md0006 - BASIC HUMAN ANATOMY.pdf - Raems.com

11. The urinary bladder is a muscular organ for storing the urine. The triangular base
of the urinary bladder is known as the trigone. The two posterior corners of the
trigone are the points where the ureters empty into the bladder. The anterior
corner of the trigone is the opening of the urethra. Nerve endings stimulated by
the stretching of the bladder walls are known as stretch receptors. (para 8-5)
12. The urethra is a tube conducting urine from the urinary bladder to the outside of
the body. It begins at the anterior base of the urinary bladder. There is an internal
urethral sphincter and an external urethral sphincter. The internal urethral
sphincter is located in the floor of the urinary bladder. It is controlled by nerves of
the autonomic nervous system. The external urethral sphincter is more inferior, in
the area of the pelvic floor. It is controlled by nerves of the peripheral nervous
system. (para 8-6a)
13. The female urethra is short and direct. The male urethra is much longer and has
two curvatures. The female urethra serves only a urinary function. The male
urethra serves both the urinary and reproductive functions. (para 8-6b)
14. Since there are different genital systems for males and females, genital systems
are an example of sexual dimorphism. (para 8-7)
15. Primary sex organs produce sex cells (gametes). Primary sex organs also
produce sex hormones. What do secondary sex organs do? Secondary sex
organs care for the product of the primary sex organ. Secondary sexual
characteristics help to ensure mating by making males and females more
attractive to each other. (para 8-9)
16. The primary sex organ of the human female is the ovary. The ovaries are located
to the sides of the upper end of the uterus. They are anchored to the posterior
surface of the broad ligaments. The broad ligaments are sheets or folds of
peritoneum enclosing the uterus and uterine tubes and extending to the sides of
the pelvis. The ovary produces the egg cell or ovum. The ovary produces
chemicals called female sex hormones (estrogens and progesterone). One ovum
is released in each menstrual period. (para 8-10)
17. Uterine tubes are two muscular tubes which extend to either side of the uterus and
open at the outer ends. Fringe-like appendages encircle the ovaries. At their
medial ends, the uterine tubes open into the uterus. The function of a uterine tube
is to pick up the ovum when it is released from the ovary and hold it until (a) it is
fertilized, or (b) the nutrient is used up and the ovum dies. (para 8-11a)
18. The uterus is the site for all but the first few days of the development of the
embryo and fetus. The uterus is shaped like a pear. The stem, or cervix, faces
downward and to the rear. It opens into the upper end of the vagina. The uterus
leans anteriorly with the body slightly curved as the body passes over the top of
the urinary bladder. (para 8-11b)
MD0006 8-20