Unit 5 Exam Review KEY
BIOL 255 SI
5A
1) The adenohypophysis is the anterior pituitary gland which is made up of
glandular tissue and is more part of the endocrine system as it synthesizes and
secretes hormones. It is inhibited or stimulated by the hypothalamus.
2) The posterior pituitary is actually part of the brain with neural connections to
the hypothalamus which is referred to as the hypothalamic-hypophyseal tract. It is
the nuclei of the hypothalamus that synthesize oxytocin and antidiuretic hormone
(ADH) and these hormones are transported to the posterior pituitary to be
released.
3) The anterior pituitary gland secretes seven major hormones and six of the
seven are tropic hormones which stimulate other endocrine glands or cells to
secrete other hormones.
4) Another anterior pituitary hormone is the thyroid-stimulating hormone (TSH)
which is made by the thyrotroph cells and these control thyroid hormone
production, which control the metabolic rate. Another hormone is the
adrenocorticotropic hormone (ACTH) which is made by the corticotroph cells that
control the adrenal cortex’s corticosteroid production.
5) The posterior pituitary gland is made of axons of the hypothalamic neurons and
it stores and releases hormones as the axons travel through the infundibulum in
the hypothalamic-hypophyseal tract. Hormones are stored in the axon terminals of
these neurons in the posterior pituitary and when these neurons are stimulated the
axons release the hormone into the bloodstream, so the posterior pituitary is not
an endocrine gland as it is the nervous tissue releasing the hormones.
5B
6) Mechanical digestion is the physical act of chewing, mixing and churning of food,
while chemical digestion is the enzymatic breakdown of food macromolecules into
monomers which can be absorbed from the GI tract into the blood or lymph.
7) The mesenteries consist of a double visceral peritoneum which attach the small
intestine to the posterior abdominal cavity and also the greater omentum which is
referred to the “fatty apron” draping from the stomach and transverse colon.
8) Hepatic portal vein collects nutrient rich venous blood from the digestive tract
and delivers this blood to the liver for metabolic processing and storage, while the
Hepatic Vein drains the liver.
9) The crown of a tooth is covered by enamel which is the hardest substance in the
body, while the root of the tooth is covered by cementum which is calcified
connective tissue which attaches the root to the periodontal ligament that anchors
the tooth in the jaw alveolus and forms the fibrous joint referred to as the
gomphosis.
10) Dental caries are the gradual demineralization of enamel and dentin by
bacterial action, while Periodontitis is a serious gum disease resulting from an
immune response in which results in carving pockets around teeth and dissolving
bone.
5C
11) In the stomach chemical digestion of proteins begins and food is churned, and
converted to chyme.
12) Epithelial lining contain goblet cells that produce alkaline mucus to protecting
epithelial lining from digesting itself. Whereas, the glands of stomach which are
the gastric glands of fundus and body contain mucous neck cells that secrete acid
mucus, and the parietal cells that secrete HCl and intrinsic factor for Vitamin B12
absorption along with chief cells that produce pepsinogen which is activated to
pepsin by the HCl in stomach and pepsin itself, in which protein is digested into
polypeptides and finally enteroendocrine cells that secrete the hormones into the
blood.
13) The functions of the Stomach are to hold ingested food, digest food, physically
and chemically, to deliver chyme to small intestine, enzymatically digests proteins
with pepsin and secrete intrinsic factor required for vitamin B12 absorption.
14) The inner surface of the small intestines contains plicae circulares which are
deep circular folds of mucosa and submucosa which increase surface area 10 fold,
which are made up of villi that are fingerlike extensions of mucosa into lumen which
also increase surface area 10 fold and finally microvilli which are tiny projections
of absorptive mucosal cells’ plasma membranes into lumen which also increases
surface area 10 fold.
5D
15) The structural and functional units of kidney are the nephrons, and the blood is
filtered in the renal corpuscle which is made up of the glomerulus and the
glomerulus capsule, also referred to as the Bowman’s capsule.
16) Every nephron has two capillary beds, the glomerular and peritubular
capillaries. Each glomerulus is fed by an afferent arteriole and then drained by an
efferent arteriole which are narrower than the afferent. The afferent are wider
to accommodate the increased blood pressure so fluids and solutes are forced
from blood through the glomerulus.
17) Filtrate contains no cells, but does contain all plasma components except
protein. Water, nutrients, and essential ions are reasorbed as filtrate and become
urine which contains water, metabolic wastes, and unneeded substances.
18) Ureters have a trilayered wall of transitional epithelial mucosa, smooth muscle
muscularis and fibrous connective tissue adventitia. The ureters actively propel
urine to bladder via peristalsis at intervals of 3 to 4 minutes. Ureters enter
bladder base through the posterior wall and their distal ends close as bladder
pressure increases which prevents backflow of urine into ureters.
5E
19) In the testes the seminiferous tubules produce sperm and converge to form
tubulus rectus which convey sperm to rete testis which then leave via efferent
ductules and enter the epididymis.
20) Interstitial cells produce androgens which in the male is testosterone and the
sustentacular cells form the blood testis barrier.
21) Spermatogenesis takes place in the seminiferous tubules that produce sperm,
which are in various stages of cell division. Mitosis of spermatogonia, forms
spermatocytes, then Meiosis forms spermatids from spermatocytes which are
haploid and nonmotile and in the final phase, spermiogenesis there the spermatids
lose excess cytoplasm and form a tail, becoming sperm.
22) Blood-testis barrier of the Sustentacular cell is made up of tight junctions
that prevent sperm antigens from getting into the blood, because sperm are not
formed until puberty, and their antigens are absent during thymic education.
Spermatogonia which are recognized as “self”, are influenced by hormones
prompting spermatogenesis.
5F
23) The uterine tubes receive ovulated oocyte and provide the fertilization site
then move ovum to uterus via isthmus, then expands distally around ovary forming
the ampulla. If there is scare tissue in the uterine tubes’ endometrium it may not
allow the fertilized ovum to pass to the uterus and an ectopic pregnancy may
result.
24) The Corpus luteum is the ruptured follicle after ovulation which produces
progesterone and estrogen then degenerates into the corpus albicans.
25) Ampulla ends in the funnel-shaped ciliated infundibulum containing fingerlike
projections referred to as fimbriae. The uterine tubes have no contact with the
ovaries. The ovulated oocyte is simple cast into peritoneal cavity and the beating
cilia on fimbriae create currents that carry the oocyte into uterine tube.
26) The Oocyte is carried to the uterus by peristalsis and ciliary action while the
nonciliated cells keep oocyte and sperm nourished and moist.
27) In oogenesis at puberty, one activated primary oocyte produces two haploid
cells the Secondary oocyte and the First polar body. The Secondary oocyte is
arrested in metaphase II is then ovulated and if fertilized by sperm, the
secondary oocyte completes meiosis II and becomes one large ovum referred to as
a functional gamete. Then sperm (pro)nucleus fuses with the egg (pro)nucleus and
becomes a zygote.