Biology of Vertebrates - Unit 3

bird adaptations for flight

endothermy, feathers, acute senses, lightweight bones, long flexible neck

plumage

all of the feathers

feathers purpose

flight surface, steering with tail, insulation, and breeding behavior

molting

shed of feathers

feather state at maturity

dead

feather coloration

pigment presence/concentration, surface irregularities, shape, angle of light

preening

the use of the beak to position and clean feathers

bird skull

fewer plates; thin, lightweight; lack teeth; have beak

bird beak

hardened, keratinized sheath over jaws and nasal cavity

bird bones

lightweight; strong w/ many air spaces between bony bars

pygostyle

fused caudal vertebrae forming a "bump" at posterior portion of bird that creates more surface area for tail feather attachment

bird forelimbs

modified as wings

bird hindlimbs

modified for perching, walking, grasping, and landing

5th appendage

skull with beak and long, flexible neck

synsacrum

posterior protective box formed by fusion of the lower thoracic, lumbar, sacral, and anterior caudal vertebrae into pelvic girdle

furcula

anterior protective box formed by fusion of clavicles into the sternum

furcula purpose

flight apparatus; protection of chest cavity; flight muscle attachment

pectoralis

largest; 15% of body weight; pulls wings down

supracoracoideus

smallest; 10% of body weight; lifts wing

bird appetite

fueled by high metabolism, endothermy, and flight

bird diet

seeds, insects, invertebrates; vertebrates, and nectar

bird differences from basic vertebrate plan

crop; stomach; cecum; cloaca; cloacal vent; proventriculus and ventriculus

crop

enlarged lower portion of the esophagus

bird heart

4 chambered heart with 2 atria and 2 ventricles; sinus venosis that is reduced to a patch of cells functioning as a "pacemaker"; rapid heart rate

bird circulatory system

distinct pulmonary and circulatory circuits; similar to crocodilians; high oxygen consumption; high heart rate

mammal versus bird lungs

bird lungs have 1/2 the volume but 3x the potential for air volume

bird ventilation cycles

air into posterior air sacs; air into lungs; air into anterior air sacs; air out of trachea

ventilation

compression and expansion; assisted by furcula

thermogenesis

generation of heat

shivering

rapid muscle constraction

endothermic

trap metabolic heat for higher temp and metabolism

countercurrent heat exchange

veins are inside coiled arteries

arteries temperature

warm blood from heart and trunk

veins temperature

blood from extremities is colder

bird thermoregulation

endothermy; thermogenesis; shivering; hormonal stimulation; panting; vessel arrangement; circulation; countercurrent heat exchange

bird vision

huge orbits with best color vision of vertebrates; nictitating membrane and moveable eyelids

bird olfaction

poorly developed with less surface area

bird hearing

well developed outer ear opening, middle ear canal and ossicle; inner ear cavity with mass of auditory epithelium

bird waste product

uric acid released into cloaca; water is reabsorbed and acid is packaged with feces for release out of cloacal vent

supraorbital salt glands

release waste ions through nasal openings to assist with ion/water balance; especially enhanced in marine birds

bird excretion

uses metanephric kidney with paste-like waste product, supraorbital salt glands and uric acid

bird reproduction

all oviparous; mostly dioecious; parthenogenesis; largest yolk; egg fertilized in upper 1/3 of oviduct before shell is secreted around egg and released into cloaca and cloacal vent

shell gland

secretes shell around fertilized egg/albumen

female bird reproduction

have 2 ovaries but usually only one matures

male bird reproduction

pair of testes; vas deferens to conduct sperm; seminal vesicles for sperm storage and maturation; most lack a copulatory organ and utilize cloacal aposition

polyandry

1 female with multiple males

polygyny

1 male with multiple females

mammal integument

thickest integument; epidermis is thinner with lots of keratin in outer cells, lots of touch receptors, and blood vessels; dermis is thicker with hair origin, sensory receptors, and capillary beds

mammal molting

shed hair regularly

vibrissae

long, stiffened "guard hairs" around sensitive areas

hypodermis

not part of skin but with lots of adipose tissue

4 integumentary glands

sebaceous; sudorferous; musk; mammary

sebaceous gland

sebum/oil

suderferous gland

evaporative cooling

musk gland

pheromones

mammary gland

milk

parthenogenesis

development of an embryo without fertilization

mammal skeleton

decreased number of skull bones; enhanced nasal cavity of skull; palate with nearly complete separation between nasal and mouth cavities

thecodont dentition

the condition of having long-rooted teeth in sockets of jaw bone

diphyodont dentition

the condition of having 2 sets of teeth in a lifetime with milk teeth

heterodont dentition

having up to 4 types of teeth; incisors, canines, premolars; and molars

axial skeleton

portion that is along the mid-longitudinal axis

axial skeleton includes

skull; sternum; ribs; vertebral column

vertebral column

for flexibility, support, and protection; includes cervical (neck), thoracic (upper back), lumbar (lower back), sacral (hip), and caudal (tail)

appendicular skeleton

related to appendages

pectoral girdle

2 clavicles and 2 scapular that attach front appendages to vertebral column

pelvic girdle

fused pelvic bones that attach rear appendages to column

appendages

pair of front and pair of rear; positioned "below" body; better locomotion on land; better joints than any other vertebrates for substrate contact; bigger bones; better limb musculature

bone

living connective tissue; continuously being formed, resorbed, reformed`

bone cells

osteocytes, osteoblasts; osteoclasts

osteoblasts

immature, newly formed bone cells

osteoclasts

construction cells; break down damaged or old bone material

compact bone

dense. provides structural support, protection, and strength to the skeleton

spongy bone

bony spikes

osteon

basic structural unit of compact bone

osteonic canal

nerves run through canal

osteocytes

mature cell formed by osteoblast

modes of mammal nutrition

carnivores, herbivores, and omnivores

carnivore teeth

sharp, pointed

herbiovore teeth

flattened for crushing/grinding plant matter

mammal alimentary canal

mostly similar to typical vertebrate plan; esophagus, stomach, small intestine with enhanced epithelial lining for more absorption); large intestine, anus

mammal mouth cavity

teeth, tongue, salivary glands; enhanced jaws/musculature

mammal species with cloaca

3 species of monotremes

herbivore digestive system

specializations for digestion of cellulose; requires microorganisms that secrete enzymes to break down cellulose

cecum

blind pouch housing microorganisms

ruminant mammals

have multiple chambers to stomach region; 1-3 for storage and fermentation and 4 is the normal stomach

cud

regurgitated mass

mammal circulatory system

endothermic with 4 chambered heart and no psuedochambers; pulmonary and systemic circuit

mammal pulmonary circuit

conducts blood to lung and back to the heart

mammal systemic circuit

conducts blood out to body and back to heart

mammal atria

receiving chambers for blood returning to the heart. smaller chambers, thinner walls

mammal ventricles

larger, thicker walls with left thicker

heart valves

prevent blood backflow

atrioventrical valves

between right atrium and ventricle and between right atrium and ventricle

semilunar valves

pulmonary and aortic semilunar valves

pulmonary sv

between right ventricle and pulmonary trunk

aortic sv

between left ventricle and aortic trunk

mammal blood path

vena cava (deoxygenated); right atrium; atrioventrical valve; right ventricle; pulmonary semilunar valve; pulmonary arteries; trunk; lungs (oxygenated blood from gas exchange); pulmonary veins; left atrium left atrium; atrioventrical valve; left ventrical; aortic semilunar valve; aorta; body

mammal heart evolutionary advances

increase in # of chambers; increase in size of heart; increase in # of psuedochambers

sinus venosis

outside of atrium receiving blood from body