Zoo lab post midterm Flashcards
What are some of the functions of integument of vertebrates? (Hint:3)
- Protecting the organism from mechanical/ frictional stress
- Maintaining an osmotic balance between the organism and the environment
- Providing coloration
What is one of the main characteristics of avian integument?
The presence of feathers.
What can we see in the cross-section of avian integument?
- Developing feathers with feather follicles
Feathers, like teeth, are dermally derived. True or False?
False. Feathers and feather follicles are epidermally derived.
What are the basic types of feathers and where are they located?
- Contour feathers (body)
- filoplume
- semiplume
- bristle - Flight feather (wings and tail)
- Downy feathers (under contours)
Avian skin lacks glands except for a uropygial gland at the base of the tail. True or False?
True.
What is the function of a uropygial gland? Where is it found?
The uropygial gland produces oils that are used to waterproof the feathers. It is found at the base of the tail of birds.
What is the function of arrector pili muscles and where are they found?
Arrector pili muscles –> smooth muscles in the dermis which are attached to the base of the feather follicle.
Used for heat, mating, defence. The flexion of muscle is involuntary.
The unlayered dermis of birds lacks melanocytes. How do birds have colour?
Melanin, and other pigments, is injected directly into the developing feather cortex to give the feather colour.
What are the two important parameters of wings which relate to flight? how are they calculated?
- Aspect ratio
Wing length/ wing width - Wing loading
body mass/ total wing area = body mass/ (wing length x wing width x 2)
How is nitrogenous waste excreted in birds?
Uric acid.
What are two special features in the digestive system of birds?
- The crop –> enlarged part of the esophagus used to store food
- The stomach –> consisting of the proventriculus (digestive enzymes mixed with food) and the gizzard (responsible for mechanical digestion of food)
What are the two major components of the integument and where are they derived?
- Epidermis –> derived from the outermost germ layer of the embryo (ectoderm)
- Dermis –> developed from the middle layer (mesoderm)
- dermis contains connective tissue (mostly collagen fibers), nerves, smooth muscle, and blood vessels.
*Note: some vertebrates may have hypodermis beneath dermis (contains lymph or fat)
The ________ layer of the skin is thinner across most of the body, but is thicker in the palm of the hand and the sole of the foot. This is mainly for _______.
The STRATUM CORNEUM layer of the skin is thinner across most of the body, but is thicker in the palm of the hand and the sole of the foot. This is mainly for PROTECTION.
What are the layers of the epidermis, from superficial to deep? Give a description of each.
(Hint: 5)
- Stratum corenum –> for protection
- Stratum lucidum –> a clear area of largely keratinized cells found in thick skin
- Stratum granulosum
- Stratum spinosum –> a tough layer where the cells are linked with intercellular bridges
- Stratum germinativum –> where mitotic cell division takes place
The dermis is composed of loose connective tissue and has finger-like projections called ______ that protrude into overlying epidermis.
The dermis is composed of loose connective tissue and has finger-like projections called DERMAL PAPILLAE that protrude into overlying epidermis.
Similar to feathers, hair follicles are dermally derived. True or False?
False. Both feathers and hair follicles are epidermally derived.
What are the types of glands found in mammalian integument? Give a description of each.
- Sebaceous glands –> appear as large clumps of large, lightly staining cells, each with a distinct nucleus.
- Associated with a hair follicle, and open into the hair follicle.
- Sebaceous secretions condition and waterproof the hair. - Sweat/ Sudoriferous glands –> highly coiled tubular grands
- Apocrine sweat glands –> open into the hair follicles in the groin and armpits (emotional stress, fatty sweat eaten by bacteria)
- Eccrine sweat glands –> open onto the surface of the skin, absent from most mammals or are restricted to the soles of the feet (thermoregulation sweat)
- Ceruminous glands –> modified sweat gland found in integument of outer ear canal of mammals.
