Endocrine System

Exocrine Glands

Exocrine glands release substances through ducts to a specific body surface or cavity.

Ducts:

Exocrine glands have ducts that carry their secretions to specific locations. DO NOT release hormones.

Secretion

The substances secreted include enzymes, sweat, mucus, and oils.

Where are exocrine glands found?

Eyes, mouth, skin, stomach, liver, pancreas, intestines, mammary glands?

What type of gland are sweat glands and what do they do?

Exocrine glands; regulate body temperature by releasing sweat

What type of gland are sebaceous glands and what do they do?

Exocrine glands; produce sebum (oily compound) to lubricate skin and hair

What type of gland are salivary glands and what does it do?

Exocrine glands; Secrete saliva to aid in digestion and oral health

What type of gland are pancreas and what does it do?

Exocrine gland; Produce digestive enzymes for the small intestine

what type of gland is the liver and what does it do?

Exocrine gland; secretes bile to aid in fat digestion

what type of gland is the mammary gland and what does it do?

Exocrine gland; it secrets milk

What type of gland is lacrimal glands and what do they do?

Exocrine gland; Secrete tears

what are exocrine gland functions?

• Maintaining homeostasis

• Produce secretions

  • Essentially Digestion

  • Temperature regulation

  • Lubrication

  • Protection of tissues

Endocrine Glands

Endocrine system consists of a group of ductless (without tubes) endocrine glands that secrete substances directly into the bloodstream

Hormones

Hormones travel through the blood to target organs

• Stimulate exocrine glands to produce secretions

• Stimulate other endocrine glands

• Regulate growth and development

• Regulate metabolism

• Maintain fluid and chemical balance

• Control various reproductive processes

What does the endocrine system consist of?

Pituitary gland, thyroid gland, parathyroid gland, adrenal gland, pancreas, ovaries, testes, thymus, pineal body and placenta

Hypothalamus - Control Center

Regulate many vital function to maintain balance within the body. Command hub that keeps everything running smoothly

Where is the hypothalamus located?

Above the pituitary gland in the brain, links the central nervous and endocrine systems

What hormones are released by the hypothalamus?

Releases hormones that control the pituitary gland “master gland”

How does the hypothalamus regulate hemostasis?

In body temperature: it monitors the body’s temp by detecting blood temp and receiving signals from skin thermoreceptors

Too Hot: Sweating and vasodilation to release heat

Too Cold: triggers shivering (muscle contractions to generate heat) and vasoconstriction (narrowing of blood vessels) to conserve heat

What happens if the body is dehydrated?

Triggers thirst and release of antidiuretic hormone from posterior pituitary to reduce water loss through urine

What hormone is release to stimulate hunger?

Ghrelin

What hormone is released to signal fullness or satisfaction after eating

Leptin (from fat cells)

How does the hypothalamus interact with sleep wake cycles?

• Interacts with the circadian clock

• Stimulates the pineal gland to produce melatonin at night, promoting sleep

• During the day melatonin production is suppressed

How does the hypothalamus interact with emotional responses?

Controls autonomic nervous system responses to emotions

Coordinates endocrine responses, such as releasing cortisol during stress

What is the central nervous system function?

Acts as the control center for processing and interpreting information. Releasing neurotransmitters at synapses at specific target cells that’s causing some sort of effect

Usually local and specific, happens very quickly within milliseconds

What does the brain do?

Controls thought, memory, emotions, and sensory processing

What does the spinal cord do?

Transmits messages between the brain and the rest of the body

Pituitary Gland location?

Base of the brain. Small pea sized gland

What hormones are produced by the pituitary gland?

Growth Hormone, prolactin

What is the pituitary glands function

Control other endocrine glands and regulates growth, reproduction and metabolism

Takes signals from hypothalamus and send other signals to all other endocrine glands to stimulate release

What hormones are produced by the Anterior Pituitary Gland?

Thyroid stimulating hormone

Luteinizing Hormone
Follicle stimulating hormone

Prolactin

Growth Hormone

Adrenocorticotropic Hormone

What hormones are produced by the Posterior pituitary gland?

Antidiuretic Hormone

Oxytocin

Thyroid stimulating hormone

Stimulates the thyroid gland to produce thyroid hormones (T3 and T4), regulate metabolism

Luteinizing Hormone

Regulate reproductive processes, including menstrual cycle in women and sperm production in men

Follicle stimulating hormone

Simulates reproductive functions, women it promotes egg development, men, it tells testicles to produce sperm

Prolactin

Stimulates milk production in women after childbirth

Growth Hormone

Stimulates growth and development, mostly in bones and muscles

Adrenocorticotropic Hormone

Stimulates the adrenal glands to produce cortisol, hormone involved in stress response and metabolism

Antidiuretic hormone

Helps regulate the body’s water balance by promoting water reabsorption in the kidneys

Oxytocin

Stimulates uterine contractions during labor

Negative feedback loop

Most common type of feedback loop in body, works to reverse or reduce output of a process

Ex. the parathyroid glands secrete parathyroid hormone, regulates the level of calcium in the blood. Calcium decrease, parathyroid glands sense it and secrete more parathyroid hormone

Positive feedback loop

Less common, Amplifies the release of a hormone until a specific event occurs

Ex. oxytocin release during childbirth

Thyroid gland location?

Neck, small butterfly shaped gland

What hormones are produced in the Thyroid GLand

Release Thyroxine (T4) and Triiodothyronine (T3) control energy body uses called metabolic rate

Thyroid Gland function?

