A&P2 Chapter 18 Endocrine System
18-2 The endocrine system regulates physiological processes by releasing bloodborne hormones that bind to receptors on remote target organs: Hormones and Extracellular Receptors: second messengers G Proteins and Calcium Ions Step 1
1. The G Protein first activates the enzyme phospholipase C (PLC).
18-2 The endocrine system regulates physiological processes by releasing bloodborne hormones that bind to receptors on remote target organs: Mechanisms of Hormone Action Binding of a hormone may do 3 things
1. alter genetic activity, 2. alter the rate of protein synthesis, or 3. change membrane permeability. Pneumonic: AGA = Alter Genetic Activity, ARPS = Alter Rate Protein Synthesis, and MP = Membrane Permeability. Any Guess About Adverse Reactions Plaguing Somebody's Metabolism Perminately?
18-2 The endocrine system regulates physiological processes by releasing bloodborne hormones that bind to receptors on remote target organs: Hormones and Extracellular Receptors: second messengers G Proteins and Calcium Ions Step 3
IP3 diffuses into the cytoplasm and triggers the release of CA2+ from intracellular reserves.
FIGURE 18-1 Organs and Tissues of the Endocrine System: adrenal glands
Medulla produces: epinephrine (E) and norepinephrine (NE) Cortex produces: cortisol, corticosterone, cortisone, aldosterone, and androgens.
FIGURE 18-1 Organs and Tissues of the Endocrine System: Organs with Secondary Endocrine Functions - Kidneys
Produces Erythropoietin (EPO) and Calcitriol
FIGURE 18-1 Organs and Tissues of the Endocrine System: Organs with Secondary Endocrine Functions - Adipose Tissue
Produces Leptin
FIGURE 18-1 Organs and Tissues of the Endocrine System: Organs with Secondary Endocrine Functions - Heart
Produces: atrial natriuretic peptide (ANP) and brain natriuretic peptide (BNP)
FIGURE 18-1 Organs and Tissues of the Endocrine System: Pineal Gland
Produces: melatonin
FIGURE 18-1 Organs and Tissues of the Endocrine System: Parathyroid Glands
Produces: parathyroid hormone (PTH)
FIGURE 18-1 Organs and Tissues of the Endocrine System: hypothalamus gland
Produces: production of ADH, OXT, and regulatory hormones
FIGURE 18-1 Organs and Tissues of the Endocrine System: Organs with Secondary Endocrine Functions - Thymus
Produces: thymosins. this goes through atrophy in adulthood and gets much smaller.
18-2 The endocrine system regulates physiological processes by releasing bloodborne hormones that bind to receptors on remote target organs: Hormones and Extracellular Receptors: second messengers G Proteins and Calcium Ions Step 2
This enzyme triggers a receptor cascade beginning with the production of diacyglycerol (DAG) and inositol trisphosphate (IP3) from membrane phospholipids.
18-1 Homeostasis is preserved through intercellular communication by the nervous and endocrine systems: Mechanisms of Intercellular Communication direct communication
This occurs between two cells of the same type and the cells must be in extensive physical contact. They do this with gap junctions which do 3 things; coordinate ciliary movement among epithelial cells, coordinate the contractions of cardiac muscle cells, and facilitate the propagation of action potentials from one neuron to the next. Transmission: through gap junctions Chemical Mediators: ions, small solutes, lipid-soluble materials. Distribution of Effects: usually limited to adjacent cells of the same type that are interconnecetd by connexons.
18-1 Homeostasis is preserved through intercellular communication by the nervous and endocrine systems: Mechanisms of Intercellular Communication autocrine communication
This occurs when the messages affect the same cells that secret them via autocrine chemicals like prostaglandins, which are secreted by smooth muscles to contract them. Transmission: through extracellular fluid Chemical Mediators: autocrines Distribution of Effects: limited to the cell that secretes the hormone
FIGURE 18-1 Organs and Tissues of the Endocrine System: thyroid gland
Thyroxine (T4), Triiodothyronine (T3), calcitonin (CT)
18-1 Homeostasis is preserved through intercellular communication by the nervous and endocrine systems
To preserve homeostasis, cell activities have to be coordinated with help from the nervous system and endocrine system.
18-2 The endocrine system regulates physiological processes by releasing bloodborne hormones that bind to receptors on remote target organs: change membrane permeability
a membrane channel or enzyme can be turned off or on by changing its shape or structure.
18-3 The anterior lobe of the pituitary gland produces and releases hormones under hypothalamic control, while the posterior lobe releases hypothalamic hormones. The Anterior Lobe of the Pituitary Gland - Histology of the Anterior Lobe, aka the adenohypophysis pars intermedia
a narrow band bordering the posterior lobe.
18-2 The endocrine system regulates physiological processes by releasing bloodborne hormones that bind to receptors on remote target organs: hormone receptor
a protein molecule to which a particular molecule binds strongly. Different tissues have different types of receptors in their cells for different hormones to attach to. These receptors are either on the plasma membrane (extracellular receptors) or within target cells (intracellular receptors).
