Lecture Final Flashcards
What are Anapsids?
organisms with 0 temporal fenestrae. ex. turtles
What characterizes the dermis of mammals?
exceptionally thick dermis with presence of hair follicles
What are four types of chemoreception?
- Olfactory
- Gustatory
- Pheromones
- Unspecialized (ex. crying with onions)
What is the K-T boundary/ extinction?
65 million years ago (between the cenozoic and mesozoic eras).
The cretacious-tertiary boundary was a mass extinction where 80% of animals died (including the dinosaurs), but birds and crocodiles survived.
What are three strategies of increasing surface area of the intestine?
- Caeca (extensions)
- Spiral Valve: found in sharks and lungfish; increase path length
- Foldings: found in tetrapods.
What are placentals?
Mammals with placentas. I.e. humans.
Most widespread group of living mammals.
In the eye, what is the function of the Iris?
Controls entrance of light
What characterizes cynodonts?
- changes in jaw muscles allowing chewing
- Two occiptal condyles
- Semi-erect hindlimbs
- nasal turbinates
What are the four types of fenestrae?
- Anapsid
- Synapsids
- Diapsids
- Eurapsids
What two parts does the Rhobencephalon contain? What are they composed of?
Metencephalon: cerebellum, pons (exclusive to birds and mammals)
Myelencephalon: medulla oblongata
What are the components of the middle ear?
The incus, malleus, stapes
What are the three extra-embryonic membranes of the cleodoic egg?
- Chorion
- Amnion
- Allantois
What are the components of the outer ear?
Pinna, ear canal and tempanic membrane
What is the Rhombencephelon?
Hindbrain
What are the three membranes in the vertebrate ear?
Tectorial
Basilar
Vestibular
What two branches come from amniotes?
Sauropsids and Synapsids
What are pelycosaurs?
They are extinct “reptile- like” organisms with one occiptal condyle at the back of their skull (that rotates with the vertebrae).
What is the visceral nervous system?
Smooth muscles and glands (either sensory or motor fibres).
What are the three groups of extant mammals?
- monotremes
- marsupials
- placentals
What is aves? When did they radiate?
Birds. They radiated in the tertiary (cenozoic).
What characterizes a pronephric kidney?
- segmented, first 4 segments
- appear in all vertebrates (rudimentary
form) and quickly degenerate - functional in fish larvae, adult hagfish and some teleosts
What type of evolution do bird and mammal hearts represent?
Convergent evolution. 4-chambered with similar
design, but different origin.
The absence of cardiac shunt probably was an adaptation to allow
different arterial pressure in lungs vs body in active animals.
What are efferent nerves?
Motor nerves: Sends signals from the CNS to the organs (i.e. for movement).
What is a buccal pump?
Its a positive pressure used to push air into the lungs.
Found in fish and amphibians.
In the sensory organs, what are the macula and the neuromast? How do they compare?
The macula are found in the ear. They are patches of sensory cells sensing head position.
Neuromasts are found in lateral line systema and sense water movement.
They are similar in both structure and function.
What is the path of food through a ruminant stomach?
Esophagus –> rumin –> reticulum –>regurgitated and chewed –> swallowed –> Omasum –> abomasum –> intestines.
What mutation allowed mammals to produce milk?
Hox genes; during early stages of development in placental mammals, mutation
produces milk along the milk line.
What is an aspiration pump?
Uses negative pressure to pull air into the lungs.
Found in reptiles and mammals.
Uses the inter-costal muscles and either the diaphragmaticus (reptiles) or the diaphragm (mammals) to pull open lungs (sucking air in).
How did the cynodont jaw muscle change?
It went from a really simple abductor –> both the masseter and temporalis jaw muscles
Helped with chewing.
How many aortic arches do Tetrapods have? Which ones?
3 (carotid system to head derived from ventral aorta) and 4, 5, 6
What are three ways that horses increase the frequency of their stride (for speed)?
- Concentrate muscle for the legs in the trunk
- reduction of toes
- Use spring like tendons for leg movement (stores energy)
What is the Traditional View of early mammals and their radiation?
Early mammals were shrew like and radiated after teh extinction of dinosaurs
What is unguligrade limb differentiation?
Walking on a single digit (i.e. a specialized form of digitigrade). ex horses.
What are diapsids?
Organisms with 2 temporal fenestrae. Found in reptiles, birds and extinct groups.
What are archosaurs?
Subsection of diapsids including crocodiles and birds.
Also includes extinct dinosaurs.
How is the aspiration pump of birds adapted?
The aspiration pump is coupled with air sac system to create unidirectional air flow.
What did the malleus evolve from?
Meckel’s cartilage–> articular –> malleus
Do mammals have a cleodoic egg?
Yes, but there has been secondary loss of the chorion (i.e. shell) such that the uterus is used instead.