Play a crucial role in regulating metabolism, energy production and growth

What does the Thyroid effect?

• Metabolism

• Heart Rate

• Digestion

• Growth and Development

• Bone Maintenance

• Brain Development

• Skin and Hair

What can hypothyroidism lead to?

Affects the digestive system and can constipation

What can thyroid disease lead to?

It can affect the skin and hair, causing dry skin, scaliness, thinning hair, hair loss

Where is the parathyroid gland located

Surface of thyroid gland

What does the parathyroid gland do?

It releases Parathyroid hormone to regulate calcium and phosphorus levels acting on the kidneys, bones, and intestines

What does Calcium do in the body?

Regulate muscular contraction and bone growth

What happens to the parathyroid if calcium levels in blood drop?

Parathyroid glands secrete more PTH to raise calcium levels

What happens to the parathyroid when calcium levels in blood rise

The secretions of PTH is inhibited to prevent excess calcium in the blood

Where are the adrenal glands located?

Small, triangular shaped glands on top of each kidney

What is the function of the adrenal glands?

Adrenal cortex is the outer part known for steroid production and produces cortisol and aldosterone

Adrenal medulla: the inner part known to produce catecholamines such as epinephrine and norepinephrine for fight or flight response

what does aldosterone do?

regulates salt and water balance

How do the adrenal glands play a role in stress response?

When stressed the brain signals the adrenal glands to release hormones like cortisol, epinephrine, and norepinephrine to prepare the body for a flight or fight reaction

How do the adrenal glands play a role in regulation of blood pressure?

they help maintain blood pressure and fluid balance. Aldosterone acts to regulate sodium and potassium levels, which controls blood pressure

How do the adrenal glands play a role in metabolism and immune function?

Cortisol helps regulate glucose metabolism and immune function. Suppresses inflammation and immune responses to prevent overreaction of the immune system.

Where is the Pancreas located?

Behind the stomach

What is the function of the Pancreas?

(1-2% endocrine) produces insulin and glucagon to regulate blood sugar levels

(98% Exocrine) secretes digestive enzymes through ducts to help digest food

What does Insulin do?

Helps lower blood sugar levels by the uptake of glucose into cells, where it can be used for energy or stored in the liver and muscles

What does glucagon do?

Works to increase blood sugar levels by stimulating the liver to break down stored glycogen into glucose through glycogenolysis and release it into the blood stream

What are the pancreas’s exocrine function?

Produces Digestive enzymes:

Amylase

Lipase

Proteases

Bicarbonate

What does amylase do?

Breaks down carbohydrates into simple sugars

What does Lipase do?

break down fats into fatty acids and glycerol

What does Proteases do?

Break down proteins into amino acids

What does bicarbonate do?

Neutralizes stomach acid entering the small intestine, providing an optimal environment for digestive enzymes to function

What are the pancreas’s endocrine functions?

After eating, when blood glucose level rise, the pancreas releases insulin to help cells absorb glucose

Between means, when blood glucose level drop, the pancreas releases glucagon to signal the liver to release stored glucose

Negative feedback loop

Where is the Pineal Gland located?

In the brain, near the thalamus

What are the pineal gland functions?

Plays a crucial role in regulating sleep patterns and circadian rhythm by producing and secreting melatonin

An increase in Melatonin means body temperature and BP drop preparing for sleep

Where are the gonads located?

Ovaries: Pelvic region for females

Testes: Scrotum for males

What the the functions of the gonads?

Ovaries produce estrogen and progesterone, regulating menstrual cycles, menopause and reproduction

Testes produce testosterone, sperm production and male secondary reproductive characteristics

Serotonin

Produced in the brain and hypothalamus

Regulates mood, emotions, sleep, appetite, and pain. Often referred to as the feel good hormone because it helps maintain happiness and emotional stability

Dopamine

Produced in brain and hypothalamus

A neurotransmitter that plays a key role in motivation, reward, pleasure, learning, and attention

Diabetes Mellitus

Chronic health condition that affects how your body turns food into energy, occurs when the body either do not produce enough insulin or cannot effectively use the insulin it produces

Hypothyroidism

Underactive thyroid

Hyperthyroidism

overactive thyroid

Cushing’s Syndrome

Excessive cortisol

Addison’s disease

Insufficient cortisol

Polycystic ovary Syndrome (PCOS)

hormonal imbalance affecting the ovaries

What symptoms are common in diabetes?

Increase thirst (polydipsia)

Frequent Urination (polyuria)

Increased hunger (polyphagia)

Fatigue

Unintended weight loss (common in type 1)

Blurred vision

Slow healing wounds or sores

Frequent infections

What is type 1 diabetes

Autoimmune Destruction of insulin producing cells

What is type 2 diabetes

Insulin resistance or insufficient insulin production

Gestational Diabetes

Hormonal changes during pregnancy causing insulin resistance

What is a normal blood sugar level?

70 - 100

What is hyperglycemia?

BS> 126

What is hypoglycemia

BS < 55

What causes high blood sugar levels?

To much glucose in the bloodstream

Insulin production issues

Consuming large amount of carbohydrate rich or sugary foods

Exercise helps lower blood sugar

Stress hormones released during illness can increase blood sugar level

less water in blood concentrate glucose level

How do you test blood glucose level?

Glucometer or continuous monitoring system (dexcom)

When is it best to test blood?

Before meals - insulin dose based on intake

at bedtime - prevent nocturnal hyper/hypo

What type of medications are needed?

Insulin (injectable), Metformin (oral drug)