18-3 The anterior lobe of the pituitary gland produces and releases hormones under hypothalamic control, while the posterior lobe releases hypothalamic hormones. The Anterior Lobe of the Pituitary Gland - Hypothalamic Control of the Anterior Lobe inhibiting hormone (IH)
a regulatory hormone that prevents the synthesis and secretion of hormones from the anterior lobe.
18-3 The anterior lobe of the pituitary gland produces and releases hormones under hypothalamic control, while the posterior lobe releases hypothalamic hormones. The Anterior Lobe of the Pituitary Gland - Hypothalamic Control of the Anterior Lobe releasing hormone (RH)
a regulatory hormone that stimulates the synthesis and secretion of 1+ hormone(s) at the anterior lobe
18-2 The endocrine system regulates physiological processes by releasing bloodborne hormones that bind to receptors on remote target organs: Hormones and Extracellular Receptors: Second messengers cyclic AMP (cAMP)
a second messenger derived from ATP
18-2 The endocrine system regulates physiological processes by releasing bloodborne hormones that bind to receptors on remote target organs: Hormones and Extracellular Receptors: Second messengers cyclic GMP (cGMP)
a second messenger derived from GTP
18-2 The endocrine system regulates physiological processes by releasing bloodborne hormones that bind to receptors on remote target organs: Hormones and Extracellular Receptors: Second messengers calcium ions (Ca2+)
a second messenger. not much else to say about it.
18-3 The anterior lobe of the pituitary gland produces and releases hormones under hypothalamic control, while the posterior lobe releases hypothalamic hormones. The Anterior Lobe of the Pituitary Gland - Histology of the Anterior Lobe, aka the adenohypophysis pars tuberalis
an extension which wraps around the adjacent portion of the infundibulum
18-2 The endocrine system regulates physiological processes by releasing bloodborne hormones that bind to receptors on remote target organs: alter genetic activity
enzyme and protein synthesis in a cytoplasm without those enzymes/proteins can be stimulated by activating genes in that cell's nucleus.
18-2 The endocrine system regulates physiological processes by releasing bloodborne hormones that bind to receptors on remote target organs: Hormones and Extracellular Receptors: second messengers receptor cascade
one enzyme can promote the release of second messengers, that can trigger enzymatic reactions that can alter many aspects of cell functions at the same time.
18-1 Homeostasis is preserved through intercellular communication by the nervous and endocrine systems: Mechanisms of Intercellular Communication paracrine communication
paracrines release chemicals into extracellular fluid which tells the neighboring cells what they are doing. Transmission: through extracellular fluid Chemical Mediators: paracrines Distribution of Effects: primarily limited to a local area, where paracrine concentrations are relatively high; target cells must have appropriate receptors.
18-2 The endocrine system regulates physiological processes by releasing bloodborne hormones that bind to receptors on remote target organs: Classes of Hormones 3 classes based on chemical structure
peptide hormones, amino acid derivatives, lipid derivatives. aka PAL.
FIGURE 18-1 Organs and Tissues of the Endocrine System: Pancreas
produces: Insulin and glucagon
18-2 The endocrine system regulates physiological processes by releasing bloodborne hormones that bind to receptors on remote target organs: Transport and Inactivation of Hormones 3 ways a circulating hormone can be inactivated
1. it diffuses out of the bloodstream and binds to receptors on target cells. 2. it is absorbed and broken down by cells of the liver or kidneys. 3. it is broken down by enzymes in the blood or interstitial fluids. pneumonic: DOB (Diffuses Out of Bloodstream) ABDLK (Absorbed and Broken Down via Liver or Kidney) BDEBIF (Broken Down by Enzymes in Blood or Interstitial Fluids) Date Of Birth Always Brings Darling Little Kids By Delivering Every Baby In Formation.
18-2 The endocrine system regulates physiological processes by releasing bloodborne hormones that bind to receptors on remote target organs: Hormones and Extracellular Receptors: second messengers G Proteins and cAMP, the 4 steps to increase cAMP level
1. the activated G protein activates the enzyme adenylate cyclase. 2. Adenylate Cyclase converts ATP to cyclic AMP. 3. Cyclic AMP then functions as a 2nd messenger usually activated by kinase 4. Cyclic AMP activates kinases that phosphorylate proteins, which effects the target cell depending on the nature of the proteins.
includes all endocrine cells and tissues that produce hormones or paracrines with effects beyond their tissues of orgin. this system's cells are glandularly secreted into extracellular fluid, where as exocrine cells secrete products onto epithelial surfaces via ducts.
18-2 The endocrine system regulates physiological processes by releasing bloodborne hormones that bind to receptors on remote target organs: Overview of Endocrine Organs and Tissues endocrine system
An introduction to the Endocrine System
30 hormones regulate human activities and are the products of the endocrine system. The endocrine system works with the nervous system to control and coordinate our body processes.
