Hormones Flashcards
Regulation is the process of maintaining homeostasis. What two body systems are the main participants in regulation of the body?
A. Nervous and digestive
B. Nervous and urinary
C. Nervous and endocrine
D. Endocrine and urinary
C. Nervous and endocrine
What is regulation?
- Regulation coordination of the organs of the body to help maintain homeostasis
- Stable internal environment
What is the endocrine system?
- Chemical messengers (hormones) secreted into bloodstream that alter function of other cells (target cells)
What are exocrine glands?
- Exocrine glands require a duct to transport secretions
- Typically non-hormone
- Ex. Sweat glands, pancreas (digestive juices), prostate gland
What are endocrine glands?
- Endocrine glands transport secretions directly into the bloodstream
- Typically hormone-related
- Ex. Pancreas (insulin/glucagon)
What is Paracrine signaling?
- Paracrine signaling is a cellular secretion that doesn’t require transport by the blood (affects neighboring cells only)
What are some types of hormones?
- Steroid
- Hydrophobic
- Made from cholesterol
- Ex. Testosterone and estrogen
- Protein
- Hydrophilic
- Made from amino acids
- Ex. Insulin
Which type of hormone can easily pass through a plasma membrane?
A. Hydrophobic
B. Hydrophilic
A. Hydrophobic
How does the hormone travel through the body?
- A hormone travels through the bloodstream (1)
- From source gland to target tissue
- Target tissue is determined by special receptors (2)
- Proteins in the plasma membrane (hydrophobic hormones) or cytoplasm (hydrophilic hormones)
- Specific to only ONE hormone
- Receptors act like switches to turn on or off gene expression (3,4,5)
- Causes molecular changes
- Primarily activation (or synthesis) of proteins
- Hormone/receptor complex must be deactivated when response is finished
What is usually the result of hormones?
- Hormones result (usually) is to increase the amount of activated protein/enzymes in the cell.
- Activated proteins/enzymes cause a change in the body.
A person is lacking (through genetic mutations) the receptor for a hydrophobic hormone receptor. Which of the following observations are correct?
A. There are fewer receptors in the plasma membrane of the cell
B. There is a decrease in gene expression and protein synthesis
C. There are more receptors in the cytoplasm
D. The hormone fails to enter the cell
B. There is a decrease in gene expression and protein synthesis
What endocrine glands are connected to the digestive, reproductive, and nervouse systems?
- Digestive
- Pancreas, liver
- Reproductive
- Gonads (testes, ovaries)
- Nervous
- Hypothalamus, pituitary gland, pineal gland
What do endocrine glands also consist of?
- Also consists of organs unique to the endocrine system
- Thyroid (parathyroid) and adrenal gland
- Some require CNS input, others work independent of CNS
How many glands are in the Pituitary Glands and what happens when horomones are released from these glands?
- Actually two distinct glands, closely connected with hypothalamus
- Anterior (adenohypophysis) synthesize and secrete hormones
- Posterior (neurohypophysis) store and secrete hormones
- Hormones released from pituitary typically trigger another endocrine organ to release hormones
- Additionally, the pituitary is regulated by hormones from the brain
What happens when hormones are released from the pituitary gland?
- Hormones released from pituitary typically trigger another endocrine organ to release hormones
- Additionally, the pituitary is regulated by hormones from the brain (hypothalamus)
- Three hormones are typically involved
What does the hypothalmus control?
- Hypothalmus brain tissue
- Control center for the body
- Secrete hormones that affect the anterior pituitary (adenohypophysis) gland or are stored in posterior pituitary gland
- RH = releasing hormone (see image)
- Some neurons can directly cause a gland to secrete hormones
What do hypothalamic neurons produce and what is it’s negative feedback?
- Hypothalamic neurons produces hormones
- Releasing hormone (RH) triggers release of hormones from anterior pituitary gland
- Inhibiting inhibit hormones from anterior pituitary gland
- Some are stored in posterior pituitary gland
- NEGATIVE FEEDBACK
- Resultant hormone release stops hypothalamic production of homones
- Creates a balance
Where are the Adrenal glands located and what are its two parts?
- Located on top of kidneys
- Contains two parts
- Medulla: innermost
- Cortex: outermost
What is the medulla and cortex a part of?
- Developmentally, the medulla is part of the nervous system
- Synthesizes epinephrine based on input from nervous system
- Fight or flight response
- A “normal” afferent/efferent pathway
- Developmentally, the cortex is part of the endocrine system
What is epinephrine used for when it’s released as a hormone?
