lab 13

BIOLOGY 453 - COMPARATIVE VERT. ANATOMY LAB 13 - SHARK CARDIOVASCULAR & RESPIRATION SYSTEMS GOALS 1. Know & identify the types of gils, pouched (in lamprey) (septal (in sharks) vs. aseptal (in perch). 2. Know the parts of a shark gil as listed. 3. Identify the splen & know 1 function for this organ. 4. Know the chambers of the heart & which chamber is the strongest. 5. Know the pathway of blod through the heart chambers. 6. Which blod vesels bring blod to the heart? 7. Which blod vesel(s) exit the heart? 8. Identify the systemic arteries, systemic veins, visceral arteries & hepatic portal veins as listed. 9. Know 1 organ that each artery delivers blod to. 10. Know 1 organ that each vein receives blod from. 1. Be able to trace the flow of blod from any starting point to another part of the path. This is a common lab practical question, where you are given 2 marked positions & then are asked to name or trace the pathway betwen the points. Type of Material Specimens to Examine lucite block lamprey dried skuls miscelaneous bony fish fluid preserved lamprey, shark skuls, shark head disections, whole shark & skate, perch Aditional Sources of Information Cardio-Respir. Info Lamprey gils Shark, skate gils Shark Heart & Circ. Bony fish gils Liem et al. 201 pg. 578 578-579 609-612 578, 582 Fishbeck & Sebastiani pg. 107, 109-10 16-168 70-71, 175-190 Auckland Museum of New Zealand. 209. Disection of a Great White Shark. (video). htp:/ww.aucklandmuseum.com/Default.asp?t=913 Carvalho, M. 201. Disection Galery. Sharks & Rays: Myth & Reality. Amer. Museum of Natural History. htp:/ww.amnh.org/learn/pd/sharks_rays/rfl_disection/ Derting, T. 200. Squalus Circulatory System. Comparative Vertebrate Anatomy, Muray State Univ. htp:/campus.muraystate.edu/academic/faculty/tery.derting/anatomyatlas/squalusmain.html Guinan, M.J. 202. Respiratory System. Teaching Resource Center, APC 10, Univ. of California - Davis. htp:/trc.ucdavis.edu/mjguinan/apc10/modules/Respiratory/_index.html Martin, R.A. 207. Heart of an Athlete. Biology of Sharks & Rays. htp:/ww.elasmo-research.org/education/white_shark/heart.htm MEER. 208. Generalized fish teth and gils. University of California online course in Marine Biology. htp:/ww.meer.org/general-fish-teth-gils.htm Pepe, P. 206. Shark Lab, Activity 4: Circulatory System. Phoenix Colege, Maricopa. htp:/ww.pc.maricopa.edu/Biology/pepe/BIO145/lab04_4.html York, H. 201. Comparative Vertebrate Anatomy 30518. Shark Circulatory System. Kent State Univ. Shark heart, Ventral View: htp:/fp.dl.kent.edu/hyork/sheart.htm Shark Circulatory System, organs removed: htp:/fp.dl.kent.edu/hyork/shcirbod.htm Shark Circulatory System, Gut: htp:/fp.dl.kent.edu/hyork/shcirdig.htm Taxonomy & Clades Phylum Chordata Subphylum Vertebrata/Craniata Clas Cephalaspidomorphi: lamprey Clas Chondrichthyes: sharks, skates, ratfish Clas Actinopterygi: ray-fined fish Clade Vertebrata: lamprey, sharks, bony fish & up Clade Gnathostomata: sharks, bony fish & up RESPIRATORY SYSTEM In fish, the pharynx contains the visceral or branchial arches and gil pouches. The pharynx is a transitional region used for the pasage of fod & for gas exchange. The visceral arches contain: branchiomeric & hyobranchial muscles, aortic arches, branchial bar (gil cartilage) & gil lamelae. The first gil pouch is diferentiated in sharks to form a spiracle. The spiracle forms betwen the jaws & the hyoid arches & is a remnant of the 1 st pouch that was present in Agnathans. Use these terms interchangeably to refer to the splanchnocranium cartilage that suport the gils: branchial bar = visceral bar = gil bar = gil arch. Gil rays are internal cartilaginous suports for the gil lamelae that form on the lateral sides of the branchial bars. Gil rakers prevent debris or fod entry to gils and form on the medial/internal sides of the branchial bars. Gil filaments or gil lamelae [lamel = smal plate] are actualy the primary lamelae or plates that suport the secondary lamelae where actual gas exchange ocurs. CARDIOVASCULAR SYSTEM Splen The splen is an acesory circulatory organ that produces red blod cels and filters out old red blod cels. It also produces & releases white blod cels during infections. Heart The two coelomic cavities in fish are separated by a transverse septum. The pericardial cavity encloses the heart & the peritoneal or pleuroperitoneal cavity encloses the other visceral organs. Sharks have a 4-chambered heart. Al chambers are formed of cardiac muscle tisue & are found within the pericardial cavity. Blod flows in a one-way path through the heart so they have a "single-circuit", low-presure circulation. The heart pumps deoxygenated