18-3 The anterior lobe of the pituitary gland produces and releases hormones under hypothalamic control, while the posterior lobe releases hypothalamic hormones. The Anterior Lobe of the Pituitary Gland - Hormones of the Anterior Lobe Follicle-stimulating hormone (FSH)
promotes follicle development in females target: ovaries/testes when combined with luteinizing hormone, it stimulates release of: estrogens (like estradiol) by ovaries and nurse cells by seminiferous tubules of testes. released by: gonadotropic cells of the anterior pituitary gland. released in response to: gonadotropin-releasing hormone (GnRH) from hypothalamus inhibited by: inhibin from cells of testes and ovaries
18-3 The anterior lobe of the pituitary gland produces and releases hormones under hypothalamic control, while the posterior lobe releases hypothalamic hormones. The Anterior Lobe of the Pituitary Gland - Hormones of the Anterior Lobe Growth hormone releasing hormone (GH-RH)
regulates production of GH alongside GH-IH from the hypothalamus. Somatomedins inhibit this.
18-3 The anterior lobe of the pituitary gland produces and releases hormones under hypothalamic control, while the posterior lobe releases hypothalamic hormones. The Anterior Lobe of the Pituitary Gland - Hormones of the Anterior Lobe Growth hormone inhibiting hormone (GH-IH)
regulates production of GH alongside GH-RH from the hypothalamus. Somatomedins stimulate this.
18-3 The anterior lobe of the pituitary gland produces and releases hormones under hypothalamic control, while the posterior lobe releases hypothalamic hormones. The Anterior Lobe of the Pituitary Gland - Hormones of the Anterior Lobe somatomedins aka insulin-like growth factors (IGFs) primary indirect mechanism to stimulate growth by GH
released from: liver target: variety of plasma membranes like skeletal muscle fibers, and cartilage cells. released in response to: release of GH
18-3 The anterior lobe of the pituitary gland produces and releases hormones under hypothalamic control, while the posterior lobe releases hypothalamic hormones. The Anterior Lobe of the Pituitary Gland - Hormone Secretion and the Hypophyseal Portal System median eminence
specific regulatory hormones are released from the median eminence near the infundibulum by hypothalamic neuron signals so those hormones are released into the surrounding intestinal fluids to enter the bloodstream through the permeable endothelial cells's fenestrated capillaries, which let large molecules enter and leave the bloodstream.
18-3 The anterior lobe of the pituitary gland produces and releases hormones under hypothalamic control, while the posterior lobe releases hypothalamic hormones. The Anterior Lobe of the Pituitary Gland - Hormones of the Anterior Lobe Growth Hormone (GH) aka somatotropin
stimulates cell growth and division by accelerating the rate of protein synthesis. released and synthesized from: anterior lobe of pituitary target: mostly the liver inhibits release of: Growth Hormone-Releasing Hormone (GH-RH) which then stimulates release of: Growth Hormone-Inhibiting Hormone
18-3 The anterior lobe of the pituitary gland produces and releases hormones under hypothalamic control, while the posterior lobe releases hypothalamic hormones. The Anterior Lobe of the Pituitary Gland - Hormones of the Anterior Lobe Prolactin (PRL)
stimulates mammary gland development and when pregnant stimulates milk production. target: breasts stimulates release of: breast milk released by: anterior pituitary released in response to: a baby suckling a teet inhibited by: dopamine aka prolactin inhibiting hormone (PIH), which is inhibited by prolactin releasing hormone (PRH), both of which are released from the hypothalamus.
18-3 The anterior lobe of the pituitary gland produces and releases hormones under hypothalamic control, while the posterior lobe releases hypothalamic hormones. The Anterior Lobe of the Pituitary Gland - Hormones of the Anterior Lobe Adrenocorticotropic Hormone (ACTH) aka corticotropin
target: cells that produce glucocorticoids stimulates release of: steroid hormones released by: adrenal cortex released in response to: stimulation of corticotropin-releasing hormone (CRH) from hypothalamus as this rises: glucocorticoids this falls: CRH and ACTH release rates
18-3 The anterior lobe of the pituitary gland produces and releases hormones under hypothalamic control, while the posterior lobe releases hypothalamic hormones. The Anterior Lobe of the Pituitary Gland - Hormones of the Anterior Lobe Luteinizing Hormone (LH)
target: ovaries and testes stimulates release of: ovulation inducing reproductive cells of females and ovarian secretion of estrogens and progesterone. stimulates sex hormone production (androgens) in males, especially testosterone. released by: anterior pituitary released in response to: GnRH from the hypothalamus inhibited by: estrogens, progesterone and androgens that inhibit GnRH production.
18-2 The endocrine system regulates physiological processes by releasing bloodborne hormones that bind to receptors on remote target organs: up-regulation
the absence of a hormone triggers an increase in the number of hormone receptors, making cells more sensitive to low levels of a particular hormone.
18-2 The endocrine system regulates physiological processes by releasing bloodborne hormones that bind to receptors on remote target organs: Hormones and Intracellular Receptors: Gene Activation. Control of Hormone Secretion neutral stimuli
the arrival of neurotransmitters at the neuroglandular junctions that control the rate of hormone secretionThis happens when a neurotransmitter arrives at a neuroglandular nunction, such as hormone secretion linked to neutral stimuli involving the activity of the hypothalamus. This type of secretion control provides the highest level of endocrine control.