What kind of oral gland is exclusive to tetrapods?
salivary glands: multicellular glands with ducts, exclusive to tetrapods
These lubricate food.
Frogs, Anurans: Allows tongue to be sticky – prey capture
Some mammals: Digestion of starch to sugar
Snakes, lizards: poison glands – moved near orbits in marine reptile and birds:
salt excretion
In amphibians, what number is the systemic artery?
four
How many aortic arches do amphibians have? Which ones?
3 (carotid system) ,
4 (systemic arteries)
5
6 (pulmonary artery; or gills in salamanders with no lungs).
How many aortic arches do Teleosts have? Which ones?
They have four: 3,4,5,6
What type of lungs do reptiles and birds have?
Faveolar lung
What are specializations to the amphibian ear?
The second ear bone of amphibians (after the stapes) is the operculum. The operculum senses ow frequency sounds.
What is the Loop of Henle in the kidney?
It is a counter-current urine concentration system which transports urine to collecting
tubule (i.e. the ureter).
What are lepidosauria?
Lizards and snakes
What are the five principle ducts in vertebrates?
- Nephric ducts
- Muellarian (Paramesenephric) ducts (reduced in males)
- Opisthenephric/ mesenephric
- The Ureter (i.e. metenephric)
- Other accessory ducts
What are synapsids?
Mammals and mammal like reptiles
What is the functional unit of a mammalian kidney?
A Nephron
Which is a filter of blood in the kidney
What is hypsodonty and lophodonty in horses?
Hypsodonty: long teeth; as they get ground down
Lophodonty: rigid grinding surface.
What are the three types of dentition? What animals have them?
acrodont. ex. teleosts
pleurodont: ex. anurans, salamanders, lizards
thecodont: some fishes, crocodilians, fossil birds,
mammals
What is the latin term for Placentals?
Eutheria
What two types of integument glands do mammals have?
- Sebaceous glands: oily/waxy secretion (includes specializations such as mammary glands, and scent glands- these are also sweat glands).
- Sweat glands (secrete water/urea/salts)
What characterizes a metanephric kidney?
- Never segmented
- Functional in amniote
- Has dual origin - nephrogenic cord and metanephric duct (ureter)
Describe the turtle/ squamate heart.
Faculative heart; i.e. 3 interconnected compartments (divided atrium, undivided ventricle)
Both single circuit (when underwater)
and double-circuit pumping (when blood is flowing to the lungs)
What are two types of mechanoreceptors?
- The lateral line system
2. The ear
What is the chorion of the cleodoic egg?
It is the shell, which surrounds the embryo and yolk sac.
What are testudines?
Turtles!
What region of the temporal bar is missing in each squamate subdivision?
Lizards: missing lower temporal bar
Snakes: missing both lower and upper
This improves jaw mobility.
What did the stapes evolve from?
Hyomandibula–> collumella (i.e. the first middle ear bone in amphibians).
Compared to birds what kinds of glands do other reptiles have?
Other reptiles have fewer; all granular
What are the divisions of lepidosauria?
- Sphenodontians/ Tuatara (i.e. dent–> two rows of teeth in their upper jaw)
- squamates (i.e. lizards and snakes)
What is the autonomic nervous system?
It is a division of the peripheral nervous system.
It is involved in controlling visceral activity (i.e. thigs we don’t think about), such as cardiac control, respiratory function.
What is the fallacy of intermediate form?
The false belief that there are always intermediate forms in evolution
What is symmorphosis? What does it stipulate?
It’s the theory of economic design.
It stipulates that a structural design should be matched to, but not exceeding the functional demand.
i.e. it’s only as good as it needs to be.
What are specializations to the snake ear?
In some snakes, there is no middle ear, but the stapes is adapted into the jaw for vibration reception.
What is the skull-atlas joint for?
Vertical nodding
What is the procencephelon?
Forebrain.
Describe the cornea and lens’ structure in water vs. in air.
In water the cornea is flat (as there is no need to refract the light). The lens changes position to focus.
In air the cornea is rounded to refract light. The lens changes shape to focus.
What’s it called when teeth are different size/shape?
heterodont
What is the Mesencephelon? What does it involve?
Midbrain. Contains the optic lobe and auditory lobe (i.e. the superior and inferior colliculi)
In the eye, what is the pigment layer?
Prevents reflection.
What fibre in the spinal cord is myelinated?
White matter
What is the function of heterdont dentition in mammals?
Lateral and vertical chewing.
What are the two subdivisions of the autonomic nervous system in amniotes?
- Sympathetic: “fight or flight”
2. Parasympathetic: “feed and breed”
Why are small animals usually ectothermic?
They have a small volume to high surface area ration, and so they lose more heat than they can make.
When does the nephron need long tubule loops?
When the organism needs to have concentrated urine (i.e. when water is in short supply).
What is the function of a rigid backbone in modern birds?
To save energy, by reducing the muscles needed to maintain the streamlined body during flight.