Lab 7 Flashcards
What can be said about the similarity of the pulmonary and systemic circulations of turtles, snakes and lizards?
have partially separated pulmonary and systemic circulations
Oxygenated blood is received where in turtles, snakes, lizards?
left atrium receives oxygenated blood from pulmonary veins
Deoxygenated blood is received where in turtles, snakes and lizards?
right atrium receives deoxygenated blood from the sinus venosus
In turtles, snakes and lizards, what happens when the atria contracts?
when the atria contracts, the atrioventricular valves cover the opening of the intraventricular canal, temporarily separating the ventricle into two parts, confining the oxygenated blood in the cavum arteriosum and the deoxygenated blood in the cavum pulmonale
In turtle, snakes and lizards, what happens when the ventricle contracts?
- when the ventricle contracts, the muscular ridge makes contact with the ventricle wall creating a separation between the cavum venosum and cavum pulmonale, preventing a back flow of blood
- the atrioventricular valves close, opening the intraventricular canal, permitting the oxygenated blood in the cavum arteriosum to flow into the cavum venosum and out the aorta, while deoxygenated blood flows from the cavum pulmonale into the pulmonary arteries
When would mixing of oxygenated and deoxygenated blood flowing into the systemic circulation occur in turtle, snakes and lizards?
under physiological stresses like diving
What can be said about the crocodilian and birds’ hearts?
- a complete septum in the ventricle
- four chambered heart
The right atrium of crocodilians and birds receives blood from?
right atrium receives blood from the head and body via the caval veins
The left atrium of crocodilians and birds receives blood from?
left atrium receives oxygenated blood from the lungs via the pulmonary veins
How is blood pumped into the aorta of crocodilians and birds?
left ventricle pumps blood into the aorta
What is the difference between the systemic arches of crocodilians and birds?
crocodilians have left and right systemic arches
birds have only a single right systemic arch
Venous blood is pumped from the right atrium to then go to which other places in the circulation system of reptilians?
venous blood flow from the right atrium, is pumped into the right ventricle, contraction of the right ventricle pumps deoxygenated blood into the pulmonary trunk which branches to the right and left of the lungs as pulmonary arteries
How is ventilation accomplished in reptilians? How does the system work? What is an additional structure that helps accomplish this process in crocodilians?
- lack a diaphragm
- action of aspiration pump
- actions of muscles/ribs enlarges the body cavity around the lung to draw air in and contracted to expel air
- aided by the liver in crocodilians
What allows for ventilation in turtles?
movement of the head and limbs into and out of the shell changes the pressure in the cavity and contributes to inhalation and exhalation
Contraction and relaxation of which muscles in the turtle alters the volume of the visceral cavity and cause inhalation and exhalation?
rectus abdominus and external abdominal obliques
What are the roles of longissimus dorsi and longus colli in the turtle?
extend the neck and head
Where does the longus colli originate and insert in the turtle?
originates and inserts on the cervical vertebrae
Where is the longissimus dorsi located on the turtle and where does it insert?
runs along the vertebral column and inserts on posterior cervical vertebrae
Where does the spinal cervical originate and insert in the turtle? What is its function?
- originates on middle cervical vertebrae and inserts on last cervical vertebrae
- raises and extends the neck
What can be said about the ventricle of the turtle?
has a partially separated ventricle
What can be said about the atrium of the turtle?
the heart is composed of fully separated left and right atria
Describe the various components of blood circulation in the turtle.
- sinus venosus receives deox blood from precaval and postcaval veins and then empties into right atrium
- right aortic arch gives rise to brachiocephalic trunk, which then separates into two subclavian arteries
- brachiocephalic trunk also gives rise to pair of common carotid arteries from its dorsal surface
- ventral cervical artery arises from subclavian artery
- axillary artery gives rise to vessels to plastro, pectoral girdle and forelimb
- left and right aortic arches give rise to the dorsal aorta, which gives rise to the arteries to the digestive tract
- pulmonary trunk becomes right and left pulmonary arteries
- right pulmonary artery passes into lung
Which three large vessels emerge from the ventricle of the turtle?
right aortic arch, left aortic arch and pulmonary trunk
Which vessel that emerges from the ventricle carries the most highly oxygenated blood in the turtle?
all the blood to the head and forelimbs originates from the right aortic arch and therefore carries the most highly oxygenated blood
Which vessel that emerges from the ventricle receives primarily deoxygenated blood?
pulmonary trunk
Function of the stomach?
secretes acids and enzymes to digest food
Function of the liver?
detoxification, secretes bile
Function of pancreas?
secretes enzymes and digestive juices into the intestine for further digestion
Function of gall bladder?
storage of bile
Function of caecum?
absorbs fluids and salts after digestion
Function of spleen?
filter for blood, recycling red blood cells
What would be the consequence of a blockage in the cystic duct?
gall bladder would become inflamed due to bile accumulating but not being able to exit this place of storage
Which has a greater diameter and is shorter in length, the small intestine or the colon?
colon
What is the cloaca?
the common opening for both the urogenital and digestive tracts
Where does the gastric artery lead?
to the stomach
Where does the coeliac artery lead?
to the stomach, pancreas, liver, small intestine, spleen, liver
Which blood vessel would be most dangerous to cut?
