Mudpuppy Salamander Dissection PDF

MUDPUPPY (SALAMANDER) DISSECTION: PART 2 Necturus maculosus BIO 415L Presented by Dr. Polekoff MUDPUPPY STRUCTURES Internal anatomy: Mesentery Bulbus arteriosus (fig 5.36) Stomach Left atrium Mandibular arc...

MUDPUPPY (SALAMANDER) DISSECTION: PART 2 Necturus maculosus BIO 415L Presented by Dr. Polekoff MUDPUPPY STRUCTURES Internal anatomy: Mesentery Bulbus arteriosus (fig 5.36) Stomach Left atrium Mandibular arch (fig 5.25) Pyloric sphincter Right atrium Pharyngeal slit Duodenum Ventricle Tongue Small intestine Pericardial sac Liver (fig 5.26) Large intestine Posterior vena cava Falciform ligament Dorsal aorta Left lung Pancreas Ovary Gall bladder Oviducts Liver Urinary bladder Testes (fig 5.30) Cloacal gland Kidney Spleen (fig 5.27) Ovary (fig 5.31) Adrenal glands ORAL CAVITY  MANDIBULAR ARCH:  Made up of: 1. Meckel’s cartilage (interior mandible) 2. Dentary bone 3. Coronoid bone 4. Prearticular bone ORAL CAVITY  PHARYNGEAL SLIT: entry into pharynx.  Probe to verify that there are two slits  The pharynx is a membrane-lined cavity connecting the mouth to the larynx and esophagus respectively.  Depending on the organism, the larynx is a muscular organ that forms an air passage for the lungs and for organisms that can make sound, the vocal cord.  Note: salamanders cannot vocalize  TONGUE: supported by the hyoid arch GASTROINTESTINAL ANATOMY  LIVER:  Large, elongated, dark  Midventral  Debuque (2021) demonstrate that, “the liver is the main source of myeloid cells trafficking to distant injury sites such as the early regenerating tail or limb and can do so without passing through or requiring education within the spleen. These studies form a foundation for understanding the immune cell requirements for adult tissue regeneration.” https://www.youtube.com/watch?v =byLDgtSMI0w GASTROINTESTINAL ANATOMY FALCIFORM LIGAMENT: Extends between the abdominal wall and the ventral surface of the liver. Much larger than in the other vertebrates considered in this lab In viviparous animals (vs. oviparous), the falciform ligament is a remnant of the ventral mesentery that includes the umbilical vein in its free borders during foetal life, which obliterates after birth to form the round ligament (Navarro et al., 2017)  STOMACH:  Long, light-colored, tubular.  Dorsal and slightly to the left of the liver.  PYLORIC SPHINCTER:  Marked constriction  End point of the stomach  Border between stomach and duodenum GASTROINTESTINAL ANATOMY  PANCREAS:  Along the duodenum  Partly within the hepatoduodenal ligament  Releases digestive enzymes and helps regulates metabolic activity through management of glucose (insulin)  MESENTERY:  Supports small intestine.  Observe by spreading the coils of the small intestine  Mesenteric vein extends within the mesentery GASTROINTESTINAL ANATOMY  DUODENUM:  First loop of the small intestine.  Exit point for the common bile duct which passes bile and pancreatic enzymes  SMALL INTESTINE:  Coiled and long  LARGE INTESTINE:  Short and straight GASTROINTESTINAL ANATOMY  SPLEEN:  Elongated and hangs from the posterior left side of the stomach  “Unlike mammals, adult axolotls do not have functional bone marrow but instead utilize liver and spleen tissues as major sites for adult hematopoiesis” (Debuque et al., 2021).  NOTE: Ambystoma mexicanum is the endangered salamander found in lakes underlying Mexico City  GASTROINTESTINAL ANATOMY  GALL BLADDER:  Posterior to liver  Thin, translucent, greenish  “The gallbladder stores and concentrates bile from the liver. The bile is then released into the first section of the small intestine (the duodenum), where it helps your body to break down and absorb fats from food” (InformedHealth.org, 2018) GENITOURINARY ANATOMY  TESTES:  Paired and elongated.  Attached to the dorsal wall of the body by a mesorchium  KIDNEY  Longer than the testis.  Considerably wider posteriorly than anteriorly.  Genital function: narrow anterior portion.  Urinary function: wider posterior portion.  