ENDOCRINE SYSTEM
Three major components of the endocrine system: Adrenal Medulla
• Glands-specialized cell cluster or organs. Functions as part of sympathetic nervous system and produce to
• Hormones- chemical substances secreted by glands in catecholamines epinephrine and norepinephrine. Because
response to stimulation. catecholamines play an important role in the autonomic nervous
• Receptors- protein molecules that bind specifically with other system ANS), the adrenal medulla is considered a neuroendocrine
molecules, such as hormones, to trigger specific physiologic structure.
changes in target cell.
Pancreas
GLANDS A triangular organ, is nestled in the curve of the duodenum,
The Major glands of Endocrine system: stretching horizontally behind the stomach and extending to the
• Pituitary glands spleen.
• Thyroid glands
• Parathyroid glands Endo and Exo Pancreas
• Adrenal glands • The pancreas performs both endocrine and exocrine function.
• Endocrine function- secrets hormones
• Pancreas glands
• Exocrine function- secreting digestive enzymes. Acinar
• Thymus
cells make up most of the gland and regulate pancreatic
• Pineal glands exocrine function
• Gonads (ovaries and testes)
Thymus
Pituitary glands (hypophysis or master gland)- rest in sella Located below the sternum and contains lymphatic tissue. Its
turcica, a depression in the sphenoid bone at the base of the reach maximal size at puberty and then starts to atrophy.
brain. This pea-sized glands connect with the hypothalamus via
the infundibulum, from which it receives chemical and nervous Pineal Gland
stimulation. It has two main regions the anterior pituitary and the Lies at the back of the third ventricle of the brain.
posterior pituitary. Produce the hormone melatonin, primarily during the dark
hour of the day. Little hormone is produced during day time
Anterior pituitary gland(adenohypophysis) hours, thereby influencing sleep-awake cycles.
• Growth Hormones (GH), or somatotropin
• thyroid-stimulating hormone (TSH) or thyrotropin Gonads- Include the ovaries (in female) and the testes (in male)
• Corticotropin Ovaries
• Follicle-stimulating hormone (FSH) • Are paired, oval glands that are situated on either side of the
• lutheinizing hormone uterus.
• Prolactin. • They produce ova(eggs) and the steroidal hormones
estrogen and progesterone. These hormones have four
Posterior pituitary function
• makes up about 25% of the gland. It serves as a storage area for • They promote development and maintenance of female sex
antidiuretic hormone (ADS), also known vasopressin, and characteristics
oxytocin, which are produced by the hypothalamus. • Regulate the menstrual cycle
• Maintain the uterus for pregnancy
Thyroid Gland • Prepare the mammary glands for lactation
• Thyroid lies directly below the larynx. Testes
• Partially in front of the trachea. Its two lateral lobes one on • Are paired structures that lie in an extra abdominal
either side of the trachea join with a narrow tissue bridge, pouch(scrotum) in the male.
called the isthmus, to give the glands its butterfly shape. • Produce spermatzoa and the male sex hormone testosteron
stimulates and maintains masculine sex characteristics and
Parathyroid glands triggers the male sex drive.
• Smallest known endocrine glands.
• These glands are embedded on the posterior surface of the Hormones
thyroid, one in each corner. Polypeptides- Protein compounds made of many amino acids
that are connected by peptides bonds.
Adrenal glands Include :
The two adrenal glands each lie on top of a kidney. • Anterior pituitary hormones
• Adrenal cortex • Posterior pituitary hormones
• Adrenal medulla • Parathyroid hormone
Adrenal cortex • Pancreatic hormones
• large outer layer. Steroids- Are derive from cholestherol.
• It forms the bulk of the adrenal gland. Include:
• It has three zones, or cell layers: • Adrenocotical hormones secreted by the adrenal cortex
o Zona glomerulosa -the outermost zone, produces • Sex hormones secreted by the gonads.
mineralocoticoids (primarily aldosterone) that help maintain Amines- It derive from tyrosine, an essential amino acid found in
fluid balance by increasing sodium reabsorption. the most proteins.
o Zona fasciculata-the middle and largest zone produce the Include:
glucocorticoids cortisol (hydrocortisone), cotisone, and • Thyroid hormones
corticosterone as well as small amount of the sex hormones • Catecholamines
androgen and strogen. Glucocorticoids help regulate
metabolism and resistance to stress. Hormone release and transport
o Zona reticularis-the innermost zone, produce some sex Hormonal action- It binds to a specific receptor on the cell
hormones. membrane or within the cell. Polypeptides and some amines bind
to membrane receptor site
, ELECTROLYTE BALANCE
Hormonal regulation- A feedback mechanism regulates • Electrolytes- are substances that dissociate (break up) into
hormone production and secretion. Involves hormones, chemical elecrically charged particles, called ions, when dissolved
and metabolism and nervous system. Mechanism that controls in water.
hormone release. • Ions- may be positively charged (called cations) or
Four basic mechanism control hormone release: negatively charged (called anions). Major cations include
• Pituitary-target glands exist sodium, potassium, calcium and magnesium. Major anions
• Hypothalamic pituitary- target glands axis include chloride, bicarbonate (HCO3-), and phospahate.
