotates right about 90 degrees and tilts slightly upward; part of colon rotates upward (becomes transverse colon); small intestine grows into medial space, surrounded by colon
What type of epithelium is found in the esophagus?
stratified squamos epithelium
Describe the structure of anal columns and anal valves?
Anal columns: mucosa folded into longitudinal and circular ridges; opposing columns line up to close off anal canal Anal valves: circular folds inferior to clumns
Where are large clusters of lymph nodes located, as presented in lecture?
At base of limbs Along descending aorta Along major blood vessels in neck In mediatstinum Along iliac artery in pelvis
What are lymphoid nodules (follicles)? What cell type is found in the nodules? Remember that lymphoid nodules are not the same as lymph nodes.
B cells form distinctive spherical structures in lymphoid tissue=nodules
How can you distinguish between the three types of granulocytes?
Basophils dyed by basic dyes (purple); usually two lobe nucleus Eosinophils dyed by eosin (pink) Neutrophils have nucleus that are multi-lobed (2-6 lobes); appear neutral colored
What is the fauces of the oropharynx? Which tonsils are located in the fauces? Where are the lingual tonsils located?
Beginning of oropharynx, at posterior border of oral cavity; contains the pailatine tonsils; consists of an archway defined by two folds of the mucosa (palatoglossal arch and palatopharyngeal arch)
What are the formed elements of blood?
Blood cells
What forces help propel lymph through the lymph vessels?
Bulging of skeletal muscles Pulsing of nearby arteries Tunica media of the lymph vessels Random movements
What are the different regions of the stomach?
Cardiac: narrow strip around esophageal sphincter Fundus: upper region Body: largest region Pyloric region: continuous with duodenum
What are the different regions of the large intestine?
Cecum Vermiform Appendiz Colon Rectum Anal canal
What are the components of blood?
Contains cellular and liquid components
What are the differences between continuous and fenestrated capillaries?
Continuous: most common Fenestrated: have pores
What is function of cytotoxic T lymphocytes? What is the function of helper T cells?
Cytotoxic T lymphocytes destroy antigen-bearing cells Helper T cells secrete molecules which causes T and B lymphocytes to divide and differentiate to fully active immune cells
What digestive organs are retroperitoneal?
Duodenum Ascending colon Descending colon Rectum Pancreas
Know the structures of teeth—how are enamel, dentine (dentin), pulp, cementum, and periodontal membrane organized and what is the function of each?
Enamel: outer layer of crown and neck; hardest substance in human body Dentine: underlies enamel; bulk of tooth Pulp: connective tissue in center of tooth that contains nerves and blood vessels Cementum: thin layer of bone on outside of root; provides an anchor for thin collagen fibers from periodontal membrane (ligament) on its outside) Periodontal membrane: dense connective tissue layer; anchors tooth in socket via collagen fibers
How are the enteric neurons organized?
Entirely within wall of alimentary canal; part of myenteric and submucosal plexuses; form reflex arcs that control many digestive processes (short sensory neurons, short visceral motor neurons, interneuron-like neurons)
What are the three layers of the heart wall?
Epicardium Myocardium Endocardium
What type of tissue makes up each layer of the heart?
Epicardium: made up of simple squamos epithelium and thin connective tissue Myocardium: consists of cardiac muscle Endocardium: endothelium resting on a layer of loose connective tissue
Name the different blast cells that give rise to erythrocytes, granulocytes, lymphocytes, and megakaryocyte, respectively.
Erythrocytes formed from proerythroblasts Granulocytes formed from myeloblasts Lymphocytes formed from lymphoid stem cells Megakaryocytes formed from megakaryoblasts
What is edema?
Excess tissue fluid
Trace the flow of blood through the liver lobule?
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Trace the flow of blood through the spleen, include the splenic artery, trabecular arteries, central arteries, sinusoids, and veins.
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Trace the flow of lymph through lymph nodes?
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Trace the flow of lymph through the different lymph vessels starting in loose connective tissue and ending with its return to the blood circulation. Include the path for lymph returning from both the left side of the body and the upper right side of the body.
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Trace the flow of venous blood from stomach and intestines to the inferior vena cava.
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Trace the path of bile from hepatocytes to 1) the gallbladder, and 2) to the duodenum?
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What are splenic sinusoids? Are they part of the white pulp or red pulp?
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What are the structures that make up the "big H" on the visceral surface of the liver?
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What causes hemorrhoids?
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What is the function of each heart valve?
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What is the function of the conducting system within the heart? Does it consist of nerves or muscle?
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What are the four routes for small molecules to pass across capillary walls?
1) Direct diffusion--lipid soluble molecules 2) Through intercellular clefts 3) Through fenestrations 4) Through cytoplasmic vesicles--pinocytosis
What is the classification of the glands that make up the exocrine portion?
Acinar glands
What are the basic types of plasma proteins?