Archinephric ducts lies along the lateral margin of the kidney.  Allows for drainage of the kidney  Females: straight and narrower than in the male. GENITOURINARY ANATOMY  CLOACAL GLAND (males):  cloacal gland and cloacal papillae consists of numerous tiny tubules.  Involved in clumping sperm to form spermatophore  Vestigial oviduct is a dark thread-like structure along the lateral edge of the archinephric duct.  Cloacal glands and papillae are absent in the female. GENITOURINARY ANATOMY  OVARY:  Elongated  Supported by the mesovarium  May be quite large  Presence of numerous eggs within follicles gives the ovary a lobulated or granular appearance, in contrast to the more regular surface of the testes.  Follicles and eggs vary in size depending on their stage of maturity, being quite large in some specimens  GENITOURINARY ANATOMY  OVIDUCTS:  Long, prominent, and convoluted tube lying between the ovary and kidney and extending nearly the length of pleuroperitoneal cavity.  Supported by the mesotubarium  At its anterior end is the open, funnel- shaped ostium tubae, into which the eggs pass after they have been released into the coelom by the ovary.  Note that the coelom is the body cavity located between the intestinal canal and the body wall. Fertilization: https://youtu.be/B_ECMpFmX2o Fertilization: https://youtu.be/B_ECMpFmX2o Embryogenesis: https://youtu.be/SEejivHRIbE  GENITOURINARY ANATOMY  ADRENAL GLANDS:  Spots found on the kidneys.  Endocrine gland producing hormones to regulate metabolism, immune function, blood pressure, response to stress  URINARY BLADDER:  Thin walled.  Posteroventral part of the pleuroperitoneal cavity. CARDIOVASCULAR SYSTEM CARDIOVASCULAR SYSTEM  LEFT and RIGHT LUNG:  Used mostly for buoyancy  Left: long, thin translucent. Dorsal to the stomach.  Right lung is similar in form; between the stomach and the liver.  According to James Hanken, “If you look at a salamander when they’re still, they’re not breathing because they don’t have lungs, but you can see a pulsing in their throat. It’s believed that they’re basically pumping air in and out of their mouths” (Reuell, 2019) CARDIOVASCULAR SYSTEM  PERICARDIAL SAC: pericardial cavity lies just anterior to the liver  Pericardial cavity encloses the pericardial sac containing the heart  LEFT and RIGHT ATRIUM:  Partially separated.  Anterodorsal to the ventricle.  Some consider the atrium a single chamber CARDIOVASCULAR SYSTEM  VENTRICLE:  Largest and most conspicuous.  Partially separated into a smaller left side and a larger right side by an incomplete interventricular septum.  CONUS ARTERIOSUS:  Narrow tube extending anteriorly between the atria from the right side of the ventricle.  BULBUS ARTERIOSUS (FIG 5.36):  From conus arteriosus  Continues anteriorly  Enlarged and modified base of the ventral aorta CARDIOVASCULAR SYSTEM CARDIOVASCULAR SYSTEM  DORSAL AORTA:  Brings oxygenated blood to body  Continues middorsally  Along the trunk and tail.  POSTERIOR VENA CAVA:  Brings deoxygenated blood back to heart  Passes through the septum to reach the pericardial cavity. References InformedHealth.org. (2018, September 6). How does the gallbladder work? Nih.gov; Institute for Quality and Efficiency in Health Care (IQWiG). https://www.ncbi.nlm.nih.gov/books/NBK27938 6/ Iuliis, G. D., & Pulerà, D. (2019). The Dissection of Vertebrates (3rd Edition). Elsevier S & T. https://bookshelf.vitalsource.com/books/978012 4105003 Debuque, R. J., Hart, A. J., Johnson, G. H., Rosenthal, N. A., & Godwin, J. W. (2021). Identification of the Adult Hematopoietic Liver as the Primary Reservoir for the Recruitment of Pro- regenerative Macrophages Required for Salamander Limb Regeneration. Frontiers in Cell and Developmental Biology, 9(750587), 750587. https://doi.org/10.3389/fcell.2021.750587 Navarro, M., Ruberte, J., Carretero, A., Nacher, V., & Domínguez, E. (2017). Digestive tract. Morphological Mouse Phenotyping, 89–146. https://doi.org/10.1016/b978-0-12-812972- 2.50005-2