• Shuffle
    Toggle On
    Toggle Off
  • Alphabetize
    Toggle On
    Toggle Off
  • Front First
    Toggle On
    Toggle Off
  • Both Sides
    Toggle On
    Toggle Off
  • Read
    Toggle On
    Toggle Off
Reading...
Front

Card Range To Study

through

image

Play button

image

Play button

image

Progress

1/61

Click to flip

Use LEFT and RIGHT arrow keys to navigate between flashcards;

Use UP and DOWN arrow keys to flip the card;

H to show hint;

A reads text to speech;

61 Cards in this Set

  • Front
  • Back
General Overview of Endocrine System
produces hormones
maintains homeostasis and coordinates growth
How does Endocrine Hormonal Stimulation compare to Neuronal Stimulation?
slower, more prolonged response
Mechanisms for Hormone Control:
Endocrine
hormone released into circulation to transport to cell
Mechanisms for Hormone Control:
Paracrine
released into CT to affect neighboring cells
Mechanisms for Hormone Control:
Autocrine
Hormone acts on cell it is released from
Classes of Hormones:
Steroids
cholesterol derived
secreted from Testes, Ovaries, and Adrenal Cortex
requires carrier protein
Classes of Hormones:
Small peptides, proteins and glycoproteins
produced in: hypothalamus, pituitary, thyroid, parathyroid, pancreas
dissolve in blood stream, no carrier protein needed
Classes of Hormones:
Amino Acid Analogues
Catecholamines and Thyroid Hormones
produced by neurons and adrenal medulla and thyroid
Catacholamines: no carrier protein
Thyroid Hormones: carrier protein
What are examples of Catecholamines?
Epinephrine and Norepinephrine
no carrier protein required
Receptors for Hormones:
Cell Surface Receptors
interact w/ peptide hormones or Catecholamines
binding causes activation of mb-associated G proteins
2nd messengers are produced
Receptors for Hormones:
Intracellular Receptors (Nuclear)
utilized by steroids, thyroid hormones (can cross membrane)
3 binding domains found on receptor
causes allosteric conformation change
directly regulates gene expression
What are the 3 binding domains found on Nuclear Intracellular Receptors?
Hormone-binding domain
DNA-binding domain
N-terminal domain
Regulation of Hormone Secretion:
Negative Feedback
response decreases original stimulus
more common
Regulation of Hormone Secretion:
Positive Feedback
response increases original stimulus
less common
What does the Pituitary Gland work with to regulate hormone levels of the endocrine system?
Hypothalamus
Components of Pituitary Gland:
Anterior Lobe
glandular epithelial tissue
derived from ectoderm of oropharynx toward brain (Rathke's Pouch)
Pars Distalis, intermedia, and tuberalis
Components of Pituitary Gland:
Posterior Lobe
Neural secretion tissue
derived from downgrowth or neuroectoderm of 3rd ventricle
Pars Nervosa, Infundibulum
Blood Supply of the Pituitary Gland
superior hypophyseal arteries
inferior hypophyseal arteries
Anterior lobe has NO DIRECT arterial supply
what directly regulates Endocrine function of the Pituitary Gland?
Hypothalamic releasing and inhibitory factors
Innervation of the Pituitary Gland
Nerves in Infundibular and Pars Nervosa are components of posterior lobe
Nerves in Anterior Lobe are Postganglionic ANS fibers
Tropic Hormones of Anterior lobe of Pituitary
regulate activity of OTHER endocrine glands
ACTH
TSH-Thyroid Stimulating
FSH-Follicle Stimulating
LH-Luteinizing
Non-Tropic Hormones of Anterior lobe of Pituitary
act directly on non-endocrine target organs
GH
Prolactin (PRL)
Pars Distalis cells
Acidophils
Basophils
Chromophobes
Acidophils:
Somatrotopes
produce GH
regulated by 2 hormones from Hypothalamus
GHRF- Growth hormone stimulating
Somatostatin
GHRF
Growth Hormone-Releasing Factor
stimluates GH release
