Lesson 9 Endocrine System Flashcards
What are lipophilic molecules?
Lipophilic molecules are lipid loving molecules. readily dissolve in fats and oils. diffuse readily through the cell membrane and stimulate the cell to make a protein.
What types of hormones are classified as lipophilic?
Steroid hormones and thyroid hormones.
What are lipophobic molecules?
Lipophobic molecules are Fat hating molecules meaning they cannot diffuse through the cell membrane and must bind to a receptor on the cell membrane.
What types of hormones are classified as lipophobic?
Peptide hormones and amine hormones.
Fill in the blanks: ‘Second messengers’ for lipophobic hormones are __________ and __________.
cAMP and diacylglycerol (DAG).
Describe the cAMP messenger system.
- Lipophobic hormones bind to G-protein coupled receptor.
- G-protein activates adenylyl cyclase.
- ATP is converted to cAMP.
- cAMP activates protein kinase A.
- Protein kinase A phosphorylates proteins that initiate regulatory responses.
What are the steps for the Phospholipase C system?
- Hormone binds to G-protein coupled receptor.
- G-protein activates phospholipase C.
- Phospholipase C converts membrane protein to DAG and IP3.
- DAG activates protein kinase C.
- IP3 facilitates Ca++ release.
What are autocrine signals?
brings cell back to homeostasis
Autocrine signals are when a cell secretes chemicals that bring the cell back to set point.
What are paracrine signals?
opposite of autocrine’s effect
Paracrine signals are when a cell secretes chemicals that act on surrounding cells.
Define a hormone.
A hormone is a chemical message/regulatory molecule secreted into the blood by endocrine glands to target cells affecting growth, development, homeostasis, or metabolism.
Where are hormones secreted into?
Hormones are secreted into the blood.
What is the concentration level of hormones?
high, low, moderate
Hormones have very low concentrations.
What do hormones bind to?
Hormones bind to specific receptors.
What are peptide hormones?
Peptide hormones are hormones made from peptides/proteins, synthesized on the Rough ER, modified in the Golgi Apparatus, and are water-soluble.
Where are steroid hormones produced?
Steroid hormones are produced in the smooth ER.
What is the cellular mechanism of action for steroid hormones?
Steroid hormones are nonpolar, slower acting, and require carrier molecules for transportation.
What are catecholamines?
Catecholamines are water-soluble amine hormones produced by the adrenal medulla.
What hormones are secreted by the posterior pituitary?
labor hormone and ADH
Oxytocin and Antidiuretic hormone (vasopressin).
What is the function of oxytocin?
think labor indunction
Stimulates contractions of the uterus during childbirth and milk-ejection reflex.
What is the function of antidiuretic hormone (vasopressin)?
think dehydration and kidneys
Promotes water conservation by the kidneys.
What hormones does the adrenal cortex secrete?
stress hormones ishh?
Al———
C——–
Aldosterone and cortisol.
What is the function of aldosterone?
think elctrolytes
Important for regulating sodium and potassium levels.
What is the function of cortisol?
Important for regulating metabolism and the stress response.
What hormones does the thyroid gland secrete?
Thyroxine (T4) and Triiodothyronine (T3).
What is the function of T4 and T3?
regulates
M——
G—–
D——-
Important for regulating metabolism and growth and development.
What occurs during hyperthyroidism?
Hypersecretion of T3 and T4, symptoms include goiter, bulging eyes, and increased metabolic rate.
What occurs during hypothyroidism?
The thyroid secretes too little hormone, symptoms include feeling cold, slow pulse, and brittle nails.
What hormones regulate blood calcium levels?
P—–Thy—–
Cal——
Parathyroid hormone and calcitonin.
What is the function of calcitonin?
Decreases blood calcium by inhibiting osteoclast activity and increasing osteoblastic activity.
What is the function of parathyroid hormone?
opposite effect than calcitonin
Increases blood calcium by stimulating osteoclast activity and decreasing calcium loss in urine.
Which pancreatic cells secrete glucagon?
A———-
Alpha cells.
Which pancreatic cells secrete insulin?
B—-
Beta cells.
What is the function of glucagon?
what increases in diabetic patients
Increases blood glucose by breaking down glycogen.
What is the function of insulin?
Decreases blood glucose by facilitating glucose uptake and storage.
Describe the hypothalamus’s communication with the anterior pituitary gland.
The hypothalamus communicates through the hypophyseal portal system.
What is a tropic hormone?
A hormone that controls the secretion of another hormone.
Name the six hormones secreted by the anterior pituitary.
- Prolactin
- Thyroid stimulating hormone (TSH)
- Adrenocorticotrophic hormone (ACTH)
- Growth Hormone (GH)
- Follicle Stimulating hormone (FSH)
- Luteinizing hormone (LH)
