lecture exam 3 Flashcards
Define Afferent
Carries towards a structure
Define Efferent
Carries away from a structure
How many gill pouches do Hagfish have?
5-15
What is the pattern of respiration for most Hagfish?
H2O > Velar chamber > afferent branchial ducts > 1 duct + slit
How many pairs of gill pouches and gill slits do Lampreys have?
7 pairs
What type of ventilation do Lampreys use?
Tital Ventilation
What is tital ventilation?
Water or air goes in and out of the same opening
How many gill pouches do Chondricthyes have?
5 pairs
What is the spiricle?
A one-way valve
What is a demibranch?
Each gill surface
What is a holobranch
2 demibranchs + interbranchial septum
Describe one side of the pharynx of Chondrichthyes.
1 pseudobranch, 4 holobranchs, and 1 demibranch
What structure allows water flow into the first two gill pouches?
Spiracle
What structure allows water flow into the last three gill pouches?
Mouth
What is Ram ventilation?
What is the issue with this kind of ventilation?
Organism must swim continuously with mouth open.
It requires a lot of energy
What kind of ventilation is used by most organisms?
Suction/Force pump
What is the suction pump responsible for?
Inspiration (negative pressure)
What is the force pump responsible for?
Expiration (positive pressure)
How does the suction pump function?
mouth > spiracle open > gill flaps shut + pharynx expands
How does the force pump function?
close lower jaw > gill flaps open > pharynx compresses
What are new modifications of the bony fish?
No spiracle
Gain operculum + chamber
Interbranchial septa are short
What is an advantage of interbranchial septa being shortened?
There is more surface area exposed to the water
What kind of ventilation do bony fish use?
Suction/force pump
What is the advantage of suction/pump ventilation?
There is continuous flow of fresh water
Name two kinds of respiratory sacs.
Swim bladder and lungs
What group was the swim bladder first recognized in?
Osteicthyes
What is the function of a swim bladder?
Maintain buoyancy within water column
What does the Physostome swim bladder connect to?
The stomach
What groups have a physostome swim bladder?
Primitive bony fish and lungfishes
How are physostome swim bladders filled with air?
Air is gulped at the surface
How is air emptied from a physostome swim bladders?
Burping
Describe the connection of physoclistous swim bladders.
No gut connection
How do physoclistous swim bladders fill with air?
By diffusing O2 from blood
What do gas glands do in physoclistous swim bladders?
Increase the concentration of O2 next to bladder
What does the ovale do in the swim bladder?
Removes gas
Name four kinds of respiration in amphibians
- gills
- cutaneous
- buccopharyngeal
- lungs
What kind of amphibians have gills?
aquatic adults and larvae
What allows cutaneous respiration in amphibians?
Highly vascularized skin
What allows buccopharyngeal respiration in amphibians?
The oral cavity is highly vascularized
What is the first step of respiration through lungs?
Nares open and pharynx expands to draw air in
Where is fresh air held in organisms that have lungs?
The pharynx
How is stale air forced out of the lungs?
The glottis opens and abdominal muscles contract
How is fresh air forced out of the pharynx and into the lungs?
Nares close and pharynx collapses
Describe lungs in amphibians
simple air sacs
Describe lungs in amniotes
highly modified to increase internal surface area
What kind of lungs do synapsids have?
Alveolar lungs
Describe the structure of alveolar lungs
- The trachea splits into primary bronchus
- Primary branches a ton
-ends in respiratory sacs
What are the respiratory sacs of alveolar lungs and what are their function?
Alveoli - increase surface area
What kind of lungs do sauropsids have?
Faveolar lungs
Describe the structure of faveolar lungs
- Primary bronchus branches once or twice
- Primary bronchus leads to chambers of air capillaries
What group of tetrapods lost/reduced their left lung?
snakes
What is the major difference between the ventilation in amphibians and amniotes?
Amniotes have long ribs
Describe the basic respiration system of amniotes
Negative pressure system
What group has a diaphram to assist in respiration?
Mammals
What group has a diaphramatic muscle? What does it connect to?