from Hypothalamus
Somatostatin
inhibits GH release
From Hypothalamus
Acidophils:
Lactotropes
produce Prolactin (PRL)
stimulates initiation of lactation
becomes Chromophobes after secretion
How is secretion of Prolactin from Lactotrophes regulated?
negative feedback
increased Prolactin increases Dopamine
causes decrease in Prolactin secretion
What stimulates Secretion of Prolactin?
TSH from Pars Distalis
VIP
Basophils:
What do Corticotropes produce?
produce precursor of ACTH, called Proopiomelanocortin (POMC)
What can Proopiomelanocortin (POMC) be turned into?
ACTH (Corticotropin)
B-Lypotrophic
MSH
Enkephalin
B-endorphin
What regulates release of POMC from Corticotropes?
Corticotrophin-releasing hormone (CRH) from Hypo
also inhibited by high levels of Cortisol
Basophils:
Gonadotropes
produce FSH and LH
regulated by Gonadotropin-releasing hormone (GnRH)
Basophils:
Thyrotopes
Produce TSH
regulated by TRH from Hypo
what is the function of TSH?
increase production of Thyroglobulin and Thyroid Hormones in Thyroid Follicular Cells
Pars Intermedia
surrounds small cystic cavities
Pars Tuberalis
extends along Infundibulum
cells often contain ACTH, FSH, and LH
Pars Nervosa
NOT endocrine gland
ending point for axons
Piuicyte: specialized Glial Cell
3 sizes of Neuronal Vesicles in Nerve Endings of Nervosa:
10-30nm
10-30nm- contain Oxytocin, ADH, ATP, and Neurophysin
3 sizes of Neuronal Vesicles in Nerve Endings of Nervosa:
30nm
contain Acteylcholine
3 sizes of Neuronal Vesicles in Nerve Endings of Nervosa:
50-80nm
resemble core vesicles of adrenal medulla
ADH Function
increases BP
Increases permeability of tubule or nephron and collecting ducts
ADH release causes increase in Osmolality or decrease in Blood Volume
Oxytcin Function
more potent than ADH
causes contraction of Uterine SM and myoepithelial cells of mammary glands
Thyroid Gland General Features
Bi-lobed
thin CT capsule
Stores its secretory product EXTRACELLULARLY
Thyroid Follicle Cells
contains Colloid
apical surface on Colloid, basal surface on Basal Lamina
Thyroid Follicular Cells
produce T3 and T4
lysosomes and endocytotic vesicles resorb colloid
Parfollicular Cells
secrete Calcitonin
regulates Calcium Metabolism
Thyroid Hormones:
Calcitonin
lowers blood Ca2+ levels
regulated directly by Ca2+ fluid levels
Thyroid Hormones:
Thyroxine
T4 and T3
regulate cell and tissue metabolism, heat, body growth and development
Regulated by TSH
Thyroid Hormones:
Thyroglobulin
NOT a Hormone
inactive storage form of Thyroid Hormones
Formation of T3 and T4
2 iodinated residues in close proximity undergo oxidative coupling to form Thyroid Hormones
remain stored as colloid within lumen of follicle
Resorption of Colloid
TSH induces follicular cells to uptake Thyroglobulin from colloid
degraded w/ lysosome
free T3 and T4
Release of T3 and T4
cross Basal membrane to lymphatic capillaries
only 5% of circulating cells are active
T4-->T3
T4 only produced by follicular cells
T3 produced by conversion of T4 in kidney, liver, and heart
Parathyroid Gland General Features
Ovoid
Thin CT capsule
fat cells increase w/ age
Chief Cells of Parathyroid
secrete Parathyroid Hormone (PTH)
regulate fetal Ca2+ metabolism
Oxiphils of Parathyroid
no Secretion
thought to be Immature Chief Cells
Parathyroid Hormone (PTH)
activates G proteins and acts as a 2nd messenger
increases Calcium level in blood
decreases blood Phosphate Level
Regulation of PTH Secretion
lower blood calcium: stimulates secretion
High blood Calcium: inhibits secretion
Fxn Parathyroid Hormone (PTH)
stimulates resorption of bone
regulates conversion of Vitamin D to active form
PTH vs. Calcitonin
PTH: slower, longer lasting
Calcitonin: faster, acute