Albumin: most abundant; maintain osmotic pressure Globulins: many varieties Firinogen: converted to fibrin- major component of blood clot
What do the cells of the exocrine portion secrete?
zymogen granules secrete stored enzymes
What is the porta hepatis?
"gateway to liver"; where most blood vessels, nerves, and hepatic ducts (bile) enter and leave liver
After final activation by an antigen, B lymphocytes become what cell type? What is the function of these cells?
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Describe the shape and location of the pancreas.
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How does the anatomic structure differ between each valve?
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How is the lymphoid tissue organized within lymph nodes so that it can come into contact with pathogens in lymph?
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Lymph nodes are found along which lymph vessels?
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Trace the circulation of blood through the two shunts that bypass the pulmonary circuit in the fetus.
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Trace the fetal blood circulation pathway.
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Trace the flow of blood through the four chambers of the heart and through the pulmonary and systemic circulations.
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What is the significance of the foramen ovale and ductus arteriosus?
Foramen ovale: hole in interatrial septum; when right atrium contracts, slightly less than 50% of blood goes through foramen ovale into left atrium instead of into right ventricle; blood bypasses lungs Ductus arteriosus: arterial shunt from pulmonary trunk to aorta; blood not going through foramen ovale still bypasses lungs
What are gastric pits? What are gastric glands?
Gastric pits: cup shaped invaginations into mucosa Gastric glands: long tubular gland extend from base of pits
What are germinal centers in the lymphoid nodules?
Germinal centers is the center of the nodule; rapidly proliferating B cells
How can you tell the difference between lymphocytes and granulocytes?
Granulocytes contain enzyme filled vesicles (look like small granules) in cytoplasm Agranulocytes lack vesicles
What are rugae in the stomach? What is their function?
Inner lining of stomach contains numerous longitudinal folds; allow for expansion of stomach to hold about a gallon, they disappear when wall of stomach is stretched
What is the difference between intrinsic and extrinsic salivary glands? List the three pairs of extrinsic salivary glands?
Intrinsic glands continually secrete and moisten oral cavity 3 pairs of extrinsic glands: Parotid Submandibular Sublingual glands
What three lymph trunks empty into the thoracic duct in the neck? Which lymph vessels empty into the right lymph duct in the neck, if present?
Left jugular, Left subclavian, and Left bronchomediastinoal ; right subclavian vein
How is lymphoid tissue organized, i.e., what type of tissue supports the immune cells?
Loose connective tissue; reticular fibers support cells
What are the different lymph vessels that carry the lymph?
Lymph capillaries Lymphatic collecting vessels Lymph trunks Lymph ducts
What is meant by MALT, including GALT and BALT, with respect to the immune system?
MALT: mucosa-assoicated lymphoid tissue GALT: gut associated lymphoid tissue BALT: bronchus associated lymphoid tissue
What is white pulp and what is its function?
Thick sleeves of lymphoid tissue; surrounds central arteries
What are the three tunics in wall of blood vessels? What type of tissue makes up each tunic?
Tunica intima made up of simple squamos epithelium (endothelium) Tunica media made up of smooth muscle (collagen and elastin) Tunica externa made up of connective tissue
What is the function of umbilical artery, umbilical vein, and ductus venosum?
Umbilical arteries provide oxygen poor blood to placenta Umbilical vein: oxygen-rich blood from placenta Ductus venosum: most blood bypasses liver and enters inferior vena cava
Compare the differences in the structure of arteries and veins of the same relative size.
Veins: thinner walls; larger lumen/vessel size ratio; thicker tunica externa Arteries: thicker tunica media; smaller lumen/vessel size ratio; more smooth muscle and/or elastin
Are villi present in the large intestine?
Villi are absent
What are sinusoids?
Wide, leaky capillaries found in some organs; intercellular clefts are wide open; usually fenestrated; occur in bone marrow and spleen
What are the two types of cells involved with nutrient regulation found in the islets?
a (alpha) cells b (beta) cells
What is a mesentery? What is their function?
a double layer of peritoneum; holds organs in place, attaches to dorsal and ventral abdominal wall; sites of fat storage; provides a route for circulatory vessels and nerves
Where are microvilli found? What is their function?
apical surface of absorptive cells; further increase surface area for absorption
Where are the central veins located?
at center of each lobule
Where is the vestibule of the mouth?
between cheek and teeth
What are islets of Langerhans?
endocrine cells located in small clusters located throughout pancreas
What type of epithelium is found inside the mouth, oropharynx, and laryngopharynx?
lined with stratified squamos epithelium
What are lacteals and where are they found?
lymphatic capillaries found on the villi of the small intestine
What is the function of the pyloric sphincter?
thick band of smooth muscle in the pyloric region in the stomach to move food through to small intestine
Which blood vessels make up the hepatic portal system? What is the definition of a portal system in the circulation?
two different capillary beds in series that picks up digested nutrients and deliver nutrients to the liver for processing; contains splenic vein, superior mesenteric vein, and inferior mesenteric vein