- Product of glands is emptied into sebaceous glands and combined secretion = earwax.
Give some examples of modifications of the mammalian integument.
Horns, antlers, pronghorn, whale bristles, hoof.
What is the furcula and where is it located?
Furcula a.k.a wishbone is located in the front of the avian skeleton.
What is the “Keel” and where is it located?
The carinate sternum, a.k.a. the keel, is the breast bone of birds.
The avian Vertebral column is separated into 4 regions. What are they?
- Cervical vertebrae
- Thoracic vertebrae
- Synsacrum
- Caudal vertebrae
Give some functions of the endoskeleton of vertebrates.
- Providing the rigid, hinged body segments across which muscles attach to affect locomotion.
- Protecting the delicate internal structures such as the viscera and the nerve cord.
- Acting as a storage site for minerals which can be mobilized when needed (ex. calcium)
- Aiding the ventilation of the lungs in amniotes.
The vertebral column of mammals can be divided into 5 regions. What are they? How many of each are there?
- Cervical (7)
- Thoracic (13)
- Lumbar (7)
- Sacral (3, fused)
- Caudal (varies)
What are the special characteristics of the cervical vertebrae?
- All but 7th have transverse foramina for the passage of the vertebral artery.
- Atlas (#1) has a pair of broad, flat transverse processes and large cup-shaped facets at the anterior edge for articulation with the occipital condyles of the skull. Centrum of vertebra is greatly reduced.
- Axis (#2) is the long odontoid process (dens) that projects into the atlas and an elongated neural spine, extending over the atlas.
-Atlas & axis allow for the free head movement of reptiles, birds and mammals.
What do the thoracic vertebrae look like?
-Thoracic vertebrae will have facets (surfaces) for the articulation of the ribs.
Anterior ribs articulate ventrally with the _______, which, in the cat, is made up of small bones called ______.
Anterior ribs articulate ventrally with the STERNUM, which, in the cat, is made up of small bones called STERNEBRAE.
What are the cranial and caudal sternebrae? What occurs caudally to the sternebrae?
Most cranial–> manubrium
Most caudal–> xiphisternum
Caudally from the xiphisternum, is a cartilaginous projection called the xiphoid process.
*Note: Posterior ribs articulate ventrally with other ribs, but the last, floating rib, only has a vertebral attachment.
What are some characteristics of the lumbar vertebrae?
- They have long, anteriorly directed transverse processes.
- A small accessory process, which helps stabilize the zygapophyses, is also present, but is greatly reduced/ absent on the last 2 lumbar vertebrae.
What is a characteristic of the sacral vertebrae? (the sacrum)
- Serves as a point of attachment for the pelvic girdle.
What are some characteristics of the caudal vertebrae
- May be a pair of small hemal processes on the ventral surface of the vertebrae (in proximal region of the tail)
- Processes + Chevron bone form the hemal arch –> surrounds the caudal artery and vein
What is the purpose of the hemal arch and what is it made up of?
Hemal Processes + v-shaped Chevron bone
-Protects/ supports the caudal arteries/ veins
Pectoral girdle of other tetrapods is reduced compared to mammals. True or False?
False. The pectoral girdle of mammals is very much reduced compared to other tetrapods.
The largest element of the pectoral girdle is the _______.
The largest element of the pectoral girdle is the SCAPULA.
What are the two regions of the scapula?
- Supraspinous fossa
- Infraspinous fossa
At the ventral end of the scapula of mammals is a pit, the glenoid fossa, which will receive the head of the humerus. The orientation of the scapula allows mammalian forelimbs to be positioned directly beneath the animal’s body.
What are some locomotory advantages of this shift in limb position?
- Faster, more coordinated movement
- Better range of motion
- Are able to have straight forward and backward movement rather than lateral undulation.
The clavicle is ______ derived, and is a component of the ______ ______ in mammals.
The clavicle is DERMALLY derived, and is a component of the PECTORAL GIRDLE in mammals.
