Internal Anatomy Flashcards
Diet, temperature, BMR
- Very efficient digestive system
- 38 - 42 degrees Celsius
- High metabolic rate
Weight gain
- voracious eaters
- prefer high energy food
- small birds eat proportionately more
Food conversion
- excellent at converting food to tissue
- rapid digestion
Digestive tract
Larynx - prevents food from entering stomach
Esophagus
Crop
Roles of a crop
- food storage
- production of milk
- chemical digestion
- resonating chamber
Pigeon “Milk”
- columbiformes
- composed of cells shed from epithelial lining
- high fat content
Proventriculus
- “Anterior glandular stomach”
- anterior to gizzard
- secretes protein digesting gastric juices
Gizzard
-grinds food into small bits
-muscular, strong
-lined with horny plates
Gastroliths - birds eat rocks
Small intestine
- digestion, absorption of carbs, fats, proteins
- longer than larger intestine
Cecae
- less important
- paired
- similar function to cecum
Describe the circulatory system
- evolved independently from mammals
- 4 chambered heart
- heart is 50-100% larger and powerful than same sized mammal
Heart rate
- faster than mammals
- at rest, slows to half of that of similar sized mammals
Blood cells
- red nucleated blood cells
- biconvex
- larger than in mammals
Describe the respiratory system
- most efficient of all vertebrates
- one way air flow over lung surface continuously supplies oxygen
Lungs
- no bronchioles ending in sac like alveoli
- has tube like parabronchi through which air flows continuously
- 2% of body volume, 20% including air sac
Air sacs. function?
-Located in pairs
-may connect to hollow bones
Diverticula - tube like extensions
-dorsally location
Function:
- buoyancy
- maintain body temperature
Syrinx
- cartilaginous rings in the trachea, turns to bone as bird matures
- located at junction of trachea and bronchi
- enables complex sounds
Breathing
- no diaphragmatic contractions
- Intercostal - muscles between ribs
Kidneys
- effective at nitrogenous waste removal
- lobed: 3 per side: along side of vertebrae
Cloaca
- No urinary bladder
- further concentrates uric acid
Uric acid
- less toxic than urea
- more efficient in removal of nitrogenous waste
Advantages of uric acid
- Nitrogen wastes can be stored without endangering embryo
- Can be concentrated to higher levels
- requires less water for elimination