- Released during “fight-or-flight response” from the adrenal gland via efferent neuron
- Has varied effects based on the target receptors
What is the Adrenal Cortex used for?
- Produces hormones when stimulated by pituitary gland
- Cortisol – “stress hormone”
- Stress = fight-or-flight
- Release extra glucose
- Keeps immune system in check (infections are a type of “stress”)
- Sex hormones – secondary source
- Help during puberty until gonads are mature
- Helps with secondary sex characteristics and estrogen production in menopausal women
What hormones are associated with the anterior pituitary gland?
Mammary Gland- PRL
Thyroid - TSH (Pituitary Thyroid Axis)
Testis, Ovary - LH, FSH (Pituitary-Gonadal axis)
Adrenal Cortex - ACTH (Pituitar-adrenal axis)
Bone, Adipose, Muscle - GH
What does the thyroid do?
- Hypothalamus secretes thyroid-releasing hormone
- Causes pituitary to secrete thyroid-stimulating
- Thyroid releases thyroid hormone (T3 and T4)
- Balances metabolic rate
- Upregulates ATP synthesis, raises heart/breathing rate, stimulates appetite, promotes alertness
What is hypothyroidism?
- Not enough hormone
- Results in fatigue, weight gain, poor muscle tone, depression
What is Hyperthyroidism (Graves disease)
- Too much hormone
- Insomnia, excessive weight loss with eating more, high heart rate
What is the Growth Hormone released from?
- Growth hormone-releasing (GH-RH) hormone is released from hypothalamus
- Growth hormone (GH) released from anterior pituitary gland
- Peptide hormone
- Promotes anabolism
What does the Growth Hormone release in the liver?
- In the liver, GH causes release of somatomedins
- Travel to tissue to stimulate protein production in muscle, bone, cartilage, organ cells (most cell types)
- Somatomedins inhibit growth- hormone releasing-hormone (GH-RH) and stimulate growth-hormone inhibiting-hormone
What are examples of bone abnormalities?
- Gigantism and Acromegaly
- Overproduction of growth hormone (GH)
- In children Causes an increase in height because bones are still elongating (gigantism)
- In adults Causes thickening of bones because bones are no longer elongating (acromegaly)
Usually the result of tumor on pituitary gland, which would directly affect the release of __.
A. GH-RH
B. Growth hormone
C. Thyroid hormone
D. Somatomedins
B. Growth Hormone
What is the exocrine and endocrine function of the pancreas?
- Exocrine function – pancreatic juices (acinar cells)
- Endocrine function – hormones (Islets of Langerhans)
Which will go directly into the bloodstream?
A. Pancreatic juices B. Islets of Langerhans
B. Islets of Langerhans
What does the islets of Langerhans cconsist of?
- Alpha cells (15-20%) – glucagon
- Beta cells (65-80%) – insulin
- Delta cells (5%) – somatostatin (growth inhibiting hormone)
- Capillaries carry these hormones to blood stream
What is the function of the pancreatic hormone?
Function: Sugar balance in the body
What does the insullin and glucagon do in the pancreas?
- Insulin (High blood glucose)
- Released in response to high blood glucose
- Stimulates muscle cells to absorb extra glucose (sugar) from blood and store it for future use
- Glucagon
- Released in response to low blood glucose
- Stimulates release of stored glucose
- The two work together to balance glucose levels in our body
What is Diabetes?
- Diabetes is defined as high blood glucose
- Type 1 – lack of insulin production
- Type 2 – inability of cells “perceive” insulin
A person has an auto-immune disease where B-cells produce antibodies for antigens on the surface of pancreatic beta cells. Which type of diabetes does this lead to?
A. Type 1 B. Type 2
A. Type 1 (auto-immune system disease - body attacks its own cells
Once result of diabetes is an increase of glucose in the initial filtrate of the nephron. Subsequently, the PCT is unable to reabsorb all of the glucose.
This causes an ________ in filtrate osmolarity.
A. increase B. decrease
A. Increase
How does the correct answer affect urination (think of osmosis in the loop of Henle)?
A. Increases urination
B. Decreases urination
C. Does not affect urination
A. Increase in urination
What happens in the Mode of Glucagon Action?
- Glucagon is released from pancreatic alpha cells
- Binds to receptor on cell surface in liver
- Causes activation of proteins involved with gluconeogenosis and glycogenolysis (processes in red circles)
- Epinephrine has the same response (helps to release sugar during flight or fight response energy source)