The clavicle in mammals usually extends from the _____ to the ______ of the sternebrae.
The clavicle in mammals usually extends from the SCAPULA to the MANUBRIUM of the sternebrae.
In cats, the clavicle is reduced to a sliver of bone embedded in the shoulder musculature. True or False?
True. This is used to be able to squeeze through tight spaces, and allows less impact on the clavicle when jumping (muscles absorb shock).
What are features found at the proximal and distal end of the humerus?
- Proximal end –> large head
- Distal end –> trochlea (for articulation with the ulna and radius) and supracondylar foramen on the medial surface (for nerve and blood vessel passage).
The trochlear notch of the _____ articulates with the humerus.
The trochlear notch of the ULNA articulates with the humerus.
There is a small radial notch in the ridge along the distal border of the trochlear notch that allows for the articulation of the head of the radius. True or False?
True.
The ilium, ischium and pubis fuse to form two innominate bones which form what?
The pelvic girdle is formed by this fusion.
*(Fusion occurs when the animal matures).
The pelvic girdle has a cup-like depression in the lateral wall (acetabulum) to receive what bone?
The acetabulum receives the head of the femur.
What does the patella ride over to connect to the femur?
The patella rides over the intercondyloid fossa on the anterior surface on the distal end of the femur.
Intercondyloid fossa –> depression between the two large condyles at the distal end of the femur.
What are considered to be the bones of the shank?
- Tibia
- Fibula
From proximal to distal, what are the bones of the foot?
*Hint: (start at ankle)
- tarsal bones
- Metatarsal bones
- Phalanges
What are the components of the vertebrate’s cranial skeleton? Give a brief description of each.
- Chondrocranium –> form the floor and lateral walls of the braincase, as well as otic and olfactory capsules.
- Dermatocranium –> cover the dorsal aspect of the brain, and form other cranial components (*formed in dermis)
- Splanchnocranium –> form the jaws, support the gills, tongue, larynx, and middle ear bones in tetrapods
why are embryological studies necessary to identify chondrocranium and dermatocranium in most mammals?
Since both these parts of the braincase ossify during development, the enchondral bone (cartilage-replacement) is indistinguishable from dermally derived bone (membranous bone).
What separates the respiratory passage from the alimentary passage in mammals? What is it made of?
The secondary palate separates the air and food passageways.
It consists of the bony hard palate and its posterior skin extension, the soft palate.
Where can elements of the splanchnocranium be found in tetrapods?
- Jaws
- Middle ear (hyomandibular is homologous to the stapes)
- Hyoid apparatus (supports tongue muscle)
- Top of trachea
What is the thecodont dentition?
Thecodont dentition –> the sockets in the upper and lower jaws of mammals in which teeth are rooted.
What is the heterodont dentition?
Heterodont dentition –> teeth that are anatomically modified to perform specific duties
What are the 4 types of teeth and what kind of function do they have?
- Incisors (premaxilla) –> nipping
- Canines (maxilla)–> Stabbing
- Premolars (maxilla) –> Shearing
- Molars (maxilla) –> Grinding
All tetrapods, mammals included, have half of their lower jaw consisting of a single dermally derived bone, the dentary. True or False?
False. Having a dentary is unique to mammals.
In most tetrapods, the lower jaw hinge consists of the articular and the quadrate bones. How do these two bones change in mammals?
Articular –> malleus
Quadrate –>incus
*Both moved into the middle ear
Along with the stapes, the incus and malleus form a chain of bones which now function in sound transmission.
What has happened to the hyoid arch and ancestral branchial arches, that used to support the gills, in mammals?
Hyoid arch and ancestral branchial arches have disappeared or have become elements of the hyoid apparatus and larynx.
What is the main musculature in the abdominal region of mammals?
(Hint: similar to necturus although most evidence of segmentation is lost)
The hypaxial musculature.