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
a method of respiration in which contraction of the diaphragmaticus muscle moves the postpulmonary septum caudally through the liver and results in inflation of the lungs
Hepatic Piston
Which type of reptile uses hepatic piston respiration?
Crocodilians
middle ear structures that functioning as calcium-secreting glands to help maintain calcium homeostasis, particularly during egg formation and metamorphosis in amphibians
Endolymphatic Sacs
an accessory olfactory organ that can detect particle gradients across the sampled area to enable animals to follow scent trails efficiently
Vomeronasal Organ
a process in which the caudodorsal aspect of the fleshy tongue is flipped forward into a cranioventral position to pull prey into the mouth
Lingual Flipping
modified salivary glands found in the upper jaw below the eyes or along the lateral aspects of the lower jaws
Venom Glands
the keratinized beaks of turtles and tortoises
Tomia
List the 3 types of reptilian dentition
- Thecodont
- Pleurodont
- Acrodont
a type of reptilian dentition in which the teeth arise from sockets in the skull bones and are only found in crocodilians
Thecodont
a type of reptilian dentition in which their associated teeth are fused to the biting edges of the mandible and maxillae
Pleurodont
a type of reptilian dentition in which the teeth are fused to the biting edges of the mandible and maxillae
Acrodont
Which type of reptilian dentition does not grow back if the tooth is lost or broken?
Acrodont
How many rows of teeth do snakes have? Where are they?
6
2 - mandibles
2 - maxillae
2 - palatine / pterygoid bones
Give the 4 categories of venomous snake dentition
- Solenoglyphous Snakes
- Proteroglyphous Snakes
- Opisthoglyphous Snakes
- Aglyphous Snakes
snakes with fangs that fold against the roof of the mouth when the mouth is closed and are moved into an erect position when the snake bites
Solenoglyphous Snakes
snakes with fangs that are fixed in an upright position
Proteroglyphous Snakes
snakes with fangs that are fixed in an upright position and are rear-fanged
Opisthoglyphous Snakes
snakes without fangs and are nonvenomous
Aglyphous Snakes
Do amphibians have teeth?
Most have teeth
well-developed cutting plates on the rostral mandibles of some frogs
Odontoid Process
The reptilian liver is supplied by blood from what 2 vessels?
- Hepatic Artery
- Portal Vein
What causes the dark brown to black color in herptile livers?
Large number of melanomacrophages
cells involved in immune function and can give the amphibian liver a mottled black appearance
Melanomacrophages
the common outflow tract in all herptiles for gastrointestinal and urogenital tracts made up of 3 chambers
Cloaca
List the 3 chambers of the cloaca
- Coprodeum
- Urodeum
- Proctodeum
Where do the ureters empty into in reptiles?
Urodeum > they do not have urinary bladders
openings in amphibian kidneys that connect the coelomic cavity to the renal tubules and function to filter coelomic fluid
Nephrostomes
paired structures that can be everted from the tail base through the vent and form a trough to transmit semen into the cloaca of female snakes and lizards
Hemipenes
List the 5 regions of the oviducts
- Infundibulum
- Magnum
- Isthmus
- Uterus
- Vagina
species in which the albumen and shell are added in the oviduct prior to egg laying
Oviparous
species in which the fetuses are retained in the uterine portion of the oviduct for development
Viviparous
the process of adding a lipid substance to the yolk within the developing follicle
Vitellogenesis
a lipid substance formed by the liver from mobilized fat and can give the liver a yellow color
Vitellogenin
the process of laying eggs
Oviposition
What 4 environmental conditions must be met for successful hatching of reptiles?
- Temperature
- Humidity
- Gas composition
- Appropriate amounts of moisture in substrate
a phase that occurs when incubation temperatures drop and development stops for a period of time, but resumes when temperatures rise again
Diapause
How is sex determined in reptiles?
- Genotype
or - Temperature at which eggs are incubated
structures that are remnants of pelvic limbs and are used by males to provide tactile stimulation to females during courtship
Pelvic Spurs
a concave structure in male chelonians that allows closer apposition of the cloaca when the male mounts the female
Plastron
ovarian remnants associated with the testes in male toads
Bidder’s Organs
the embrace carried out by male anurans in order to fertilize the eggs as they are laid
Amplexus
pockets within the female salamander’s cloaca that store sperm
Spermatotheca
retaining the larval form into adulthood
Neotenic
List the 3 major divisions of the reptilian brain
- Forebrain
- Midbrain
- Hindbrain
the division of the reptilian brain consisting of the olfactory lobes, cerebral hemispheres and the diencephalon
Forebrain
the division of the reptilian brain consisting of the optic lobes, cerebral peduncles, and nerve fibers connecting the hindbrain to the forebrain
Midbrain
the division of the reptilian brain consisting of the cerebellum and the medulla oblongata
Hindbrain
a brain with no gyri or sulci present on the surface
Lissencephalic
List the 2 meninges of the reptilian brain
- Pia-Arachnoid Layer
- Dura Mater
the vascular meninge that lies directly on the surface of the brain and spinal cord in reptiles
Pia-Arachnoid Layer
the avascular and outer meninge in the reptilian brain and spinal cord
Dura Mater
What are the 2 types of reptile skulls?
- Anapsid
- Diapsid
the type of reptilian skull with no temporal opening
Anapsid Skull
the type of reptilian skull with temporal openings
Diapsid Skull
List the 3 regions of the reptilian vertebral column
- Presacral
- Sacral
- Caudal
the ability of lizards to drop their tails when being pursued or attacked by a predator
Tail Autonomy
the last caudal vertebrae in anurans
Urostyle
The arrangement of skeletal muscles in snakes allows for what 4 methods of locomotion?
- Concertina
- Lateral Undulation
- Sidewinding
- Rectilinear
abnormal shedding
Dysecdysis
the condition in which epithelial cells become flattened, lose their ability to perform normal functions
Squamous Metaplasia
Hypovitaminosis A can result in what condition?
Squamous Metaplasia
What glands are frequently associated with squamous metaplasia?
- Lacrimal Glands
- Harderian Glands
the most commonly used vessel for reptilian blood collection
Ventral Coccygeal Vein
Where is the ventral coccygeal vein located?
Courses on the midline just ventral to the vertebrae of the tail
What 4 vessels are used for blood sample collection in chelonians?
- Jugular vein
- Dorsal coccygeal vein
- Brachial vein
- Subcarapacial vein
List 3 alternative blood collection options are there for herptiles
- Cardiac puncture
- Ventral abdominal vein
- Postoccipital sinus
a condition in which fibrous connective tissue develops in place of bone in an effort to provide support to the limbs
Fibrous Osteodystrophy