• Chemical regulation
• Nervous system regulation Regulatory mechanisms for common electrolytes:
Aldosterone- are the chief sodium regulators. The small
Hypothalamic-pituitary target gland axis intestine absorbs sodium readily from food, and the skin and
Hypothalamus also produces trophic hormones that regulate kidneys excrete sodium.
anterior pituitary hormones. Which regulate the target glands ACID-BASE BALANCE- a stable concentration of hydrogen ions
hormones, hypothalamus affects the target as well. in body fluids.
• Acid- is a substance that yields hydrogen ions when
Chemical regulation dissociated (changed from a complex to a simpler
Endocrine glands not controlled by the pituitary gland maybe compound) in solution.
controlled by specific substances that trigger glands. When blood • Base- dissociates in water, releasing ions that can
glucose level is a major regulator of glucagon secretion. A combine with hydrogen ions.
depressed level of blood glucose, triggers increase.
Body produces acids, yielding hydrogen ions through the
following mechanism:
Fluids, Electrolytes, Acids, and Bases • Protein catabolism yields nonvolatile acids, such as sulfuric,
FLUID BALANCE phosphoric, and uric acids.
• Homeostasis- (equilibrium of the various body functions) of • Fat oxidation produces acid ketone bodies.
the human body depend on fluid, electrolyte, and acid-base • Buffer systems- reduce the effect of an abrupt change in
balance. Factors that disrupt this balance, such as surgery, hydrogen ion concentration by converting a strong acid or
illness, and injury, can lead to potentially fatal changes in base (which normally would dissociate completely) into a
metabollic activity. weak acid or base (which releases fewer hydrogen ions).
• Body fluid- is made up of water containing solutes, or
dissolved substances, that are necessary for physiologic Buffer systems that help maintain acid-base balance:
functioning. Solutes include electrolytes, glucose, amino • Sodium bicarbonate-carbonic acid
acids, and other nutrients. • Phosphate
• Protein
The four types of body fluids: • Phosphate- buffer system works by regulating the pH of
• Intracellular fluid (ICF)- is found within the individual cells of fluids as they pass through the kidnevs.
the body. • Sodium bicarbonate- regulated by the kidneys, and
• Intravascular fluid (IVE)- also known as plasma, is found carbonic acid concentration is regulated by the lungs.
within the blood vessels and the lymphatic system.
• Interstitial fluid (ECF) - found in the loose tissue around Hematologic system
cells. • The hematologic system consists of the blood and bone
• Extracellular fluid (ECF)- found in the spaces between cells, marrow blood delivers oxygen and nutrients to all the tissues,
includes IVF and ISF. removes wastes, and transports gases, blood cells, immune
cells, and hormones throughout the body.
Fluids forms and movement: Fluids in the body generally aren't • The hematologic system manufactures new blood cells
found in pure forms. They're most commonly found in three through a process called hematopoiesis. Multipotentials
different types of solutions: Isotonic, Hypotonic, and Hypertonic stem cells in bone marrow give rise to five district cell types,
• Isotonic- has the same solute concentration as called unipotential stem cells, unipotential cells differentiate
another solution. into one of the following;
• Hypotonic- has a lower solute concentration than Four types of blood cells:
another solution. • erythrocute (the most common type)]
• Hypertonic- has a higher solute concentration than • granulocyte
another solution. • agranulocyte
Active transport- solutes move from an area of lower • platelet
concentration to an area of higher concentration.
Blood components:
Osmosis- refers to the passive movement of fluid across a Blood consists of various formed elements, or blood cells,
membrane from an area of lower solute concentration and suspended in a fluid called plasma
comparatively more fluid into an area of higher solute
concentration and comparatively less fluid. Osmosis stops when THE RBCS OF BLOOD, WBCs AND PLATELETS,
enough fluid has moved through the membrane to equalize the Formed elements in the blood include:
solute concentration on both sides of the membrane. • red blood cells (RBC’s)- erythrocytes
• white blood cells (WBC’s)- leukocytes
Adenosine triphosphate- energy required for a solute to move • platelets- thrombocytes
against a concentration gradient comes from a substance. RBC's and platelets- function entirely within blood vessels.