18-2 The endocrine system regulates physiological processes by releasing bloodborne hormones that bind to receptors on remote target organs: Hormones and Intracellular Receptors: Gene Activation. Control of Hormone Secretion hormonal stimuli
the arrival or removal of a specific hormone that control the rate of hormone secretion.
18-2 The endocrine system regulates physiological processes by releasing bloodborne hormones that bind to receptors on remote target organs: Hormones and Extracellular Receptors: second messengers G Proteins and Calcium Ions Step 5
the calcium ions serve as messengers in combination with intracellular protein Calmodulin. One it binds calcium ions, it can activate specific cytoplasmic enzymes. Calmodulin activation also is involved in responses to oxytocin and other regulatory hormones of the hypothalamus.
18-2 The endocrine system regulates physiological processes by releasing bloodborne hormones that bind to receptors on remote target organs: alter the rate of protein synthesis
the changing rate of transcription or translation changes the rate of enzyme and protein synthesis.
18-3 The anterior lobe of the pituitary gland produces and releases hormones under hypothalamic control, while the posterior lobe releases hypothalamic hormones. The Anterior Lobe of the Pituitary Gland - Hormones of the Anterior Lobe secondary direct mechanism to stimulate growth by GH
the direct actions of GH appear after blood glucose and amino acid concentrations return to normal levels.
18-3 The anterior lobe of the pituitary gland produces and releases hormones under hypothalamic control, while the posterior lobe releases hypothalamic hormones. Control of Pituitary Activity by the Hypothalamus 2. the hypothalamus secretes regulatory hormones.
the hypothalamic regulatory hormones control the secretory activities of anterior lobe endocrine cells of the pituitary. those hormones then control the activities of endocrine cells in target organs.
18-2 The endocrine system regulates physiological processes by releasing bloodborne hormones that bind to receptors on remote target organs: Hormones and Intracellular Receptors: Gene Activation thyroid hormones
these hormones cross the plasma membrane by a transport mechanism, and once in the cytoplasm bind to nucleus and mitochondria receptors. These hormone-receptor complexes in the nucleus activate certain genes or change transcription rate to affect the metabolic cell activity by increasing or decreasing the concentration of specific enzymes, while mitochondrial bound thyroid hormones increase the rates of ATP production.
18-3 The anterior lobe of the pituitary gland produces and releases hormones under hypothalamic control, while the posterior lobe releases hypothalamic hormones. The Anterior Lobe of the Pituitary Gland - Hormones of the Anterior Lobe Gonadotropins
these hormones regulate the activities of the gonads which produce reproductive cells and hormones. testes = male, ovaries = female.
18-2 The endocrine system regulates physiological processes by releasing bloodborne hormones that bind to receptors on remote target organs: Classes of Hormones: peptide hormones - glycoproteins
these proteins have more than 200 amino acids and have carbohydrate side chains. They include thyroid-stimulating hormone (TSH), luteinizing hormone (LH) and follicle-stimulating hormone (FSH) from the anterior lobe of the pituitary gland.
18-3 The anterior lobe of the pituitary gland produces and releases hormones under hypothalamic control, while the posterior lobe releases hypothalamic hormones. The Anterior Lobe of the Pituitary Gland - Hormone Secretion and the Hypophyseal Portal System superior hypophyseal artery
this artery supplies the capillary network in the median eminance. the capillary networks unite to form larger vessels around the infundibulum to reach the anterior lobe before leaving the hypothalamus. in the anterior lobe, those vessels form a second capillary network that branches among endocrine cells to carry blood from one capillary network to the other. This system is called the hypophyseal portal system.
18-1 Homeostasis is preserved through intercellular communication by the nervous and endocrine systems: Mechanisms of Intercellular Communication - Synaptic Communication
this communication causes neurons to release a neurotransmitter at a synapse close to the target cells with the correct receptors, triggering the signals rapid travel through action potentials along the axons. Transmission: across synapses Chemical Mediators: neurotransmitters Distribution of Effects: liited to very specific area; target cells must have appropriate receptors.
18-2 The endocrine system regulates physiological processes by releasing bloodborne hormones that bind to receptors on remote target organs: Classes of Hormones: peptide hormones- short polypeptides/small proteins
this group is large and diverse, including hormones ranging from short-chain polypeptides like antidiuretic hormone (ADH) and oxytocin (OXT), to small proteins like insulin, growth hormone, and prolactin. This group includes all hormones of the hypothalamus, hearth, thymus, digestive tract, pancreas and posterior lobe of the pituitary gland. It also includes a few other hormones of other organs.
18-3 The anterior lobe of the pituitary gland produces and releases hormones under hypothalamic control, while the posterior lobe releases hypothalamic hormones. The Anterior Lobe of the Pituitary Gland - Hormones of the Anterior Lobe Gonadotropin Releasing Hormone (GnRH)
this hormone from the hypothalamus stimulates the production of gonadotropins. there are two types of these: follicle stimulating hormones and luteinizing hormones.
