Class Exam 1

what phylum do all mammals belong to

phylum chordata

what is the first of the distinct features of the chordata

the notocord

what is the second of the distinct features of the chordata

dorsal hollow nerve cord

what is the third of the distinct features of the chordata

pharyngeal slits or gill slits

what is the fourth of the distinct features of the chordata

tail

what are the three defining features of the subphylum vertebrata

true back bone, endoskeleton, cranial cavity (skull)

what is the first subclass of the class mammalia

prototheria (monotremes, egg layers)

what is the second subclass of the class mammilia

theria (marsupials and true placentals)

What are some distinguishing features of mammals

mammary glands, hair, endothermic, (most) bear live young, increased brain size

what is pelage hair

stiff guard hairs and downy underfur

what is the primitive pattern of mammal hair

Dreiartgruppen (hair in threes)

what are some advantages of hair

coloration, insulation (hot and cold), tactile purposes (think whiskers)

what is the hair folicile

living cells in the skin from which the hair grows

what is hair

nonliving dead epidermal cells strengthed by keratin

what is the medulla of the hair

The inner layer of cells

what is the cortex of the hair

middle layer of cells

what is the cuticular scales of the hair

outer layer, scale like, can be used to ID species

the alveoli connect to the milk ducts which open into nipples in all but what mammals

monotremes

what triggers mammary gland development

estrogen

milk production is stimulated by the secretion of what chemicals

prolactin and somatotropin

the command for milk production comes from what area of the brain

the anterior lobe of the pituitary gland (link to the placenta)

Nursing suppresses what

ovulation

what chemical in the brain must be released for milk “letdown”

oxytocin

what are the main components of milk makeup

water, lipids, protein, sugars, minerals

in what group are nipples first found

marsupials

what are scent and musk glands used for

mark territory, defense, attract mates

what do the sebaceous glands help with

water repelent, skin protectant

what is adipose tissue

Body fat that stores energy and insulates the body.

what is the heart set up in mammals

four chambered, two distinct halves

what is unique about mammilian red blood cells

no nucelus

why do mammilian cells have no nucleus and are disc shaped (expecept in cammels)

allows them to hold more O2

what is a choriovitelline placenta

combination of yolk sac and chorion, found in marsupials

what is a chorioallantoic placenta

complex placenta providing greater nutrient exchange, found true placental mammals

what do the vili do in the placenta

facilitate nutrient and gas exchange between mother and embryo, increase surface area for absorption.

what is a peramelid placenta

Basically an inbetween of a chorioallantoic and choriovitelline placenta, found in the order Permaelemorphia

what is the baculum

penis bone, not found in elehants, whales, humans, monotremes, hoofed mammals

what is cecal fermentation

A digestive process where herbivores break down fibrous plant material using microbial fermentation.

what is the advantage of a multi chambered stomach

more efficient digestion and absorption of nutrients by breaking down food in stages

what waste product do mammals produce

urea

what part of the ear is unique to mammals

the external pinna

what is the function of the external pinna

captures and funnels incoming sound waves

what are the three mammilian ear bones

incus, malleus, stapes

what are rods in the eye

Photoreceptor cells responsible for low-light vision

what are cones in the eye

Photoreceptor cells that detect color and are responsible for high acuity vision.

what is the basal rate of metabolism

minimial cost of maintaining body functions at rest

what is the general trend of basal metabolic rates in relation to size

increases with decreasing body size

what is the peripheral nervous system

sensory and motor system

what is the neopallium of the brain

the “control center” that processes information and motor outputs

what does the wrinkling of the brain imply

surface of the brain simpily trying to keep pace with increased volume of the brain, not a sign of increased intelligence

what is the corpus callosum

bridge betwwen brain hemispehres, NOT present in monotremes and marsupials

what is ossification

bones being hardened by calcium salts and fusing of bones

what are the advantages to better, complete ossification of bones

better joint formation, stable anchor for muscles

relative to reptiles, mammals and ____ and ____ bones

fewer, simpler

what are the advangtages to having less and simpler bones

more flexibility, less developmental costs, increased limb speed, decreased mass

what is determininant bone growth

bones don’t continously grow, ossification happens early, well formed joints

what did the fusion of the pelvic girdle do for mammals

allowed for a more upright stance with limbs in the center of gravity allowing for rmore efficent movment

what is the epiphysis of a bone

articular surface of long bones

what is the diaphysis of a bone

bone shaft

what is the epiphyseal plate of a bone

cartiliege zone between the diaphysis and the epiphysis that allows for bone growth.

what is the axial skeleton

head, backbone, ribs

what is the first vertebral division

the cervical (neck) - usually seven

what is the second vertebral division

the thoracic (chest), where the rib attaches

what is the third vertebral division

lumbar (lower back), largest vertebrate, back muscle attachment

what is the fourth vertebral division

sacral (pelvis region), pelvic girdle attachment

what is the fifth vertebral division

caudal (tail)

what is the appendicular skeleton

limbs, classic 1 block - 2 block bone pattern, makes up limbs

what is a sutural joint

immovable joint found in the skull

what is a symphyseal joint

slightly moveable joint, found in jaw, discs, pubis (in females)

what is a synovial joint

a fully moveable joint characterized by a fluid-filled cavity, allowing for a wide range of motion.

what is a gliding joint

a joint that can slide side to side of back to front

what is a hinge joint

a joint that can bend in one plane only (ie the knee)

what is a ball and socket joint

a joint with several planes of movment

what are the two main components of the skill

cranium and mandible

what is the premaxillary bone

anterior portion of the upper skull, origin of upper incisors

what is the nasal bone

anterdorsal surface following premaxillary

What is this arrow pointing to

premaxillary

what is the maxillary bone

behind premaxillary, includes bones of all upper teeth excpet incisors

what is the intraorbital foramen

small opening in the maxilla located below the orbit that allows for the passage of nerves and blood vessels.

what is this arrow pointing to

nasal bone

what is this arrow pointing to

maxillary bone

what is this arrow pointing to

intraorbital foramen

what is the frontal orbital

eye socket

what is the lacrimal

opening for tear duct, small bone on anterior portion of the frontal orbital

what is the frontal of the skull

the bone set right beind the maxillary in between that and the parietal

what is this arrow pointing to

frontal bone of the skull

what is the parietal of the skull

bone behind the frontal but before saginal crest

what is this arrow pointing to

parietal bone of the skull

what is the sagital crest

a bony ridge along the midline of the skull, serving as an attachment point for skull muscles.

what is this arrow pointing to

saginal crest

what is the foramen magnum

large opening in base of skull for spinal cord

what is the name of the skull part that is highlighted in green

foramen magnum

what is the occipital bone

back of the skull, surrounds the foramen magnum

what is the area in red refering to

occipital

what is the occipital condyle

rounded protrusions that articulate with the first cervical vertebra, facilitating head movement.

what is the area in blue referring to

occipital condyle

what is the highlighted bone

zygomatic arch (actually two bones)

what is the zygomatic arch

two arched bones protecting the orbit

what is the name of the bone closest to the eye socket in the zygomatic arch

jugal bone

what is the name of the bone farthest away from the eye socket in the zygomatic arch

squamosal bone

what is the area in blue referring to

jugal bone