Lecture 1 - Cell and molecular physiology Flashcards
What are 3 main components of CLASSIC endocrine glands?
- ductless
- Secrete hormones DIRECTLY into the bloodstream or EC
- Entire organ is dedicated to endocrine function
What are the 7 classical endocrine organs?
What is the exception?
- Pineal Gland - sits on the epithalamus technically outside of the BBB can respond to peripheral signals
- Pituitary gland
- Parathyroid (calcium & phosphate regulation)
- Thyroid gland
- Adrenal Gland
- Pancreas
- Ovary
- Testes (gonads)
- PLACENTA - considered endocrine during fetal development
PANCREAS is the exception since it is both endocrine & exocrine
What are the 6 NON-classical endocrine organs?
Brain – especially hypothalamus (“releasing hormones”)
Kidney – Renin, Vitamin D, erythropoietin (EPO)
Heart – atrial/brain natriuretic peptide (ANP, BNP)
Liver – Insulin-like growth factor
(IGF-I)
GI – small intestine, stomach (serotonin, ghrelin)
Adipose Tissue - leptin
What are 2 key concepts in homeostasis?
HYPER = overproduction of a hormone and/or hypersensitivity
(at the receptor level or receptor signaling pathway) to hormonal effects
HYPO = underproduction of a hormone and/or insensitivity to hormonal effects.
(ex: insulin resistance - body no longer responding)
What organ is a good example of integration?
Name the 6 organs that affect this
THYMUS
- Cortisol/adrenalin from ADRENAL glands
- Thyroid hormones from thyroid gland
- GH/GnRH from CNS
- Testosterone
- Grhelin - Stomach
- Leptin/Adipokinase - Adipose tissue
How are endocrine pathologies characterized?
Why are they often difficult to characterize?
Characterized by a hormone imbalance
Defect can be in classical endocrine gland (primary defect) or other organ (secondary/tertiary)
Symptoms can be vague and hard to diagnose
Weight/Appetite changes
Fatigue
Hair loss/Hirsutism
Cognitive (forgetfulness/confusion)
Dizziness
Moodiness (depression/anxiety/aggression)
Symptoms can take a long time to develop and might seem unrelated
What is an example of a CONGENITAL endocrine pathology?
What causes it?
What are the 3 symptoms?
CRETINISM
- Iodine deficiency during development
- Short stature/impaired bone formation
- Mental retardation
- Delayed motor development
What is MEN (Multiple Endocrine Neoplasia)?
Is this an genetic or congenital pathology?
Multiple Endocrine Neoplasia (MEN)
characterized by 2-3 tumors in multiple endocrine glands
(parathyroid, pituitary, entero-pancreatic)
State some examples of the following categories of endocrine pathologies:
- Malignant and benign tumors
- Infections/immunological problems
- Environmental Factors
1.Neoplastic tissues
Small lung cell carcinoma
- Autoimmune – Diabetes Mellitus Type
- PCBs, DES, birth control
- either compete for receptor or change how hormone delivered to cells
State examples for the following endocrine pathologies:
- Trauma/ Stress
- Surgical
- Therapeutic
1.Trauma/stress:
Sheehan’s Syndrome – postpartum hemorrhage/shock; results in massive pituitary cell death
(SMALL GROUP)
- Surgical
Thyroid gland removal (often parathyroid injury)
3.Therapeutic: Glucocorticoid therapy (Crohn’s disease and others)
What is Diabetes mellitus highly correlated with?
Highly correlated with OBESITY
- correlated with BMI
What are the 3 main mechanisms of hormone action? How do they function?
- Endocrine
– hormones secreted into the blood acting on downstream target tissues. - Paracrine
– hormones secreted into the interstitial space acting at nearby cells. can be at a synapse (considered a NT) - Autocrine – hormones secreted into the interstitial space acting back on same cell.
______ binds to hormones to facilitate transport.
They generally increase what of the hormone?
What type of hormones uses them most often?
- Hormone Binding Proteins
- Increase the HALF - LIFE of the hormone
- Mostly for STEROID hormones (lipophilic)
Also: IGF-I, GH, T4/T3
If the hormone is bound/unbound there is action in the cell. (choose one)
UNBOUND
- only free hormone has action
What do the following have in common? What do they bind?
- Sex hormone binding globulin (SHBG)
- Corticosteriod binding globulin (CBG)
- Thyroxine binding globulin (TBG) and transthyretin (TTR)
- Sex hormone binding globulin (SHBG) – binds estrogens and testosterone
- Corticosteriod binding globulin (CBG) – binds cortisol/corticosterone
- Thyroxine binding globulin (TBG) and transthyretin (TTR) – binds thyroid hormone
What is an example of a nonspecific hormone binder?
ALBUMIN
- binds most lipophilic compounds in blood
- weak interaction