18-3 The anterior lobe of the pituitary gland produces and releases hormones under hypothalamic control, while the posterior lobe releases hypothalamic hormones. The Posterior Lobe of the Pituitary Gland antidiuretic hormone (ADH)
this hormone is also known as vasopressin(VP) and is released in response to a few different stimuli, but mostly in response to an increase in the solute concentration in blood or decrease in blood volume/pressure. the osmoreceptor neurons in the hypothalamus respond to this change which stimulates the neurosecretory neurons that release ADH.
18-2 The endocrine system regulates physiological processes by releasing bloodborne hormones that bind to receptors on remote target organs: Hormones and Extracellular Receptors: second messengers G protein
this is an enzyme complex coupled to a membrane receptor which gets binded to GTP. this is activated when a hormone binds to its receptor at the membrane surface. after that the G protein effects the second messengers in the cytoplasm, but how it affects it depends on the type of G protein. There are three types of this. Gs = stimulating. Gi = inhibiting. Gq = inhibits or stimulates. they are called G proteins because they bind the guanine nucleotides GDP and GTP.
18-3 The anterior lobe of the pituitary gland produces and releases hormones under hypothalamic control, while the posterior lobe releases hypothalamic hormones. The Anterior Lobe of the Pituitary Gland - Hormones of the Anterior Lobe hypogonadism
this is caused by an abnormally low production of gonadotropins, so kids with this can't mature sexually and adults with it can't produce functional sperm or oocytes.
18-3 The anterior lobe of the pituitary gland produces and releases hormones under hypothalamic control, while the posterior lobe releases hypothalamic hormones. The Posterior Lobe of the Pituitary Gland (the neurohypophysis gland)
this lobe of the gland contains the axons of hypothalamic neurons. su
18-3 The anterior lobe of the pituitary gland produces and releases hormones under hypothalamic control, while the posterior lobe releases hypothalamic hormones. The Anterior Lobe of the Pituitary Gland - Histology of the Anterior Lobe (aka the adenohypophysis)
this lobe of the pituitary has a variety of endocrine cells and is split into 3 regions; the pars distalis, the pars tuberalis, and the pars intermedia. an extensive capillary network radiates through these regions, giving every endocrine cell immediate acess to the bloodstream.
18-1 Homeostasis is preserved through intercellular communication by the nervous and endocrine systems: Mechanisms of Intercellular Communication endocrine communication
this occurs when hormones relay info and instructions between cells in distant portions of the body. the endocrine cells release hormones in one tissue, it travels through the bloodstream and a it binds to target cells that change the types, quantities, or activities of important enzymes and structural proteins. Transmission: through the blood stream Chemical Mediators: hormones Distribution of Effects: target cells are primarily in other tissues and organs and must have appropriate receptors.
18-2 The endocrine system regulates physiological processes by releasing bloodborne hormones that bind to receptors on remote target organs: Hormones and Extracellular Receptors: second messengers G Proteins and Calcium Ions Steps involved
AN activated G protein can trigger either opening calcium ion channels in the plasma membrane or the release of calcium ions from intracellular compartments. There are 5 steps to this. 1. The G Protein first activates the enzyme phospholipase C (PLC). 2. This enzyme triggers a cascade. 3. IP3 diffuses into the cytoplasm and triggers release of calcium. 4. Combination of DAG and intracellular calcium ions activates a cytosolic protein that opens channels for calcium to go into cell. 5. Calcium ions serve as messengers that bind to calmodiulin.
FIGURE 18-1 Organs and Tissues of the Endocrine System: pituitary gland
Anterior lobe produces: ACTH, TSH, GH, PRL, FSH, LH, and MSH. Posterior lobe: OXT and ADH
18-3 The anterior lobe of the pituitary gland produces and releases hormones under hypothalamic control, while the posterior lobe releases hypothalamic hormones. The Anterior Lobe of the Pituitary Gland - Hormones of the Anterior Lobe Thyroid Stimulating Hormone (TSH) aka thyrotropin
BY THE WAY, ALL OF THESE WILL BE MORE SIMPLY EXPLAINED FURTHER IN THIS FLASHCARD SET UNDER TABLE 18-2. target: thyroid gland stimulates release of: thyroid hormones released by: hypothalamus released in response to: thyrotropin releasing hormone (TRH) as this rises: thyroid hormones T3&T4 this falls: TRH and TSH
18-2 The endocrine system regulates physiological processes by releasing bloodborne hormones that bind to receptors on remote target organs: Hormones and Intracellular Receptors: Gene Activation steroid hormones
Most hormones that target intracellular receptors are steroid or thyroid hormones. Steroid hormones can diffuse across the lipid part of the plasma membrane and bind to receptors in the cytoplasm or nucleus. The hormone-receptor complexes then activate or deactivate specific genes. By this mechanism steroid hormones can alter the rate of DNA transcription in the nucleus, and so change the pattern of protein synthesis. This allows steroid hormones to alter the rate of DNA transcription, and therefore alters the pattern of protein synthesis and the metabolic activity and structure of the target cell.