Dorsal aorta since it is the origin of the right and left aortic arches (major vessels of the heart)
Which sheets of muscles within the turtle’s shell contract and relax to force air in and out of the lungs?
- diaphragmaticus and transverse abdominals compress the cavity to cause exhalation
- glottis opens and obliques expand abdominal cavity for inhalation
How can air pressure be altered to help the aspiration pump of the turtle?
moving limbs in and out of the shell
What supports the trachea of the turtle? Function?
cartilaginous rings that help for support and allow the trachea to move and flex during breathing
The trachea of the turtle bifurcates in the region of the heart into which structures?
left and right bronchi which pass into the lungs
the bronchi of the turtle are in close association with which arteries?
pulmonary arteries
Where are the lungs located in the turtle?
lungs adhere closely to the inner surface of the carapace
What is the function of the septa in the lungs?
internal septa increase surface area for more efficient gas exchange
Accessory bladders function?
paired vascularized sacs that are extra storage spaces for air and water
Kidneys function
filter blood, balance body fluids, create urine
Urethra function
drains urinary bladder
Ovaries function
where developing eggs are located in the mother turtle
What can be found in the inner surface of the ostia of the mother turtle?
has cilia lining the inner surface of the ostia which create currents to draw the eggs into it
Oviduct function
transports mature egg from the ovary to the uterus of the mother
Epididymis function
sperm from the testis are stored and mature here before passing into the vas deferens
How is the penis divided in the turtle?
divided into two long ridges by a deep median urethral groove
What are the multifidid cervicis in birds?
a complex group of small muscles which each surround a cervical vertebra, giving the neck flexibility
Function of the longus colli in birds?
moves the neck down and forward
Which two muscles in birds make up for 20-30% of their body weight? Why is this advantageous?
pectoralis and supracoracoides = flight muscles
allows for stronger flying and lift off the ground to escape from predators or travel long distances
Which muscles are responsible for the upstroke and downstroke of the bird? Which is an adductor and abductor?
Pectoralis=contracts, downstroke, wing toward body, adductor
Supracoracoide=contracts, upstroke, raises wing, abductor
Describe the relative size of the axial muscles of the bird. What aspect of the bird skeleton allows for this reduction?
axial muscles are reduced since add extra weight for nothing
the keel is less weight and allows for better muscle attachment of flight muscles
Where does air pass in the bird?
into oral cavity, tracea, through bronchci, to parabronchi (air tubes) in lungs
What is the syrinx in birds?
sound producing organ formed by modifications of tracheal rings, bronchial half rings or both
What kind of respiratory system do birds have?
system of air sacs (reservoirs of inhaled air) that have no blood vessels
When does gas exchange occur in birds?
-exchange of air occurs on exhalation as air passes out of the air sacs back into the lungs
What is the name of the membrane that contains the heart of the bird?
pericardium
The heart of the bird has how many chambers?
four chambers: two thin walled atria and two large thick ventricles
Due to the absence of teeth, what adaptations do birds have in their digestive tract to compensate for this?
- food storage in the crop
- mechanical digestion of food in gizzard (due to no teeth)
In some birds, like pigeons, the esophagus has what type of special adaptation?
esophagus has out-pocketings that can be inflated and used to resonate sounds in courtship displays, used as visual signals, carry seeds
What are the two parts of the stomach of birds?
proventriculus and gizzard
What type of birds have well-developed gizzards?
seed eating birds
Which is the largest organ in the bird?
liver
What is strange about the kidneys of birds?
are irregularly shaped and have three lobes
How is a kidney divided?
medulla and cortex
With the exception of South American rheas, what do birds lack in their excretory system that was seen in turtles? How does this relate to nitrogenous waste that they produce?
birds do not have a urinary bladder for storage, probably due to the uric acid they produce is quite toxic and therefore cannot be stored inside their body (must be excreted right away)
What is the role of the vasa deferentia in male birds?
carry sperm from the testes to the cloaca
How many ovaries does a female bird have?
one functional ovary on the left side (right ovary is vestigial if present)
In the snake, what are the two main extensor muscles? What are they used for?
- semispinalis and longissimus, held under high tension with ligaments
- striking involves rapid extension of these muscles along parts of the body curve
What do you notice about the general morphometrics of the snake viscera?
All viscera are elongated and flattened due to the snake’s long and thin shape
What is the purpose of the glottis in snakes?
can be protruded so that the airway is not obstructed as prey is swallowed
What other digestive adaptations are seen in snake viscera?
- esophagus is very long and has more internal folds to swallow large and whole prey
- peristaltic movement in esophagus
Where is the heart located in snakes?
a third of the way down the body of the snake
What is different about the lungs of the snake?
- have a single functional right lung and a small nonfunctional left lung
- right lung extends more than half the length of the snake
- also have a tracheal lung (vascularized sac that extends from the trachea and found next to the right lung)
Function of the bird muscle called peroneus longii?
flexes the digits
What is the order through which food passes through the digestive system of the bird?
1) esophagus
2) crop
3) proventriculus
4) gizzard
5) small intestine
Match.
Cystic duct, accessory bladders, duodenum, anus
additional respiratory organ, connection between gall bladder and duodenum, part of small intestine closest to stomach, external opening of cloaca
cystic duct-connection between gall bladder and duodenum
accessory bladders-additional respiratory organ
duodenum-part of small intestine closest to stomach
anus-external opening of cloaca