Sodium potassium pump- use ATP to move in and out of cells
in a form of active transport. Red blood cells
• Rbc's transport oxygen and carbon dioxide to and from body
tissues, they » contain hemoglobin, the oxygen carrying
substance that gives blood its red color
Three major components of the endocrine system: Adrenal Medulla
• Glands-specialized cell cluster or organs. Functions as part of sympathetic nervous system and produce to
• Hormones- chemical substances secreted by glands in catecholamines epinephrine and norepinephrine. Because
response to stimulation. catecholamines play an important role in the autonomic nervous
• Receptors- protein molecules that bind specifically with other system ANS), the adrenal medulla is considered a neuroendocrine
molecules, such as hormones, to trigger specific physiologic structure.
changes in target cell.
Pancreas
GLANDS A triangular organ, is nestled in the curve of the duodenum,
The Major glands of Endocrine system: stretching horizontally behind the stomach and extending to the
• Pituitary glands spleen.
• Thyroid glands
• Parathyroid glands Endo and Exo Pancreas
• Adrenal glands • The pancreas performs both endocrine and exocrine function.
• Endocrine function- secrets hormones
• Pancreas glands
• Exocrine function- secreting digestive enzymes. Acinar
• Thymus
cells make up most of the gland and regulate pancreatic
• Pineal glands exocrine function
• Gonads (ovaries and testes)
Thymus
Pituitary glands (hypophysis or master gland)- rest in sella Located below the sternum and contains lymphatic tissue. Its
turcica, a depression in the sphenoid bone at the base of the reach maximal size at puberty and then starts to atrophy.
brain. This pea-sized glands connect with the hypothalamus via
the infundibulum, from which it receives chemical and nervous Pineal Gland
stimulation. It has two main regions the anterior pituitary and the Lies at the back of the third ventricle of the brain.
posterior pituitary. Produce the hormone melatonin, primarily during the dark
hour of the day. Little hormone is produced during day time
Anterior pituitary gland(adenohypophysis) hours, thereby influencing sleep-awake cycles.
• Growth Hormones (GH), or somatotropin
• thyroid-stimulating hormone (TSH) or thyrotropin Gonads- Include the ovaries (in female) and the testes (in male)
• Corticotropin Ovaries
• Follicle-stimulating hormone (FSH) • Are paired, oval glands that are situated on either side of the
• lutheinizing hormone uterus.
• Prolactin. • They produce ova(eggs) and the steroidal hormones
estrogen and progesterone. These hormones have four
Posterior pituitary function
• makes up about 25% of the gland. It serves as a storage area for • They promote development and maintenance of female sex
antidiuretic hormone (ADS), also known vasopressin, and characteristics
oxytocin, which are produced by the hypothalamus. • Regulate the menstrual cycle
• Maintain the uterus for pregnancy
Thyroid Gland • Prepare the mammary glands for lactation
• Thyroid lies directly below the larynx. Testes
• Partially in front of the trachea. Its two lateral lobes one on • Are paired structures that lie in an extra abdominal
either side of the trachea join with a narrow tissue bridge, pouch(scrotum) in the male.
called the isthmus, to give the glands its butterfly shape. • Produce spermatzoa and the male sex hormone testosteron
stimulates and maintains masculine sex characteristics and
Parathyroid glands triggers the male sex drive.
• Smallest known endocrine glands.
• These glands are embedded on the posterior surface of the Hormones
thyroid, one in each corner. Polypeptides- Protein compounds made of many amino acids
that are connected by peptides bonds.
Adrenal glands Include :
The two adrenal glands each lie on top of a kidney. • Anterior pituitary hormones
• Adrenal cortex • Posterior pituitary hormones
• Adrenal medulla • Parathyroid hormone
Adrenal cortex • Pancreatic hormones
• large outer layer. Steroids- Are derive from cholestherol.
• It forms the bulk of the adrenal gland. Include:
• It has three zones, or cell layers: • Adrenocotical hormones secreted by the adrenal cortex
o Zona glomerulosa -the outermost zone, produces • Sex hormones secreted by the gonads.
mineralocoticoids (primarily aldosterone) that help maintain Amines- It derive from tyrosine, an essential amino acid found in
fluid balance by increasing sodium reabsorption. the most proteins.
o Zona fasciculata-the middle and largest zone produce the Include:
glucocorticoids cortisol (hydrocortisone), cotisone, and • Thyroid hormones
corticosterone as well as small amount of the sex hormones • Catecholamines
androgen and strogen. Glucocorticoids help regulate
metabolism and resistance to stress. Hormone release and transport
o Zona reticularis-the innermost zone, produce some sex Hormonal action- It binds to a specific receptor on the cell
hormones. membrane or within the cell. Polypeptides and some amines bind
to membrane receptor site
, ELECTROLYTE BALANCE
Hormonal regulation- A feedback mechanism regulates • Electrolytes- are substances that dissociate (break up) into
hormone production and secretion. Involves hormones, chemical elecrically charged particles, called ions, when dissolved
and metabolism and nervous system. Mechanism that controls in water.
hormone release. • Ions- may be positively charged (called cations) or
Four basic mechanism control hormone release: negatively charged (called anions). Major cations include
• Pituitary-target glands exist sodium, potassium, calcium and magnesium. Major anions
• Hypothalamic pituitary- target glands axis include chloride, bicarbonate (HCO3-), and phospahate.
