Download Chapter 34 Biology Notes 2013

Endocrine &
Reproductive
Systems
Chapter 34 Biology
34.1 The Endocrine System
• Hormones and Glands
o Chemicals that are released in one part of the body and
travel to other parts.
o Hormones act on specific cells called target cells or the
message is ignored.
o Over 40 glands exist in our bodies
o Ex: gland: pancreas
• hormone: insulin
• target cells: liver, muscles
Gland
Location
Job
Hormones Released
Hypothalamus
Brain
-Master control
Sends Releasing
-signals pituitary Hormone to pituitary
Pituitary
Brain
ADH, oxytocin, growth
hormones
Pineal
Brain
Thyroid
Neck (at
trachea)
Controls
hormone
secretion of
glands
Control sleep/wake
cycles
Maintains
metabolism
Parathyroid
Next to thyroid
Regulate calcium
Pancreas
Abdomen near Maintains blood
stomach
sugar level
Parathyroid hormoneincrease blood Ca levels
-insulin- decreases blood
sugar levels
-glucagon- increases
blood sugar levels
Thymus
Chest
thymosin
Adrenal
Above kidneys Responds to
stress
Immune response
Melatonin
-thyroxine- metabolism
rates
-calcitonin- reduce blood
Ca levels
epinephrine (also called
adrenaline)
Norepinehprine
• Exocrine Glands
o Tube-like structures (ducts) that secrete directly out of body or
into digestive system.
• Ex: tear ducts, bile duct, sweat glands
• Endocrine Glands
o Release hormones directly into blood
• Ex: pituitary, adrenal, thyroid
• Prostaglandins
o Small hormone-like substances secreted by cells
o “local hormones”
• Steroid v non-steroid hormones
34.2 Glands of the
Endocrine System
• How is the Endocrine System Controlled?
o The HYPOTHALAMUS
o Regulated by negative feedback
o Maintaining water balance (ADH) keeps levels of many
hormones in check.
o Controlling metabolism also affects many hormones
o Body temperature is another method of regulation
34.3 The Reproductive System
• How Hormones Relate to the Reproductive System
Hormone
Releasing Hormone
Follicle Stimulating
Hormone (FSH)
Source
Hypothalamus
Pituitary
Luteinizing Hormone Pituitary
(LH)
Estrogen
Progesterone
Testosterone
Function
Stimulates pituitary
Stimulates sperm production
or
Stimulates follicle and oocyte
development in ovary
Stimulates testes to produce
testosterone or
in females causes follicle to mature
and break open
Follicle and corpus luteum
Causes endometrium to thicken;
development of secondary sex
traits
Corpus luteum
Causes and maintains endometrial
thickening; controls menstrual
cycle.
Testes
Stimulates sperm production;
development of secondary sex
traits
• Male Reproductive System
o Testes (2)
• produce sperm and sex hormones. (equivalent to
ovaries)
• contained in scrotum maintain temperature suitable for
sperm
o Epididymis (2)
• sperm maturation site
• coiled duct from testes.
o Vas deferens (2) tube for mature sperm to travel from
epididymis to ejaculatory duct.
o Ejaculatory duct (2) conduct sperm to penis.
o Urethra- dual purpose duct for sperm or urine.
o Penis- organ for sexual intercourse and expels semen
o Accessory Glands
• Seminal vesicle
secretes fructose and
prostaglandin
• Prostate gland
secretes buffer
• Bulbourethral gland
secretes mucus
• Female Reproductive System
o Ovaries (2)
• oocyte production and maturation
• sex hormone production
o Oviducts (2) fallopian tubes
• connecting tube between ovaries and uterus
• fertilization occurs here.
o Uterus
• chamber for embryonic growth and
development.
• endometrium- inner lining necessary for
embryo
• myometrium- muscle layers for contractions.
o Cervix
• secretes mucus to enhance sperm mobility
into uterus.
• mucus helps reduce embryonic infection.
o Vagina organ for intercourse and childbirth
o Clitoris external organ
sensitive to sexual
stimulation.
o Vulva external fat
padded skin
• Sperm and Egg Production
o For every immature sperm, 4 mature sperm are produced
o For every immature egg, 1 mature egg is produced
o Sperm consist of a head with DNA, mid-piece with
mitochondria and a flagellum.
o Eggs contain all of the cytoplasm and organelles needed
once fertilized
• Ovarian and Menstrual Cycles
o Assume this to be a 28 day cycle, but it does vary in reality.
Phase
Events
# of Days
Follicular
Phase
Menstruation;
endometrium breaks down
1-5
(includes two parts)
Follicle matures;
endometrium rebuilds
6-13
Egg released from ovary
Ovulation
Luteal Phase
14
Corpus luteum forms &
secretes progesterone;
endometrium thickens
15-28
• Fertilization and Embryonic Development
o Gamete formation
o Fertilization
• Sperm + egg = zygote
• 2 haploid cells become 1 diploid
o Implantation
• Burrow into uterus as blastocyst
o Gastrulation
• Ectoderm, mesoderm, endoderm
o Neurulation
o 8 weeks = fetus
o 4-6 mo: complex and specialized cells/tissues
o 7-9 mo: organ systems mature; size and mass changes of
fetus
o 40 weeks is full term pregnancy