Amphibian & Reptilian Anatomy & Physiology Flashcards
the collective term for amphibians and reptiles
Herptiles
animals that are unable to generate body heat internally and thus their body temperatures are dependent on environmental temperatures
Ectothermic
the mechanisms used by herptiles to maintain their body temperature in an appropriate range
Behavioral Thermoregulation
Give 3 behavioral thermoregulation mechanisms
- Movements within the thermal gradient of their habitat
- Postural changes
- Adjust color and pattern of skin (some species)
a range of temperatures in which an animal can perform all necessary metabolic functions
Preferred Optimal Temperature Zones (POTZ)
periods of hibernation herptiles go through when temperatures drop out of the range in which the animal can remain active
Brumation
pigment-containing cells that allow some lizards to change their skin color and pattern drastically
Chromatophores
bony plates within the dermis of some lizards and crocodilians
Osteoderms
modified scales that cover the eyes of snakes
Spectacle (Brille)
overlapping structures formed by a folding of the reptile epidermis that can vary greatly in size and shape
Scales
the rigid type of keratin that is found in scales
Beta Keratin
structures formed in the lower vascular layer of reptile skin that produce a horny outer layer that does not overlap
Scute
the softer and more flexible type of keratin that is found in the interscalar skin
Alpha Keratin
the process of shedding skin and is controlled by the thyroid gland
Ecdysis
dead skin
Exuvia
areas of increased permeability on the ventral surfaces of amphibians that amphibians absorb the majority of their water from
Drink Patches
List the 2 types of periocular glands in reptiles
- Lacrimal Glands
- Harderian Glands
the gland in most reptiles that lies in a caudodorsal position of the orbit
Lacrimal Glands
the gland in most reptiles that lies medial to the eye in the rostral aspect of the orbit
Harderian Glands
scleral bones that help the eye maintain its shape and provide protection from trauma in reptiles
Ossicles
modified vessels in the eye of reptiles that protrude into the vitreous humor in order to bring nutrition and remove waste
Choroidal Vessels
a structure in the eye of lizards that extends into the vitreous humor from the optic disc to provide nutrition and remove waste
Conus Papillaris
a structure with a rudimentary retina and cornea, but no iris, lids, or musculature and likely functions to play a role in light-cycle-mediated hormone function due to its connection to the pineal gland
Parietal Eye
How many chambers do most reptilian hearts have?
2 - atria
1 - ventricle
List the 3 structures within the reptilian ventricle
- Cavum Venosum
- Cavum Arteriosum
- Cavum Pulmonale
the structure from which the paired aortic arches arise from and lead into systemic circulation
Cavum Venosum
the structure within the reptilian heart that receives blood from the pulmonary veins and directs oxygenated blood to the cavum venosum
Cavum Arteriosum
the structure within the reptilian heart that receives blood from the right atrium and directs flow into lung circulation
Cavum Pulmonale
Which type of reptile does not have 3 heart chambers and how many does it have?
Crocodilians have 4 chambers
2 atria
2 ventricles
2 aortas
the structure in the crocodilian heart that allows blood from the right ventricle to bypass the pulmonary circulation when necessary
Foramen Panizza
a structure at the opening of the pulmonary artery in the crocodilian heart that diverts blood into the left aorta and systemic circulation when closed instead of allowing the blood to enter pulmonary circulation
Cog-Wheel Valve
How many chambers does the amphibian heart have?
2 atria
1 ventricle
Equation employing metabolic scaling for determination of the “appropriate” heart rate in reptiles
HR = 33.4 x (weight in kg ^-0.25)
How is cardiac monitoring achieved in reptiles?
Place animal on its back > observe movement of ventral scutes or scales
smooth muscle in the walls of some lymph vessels that actively pump lymph through the vessels
Lymph Hearts
What is important to remember with the presence of large lymph vessels in association with blood vessels in reptiles?
Results in frequent lymph contamination of a sample during venipuncture
List 3 reasons why reptiles are capable of functioning with very low oxygen levels
- Large pulmonary valve
- Efficient anaerobic metabolism
- Cardiac shunting capabilities
a structure possessed by some species of snake that increases the volume of vocalizations
Glottal Keel
a reptilian lung structure whose cranial portion contains tissue involved in gas exchange and an avascular caudal portion comparable to the avian air sac (found in snakes and some lizards)
Unicameral Lung
a reptilian lung structure that divides into many compartments, possesses intrapulmonary bronchi, and is found in chelonians, some lizards, and crocodilians
Multicameral Lung
a reptilian lung structure that shares characteristics of unicameral and multicameral lungs, and is found in iguanas and chameleons
Paucicameral Lung
gas-exchange structures in herptile pulmonary tissue that do not expand or contract and are surrounded by capillary beds where the blood takes up oxygen and releases carbon dioxide
Faveoli
a muscular structure located caudal to the lungs that attaches to the cranial aspect of the liver in crocodilians
Postpulmonary Septum
a muscle that attaches the caudal aspect of the liver to the pubis in crocodilians
Diaphragmaticus