Crocs - connects pelvis and liver
What kind of ventilation do mammals use?
Tital ventilation
What relaxes/contacts during inhalation in mammals?
Diaphram and external costal muscles contact
What kind of pressure is created during inhalation?
Negative pressure
What relaxes/contacts during exhalation in mammals?
Diaphram relaxes and internal costal muscles contract (collapse rib cage)
What kind of pressure is created during exhalation?
positive pressure
Describe the ribs of turtles
Ribs are fused to carapce
What are lungs attached to in turtles?
Viscera (digestive organs)
What muscle contraction is responsible for moving the limiting membrane and viscera cranially during exhalation in turtles?
Transversus abdominis
Where is the transversus abdomonis connected to the viscera in turtles?
Posterior limiting membrane
What muscle pulls the shoulder caudally and pushing viscera into lungs during exhalation in turtles?
Pectoralis muscles
What muscles pulls the posterior limiting membrane and the viscera caudally during inhalation in turtles?
abdominal obliques
What muscles pull the lungs down to increase lung volume during inhalation in turtles?
Serratus muscles
What makes up the respiratory system of birds?
9 air sacs and paired lungs
What is the function of air sacs in birds?
To increase the respiratory system’s capacity.
- NO gas exchange
Does gas exchange occur during inhalation or exhalation in birds?
Both
Name two types of blood vessels
Arteries and veins
What is the function of veins?
Carry blood to the heart
What is the function of arteries?
Carry blood away from the heart
What is the inner layer of a blood vessel called? What is it made of?
Intima- made of endothelium
What is the middle layer of a blood vessel called? What is it made of?
Media - made of smooth muscle
What is the outer layer of a blood vessel called? What is it made of?
Adventitia - Made of elastic fibers, connective tissue
Describe the blood pressure and flow rate of arteries.
High pressure and high flow rate
Why do arteries have high blood pressure and flow rate?
Close to the heart + receive pressurized blood
Describe the media and adventitia layer of arteries
Both are thick and have elastic fibers
Describe the blood pressure and flow rate of veins
Low pressure and low flow rate
Why do veins have a low blood pressure and flow rate?
Blood is farther from the heart
Describe the media and adventitia layer in veins
Both are thin
What is the function of valves in the circulatory system?
Prevent backflow of blood
Describe the blood pressure and flow rate of capillaries
Lowest pressure and flow rate
Why do capillaries have the lowest blood pressure and flow rate?
They do not have muscle or connective tissue
Describe the blood flow into capillaries
Only portions of capillaries have blood at a time
What is the function of smooth muscle in arterioles?
Decrease the blood flow to capillaries
What is the function of precapillary sphincters?
Stop blood flow- they are a muscular shut-off valve
Define shunt
Blood flow around capillaries
What is single circulation?
Blood is pumped once to make a single circulation of the body
What vertebrates are the exceptions to single circulation?
lungfishes (bony fish)
What is double circulation?
blood is pumped twice by the heart to make a full circuit through the body
What vertebrates have double circulation?
lungfishes and tetrapods
What is the advantage of double circulation?
Increases blood pressure and flow rate
what is the pulmonary circuit?
Blood goes through the lungs
What is the systemic circuit?
Bood goes through the body
Describe the pattern of circulation in larval amphibians
Systemic circuit only
Describe the pattern of circulation in adult amphibians
Both pulmonary and systemic circuit
How many chambers are there in fish hearts
4
Name the chambers of the fish heart
- Sinus venosus
- Atrium
3.Ventricle
4.Conus arteriosus
What is the conus arteriosus modified into in the fish heart?
Bulbous arteriosus
What is the function of the ventricle in the fish heart?
Create pressure for circulation
Describe the sinus venosus
Thick, connective tissue
What is the function of the atrium in the fish heart?
Pump blood to the ventricle
What vertebrate groups first develop an interatrial septum?
Lungfish and amphibians
What does the interatrial septum do?
separates the atrium into left and right sides
Why is the interatrial septum important?
