Flashcards in Comparitive Anatomy Deck (112):
Briefly describe birds
Highly evolved reptiles, and endothermic, Oviparous amniotes
Briefly describe reptiles that are non-avian
Ectothermic oviparous and Viviparous amniotes
Briefly describe amphibians
Ectothermic, oviparous, viviparous and pulmocutaneous respiration
Briefly describe fish
Ectothermic, oviparous, viviparous, gills
Describe five key differences of a birds respiratory system then versus a mammal
1.entrance to trachea is the glottis at the base of the tongue different then the opening to the digestive tract.
2. No diaphragm expiration relies on their abdominal muscles.
3. lungs are rigid and do not expand when filled with air.
4. air sacs fill body cavities and spaces in large bones.
5. have continuous flow of air through the lungs (not tidal)￼
What is a Choana
Slit between nasal and oral cavities
What is a glottis
Opening to larynx. Contains no epiglottis. Sound is produced in syrinx
Where is the syrinx located
Right before the bronchial split
How many air sacs do most birds have
Nine in addition to two lungs
Where does gas exchange occurs in birds
Gas exchange only occurs in the lungs. Air sacs of her storage lightning the body for flight and thermal regulation
Describe the cycle of gas exchange in birds
Gas exchange incurs in the small parabronchi that are surrounded by capillories. Two cycles are required to expel the air. Due to high efficiency of respiratory system birds are very sensitive to toxic fumes and inhalant anesthesia
Describe the respiratory system of non-avian reptiles
Lack a true diaphragm. Use ribs and abs. Require much less oxygen due to low metabolism.
Where is the glottis located in non-avian reptiles
At the bottom of the tongue. Snake can move the glottis laterally while feeding.
Do snakes have both lungs
No usually they only have the right lung
How do aquatic turtles breathe underwater
Describe the respiratory system of amphibians
Simple lungs with few to no lobes. Reduced/no ribs force air down by pushing up floor of mouth-- positive pressure breathing. Also respire through skin and mouth thus surfaces must remain moist
Describe the cardiovascular system as birds
Four chambered heart with no mixing of deoxygenated and oxygenated blood.
What are three key differences in the cardio system of birds versus mammals
1. Large arteries supplying flight muscles and wings.
2. Some birds have a countercurrent heat exchange system in legs to reduce heat loss and conserve energy. 3. Birds and reptiles have a renal portal system which can shunt blood from the caudal region to kidneys or vena cava
What's different about the leukocytes in birds and reptiles
Neutrophils are actually called heterophils
What's different about The erythrocytes in birds and reptiles
There oval and nucleated
What's different about thrombocytes in birds and reptiles
Where is the heart in reptiles
The location varies with the species. Snake hearts are mobile to comedy ingestion of large pray.
Do reptile hearts have three chambers or four
Most have three Chambers but ventricle is partially divided to reduce mixing
What can aquatic reptiles and feeding snakes do
Shunt blood away from the pulmonary circulation.
Describe a reptiles well developed lymphatic system
Nodes are replaced by hearts which pump. Venipuncture samples often contain lymph due to large vessels nearby
What is a cloaca
Common caudal opening for digestive reproductive and urinary systems. Found in monotreme mammals, birds and reptiles and amphibians
What is the monotreme mammal
What are the three regions of the cloaca
Coprodeum: terminus of rectum
Urodeum: terminus of ureter and vas deferens.
Proctodeum: connects with bursa of fabricus
What is the bursa of fabricius
Found only in birds. Largest lymphoid organ. Site of maturation of B cells
What is the primary nitrogenous waste in a birds urinary system
Uric acid which is relatively insoluble and non-toxic. Important for amniotic egg and water conservation
Describe the kidney of a bird
Has three divisions and lacks a renal pelvis
Do birds have a bladder
No they have no bladder and no urethra
What is a bird mute
Bird poop. Urine is the liquid portion, uric acid is the pasty portion, feces is the color variation.
What percent of birds have penises
How do birds copulate without a penis
They copulate through a cloacal kiss.
