Respiratory System
Respiratory System
Respiration
Classified into:1.External respiration2.Internal respiration
the diffusion of gases across moist linings of the mouth and the pharynx
accounts 1-7% of the total gas exchange
Pulmonary ventilation occurs by the buccal pump mechanism
muscles of the mouth and pharynx create a positive pressure to force air into the lungs
called Integumentary Respiration
Skin has the simplest structure of all the major vertebrate respiratory organs
Facilitated by a uniform capillary network lies in a plane directly beneath the epidermis
Gives 25% of oxygen
Aided by the mucous layer
consists of stratified epidermis and dermis
contains mucous, poison and serous glands
keeps the skin of amphibians moist
protects the skin against injuries
Facilitates gas exchange through the skin
Makes body slimy as defense mechanism
tuck legs
seek shelter
put themselves in wet surfaces
burrow themselves
simply breathing
the exchange of gases between the lungs and the air
Air passages1.External nares or nostril2.Nasal cavities3.Internal nares4.Mouth or buccal cavity
5. Glottis
made up of a main framework of cartilage plates joined together by a dense connective tissue
Trachea
Histology of the trachea
Tunica mucosa – pseudostratified columnar epithelium
Tunica or lamina propria- elastic fibers
Tunica submucosa- layer of collagenous and elastic fiber
Hyaline cartilage- C or Y shapedTracheal muscle- smooth muscleTunica adventitia- CT surrounding
the trachea
• Lung
HISTOLOGY OF THE LUNGS
• Peritoneal membrane- plura• Alveoli- capillary network• Interalveolar septa –Elastic Ct
w/ B.V and L.V
Air sacs of lung tissue
Nuclei of squamous epithelial cells
Inter-alveolar septum
Urogenital
Urogenital System
• Consists of excretory and reproductive system• In frog, the skin, the lungs, the liver and the
kidney ---- major excretory organ
Histology of the kidney
• Flattened bean– hilus (medial)
• Tunica fibrosa- Renal capsule (dense collagenous bundles)
• Tunica adiposa
kidney
Histology of the kidney
Divided into:• Cortex • medulla
Structure of the Nephrons
Made up of:• Malphigian body• Uriniferous tubule– Secretory tubules– Excretory/ collecting
tubules
Histology of the Urinary bladder
• Tunica mucosa– Transitional epithelium• Tunica submucosa- Connective tissue and blood vessel• Tunica muscularis–Smooth muscle• Tunica adventitia- Loosely arranged tissue-Covered externally by peritoneum
Tunica muscularisSmooth muscle
Tunica submucosa
Tunica mucosa
Reproductive System
Reproductive
Ovaries-ventral to the kidney-mesovarium-visceral peritoneum
(covering)-egg lies in follicles
Reproductive
Oviducts/Mullerian ducts-whitish convuluted tubes (sides of the body)-extend anteriorly to the lungs
Oviduct-opens anteriorly into the
coelom– ostium-ostium dilates to form the
ovisac or uterus
Oviducts/Mullerian ducts
ovary Ostium of the oviduct
Ovisac/ uterusOviduct proper
cloacaanus
Male reproductive• Testes– Surrounded by visceral
peritoneum– Attached by mesorchium
• Vasa efferentia• Slender tubule that passes
through the mesorchium to the longitudinal canal and then the collecting tubules of the kidney
testis
• Vasa deferentia /wolffian duct– Refers to the ureters– dilate to form seminal
vesicle
testis Vasa efferentia
cloacaSeminal vesicle
anus
• Vestigial oviducts– Wavy whitish tubules
lying besides the ureters• Corpora adiposa
Corpora adiposa