blod toward the gils: low O2 blod -> sinus venosus -> atrium -> ventricle -> conus arteriosus -> low O2 blod The sinus venosus is a very thin sac that tears easily when exposing the heart or the liver. The atrium is large, but very soft or spongy in texture. The ventricle wil fel hard and muscular, but loks smaler than the atrium because of its contracted state. The ventricle generates most of the presure that moves the blod forward. There are 1-way valves at the junction betwen the heart chambers to control the flow of blod. The conus arteriosus is a smal, narow tube that contains a series of semilunar valves to prevent back flow of blod. The conus contracts or recoils slowly, regulating presure in the ventral aorta & keps the flow of blod more uniform. Blod Vesels The heart is ventraly located. The first vesel that exits the heart is caled the ventral aorta. The ventral aorta divides into a series of paired aferent branchial arteries. These arteries are ventral to the gils & take deoxygenated blod up into the gils for gas exchange, thus they "arive" at the gils. Oxygenated blod leaves the gils dorsaly via a series of paired eferent branchial arteries (blod "exits" the gils). One smal branch forms the comisural artery that leads directly to the heart. When this vesel enters the pericardium it divides into a pericardial artery on the parietal pericardium wal & into the coronary artery that suplies cardiac muscle tisue with oxygen. The eferent branchial arteries merge dorsaly into the dorsal aorta. Branches of of the dorsal aorta may be divided into several categories: Somatic branches that are typicaly paired (R & L) wil go to the body wal or limbs & include: R & L subclavian arteries that enter the pectoral fins, R & L iliac arteries that enter the pelvic fins and a caudal artery that is an unpaired somatic branch into the tail via the hemal canal. Unpaired, visceral branches go to digestive system organs & include: celiac artery with its branches, anterior mesenteric artery, gastrosplenic artery, and a posterior mesenteric artery. There are 3 major venous circuits that return deoxygenated blod via separate pathways to the sinus venosus. Paired, lateral abdominal veins takes blod from the fins & muscle tisue of the body wal. This vein empties into the subclavian vein that then empties into the comon cardinal sinus just before blod enters the sinus venosus. Blod from the caudal vein is split into smal, paired vesels, caled renal portal veins, on the lateral sides of the kidney tisue. This blod flows through capilary beds in the kidney tisue & then enters paired, posterior cardinal veins. The posterior cardinal veins cary blod up into large, sac-like chambers caled posterior cardinal sinuses & then into the comon cardinal sinuses. The hepatic portal circulation is a special subdivision of the venous blod flow. The venous blod from al of the digestive system organs & splen goes into the liver before it goes back to the heart. Find out why. The blod in the hepatic portal vein merges with blod from the hepatic artery to ensure that the liver receives some oxygenated blod. A portal circuit takes blod from 1 capilary bed (e.g. stomach) caries blod in vein(s) to another capilary bed (e.g. liver). The procesed blod exits the liver in paired hepatic sinuses that empty directly into the sinus venous through the transverse septum. Se the details of the venous circuits in your lab manual or below. Gil Comparison Clas Cephalaspidomorphi (Lamprey) Locate the lamprey's smal, pouched gil chambers in the lucite block of a lamprey or the fluid preserved sections on demo table. Clas Chondrichthyes (Shark & skate) Lok at the fluid-preserved skuls & find branchial arches, gil rakers & remnants of the gil rays that suported the gil lamelae. Folow the disection instructions & find the septa that divide the gils into a series of separate compartments. Identify the gil lamelae. Then scrape away gil lamelae from the surface of one gil to expose the cartilaginous gil rays. Locate the gil rakers inside the pharyngeal cavity. Locate the spiracle & external gil slits on the preserved skate & sharks. What is an important function of the skate?s spiracle in relationship to the location of the other gil slits that is not typical of the dogfish shark?s spiracle? Clas Actinopterygi (Preserved Perch & Dried Bony Fish Skuls) Lok at the cut section to se the gil lamelae & gil rakers on the gil bars(arches). Lok at the other side of the head to examine the opercular region covering the gils. Their gils are caled opercular or aseptal gils because the septum that divides the gil chambers is absent. Lamprey Pouched Gils