It keeps pulmonary and systemic blood separate
What vertebrate groups are considered to have a 3-chambered heart?
Lungfish and Amphibians
What vertebrate group has an interventricular septum?
lungfishes
What vertebrate group has ventricular trabeculae?
Amphibians
Where is the spiral valve located in the circulatory system?
Conus arteriosus
Where does the spiral valve direct O2-rich blood?
aorta
Where does the spiral valve direct O2-poor blood?
pulmonary
How many chambers is the amniote heart?
Most have 4
What chamber is lost in amniote hearts?
Conus arteriosus
What happens to the sinus venosus in birds and mammals?
It is fused to the R. atrium
What vertebrate groups have a complete septum between atria and ventricles?
crocs, birds, and mammals
What are auricles? What vertebrate group has them?
Blind sacs off the atria- found in mammals
What is the function of Auricles in mammals?
Increase the capacity of atria
What groups of vertebrates have a 3rd ventricle?
Turtles and squamates
What is the name of the 3rd ventricle in turtles and squamates?
Cavum Venosum
where is the Cavum Venosum located?
Between the R +L ventricle
What is the function of the Cavum Venosum?
Shunt blood to or away from certain arteries when under certain environmental conditions
What is the function of amniote heart valves?
allow pumping of blood and prevent backflow
Where are the semilunar valves located in amniote hearts?
Between the ventricles and arteries
Where are the atrioventricular valves located in amniote hearts?
Between the atria and ventricles
What are the words that describe the number of cusps in reptile hearts?
Unicuspid or bicuspid
What are the words that describe the number of cusps in bird and mammal hearts?
Bicuspid or tricuspid
Does the left or right ventricle have thicker muscle? By how much?
Left ventricle: 3-6 x thicker
Why is the left ventricle thicker than the right?
Under high pressure for a long systemic circuit (pumps blood to the entire body)
What does the first aortic arch become in sharks?
The afferent and efferent spiracular arteries
What does aortic arch 2-6 become in sharks?
The afferent and efferent branchial arteries.
What aortic arches are usually lost in bony fishes?
Aortic arches 1 and 2
Why do bony fish lose aortic arch #1?
They do not have a spiracle
Why do bony fish lose aortic arch #2?
They have fewer gills
What aortic arches are lost in tetrapods?
Aortic arch 1 and 2
What becomes the internal carotid artery in tetrapods?
Aortic arch #3 and cranial dorsal aorta
What becomes the external carotid artery in tetrapods?
Ventral Aorta
Where do the internal and external carotids supply blood?
To the head
What does aortic arch #6 become in tetrapods?
The pulmonary artery
What group is the pulmonary artery first seen in?
The lungfishes
What is the dorsal aorta section between arches #3 and #4 in tetrapods?
Ductus Caroticus
What is the dorsal part of arch #6 in tetrapods?
Ductus Arteriosus
How many aortic arches do terrestrial salamanders have?
4 arches
How many aortic arches do aquatic and gilled salamanders have?
3 arches, with pulmonary artery
Which aortic arches fuse in aquatic salamanders?
Arche 5 and part of #6
What does the gill bypass do?
Opens when breathing air, constricts during gil operation
What happens to the gill bypass when H2O and O2 levels drop?
Gill bypass opens + blood flows around gills to dorsal aorta > pulmonary artery > lungs
What two structures are lost in terrestrial frogs/toads?
- Ductus caroticus
- Ductus arteriosus
What is aortic arch #3 called in terrestrial frogs/toads?
Carotid arch
What is aortic arch #4 called in terrestrial frogs/toads?
Systemic arch
What is the remaining part of arch #6 in terrestrial frogs/toads?
Pulmonary artery
What circulatory pattern do larval frogs/toads have?
The same as aquatic salamanders
What aortic arches are retained in reptiles?
3,4, and 6 (same as frogs)
What arches are usually lost in reptiles?
Ductus arteriosus
Ductus caroticus
Which vertebrate group is the first to lose the spiral valve in their heart?
Reptile
How are high O2 and low O2 blood kept separate?
