Exam 2: Hormone Physiology Flashcards
How does nervous system signaling differ from endocrine signaling?
It is rapid and signals are precisely targetted
How does endocrine signaling differ from nervous system signaling?
It is slow, long lasting, and not directly targeted
What are steroids hormones synthesized from?
Cholesterol
What type of solubility do steroid hormones exhibit?
Lipid soluble, not water soluble
How do steroid hormones move throughout the blood?
They bind to transport proteins
What are three kinds of steroid hormones?
Sex hormones, glucocorticoids, and mineralocorticoids
What do glucocorticoids do?
Facilitate glucose cycling from glands
What do mineralocortocoids do?
Help regulate mineral homeostasis
What are peptide hormones synthesized from?
Amino acids
What kind of solubility do peptide hormones exhibit?
Water soluble
What are the largest hormones?
Peptide hormones
What are preprohormones?
Protein precursors to hormones
Which hormones have the shortest half life?
Peptide hormones
What are amine hormones synthesized from?
Amino acids
How large are amine hormones compared to peptide hormones?
They are smaller than peptide hormones
What are a large portion of amine hormones derived from?
Tyrosine
What solubility do amine hormones exhibit?
They can be water soluble or lipid soluble
What kind of hormones are thyroid hormones?
Amine hormones
What kind of hormones do intracellular receptors interact with?
Small, lipid-soluble hormones
What kind of hormones do membrane receptors interact with?
Water soluble hormones
How do membrane receptors work?
Hormone interacts with receptor and starts a G-protein signal cascade
How do intracellular receptors work?
Hormones interacts with transport protein to cross cell membrane influence structures within the cd,,
What controls hormone secretion?
Neural control
What part of the pituitary gland is a true endocrine gland and secretes hormones?
Anterior pituitary
What part of the pituitary gland is a true endocrine gland and secretes hormones?
Anterior pituitary
What part of the pituitary gland contains capillaries to bring secreted hormones to blood steam?
Posterior pituitary
What is the hypothalamo-hypophysial portal system?
A system of neurons and capillaries that carries hormones from hypothalamus to the pituitary
What does HPA stand for in the HPA axis?
Hypothalamic-pituitary-adrenal axis
What nervous system triggers HPA axis?
autonomic nervous system
What is the order of hormone secretion in the HPA axis?
Hypothalamus sends hormones to the anterior pituitary which sends another hormone signal to the adrenal cortex which secretes cortisol
Why does the HPA axis trigger cortisol secretion?
Because cortisol upregulates glucose metabolism for quick energy
What stress responses in the body are produced by the HPA axis?
Increases: heart rate, blood pressure, ventilation and catabolic pressure
Decreases: digestion, excretion, and anabolic processes
What is phase 1 of the HPA axis
Activation of the hypothalamus and adrenal medulla by the sympathetic nervous system
What are catecholamines?
Neurotransmitters/hormones that contribute to increasing heart rate, blood pressure, and respiration rate
What is the purpose of ADH in the HPA axis?
To help the body retain water
What occurs during phase 2 of the HPA axis?
The axis is at full capacity and glucocorticoids are in high production, like cortisol
Why is it bad if cortisol levels remain high for an extended period of time?
Cortisol encourages the body to use up tissue and necessary materials to make glucose
Why does water need to be retained during HPA axis activation?
To make up for water lost exerting work to get away from the threat
How is the HPA axis shut off?
Cortisol performs negative feedback on the hypothalamus and pituitary, preventing them from further triggering cortisol expression in adrenal glands
What is the purpose of insulin?
To stimulate nutrient storage in resting muscle and adipose tissue
What is insulin production regulated by?
Parasympathetic nervous system, amino acids, and blood glucose levels
What are GLUT proteins?
Insulin receptors located in the membrane of cell that opens GLUT4 channels to allow glucose to enter the cell
What is the main organ responsible for regulating cell metabolism (insulin production)?
Pancreas
What processes does insulin promote?
Glycogenesis, lipogenesis, and protein synthesis from glucose
What does processes does glucagon promote?
Glycogenesis, lipolysis, gluconeogenesis -> making of glucose (opposite of insulin)
What is glycogenolysis
Break down of glyocgen into glucose
What is lipolysis?
Breaking down fats into glucose
What is gluconeogenesis?
When the liver makes glucose from anything available
What is glucagon production promoted by?
high protein meals or periods of fasting