Shark Septal Gils showing gil rakers Shark Septal gils Shark Gil Rakers Shark Spiracle Perch Opercular (Aseptal) Gils Clas Chondrichthyes (Cardiovascular System) Sharks that have porly disected throat muscles can expose the shark hearts. The heart is located in front of the pectoral girdle and dep to the hypobranchial muscles. If your hypobranchial muscles are god you should NOT atempt this disection. tudents who disected the heart can show their disections to the neighboring students Other teams should folow the directions in their lab manual to lok at the gils & expose the arteries in the rof of the mouth. Be sure to cut through the side of your shark that does NOT have the muscles exposed. You want to leave the muscles intact. Students who disect out these dorsal arteries should show their disection to others. Most arteries wil be injected with red latex, however, the ventral aorta & the aferent branchial arteries wil not be injected so they are harder to find, and are easily torn. The eferent arteries & the arterial circulation that branches of of the dorsal aorta should be filed with red latex. Some arteries are never injected with latex. These arteries are marked with a * in the list below & cary deoxygenated blod. Lok at the two shark heads preserved in Plexiglas at the front table. They have the major blod vesels & the heart exposed. One specimen has labels for many of the major blod vesels. Use these models to understand the 3- dimensional aspects to the pathway of blod flow into & out of the gils & heart. Often the latex fails to enter some of the vesels you ned to find. If this hapens (its especialy common in the hepatic artery branch of of the celiac artery), lok at another student's shark that does have visible blod vesels. Major Arterial Pathways Conus arteriosus -> ventral aorta -> aferent branchial arteries -> gil capilaries -> eferent branchial arteries eferent branchial artery -> commisural artery -> coronary artery -> heart muscle capilaries commisural artery -> pericardial artery -> parietal pericardium capilaries eferent branchial arteries -> dorsal aorta -> numerous branches as listed: Paired, somatic arteries Unpaired, arteries to visceral organs: Unpaired, somatic artery R & L subclavian a.: pectoral fin R & L iliac artery: pelvic fin Celiac artery has 3 main branches: Pancreaticomesenteric a.: pancreas, intestine Gastric a.: stomach Hepatic a.: liver Anterior mesenteric a.: intestine (ventraly) Gastrosplenic a.: stomach & splen Posterior mesenteric a.: rectal gland & intestine (dorsaly) Caudal a.: tail (in hemal arch) Major Systemic Vein Pathways: filed with blue latex. Caudal vein -> renal portal veins -> posterior cardinal vein -> posterior cardinal sinus -> common cardinal veins ->sinus venosus Lateral abdominal veins -> posterior cardinal sinus -> common cardinal veins -> sinus venosus Hepatic veins -> sinus venosus Major Hepatic Portal Vein Pathways: filed with yelow latex & may lok "grenish". Posterior intestinal vein -> lienomesenteric vein -> hepatic portal vein -> liver capilaries -> hepatic veins Pancreaticomesenteric vein -> hepatic portal vein -> liver capilaries -> hepatic veins Gastric vein -> hepatic portal vein -> liver capilaries -> hepatic veins Large arows are used to indicate anterior or rostral regions. Labeling codes for the heart: parietal pericardium (P), visceral pericardium (not labeled, shiny surface over the heart chambers). The 4 heart (cardiac muscle) charmbers, in oder of blod flow are: sinus venosus (SV), atrium (A), ventricle (V) & conus arteriosus (CA). Lateral diagram of a shark?s heart. Ventral views of the shark?s heart. Comissural artery Pericardial artery, Coronary Artery Sinus venosus Falciform ligament & transverse septum Pericardial artery Comissural Arteries Coronary Arteries P A V V CA SV A CA V Liver A CA V A Aferent Branchial Artery, Eferent Branchial Artery Lateral view Dorsal aorta, part of Celiac Artery, Subclavian Artery, Eferent Branchial Artery Ventral view Ventral aorta, Aferent branchial artery Ventral aorta & aferent branchial arteries will not be injected in your sharks, but remind yourself that they carry deoxygenated blood. Label this one on your own! Ventral view Rostral Dorsal Gastric Artery & Vein Pancreaticomesenteric Artery & Vein Celiac Artery, Hepatic Artery & Hepatic Portal Vein, Posterior Cardinal Vein Intestine Spleen Posterior Mesenteric a. Anterior Mesenteric a. Gastrosplenic a. Lienomesenteric vein Posterior Intestinal vein Lateral Abdominal Vein Iliac Artery Rectal gland Caudal Artery Caudal Vein Posterior Cardinal Vein & Posterior Cardinal Sinus Karen Microsoft Word - 453lab13-09.doc