How does reproductive organ size fluctuate
With the breeding season; hormonaly influenced and gonads are small during non breeding seasons.
Describe male birds
Testes are internal and sperm is stored in seminal vesicles At the base of vas deferens in the cooler location
What is seminal fluid produced by in male birds
Describe the reproductive system in female birds
Right ovary is usually vestigial. During breeding season one ovum is ovulated every 24 hrs until clutch is complete. The oviduct is divided into 5 regions which help the amniotic egg
What is the infundibulum in the female reproductive tract
Egg and yolk ovulated; site of fermentation
What is the magnum of the female reproductive tract in a bird
Layers of albumin (egg white) added
What is the isthmus in the female reproductive tract
Keratinized shell membranes added
What is the shell gland/uterus in female birds
Adds more albumin and adds the hard shell and pigmentation
What is the vagina in the female bird
Secrets mucus to assist in egg laying, also the site of sperm storage.
What is a clutch
# of eggs laid- varies by species
What determines egg layers
Have a set # of follicles that develop, hence the # of eggs laid
What are inderterminant egg layers
Will continue to lay eggs if some are removed
What is egg binding
Egg stuck in oviduct
What must happen to eggs
Must be kept warm and moist throughout incubation period.
What is a brood patch
Well vascularized area on lower stomach
What stimulates the formation of a brood patch
Prolactin and estrogen
What is hatching assisted by
The egg tooth and strong neck muscles which both atrophy after hatching.
What is a altricial
Eyes closed, no feathers. Require a lot of parental care before leaving nest (parrots)
What is semialtricial
Eyes open or closed, covered with down and immobile. (Hawk and owls)
What is precocial
Eyes open, covered with down, mobile and leave nest quickly (geese, ducks, chicken)
Describe a turtles bladder
Short wide urethras
What do terrestrial and embryonic reptiles produce
What do aquatic animals produce
Urea in ammonia.
Describe male reproduction in reptiles
Have internal testes
Have copulatory organs
Describe crocodilian and chelonian reproductive organs
Have a mound of erectile tissue on floor of cloaca. Forms through to transfer sperm and has no urinary function.
Describe snakes and lizards
Have hemipenes which form through for sperm transfer
Penises of snakes and lizards.
Each attached to a testis: transfers sperm to female.
Some have hooks and spines to improve success.
How do you sex snakes
Stick a sexing probe in
Why do snakes have two penises
Females want to mate and can store sperm for 5 yrs. they choose best male to fertilize the eggs and they can detect MHC molecules
Describe female reproduction in reptiles
Paired ovaries and oviducts.
Oviduct structure and function is similar to birds
Most species are oviparous - viviparous
Most species do not incubate or protect eggs.
How does temperature determine offspring
Typically cooler temperatures during incubation form males
Describe bird integument
Keratinized thin epidermis.
Dermis with smooth muscle, fat, blood vessels, nervous, feather follicles
No sweat or sebaceous gland
What grows continuously on a bird
Beak and claws
What is the uropygial gland
At base of tail and secretes oil.
Unique to birds
Likely first evolved for thermoregulation in dinosaurs then flight.
Important to flight, thermoregulation, sensory, camouflage, social behaviour
What are contour feathers
Flight feathers that can be moved by muscles attached to the follicle
What are semi plume feathers
Rashi's lacking barbules and hooks, under the contours, aid in insulation and Boyance in aquatic birds
What are Filoplume feathers
Plays a sensory role in feather movement
What is a bristle
Sensory roll, usually located in facial region
What is a Downy feather
Insulation, located under contours
What is the blood feather
Normal developing feather that has a blood supply in the shaft. Also called pinfeather. Can bleed a lot of broken
Describe the adaptations for flight that the bird skeletal system has
1. Reduction in number of bones.
2.Fusion of bones into plates to strengthen the skeleton.
3.Reduced density of compact bone. Internal braces to support thin margins.