The ventral aorta splits into three trunks
Name the three trunks the ventral aorta splits into.
- pulmonary arch
- left systemic arch
- right systemic arch
What is odd about systemic arch attachment in crocodiles?
Right systemic arch is attached to the left ventricle
The left systemic arch is attached to the right ventricle
What is the foramen of panizza?
Opening between the R and L systemic arches in crocs
What is the function of the foramen of panizza?
Shunt high O2 blood from R to L systemic arch
Why does the valve close during normal circulation in Crocs?
High-pressure blood from L ventricle pushes the valve closed
What is the importance of the foramen of Panizza and valve in the normal circulation of Crocs?
Prevents low O2 blood from the R ventricle entering the L systemic arch
What modification do crocs have that allow them to stay underwater for long periods?
Lung bypass
What are the advantages of crocs having lung bypass?
- No loss of O2 or energy at lungs
- more blood in systemic circuit + more O2 extracted
How many trunks make up the ventral aorta in birds and mammals?
2
Name the two trunks of the ventral aorta in birds and mammals.
- Pulmonary arch
- Aortic arch
Which ventricle is the pulmonary arch attached to?
Right Ventricle
Which ventricle is the aortic arch attached to?
Left ventricle
Where does the systemic arch in mammals carry blood to in mammals?
Most of the body
Where does the subclavian artery carry blood to in mammals?
Right forelimb
Which vertebrates have a complete and paired dorsal aorta in the pharynx?
Only gilled vertebrates
Which vertebrates have a paired dorsal aorta in their head, that becomes the internal carotid artery?
All vertebrates
Name the specific somatic branches formed from the trunk of the dorsal aorta
Subclavian, parietals, iliacs, and caudal
Where do the subclavian branches carry blood?
Forelimbs/pectoral fins
Where do the parietal branches carry blood?
Around the body wall
What is the name of parietal branches in amniotes with ribs?
Intercostals
Where do iliac branches carry blood?
hindlimbs/pelvic fins
Where do caudal branches carry blood?
Tail region
Name the specific unpaired visceral branches formed from the trunk of the dorsal aorta
Coeliac, Cranial mesentaric, and caudal mesenteric
Where do coeliac branches carry blood?
Liver, duodenum, stomach, and spleen
Where do cranial mesenteric branches carry blood?
Intestine and pancreas
Where do caudal mesenteric branches carry blood?
colon
What venous channels are present in all vertebrates?
1.cardinals
2.renal
3. lateral abdominals
4.hepatic protals
5.hepatic sinuses
6. coronary veins
What is the function of coronary veins?
Drains heart muscles and returns blood to sinus venosus / vein close to heart
What vertebrate groups have a pulmonary vein?
lungfishes and tetrapods
What does the anterior and posterior cardinal veins drain in jawed fish?
anterior: drains head
posterior: drains kidneys
Where do the anterior and posterior cardinal veins empty in jawed fish?
To common cardinal vein
What is a portal system?
Veins are bound by capillaries at both ends
Where do the lateral abdominal veins receive blood from in jawed fish?
Pelvic fins, cloaca, and pectoral fins
What does the hepatic portal system do in jawed fish?
Drain blood from digestive organs to the liver
What does the hepatic sinus vein do in jawed fish?
Drain blood from liver to sinus venosus
What venous channel is lost in bony fishes?
Lateral abdominals
Where does the pelvic region drain to in bony fishes?
posterior cardinals
Where does the pulmonary vein drain into for all tetrapods?
Left atrium
What venous system is lost in all tetrapods?
Posterior cardinal and hepatic sinuses
What replaces the posterior cardinals and hepatic sinuses in tetrapods?
Postcava
What does the anterior and common cardinal veins become in tetrapods?
Anterior: internal jugular
Commons: left and right precava
What do the posterior cardinals become in mammals?
