Download Biology 30 Notes October 3, 2014 Introduction Endocrine System

Biology 30 Notes October 3, 2014 Introduction Endocrine System
Describe the structure and function of the parts of the human eye; i.e., the cornea, lens,
sclera, choroid, retina, rods and cones, fovea centralis, pupil, iris and optic nerve.
Describe the structure and function of the parts of the human ear, including the pinna,
auditory canal, tympanum, ossicles, cochlea, organ of Corti, auditory nerve, semicircular
canals and Eustachian tube.
Make Flashcards for the ear.
Handout for Eye Dissection on Monday.
Lab Report for Brain Dissection.
Inner Ear
Video - https://www.youtube.com/watch?v=p3Oy4lodZU4
3 interconnecting structures, the semicircular canals, the vestibule and the cochlea.
In the cochlea that mechanical energy of sound is converted into the electrochemical impulses that are
transmitted to the brain.
Oval window, separate the air filled space of the ear from the fluid filled space. Vibrations in the oval
window must be converted to pressure waves in the fluid.
Inside the Cochlea – inside the middle chamber is the organ of corti, which is the organ of hearing.
Along the base of the organ of corti is the basilar membrane to which sensory mechanoreceptors known
as hair cells are attached. When the stapes strikes the oval window, this vibrates the window and creates
pressure waves in the fluid of the cochlea. The pressure makes the hair cells bend activating the auditory
nerve.
Biology Notes October 7, 2014
NEW: Endocrine System
What you need to know!!! Check out your data table.
Identify the principal endocrine glands of humans; i.e., the hypothalamus/pituitary complex, thyroid,
parathyroid, adrenal glands and islet cells of the pancreas.
Describe the function of the hormones of the principal endocrine glands, i.e., thyroidstimulating
hormone (TSH)/thyroxine, calcitonin/parathyroid hormone (PTH), adrenocorticotropic hormone
(ACTH)/cortisol, glucagon/insulin, human growth hormone (hGH), antidiuretic hormone (ADH),
epinephrine, aldosterone, and describe how they maintain homeostasis through feedback.
Explain the metabolic roles hormones may play in homeostasis; i.e., thyroxine in metabolism; insulin,
glucagon and cortisol in blood sugar regulation; hGH in growth; ADH in water regulation; aldosterone in
sodium ion regulation.
Nervous System vs Endocrine System
-
NS messages tend to be quick, transmitted rapidly and to precise location in the body
Endocrine System body secretes chemical messengers from glands. Endocrine glands secrete
chemical messengers call HORMONES directly into the blood stream.
System is slower and has longer lasting effects and affects a broader range of cell types.
Assignment – Drawing of a body and main/key glands
Hypothalamus, Pituitary Gland, Spinal Cord, Peripheral Nerves, Thyroid Gland, Adrenal Gland, Thymus,
Pancreas, Testes, and Ovaries.
Example: Pancreas, secretes the hormone insulin into the bloodstream. Insulin affects its target cells by
making them more permeable to glucose.
Homeostasis depends on the close relationship between the nervous system and the endocrine system.
Work together and not always easy to distinguish between the two. Some hormones are also
neurotransmitters and some glands are also parts of the nervous system.
Pituitary Gland “Master Gland”
Located underneath the hypothalamus at the base of the brain.
Only the size of a pea but releases at least 8 different hormones involved in the body’s metabolism,
growth, development, and reproduction.
Often called the “master gland” because it releases many tropic hormones (hormones that trigger other
glands).
It is controlled by the hypothalamus, via releasing and inhibiting hormones.
Two parts (lobes), the posterior and anterior pituitary, separate they release different hormones.
Posterior Pituitary – part of the nervous system since it does not produce any of its own hormones. It
instead stores and releases hormones produced by the hypothalamus. ADH (antidiuretic hormone) and
oxytocin.
Anterior Pituitary – is a true hormone gland. It produces and releases hGH (human growth hormone),
PRL (prolactin), TSH (thyroid-stimulating hormone), ACTH (adrenocorticotropic hormone), FSH
(follicle-stimulating hormone), and LH leutinizing hormone.
Blood vessels carry releasing hormones from the hypothalamus to the anterior pituitary these hormones
either stimulate or inhibit the release of hormones from this gland.
ANTERIOR PITUITARY HORMONES
hGh – Human Growth Hormone
Regulates growth, development, and metabolism, this hormone effect many cells and tissue both directly
and but also has tropic effects.
It stimulates the growth of muscles, connective tissue, and plates at the ends of bones.
Gigantism – too much or excessive amounts of hGH, during childhood development
Dwarfism – not enough hGH, during childhood development
SHOW SOME IMAGES OF GIGANTISM AND DWARFISM
TSH – Thyroid Stimulating Hormone
Is produced and release by the anterior pituitary.
It causes the thyroid gland to secrete thyroxine (T4). The role of thyroxine is to increase the rate at which
the body metabolizes fats, proteins, and carbohydrates for energy.
The thyroid gland lies directly below the larynx (voice box) and has two lobes one on either side of
trachea (windpipe).
Thyroxine is controlled by a negative feedback.
1) The anterior pituitary releases TSH, thyroid stimulating hormone.
2) This causes the thyroid to secrete thyroxine.
3) When thyroxine levels increase it feed back to the hypothalamus and anterior pituitary.
4) TSH secretion is suppressed which supresses thyroxine.
Hypothryroidism – extremely low amounts of thyroxine, adults feel tires, slow pulse, weight gain, and
hair lose.
Hyperthyroidism – over production of thyroxine, stimulate metabolism, releases energy as ATP.
Symptoms include anxiety, insomnia, weight lost, irregular heart beat.
Gland
Hypothalamus
Hormone
Hypothalamic releasing and
inhibiting hormones
Anterior Pituitary
hGH – human growth hormone
TSH – thyroid stimulating
hormone
ACTH – adrenocorticotropic
hormone
FSH – follicle stimulating
hormone
LH – luteinizing hormone
PRL – prolactin
Effect on Target
Regulates anterior pituitary
hormones.
-
-
-
-
Posterior Pituitary
ADH – antidiuretic hormone
OCT – oxytocin
-
Thyroid
Thyroxine (T4)
Calcitonin
-
-
Stimulates cell division,
bone, muscle growth,
and metabolic functions
Stimulates the thyroid
glands
Stimulates the adrenal
cortex to secrete
glucocorticoids
Stimulates the
production of ova and
sperm
Stimulates milk
production from the
mammary glands
Promotes the retention of
water by the kidneys
Stimulates uterine
muscle contraction and
release of milk by the
mammary glands
Affect all tissues,
increases metabolic rate
and regulates growth and
development.
Targets bones and
kidneys to lower blood
calcium by inhibiting
release of calcium from
bone and reabsorption of
calcium by the kidneys.