• Chemical regulation
• Nervous system regulation Regulatory mechanisms for common electrolytes:
Aldosterone- are the chief sodium regulators. The small
Hypothalamic-pituitary target gland axis intestine absorbs sodium readily from food, and the skin and
Hypothalamus also produces trophic hormones that regulate kidneys excrete sodium.
anterior pituitary hormones. Which regulate the target glands ACID-BASE BALANCE- a stable concentration of hydrogen ions
hormones, hypothalamus affects the target as well. in body fluids.
• Acid- is a substance that yields hydrogen ions when
Chemical regulation dissociated (changed from a complex to a simpler
Endocrine glands not controlled by the pituitary gland maybe compound) in solution.
controlled by specific substances that trigger glands. When blood • Base- dissociates in water, releasing ions that can
glucose level is a major regulator of glucagon secretion. A combine with hydrogen ions.
depressed level of blood glucose, triggers increase.
Body produces acids, yielding hydrogen ions through the
following mechanism:
Fluids, Electrolytes, Acids, and Bases • Protein catabolism yields nonvolatile acids, such as sulfuric,
FLUID BALANCE phosphoric, and uric acids.
• Homeostasis- (equilibrium of the various body functions) of • Fat oxidation produces acid ketone bodies.
the human body depend on fluid, electrolyte, and acid-base • Buffer systems- reduce the effect of an abrupt change in
balance. Factors that disrupt this balance, such as surgery, hydrogen ion concentration by converting a strong acid or
illness, and injury, can lead to potentially fatal changes in base (which normally would dissociate completely) into a
metabollic activity. weak acid or base (which releases fewer hydrogen ions).
• Body fluid- is made up of water containing solutes, or
dissolved substances, that are necessary for physiologic Buffer systems that help maintain acid-base balance:
functioning. Solutes include electrolytes, glucose, amino • Sodium bicarbonate-carbonic acid
acids, and other nutrients. • Phosphate
• Protein
The four types of body fluids: • Phosphate- buffer system works by regulating the pH of
• Intracellular fluid (ICF)- is found within the individual cells of fluids as they pass through the kidnevs.
the body. • Sodium bicarbonate- regulated by the kidneys, and
• Intravascular fluid (IVE)- also known as plasma, is found carbonic acid concentration is regulated by the lungs.
within the blood vessels and the lymphatic system.
• Interstitial fluid (ECF) - found in the loose tissue around Hematologic system
cells. • The hematologic system consists of the blood and bone
• Extracellular fluid (ECF)- found in the spaces between cells, marrow blood delivers oxygen and nutrients to all the tissues,
includes IVF and ISF. removes wastes, and transports gases, blood cells, immune
cells, and hormones throughout the body.
Fluids forms and movement: Fluids in the body generally aren't • The hematologic system manufactures new blood cells
found in pure forms. They're most commonly found in three through a process called hematopoiesis. Multipotentials
different types of solutions: Isotonic, Hypotonic, and Hypertonic stem cells in bone marrow give rise to five district cell types,
• Isotonic- has the same solute concentration as called unipotential stem cells, unipotential cells differentiate
another solution. into one of the following;
• Hypotonic- has a lower solute concentration than Four types of blood cells:
another solution. • erythrocute (the most common type)]
• Hypertonic- has a higher solute concentration than • granulocyte
another solution. • agranulocyte
Active transport- solutes move from an area of lower • platelet
concentration to an area of higher concentration.
Blood components:
Osmosis- refers to the passive movement of fluid across a Blood consists of various formed elements, or blood cells,
membrane from an area of lower solute concentration and suspended in a fluid called plasma
comparatively more fluid into an area of higher solute
concentration and comparatively less fluid. Osmosis stops when THE RBCS OF BLOOD, WBCs AND PLATELETS,
enough fluid has moved through the membrane to equalize the Formed elements in the blood include:
solute concentration on both sides of the membrane. • red blood cells (RBC’s)- erythrocytes
• white blood cells (WBC’s)- leukocytes
Adenosine triphosphate- energy required for a solute to move • platelets- thrombocytes
against a concentration gradient comes from a substance. RBC's and platelets- function entirely within blood vessels.
Sodium potassium pump- use ATP to move in and out of cells
in a form of active transport. Red blood cells
• Rbc's transport oxygen and carbon dioxide to and from body
tissues, they » contain hemoglobin, the oxygen carrying
substance that gives blood its red color