Azygos and hemiazygos
What do the azygos and hemiazygos drain in mammals?
intercostal spaces
What is the left precava called in humans + mink?
cranial vena cava
What happens to lateral abdominal veins in amphibians?
they unite and become ventral abdominal vein
Where does the ventral abdominal vein empty?
into liver
What vertebrate groups lose the lateral abdominal veins?
birds and mammals
Where does the pelvic region drain in birds and mammals?
postcava
describe the hepatic portal system in tetrapods
drains digestive organs
what are the vessels in the hepatic portal system of tetrapods
gastrosplenic vein
cranial mesenteric vein
caudal mesenteric vein
what does the gastrosplenic vein drain?
the spleen and stomach
what does the cranial mesenteric vein drain
the intestines and pancreas
what does the caudal mesenteric vein drain
colon
what are lost in most tetrapods?
hepatic sinuses lost
posterior cardinal veins (replaced with post cava)
what does the lymphatic system do?
removes H2O from interstitial spaces (interstitial spaces=the fluid-filled area between cells and blood vessels in tissue)
what is the fluid inside interstitial spaces called?
lymph
how does lymph flow in the body?
towards heart
assisted by lymph hearts (lacking in birds and mammals)
empties into veins
what are lacteals?
lymphatic vessels that absorb lipids from intestines
where to lacteals empty in mammals
empties into thoracic duct and left brachiocephalic vein
what are lymph nodes?
masses of hemopoietic tissue only found in birds/mammals
what lymph node do most vertebrates have
spleen
considered the largest lymph node
what does hemopoietic mean?
produces blood cells
what do lymph nodes contain?
phagocytes and lymphocytes for “filtering” lymph
what is the importance of the lymphatic system?
blockage can cause serious disease such as one caused by nematodes (elephantiasis) where fluid builds up due to blockage
what are the parts of the urogenital system?
kidneys and ducts
reproductive tracts
what are the function of kidneys?
filter nitrogenous waste from blood and osmoregulation
what is osmoregulation?
balancing movement of H2O and solute in and out of the body and external environment
what problems do terrestrial verts have with osmoregulation?
lose H2O to environment
what problems do aquatic verts have with osmoregulation
freshwater: hyper osmotic, body have greater concentration than freshwater, body takes in too much water
marine: hypo osmotic, water has higher concentration that body, body loses water
how do terrestrial verts handle problems with osmoregulation
- kidneys can conserve H2O when the body is dehydrated by removing excess H2O from urine (liquid metabolic waste), making it more concentrated
- concentrated nitrogenous waste
- salt glands remove salt from blood (arid squamates and marine birds)
what is the problem with osmoregulation for freshwater bony fishes and their solutions
problem: gain H2O and lose salt from gills
Solution: get salt from diet, have chloride cells that keep salts in, kidneys excrete very dilute urine
what do chloride cells do?
keep salts in or out by moving them against the concentration gradient via active transport
what is the problem with osmoregulation in marine bony fish and what are their solutions?
problem: lose H2O and gain salt through gills
Solutions: drink seawater, chloride cells remove salts, kidneys remove salts and excrete concentrated urine
what is osmoconformity?
when an animal is isoosmotic, meaning there is the same concentration inside the body and outside
what animals osmoconform?
most invertebrates
rare in vertebrates: ONLY hagfishes
what are the benefits and disadvantages of osmoconformity?
benefits: save energy
disadvantages: limited in distribution because they can only tolerate one salt concentration
what are the 3 types of nitrogenous waste products?
ammonia
urea
uric acid
what is the byproduct of protein digestion?
ammonia
what is ammonia?
high solubility and high toxicity
must be excreted in very dilute urine
good in freshwater fish and aquatic amphibians
what do the animals that can’t use ammonia as their waste product do?
converted from ammonia by the liver
the disadvantage of this is it costs energy
what is urea?
less toxic, less H2O (conserve water)
good in mammals and terrestrial amphibians
what is special about the waste products of marine fish?
they excrete both ammonia and urea
what is uric acid?
conversion from ammonia (requires lots of energy)
insoluble in water and least toxic (conserve the most water)
good in birds and most reptiles
why is uric acid good in bird and most reptiles?
