In Section 1, you will learn that: The endocrine system functions with the nervous system to regulate other body systems and maintain homeostasis. The endocrine glands secrete hormones directly into the bloodstream. Hormone secretion is regulated by the nervous system, other hormones, or negative feedback mechanisms. The Endocrine System

In this section, you will: Explain how the endocrine system contributes to homeostasis Compare the nervous system with the endocrine system Identify the principal endocrine glands in the human body and the hormones they secrete Explain how the endocrine system allows the body to sense and respond to the internal environment Explain the relationship between negative feedback and hormonal regulation in the body Explain how the endocrine system is involved in seasonal affective disorder (SAD) and the sleep-wake cycle

The Glands and Hormones of the Endocrine System The nervous and endocrine systems are, and help regulate other body systems, thereby maintaining. The endocrine and nervous system work closely together

Endocrine System The nervous system rapidly affects tissues, to which it is directly connected by neurons. The endocrine system relies on called, which circulate in the blood and have, effects.

Let’s Compare… Nervous vs. Endocrine SystemDuration of ResponseLocation Nervous Endocrine

Hormone action is than nerve because hormones circulate through the. The nervous system, on the other hand, involves swift reaction to. – Example: moving your hand off of a hot stove element Adrenaline is the only hormone who’s action is considered to be immediate as it is functional in life threatening situations.

Speed up the action of an organ Slow down the action of an organ Cause the release of other organs () Alter the permeability of a cell to various nutrients – Example: Insulin Hormones can be produced or released in response to the Nervous System or to other chemicals in the blood (hormones) What do Hormones do?

Many hormones are regulated by negative feedback mechanisms (the response acts in to the stimulus). For example, ADH is released when the blood plasma concentration is high (and blood pressure is low). ADH stimulates the kidneys to absorb more water, which dilutes the blood plasma (and increases blood pressure). Negative Feedback Loops

Processes in the body that small changes Less common in the human body One hormone stimulates another which will amplify the effect even more Example: Positive Feedback Systems

Hormone Analogy Another gland/ receptor site

Hormone An organic molecule (most are) secreted, usually in minute amounts, in one part of an organism that regulates the function of tissue or organ. Example: adrenalin in blood = 1 tsp. in a lake 2 m deep and 100 m diameter)

Hormones trigger changes in their target cells when they to proteins on or within the cells. Hormones A model of a hormone (A) bound to its protein receptor (B). Each hormone of the endocrine system has a unique molecular shape, which fits into a specific receptor protein on its target cells.

Hormones Each hormone has its own specific receptor () Some hormones alter the cells permeability to glucose ( > or < ) while others control the rate of enzyme reactions Hormones are released in response to a specific signal from the nervous system or from some other gland

Non-Target Hormones: Affect cells throughout the body instead of just one target site. » Example: Growth hormone (regulates the development of long bones and repairs tissue), insulin, adrenalin Target Hormones: Affects cells of the body or target tissues. » Example: Parathyroid hormone (regulates calcium levels in blood), ACTH, thyroxin Hormone Classification

Chemicals produced by endocrine glands and secreted into the blood are referred to as hormones The system carries these hormones to the various organs of the body Hormones

Water-soluble hormones Protein receptor sites must have the appropriate configuration on its membrane in order to respond to the specific hormone Protein Hormones

Fat-soluble hormones Act from the of a cell, by diffusing into a specific cell and binding with receptor molecules in the cytoplasm. Steroid hormones are able to the cell membrane and enter the nucleus of the cell where they can activate. Steroid Hormones

Types of Hormones LIPID‐SOLUBLE Can diffuse across cell membranes Bind to receptor proteins inside the cell Activate specific genes which cause changes in the cell Example: testosterone, estrogen, WATER‐SOLUBLE Cannot across the cell membrane Combine with receptor proteins on the surface of the target cell Starts a of reactions inside the cell Example: epinephrine, GH, thyroxin,

Tropic Hormones Many hormones from the hypothalamus and pituitary are called hormones (stimulate endocrine glands to produce other hormones). The generalized regulatory pathway of tropic hormones.

Endocrine Glands The endocrine glands have, and secrete hormones into the bloodstream. These hormones then bind to receptor proteins on their target cell membranes. The pancreas is an endocrine gland that secretes the hormone insulin into the bloodstream. Pancreas tissue

Glands of the Endocrine System

The interaction between the nervous system and endocrine system is evident in the hypothalamus- pituitary complex The pituitary gland and hormones while the hypothalamus the of hormones by the pituitary gland by nerves and releasing hormones. Nervous- Endocrine Link

The pituitary gland controls all other endocrine glands Once considered to be the “ " (it controls hormonal secretions of many other endocrine glands) but it is now known that it is controlled by at least 9 hormones (and releasing factors) from the hypothalamus Connected to the hypothalamus (this allows the nervous system and endocrine system to interact) Regulated by feedback The pituitary gland is split into the pituitary and pituitary The MASTER GLAND

Does produce any hormones- stores and releases hormones – Example: antidiuretic hormone (ADH) and oxytocin Posterior Pituitary

ANTIDIURETIC HORMONE () TARGET ORGAN: Stimulates the kidneys to water back into the blood for hydration Is released in response to low blood levels, low blood pressure, dehydration and pain Without ADH copious amounts of would be produced Inhibited by hydration, increased levels of blood, alcohol and caffeine

Two Types: 1)= lack of 2) diabetes insipidus = kidneys do not respond to ADH – CDI- caused by to hypothalamus or pituitary gland – NDI- there is a in the parts of the kidney involved in reabsorption Diabetes Insipidus

Excessive May be intense or uncontrollable Excessive urine volume Symptoms

Posterior Pituitary Gland - OCT Oxytocin is important in the birth process and the supply of milk by the glands.

Anterior Pituitary/Hypothalamus Releasing factors, carried to the pituitary from the hypothalamus through the portal system, control the release of six major hormones

The anterior pituitary produces 6 hormones: human Growth Hormone () thyroid –stimulating hormone () adrenocorticotropic hormone () follicle-stimulating hormone () luteinizing hormone () prolactin () Anterior Pituitary Gland

Affects nearly every body tissue Will affect some tissues by stimulation but the majority of tissues it affects is by using tropic hormones (protein hormone) Target organs:, muscle, bone, cartilage and other tissue for growth Now produced by techniques human Growth Hormone (hGH) (aka. )

Causes an increase in: – Protein synthesis – Cell division and growth (bones and muscles) – Fat usage human Growth Hormone (hGH)

Too much hGH before your growth plates have fused  Symptoms: » Very tall » Large muscles and organs » Delayed puberty » Headache » Sweating » Irregular menstrual cycles » Large hands and feet with thick fingers and toes human Growth Hormone (hGH) Dysfunctions in Children

Overproduction of can lead to Bones and soft tissue of the body - Ribs thicken – Face widens – Feet and hands Can also cause cardiovascular disease, sugar intolerance (diabetes), breathing problems, muscle weakness or colon cancer. hGH Dysfunctions in Adults

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If absent or  hGH Dysfunctions makes-size-year-old.html

Read pages and take notes Read pages and take notes Complete questions on – page 472 # 1-3 – Page 475 # 4-6 – Page 477 # 1-8 Your Task