18-1 Homeostasis is preserved through intercellular communication by the nervous and endocrine systems: Comparison of Endocrine and Nervous Communication the differences
Neurons use action potentials and neurtransmitters to control specific cells or cell groups almost instantaneously, where as the endocrine system hormones travel through the bloodstream to reach almost each cell in the body, scanning for target cells, and those hormones cause effects that can last for days.
FIGURE 18-1 Organs and Tissues of the Endocrine System: Organs with Secondary Endocrine Functions - Female Gonads
Ovaries produce Estrogens, Progesterone and Inhibin
FIGURE 18-1 Organs and Tissues of the Endocrine System: Organs with Secondary Endocrine Functions - Digestive Tract
Secretes numerous hormones involved in coordination of system functions, glucose metabolism, and appetite
FIGURE 18-1 Organs and Tissues of the Endocrine System: Organs with Secondary Endocrine Functions - Male Gonads
Testes produce androgens (namely testosterone) and inhibin
18-3 The anterior lobe of the pituitary gland produces and releases hormones under hypothalamic control, while the posterior lobe releases hypothalamic hormones. The Anterior Lobe of the Pituitary Gland (aka the adenohypophysis)
The anatomy of the anterior lobe and associated blood vessels facilitates it's function and the hypothalamus controls the secretion and actions of anterior lobe hormones.
18-2 The endocrine system regulates physiological processes by releasing bloodborne hormones that bind to receptors on remote target organs: Hormones and Extracellular Receptors: second messengers G Proteins and Calcium Ions Step 4
The combination of DAG an dintracellular calcium ions activates protein kinase C (PKC). This activation leads to phosphorylation of calcium ion channel proteins, which opens the channels and lets extracellular Ca2+ to enter the cell, setting up a positive feedback loop to elevate the intracellular calcium ion concentration.
18-3 The anterior lobe of the pituitary gland produces and releases hormones under hypothalamic control, while the posterior lobe releases hypothalamic hormones. Anatomy of the Hypothalamus and Pituitary Gland (aka hypophysis gland)
The hypothalamus contains both brain centers and endocrine tissue. It's superior to the pituitary gland and is connected to it by the infundibulum. the pituitary gland (aka hypophysis) is held by the dural sheet called the sellar diaphragm that also encircles the infundibulum, isolating the pituitary gland from the cranial cavity.
18-2 The endocrine system regulates physiological processes by releasing bloodborne hormones that bind to receptors on remote target organs: Classes of Hormones: lipid derivatives (2 groups)
These are secreted either from arachidonic acid or cholesterol. 2 groups include eicosanoids and steroids.
18-2 The endocrine system regulates physiological processes by releasing bloodborne hormones that bind to receptors on remote target organs: Classes of Hormones: amino acid derivatives
These are small molecules that are structurally related to amino acids which are part of proteins. They include derivatives of tyrosine (thyroid hormones like Thyroxine T4 and catecholamines like epinephrine, norepinephrine and dopamine) and derivatives of tryptophan (primarily, melatonin produced by the pineal gland).
18-2 The endocrine system regulates physiological processes by releasing bloodborne hormones that bind to receptors on remote target organs: Hormones and Extracellular Receptors: second messengers
an intermediary molecule that appears due to a hormone-receptor interaction. The hormone is known as the first messenger and it causes the appearance of this type of messenger. It can act either as an enzyme activator, inhibitor or cofactor. Important ones are cyclic AMP (cAMP), cyclic GMP (these 2 are most common), and calcium ions (Ca2+). WHen a small number of hormones bind to extracellular receptors, thousands of second messengers can appear in a cell in the process of amplification, which magnifies the effects of a hormone on the target cell. One hormone can promote multiple types of these messengers.
18-3 The anterior lobe of the pituitary gland produces and releases hormones under hypothalamic control, while the posterior lobe releases hypothalamic hormones. The Anterior Lobe of the Pituitary Gland - Hormone Secretion and the Hypophyseal Portal System portal vessels/veins that make up the portal system
blood vessels that link two capillary networks together. portal systems are named for their destinations. these systems provide efficient means of chemical communication by (in the case of the hypophyseal portal system) ensuring all hypothalamic hormones entering the portal vessels reach the anterior lobe target cells before going into general circulation. This is a one-way system in that chemicals released by cells downstream must circulate through the entire cardiovascular system before reaching the portal system capillaries.
18-1 Homeostasis is preserved through intercellular communication by the nervous and endocrine systems: Comparison of Endocrine and Nervous Communication the similarities
both systems rely on the release of chemicals that bind to specific receptors on their target cells. Both share many chemical messengers. Both are regulated by negative feedback control mechanisms for the most part, and both share the common goal of preserving homeostasis by coordinating and regulating the activities of other cells, tissues, organs and systems. Pneumonic: SR (specific receptors) CM (chemical messengers) NF (negative feedback) HVR (homeostasis via regulation). Stop Ruining Camping Man, Now Friends Have Varied Reactions.
18-2 The endocrine system regulates physiological processes by releasing bloodborne hormones that bind to receptors on remote target organs: Hormones and Intracellular Receptors: Gene Activation. Control of Hormone Secretion humoral stimuli
changes in the composition of the extracellular fluid that control the rate of hormone secretion of the heart, pancreas, parathyroid glands and digestive tract.