they lay eggs and nontoxic waste is beneficial if embryo is stuck with the waste in a shelled egg
how do cartilaginous fish osmoregulate?
they retain urea in the body to increase internal solute concentration
are hyper osmotic to seawater (gain water and salts thru gills)
how do cartilaginous fish get rid of excess salt since they lack chloride cells?
rectal gland excretes excess salt
what is the functional unit of the kidney?
nephron
what is the path of urine after it is produced in the nephron
goes into common collecting tubule then to longitudinal duct then to cloaca or bladder
what are the 3 parts of the nephron
renal corpuscle
renal tubule
peritubular capillaries
what is the structure of the renal corpuscle
made up of glomeruli (singular:glomerulus) which are loops of capillaries and Bowmans capsule which surrounds the glomerulus
what is the function of the renal corpuscle
forces H2O and solutes out (glucose and salts) to become filtrate that goes into Bowman’s capsule
how does the renal corpuscle filter blood?
blood has to be high pressure so it has a smaller efferent arteriole to make sure it can be filtered
what are the functions of the renal tubule and peritubular capillaries?
reabsorption from filtrate (glucose, and H2O/salt IF NEEDED)
secretion into filtrate (puts nitrogenous waste into filtrate)
what animals don’t have the renal tubule and peritubular capillaries secrete nitrogenous waste into the filtrate
most fishes (out gills)
[some salts removed this way in marine fish]
what is a collecting tubule?
many nephrons drain to one connecting tubule which is when the filtrate becomes urine
[especially in tetrapods the collecting tubule can do optional h2o absorption]
what is the mechanism of optional H2o absorption?
body’s dehydration is detected by the hypothalamus which will produce anti-diuretic hormone (ADH/Vasopressin) which will go to the collecting tubule and increase permeability of the collecting tubule to H2O
then, when the body is hydrated ADH production stops
how does alcohol work with ADH?
alcohol inhibits ADH production which means there is more H2O in urine which causes you to pee a lot and possibly dehydrate
what does the nephron look like in freshwater verts?
large glomeruli and short renal tubules to get rid of water quickly
what does the nephron look like in marine verts and terrestrial tetrapods?
small glomeruli and long renal tubules to conserve water
what does the nephron look like in Chondrichthyes?
large glomeruli and medium renal tubules
what does the nephron look like in birds and mammals
renal tubule with Loop of Henle to alter osmotic pressure (to absorb or secrete H2O)
longest in terrestrial mammals
what is the function of the renal portal system?
poorly understood function
allows some filtration of blood from caudal ends
may conserve h2o (limit blood flow to glomerulus= less water loss)
where do kidneys develop from?
mesoderm
what are the 4 types of kidneys?
pronephric
mesonephric
opisthonephric
metanephric
what are pronephric kidneys?
kidneys only present during development (embryonic kidneys) that start from the anterior mesoderm and have pronephric tubules (developing nephrons) that drain to the pronephric duct and then out to cloaca
what are mesonephric kidneys?
pronephric disappears, then mesonephric forms from middle mesoderm
pronephric duct becomes mesonephric duct
what groups have mesonephric kidneys?
all non-amniotes
what are opisthonephric kidneys?
modified mesonephric kidney
nephrons extend toward cloacal region
VERY long mesonephric kidney
what groups have opisthonephric kidneys?
some jawed fish and some amphibians
(Chondrichthyes do)
what are metanephric kidneys?
mesoderm is displaced and offset
amniotes have them
Describe the kidneys in jawed fishes and amphibians
opisthonephric kidneys
anterior end is the sexual kidney called Leydigs gland in males
describe the parts of the sexual kidney in jawed fishes and amphibians
mesonephric tubules now transport sperm= vas efferentia
mesonephric duct takes sperm to cloaca
highly coiled sperm duct= epididymis
HAVE ACCESSORY URINARY DUCTS THAT CARRY URINE
describe the kidneys in amniotes
metanephric ducts= ureters that drain kidneys (to cloaca in most)
in placentals: ureters drain to blader
what are the layers of the kidney in mammals?
