Life on Land Part 3 Flashcards
Excretory system consists of…
Paired kidneys, ureters and an unpaired bladder and urethra.
Kidney shape and position
Bean-shaped, retroperitoneal
Located in the region of the 4th lumbar vertebra
Hilus
Concavity on the medial side of the kidney.
Where the renal artery and vein and the ureter join the kidney
Internal anatomy of the kidney
Cortex-outer layer of kidney tissue
Medulla-central part
Different parts of the nephron (functional unit of the kidney) reside in the two regions
The kidneys of the are are _______, and are drained by a _____
Metanephric
Ureter (tubular structures extending from the kidneys to the bladder)
Urinary bladder of cat
Musculomembranous, pear shaped sac just anterior to the pubic symphysis
Stores urine before it is released from the body
Land vs water comparison of the kidney
Mammals have a high metabolic rate and require an efficient means of filtering the blood to eliminate a large amount of nitrogenous waste resulting from a high rate of Protein metabolism.
Mammals must conserve water by reabsorbing it from the filtrate. They have more nephrons, a higher glomerular filtration rate, and a higher rate of tubular reabsorption.
Mammals can filter hundreds of times their own body fluid volume in 24 hours, reabsorbed 98-99% of this and produce a highly concentrated urine.
The male reproductive system of mammals consists of….
Parked testes, epididymis, ductus deferens and bulbourethral glands as well as the prostate gland and penis
Mammal testes
Paired oval male gonads which at the time of birth, descend from the abdominal cavity into the scrotum.
On the dorsal surface of each lies an epididymis.
Epididymis
On each testes
Consists of an extensively cooled tube that is connected to the testis by a number of delicate efferent ductules.
Large cranial end is the head and narrow middle part is the body. Expanded caudal portion is known as the tail.
The tube that continues onward from the tail of each epididymis is called the ….
Ductus deferens
It ascends in a coiled fashion in the spermatic cord from the scrotum to the abdominal cavity through the inguinal canal.
Urethra (male)
A tube that extends from the neck of the bladder as far as the tip of the penis.
Homologous Urogenital structures
Cranial tubules of the mesonephros become the efferent ductules of the testis and their highly coiled tips become the head of the epididymis.
The convoluted cranial portion of the Archinephric duct becomes the body and tail of the epididymis.
Thus the amniote epididymis is homologous to the cranial part of the opisthonephros and the Archinephric duct of anaminotes.
Prostate gland
Bi-lobed gland located at the junction of the ductus deferens and the neck of the bladder.
Tiny ducts arising within the gland open into the lumen of the urethra.
Bulbouetrhral glands location
Located on either side of the urethra, dorsal to the root of the penis.
Each opens into the urethra by means of a single fine duct.
Purpose of prostate and bulboerthral glands
Produce seminal fluid that allows transfer of the sperm without the need for water and it also helps to nourish the sperm to keep them viable
Parts of the penis
Glans penis-enlargement at the distal end of the penis and it is covered by a piece of loose skin called the prepuce.
Urogenital aperture-opening at the end of the penis
Erectile tissue:
-corpora cavernosum: lie on side forming dorsal part of the penis.
-corpus Spongiosum: erectile tissue on the ventral surface of the penis in the groove between the corpora cavernosa.
Os penis: small bone embedded in the posterior portion of the penis and helps to stiffen this section
How many young do cats have at a time
What is the length of gestation
How many breeding seasons a year
When are cats capable of breeding
3-12
63 days
3-4
From age 1-9
Female mammal reproductive system consists of…
Ovaries, uterine tubes (oviducts), uterus, and vagina
Oviducts
Coiled ducts that concert the ova to the uterus
Each tube has an expanded free end, the ostium, which receives the ova
The opposite end of each tube leads into a horn of the uterus
How many uterine horns do cats have
2 (expand during pregnancy)
Vagina
Chamber extending from the uterus to the Urogenital sinus
Cervix
Distal end of the body of the uterus that projects somewhat into the vagina and acts as a division between the two regions.
The vagina and urethra open into the….
Urogenital sinus (vestibule)
The small prominence consisting of erectile tissue in the ventral wall of the Urogenital sinus is the
Clitoris (homologous to the penis)
Membranes around fetus
Outermost membrane that enclosed the embryo is the chorion
Amnion is a thin, transparent membrane immediately around the embryo