18-2 The endocrine system regulates physiological processes by releasing bloodborne hormones that bind to receptors on remote target organs: major processes affected by hormone actions include
growth and development, reproduction, regulation of cell metabolism and energy balance, regulation of body water content and levels of electrolytes and organic nutrients, and mobilization of body defenses. Pneumonic: GD (Growth and Development) R (reproduction) RCMEB (Regulation of Cell Metabolism and Energy Balance) BWC (Body Water Content) EN (Electrolytes and Nutrient) MBD (Mobilization of Body Defenses). God Darn Robert, Really Can't Make Every Body Break With Customs, Enough Nagging Me By Demands. (quizlet won't let me use cusswords... they turn them into astricks.)
18-2 The endocrine system regulates physiological processes by releasing bloodborne hormones that bind to receptors on remote target organs: Hormones and Intracellular Receptors: Gene Activation. Control of Hormone Secretion
hormone secretion aka endocrine activity is controlled mostly by negative feedback in which a stimulus trigggers the production of a hormone that directly or indirectly reduces the rate of intensity of the stimulus. This hormone secretion is triggered by 1 of 3 things. 1. humoral stimuli, 2. hormonal stimuli, or 3. neutral stimuli.
18-2 The endocrine system regulates physiological processes by releasing bloodborne hormones that bind to receptors on remote target organs: Overview of Endocrine Organs and Tissues summary
hormones can produce complex changes in the body's physical structure and physiological capabilities, impacting growth and development, reproduction, cell metabolism and energy balance regulation, body water content and levels of electrolytes and organic nutrients, and mobilization of body defenses.
18-3 The anterior lobe of the pituitary gland produces and releases hormones under hypothalamic control, while the posterior lobe releases hypothalamic hormones. Control of Pituitary Activity by the Hypothalamus 1. the hypothalamus acts as a regulatory organ
hypothalamic neruons synthesize and transport hormones along axons to the posterior lobe of the pituitary gland where they are released into circulation.
18-3 The anterior lobe of the pituitary gland produces and releases hormones under hypothalamic control, while the posterior lobe releases hypothalamic hormones. The Anterior Lobe of the Pituitary Gland - Hormones of the Anterior Lobe secondary direct mechanism to stimulate growth by GH: Epithelia and Connective tissues
in these tissues, GH stimulates stem cell divisions and differentiation of daughter cells.
18-3 The anterior lobe of the pituitary gland produces and releases hormones under hypothalamic control, while the posterior lobe releases hypothalamic hormones. The Anterior Lobe of the Pituitary Gland - Hormones of the Anterior Lobe secondary direct mechanism to stimulate growth by GH: Adipose tissue
in this tissue, GH stimulates breakdown of stored triglycerides by adipocytes which then release fatty acids into the blood. As circulating fatty acid levels rise, tissues stop breaking down glucose to generate ATP and start breaking down fatty acids in a process called glucose-sparing effect.
18-3 The anterior lobe of the pituitary gland produces and releases hormones under hypothalamic control, while the posterior lobe releases hypothalamic hormones. The Anterior Lobe of the Pituitary Gland - Hormones of the Anterior Lobe secondary direct mechanism to stimulate growth by GH: Liver
in this tissue, GH stimulates the breakdown of glycogen reserves by liver cells which then release glucose into the blood stream, causing the blood glucose concentration to climb higher than normal in what is known as a diabetogenic effect. the condition of having an abnormally high blood glucose concentration is known as the endocrine disorder, diabetes mellitus.
18-3 The anterior lobe of the pituitary gland produces and releases hormones under hypothalamic control, while the posterior lobe releases hypothalamic hormones. Control of Pituitary Activity by the Hypothalamus
the hypothalamus regulates both lobes of the pituitary gland and integrates the nervous and endocrine activities in 3 ways; 1. the hypothalamus acts as an endocrine organ. 2. the hypothalamus secretes regulatory hormones. 3. the hypothalamus contains autonomic centers that control the endocrine cells of the adrenal medulla. The hypothalamus secretes regulatory hormones and ADH in response to changes in the composition of the circulating blood. OXT, E, and NE involve both neural and hormonal mechanisms in neuroendocrine responses. some hypothalamic and pituitary hormones are released in pulses so the target cells vary their response with the frequency of the pulses and amount secreted per pulse.
18-2 The endocrine system regulates physiological processes by releasing bloodborne hormones that bind to receptors on remote target organs: Hormones and Extracellular Receptors: second messengers G Proteins and cAMP, phosphodiesterase
the increase is usually short-lived because the cytoplasm contains the enzyme phosphodiesterase (PDE) inactivates cyclic AMP by changing it to AMP.
