Respiratory and Digestive Systems Flashcards
Respiratory system
Delivers O2 to tissues and removal of CO2, exchange of gases across membrane
Open system
External vs internal respiration
External is gas exchange between environment and blood
Internal is gas exchange between blood and tissues
Ventilation
Act of moving environmental medium that O2 and CO2 are being exchanged with water or air
Apnea vs perfusion ventilation
Apnea actively ceasing the movement of media
Perfusion is pumping blood through capillaries
Ficks law of diffusion
Rate = kA(p2-p1)/D
Partial pressure vs concentration
partial pressure changes with altitude while concentration in constant
For high rate of diffusion (4)
high partial pressure difference, high surface area, low wall thickness, and wet surface
cutaneous respiration
breathing through skin, mostly seen in small organisms, common in amphibians
gills
dense capillary beds in the branchial region of the head, gas exchange occurs between water and capillaries
external gills
protrude out into the water, found in most amphibians and larval vertebrates, often have muscle at base that allow for gills to be waved back and forth
internal gills
associates with pharyngeal slits,
supported by branchial arches,
blood fed by aortic arches, covered in bony shields called operculum
gill structure
primary lamella branch from branchial arches and support secondary lamella
secondary lamella house capillary beds that exchange gas with water
afferent and efferent arteries in branchial arch
how do gills increase surface area?
have lots of tiny folds
why is ventilation key
blood moving through capillaries is constantly being replaced by new deoxygenated blood
water must be moved over the gills at a constant pace to keep exchange going
cilia
microscopic hair-like organelles found in anatomical systems, beating over cilia, create small scale flow that brings water over respiratory surfaces
ram ventilation
fish create movement over gills by opening their mouth as they swim
dual pump
2 pumps- buccal and opercular result in almost continuous unidirectional flow across the gills
dual pump structure
gill curtain lies between buccal cavity and opercular cavity
oral valve is mouth opening
opercular valve is creates by opercular flap over the gills
dual pump phases
suction phase: opercular valve is closes, orval valve is open, both cavities expand causing water to flow
force: opercular valve opens, oral valve closes, buccal and opercular cavities are compressed (pushing water across gills)
countercurrent exchange
water and blood move in parallel opposite directions so there is constant exchange
basic anatomy of lung
deformable bags in the thoracic cavity, covered in epithelial cells to allow the gas transfer, connect to the environment via the trachea, glottis muscle opens and closes the entrance to the trachea, trachea branch into brachial, bronchi divide into bronchioles
swim bladders
air-filled sacs in fish that fulfill both respiratory and hydrostatic functions help maintain buoyancy
swim bladder vs lung
swim bladder located more dorsal to digestive tract
swim bladder is usually single sac
blood from swim bladder does not return to the heart
respiratory gas bladder is swim bladder that aids in supplementary gas exchange
physoclistous bladders do not maintain connection to pharynx to fill with air
physoclistous bladders
O2 fed to swim bladder via gas gland
rete mirabile feeds blood to gas gland
oval removes O2 and is controlled by smooth muscle
rete mirabile
cluster of capillaries that feed blood to the gas gland and allow absorption of oxygen
faveoli in lungfish
pair of lungs fed by trachea from esophagus
walls of lung covered in septa
septa create faveoli
faveoli open the main chamber of the lungs
faveoli
compartments created by septa that increase surface area
faveoli in reptiles
on the surface of the lungs, controlled by smooth muscle
alveoli
air sacs which act as focus (and only place) of gas exchange in mammalian lung, capillaries surround cluster of alveoli at end of bronchiole trees, alveoli have greater SA with branched compartments
mammalian respiratory tree
respiratory channel is divided creating tree like structure- trachea, bronchi, and bronchioles, branches terminate into comparments called alveoli where gas exchange occurs
ventilation muscular pumps
dual pump
buccal pump
aspiration pump
buccal pump
In fish
two stroke pump- mixes old and fresh air
four stroke pump- requires twice the number of movements of single cycle
two stroke pump vs four stroke pump
two stroke (amphibians): has expansion to draw air in then compression to expel air
four-stroke (air breathing fish): has inhalation phase (intake then pushed into lungs) and exhalation phase (old air moves to mouth then expelled to air)
aspiration pump
separates feeding mechanism from the respiratory system
bidirectional movement of air
lung within pump, and size is manipulated by musculature
muscles open chest to pull air into lungs and compresses to move air out
mammalian ventilation
comes from movement of ribcage
during inhalation external intercostalis muscles between ribs pull ribcage in and diaphragm contracts
during exhalation internal intercostalis muscles pull ribs inward and diaphragm relaxes
ventilation and locomotion
when limbs contact the ground it shifts the ribcage
viscera move back and forth during locomotion pushing diaphragm and lungs in rhythm
lungs in snakes
have elongated single lung
bird lungs
no avleoli at end of bronchiole passages
air passage in one way path and divide into parabronchi lined with air capillaries
air flow in birds
inhalation: trachea to posterior sac, air in lungs enters anterior sac
exhalation: posterior sac to lungs, anterior sac air pushed out, air leaves trachea
cross current
blood and medium flow perpendicular to each other
the constant partial pressure difference between blood and air
uniform pool
air flows into chamber then is expelled
air is constantly replaced maintaining partial pressure
blood in capillaries is the same partial pressure as oxygen
digestion
breakdown of food items into nutrients, chemical and mechanical
absorption
uptake of nutrients
elimination
removal of waste
boundaries of buccal cavity
oral openings is entrance to buccal cavity from environment
lips form margins (normally at back end of tooth row)
mammals have cheeks that hold food (lips meet near front)
primary palate
roof of mouth made from ventral skull bones, formed from dermal bones, in some fish and tetrapods openings allow for nasal passages to connect to mouth
secondary palate
separates the mouth from nasal passages, lateral bones in crocodiles and mammals fold and meet at the midline, underneath primary palate, divided into hard (front) and soft (back)