4.loss of bone matrix: hollow bones pneumatic bones that are filled with air sacs
Describe the skull of a bird
Teeth replaced by keratinized beak that's covering bone, beak varies with diet. Many species have a joint between the maxilla and skull called the craniofacial hinge which increases mobility during feeding. Large orbit for large eyes and to lighten skull, some have Sclerotic ring to support the eye
Describe a cervical vertebrae
(Parakeets) have 11 to 25 (swans), joints allow much movement
Describe the thoracic vertebrae of a bird
Rigid, supports ribs. Cranial ribs not attached to sternum. Urcinate processes connect ribs caudally
Describe what the distal lumbar, sacral and first few coccygeal vertebrae do
Fuse to form the synsacrum which supports legs and acts as a shock absorber during landing
What do the distal coccygeal vertebrae fused to form
Pygostyle that supports tailfeathers
Describe the sternum of a bird
Protects thoracic region, has a keel for flight muscle attachment.
The contraction of the pectoralis muscle lowers wings in the down stroke.
in the contraction of the Supracorcoideus muscle raises wings in the upstroke
What is the preferred site for intramuscular injections in the bird
What is the carpometacarpus
The carpals metacarpals are fused to form it
How many phalanges do birds have in their wing
Two digits. First digit forms aLula that assists in landing and takeoff. Second and third digit supports primary wing feathers.
What is the pelvis of the bird composed of
Ilium, ischium, pubis. Non Fused distally to facilitate egg development in uterus and egg laying
Describe the legs of a bird
Fused bones: the tibiotarsus (drumstick) and the tarsometatarsus.
Proximal to tarsometatarsus is muscle, distal is tendons
Why don't birds fall off their perch when they're asleep
Birds cannot fall off a perch when asleep. Each toe is connected to a cord inside the leg. When the leg is bent the cord stretch tight and pull the toes around the branch, it takes more energy to leave the perch then to stay there.
What are birds feet considered
Bipedal, digitigrade. Most species have four toes in various arrangements
What is the anisodactyl
Mainly perching birds
What is a zygodactyl
Many perching birds
What are rooster spurs
Calcar protruding from the tarsometatarsal bone. Surrounded by an extensive horny keratinized layer
Describe the birds digestive system
Have an efficient system to meet high caloric commands, birds assimilate 60 to 99% of food eaten. Many have salivary gland to Morrison food and start starch digestion
What is the use of the esophagus in birds
Moistens and transports food
What is the use of the crop in birds
Used to store food. Can be an enlargement of the esophagus, single pouch or double pouch. Pigeons and doves form pigeon milk from mucosal lining to feed hatchlings. Owls lack a crop and regurgitate pellets.
What are the two divisions of the stomach in birds
Proventriculus and the gizzard
What is the proventriculus
Glandular stomach which is the site of chemical digestion. Low pH
What is the gizzard
Muscular stomach, grinding of food such as bones seeds or scales. Some species ingest grit to improve mechanical digestion
Describe the small intestine of a bird
Digestion, absorption, length. depends on diet short for carnivores and fruit eaters but long for seed eaters. Pancreas add digestive enzymes and bicarbonate.
What are the caecae
Paired sacs at junction of si and li. Present in some species. Function in water reabsorption and cellulose digestion
Describe the large intestine
Reabsorption of minerals and water
Describe the cloaca
Muted are released out vent
Describe the integumentary system for reptiles
Adaptation for dry environment: epidermis forms keratinized scales and horny plates called scutes. Claws. Some species went back to the water so have evolved aquatic adaptations such as webbed feet.
What is ecdysis
Shedding skin. Done 2-4 times per year depending on nutrition, age. Etc. Prior to shedding color gets dull and eye caps opaque. Important that scale over eyes are shed. Can lead to infection/scratched eyes.
What is dysecdysis
Difficulty shedding. Can be due to low humidity.. Parasites etc
What are the three distinct skull types
Anapsid, synapsid, diapsid
What is anapsid
Lack temporal fenestrae - chelonians
What is synapsid
Temporal fenestrae pair. - mammals
What is diapsid
2 temporal fenestrae pair. Non chelonian reptiles including birds.
Describe the skeletal system of a snake
Composed of complex skull, vertebrae, and 150+ ribs,. Mandibles held together by ligaments not fused highly mobile jaw to assist in feeding