renal cortex (external layer)
renal medulla (inner layer)
what is contained in the cortex of mammal kidneys? the medulla?
cortex: renal corpuscles and anterior end of renal tubule
medulla: loop of Henle and collecting tubule
how did the urinary bladder come about?
adaptation for terrestrial life as a water reservoir for later use
which groups have bladders
amphibians, lizards, turtles, mammals
only connected to cloaca in most
how does urine drain out of the bladder?
through urinary papilla
in mammals what connects the kidneys to the bladder? bladder to outside?
kidney to bladder=ureter
bladder to out= urethra
what is the bladder the site of?
optional H2O absorption ( stimulated by ADH)
what are other uses for urine?
marking territory
turtles use it to soften sand to make their nests
what do the gonads do?
produce gametes
synthesize steroid hormones
what are the functions of steroid hormones
maintain reproductive tract
stimulate and maintain secondary sexual characters
what are secondary sexual characters in males? females?
facial hair, deep voice, muscles
curves, menstruation
describe the male gonads
called testes
paired organs with seminiferous tubules where sperm is produced
describe the path sperm take after production
leave testes to vas efferentia to sperm duct to cloaca
which animals are exception to the general path sperm take
cyclostomes: sperm to coelom to cloaca and urogenital papilla
placentals: sperm duct to urethra
what is the mesonephric duct?
duct that drains sperm and urine ( sperm only in Chondrichthyes)
what groups have a mesonephric duct?
many non-amniotes
called vas deferens when duct only carries sperm
what is the marginal duct?
carries only sperm but many merge with mesonephric duct to carry sperm and urine
what groups have marginal ducts?
some fish and amphibians
what’s special about the marginal duct in bony fish
its completely separate, never merges with mesonephric duct
what are the secondary sex glands in amniotes?
prostate
seminal vesicles
coagulating
what do secondary sex glands do?
add materials to sperm to produce semen
what does semen contain?
sperm, nutrients, buffering compounds (to neutralize acidity)
what do seminal vesicles do?
store sperm in most verts
glandular in mammals
what is the coagulating gland?
causes semen to coagulate in vagina creating a copulatory plug which prevents further mating for several hours
which groups have coagulating glands?
occurs in some squamates and some mammals (marsupials, rodents, some primates)
what happens to testes in mammals
they move caudally in development
descend outside the Body
vas deferens is looped over ureters
covered by scrotum
what are the two ways testes can be outside the body?
permanently
temporary (during breeding season then retract back into abdomen)
what animals have temporary testes outside the body
rabbits, bats, some primates
how do mammal testes descend?
occurs through the inguinal canal (passage for testes and spermatic cord (vas deferens and vessels))
why do mammal testes descend?
to keep sperm cooler outside the body for higher survival rate
what are copulatory organ needed for?
internal fertilization
describe copulatory organs in Chondrichthyes
claspers are assisted by siphons (add mucopolysaccharides [energy] and water to flush sperm)
describe copulatory organs in bony fish
gonopodium: modified anal fin
describe copulatory organs in frogs and toads
most do external fertilization
internal fertilization in Ascaphidae (tailed frog)
what is the “tail” in ascaphidae?
tubular outgrowth of cloaca
what are the copulatory organs in squamates?
hemipenes
what groups have an erectile penis?
turtles, crocs, some birds
describe the erectile penis
cloacal floor contains corpus spongeosum (erectile tissue- contains cavities that fill with blood)
urethral groove –> sperm
glans penis: sensory receptors for ejaculation
what is special about a duck’s penis
40 cm corkscrew
describe the mammal copulatory organs
urethra completely enclosed
glands covered by prepuce
3 pockets of erectile tissue
baculum or os penis (in some)
what is the prepuce?
foreskin
what are the 3 pockets of erectile tissue in mammals?
corpus spongeosum
corpora cavernosa (2 pockets)
what is the baculum?
bone that assists with copulation in most mammals
What is the largest baculum in the animal kingdom?
Walrus
Oosik