18-3 The anterior lobe of the pituitary gland produces and releases hormones under hypothalamic control, while the posterior lobe releases hypothalamic hormones. The Anterior Lobe of the Pituitary Gland - Histology of the Anterior Lobe, aka the adenohypophysis pars distalis
the largest and most anterior portion of the pituitary gland
18-3 The anterior lobe of the pituitary gland produces and releases hormones under hypothalamic control, while the posterior lobe releases hypothalamic hormones. The Posterior Lobe of the Pituitary Gland supra-optic neurons and paraventricular nuclei
the neurons and nuclei manufacture antidiuretic hormone (ADH) and oxytocin (OXT), respectively. those hormones end up on the basement membranes of the capillaries in the posterior lobe via axoplasmic transport. The inferior hypophyseal artery delivers blood to it and the hypophyseal veins carry those hormones and blood away to their target organs, where the hormones bind to extracellular receptors to use cAMP as a second messenger.
18-3 The anterior lobe of the pituitary gland produces and releases hormones under hypothalamic control, while the posterior lobe releases hypothalamic hormones. summary
the pituitary gland has anterior and posterior lobes that differ in function and developmental anatomy, releasing 9 important peptide hormones, 7 of which come from the anterior lobe and 2 from the posterior lobe. The hypothalamus is closely linked in anatomy and function with both pituitary lobes.
18-2 The endocrine system regulates physiological processes by releasing bloodborne hormones that bind to receptors on remote target organs: down-regulation
the presence of a hormone triggers a decrease in the humber of hormone receptors, causing cells to become less sensitive to high levels of a particular hormone.
18-3 The anterior lobe of the pituitary gland produces and releases hormones under hypothalamic control, while the posterior lobe releases hypothalamic hormones. The Anterior Lobe of the Pituitary Gland - Hypothalamic Control of the Anterior Lobe
there are 2 classes of hypothalamic regulatory hormones - releasing hormones and inhibiting hormones. once secreted, the anterior pituitary hormones stimulate the cells of their target organs, many of which are endocrine glands that secrete hormones in response to the stimulation. the anterior lobe hormones are called tropic hormones because they turn on endocrine galnds or support functions of other organs until negative feedback from those target organ hormones control the rate at which regulatory hormones are secreted from the hypothalamus.
18-3 The anterior lobe of the pituitary gland produces and releases hormones under hypothalamic control, while the posterior lobe releases hypothalamic hormones. The Anterior Lobe of the Pituitary Gland - Hormones of the Anterior Lobe melanocyte-stimulating hormone
there are two forms of this hormone, both of which are secreted by the pars intermedia of the pituitary (meaning its in the middle of the anterior and posterior pituitary). MSH stimulates the melanocytes of the skin, increasing their production of melanin. Dopamine inhibits this release. MSH is produced locally in adults via skin exposure, but the pars intermedia in adults is basically nonfunctional and circulating blood doesn't contain it. The pars intermedia secretes MSH only during fetal development, in very young children, in pregnant women and as a result of certain diseases.
18-2 The endocrine system regulates physiological processes by releasing bloodborne hormones that bind to receptors on remote target organs: Classes of Hormones: peptide hormones (2 groups)
these hormones are chains of amino acids, which for the most part are synthesized by prohormones, inactive molecules that are converted to active hormones before or after they are secreted. 2 groups include a group of glycoproteins and a group of short polypeptides and small proteins
18-2 The endocrine system regulates physiological processes by releasing bloodborne hormones that bind to receptors on remote target organs: Classes of Hormones: lipid derivatives - eicosanoids
these hormones are derived from arachidonic acid. they are important paracrines that coordinate cellular activities and effect enzymatic processes like blood clotting. Includes leukotrines which have a secondary role as hormones, and prostaglandins which coordinate local cellular activities and can be converted to thromboxanes and prostacyclines.
18-2 The endocrine system regulates physiological processes by releasing bloodborne hormones that bind to receptors on remote target organs: Classes of Hormones: lipid derivatives - steroids
these hormones are released by reproductive organs (androgens = testes, estrogens and progesterone = ovaries), by the cortex of the adrenal glands (corticosteroids) and by the kidneys (calcitriol). They remain in circulation longer than secreted peptide hormones.
18-3 The anterior lobe of the pituitary gland produces and releases hormones under hypothalamic control, while the posterior lobe releases hypothalamic hormones. The Anterior Lobe of the Pituitary Gland - Hormones of the Anterior Lobe
thyroid stimulating hormone, adrenocorticotropic hormone, and the gonadotroipins follicle-stimulating hormone and luteinizing hormone follow the typical regulatory pattern in which the hypothalamus produces a releasing hormone to stimulate hormone production by other glands and homeostatic control occurs by negative feedback. Prolactin is different in that the hypothalamus produces both a releasing hormone and an inhibiting hormone so when one is stimulated, the other is inhibited as they're produced by the anterior lobe. Growth hormone is also different in that when GH-RH (growth hormone-releasing hormones) release is inhibited, GH-IH (growth hormone-inhibiting hormone) is stimulated as they're produced by the anterior lobe.
18-3 The anterior lobe of the pituitary gland produces and releases hormones under hypothalamic control, while the posterior lobe releases hypothalamic hormones. Control of Pituitary Activity by the Hypothalamus 3. the hypothalamus contains autonomic centers that control the endocrine cells of the adrenal medulla.
when the sympathetic division is activated, the adrenal medulla releases epinephrine and norepinephrine into the bloodstream.
