Anatomy And Physiology Flashcards
What hormones does the anterior pituitary secrete?
- Leutenizing hormone
- Follicle stimulating hormone
- Prolactin
- Thyroid stimulating hormone
- Adrenocorticotrophic hormone
- Growth hormone
What hormones does the posterior pituitary secrete?
ADH
Oxytocin
What properties do protein/peptide hormones have?
- Made from amino acid chains
- Lipophobic- cannot pass cell membrane
- So can be stored in vesicles
What properties do steroid hormones have?
- Derived from cholesterol
- Lipophilic so freely diffuse across membranes
- So cannot be stored
- Transport in blood usually bound to carrier proteins
How does a Gprotein receptor work?
- Hormone binds receptor extra cellular domain
- GTP binds to alpha domain of G protein
- This is now ACTIVE
- Alpha subunit detaches, binds other protein coupled to receptor
- May activate second messenger systems: cAMP, CGMP, DAG, IP3, calcium
How do enzyme linked receptors work?
- Transmembrane protein
- Hormone binding induces conformational change
- Causes activation of intracellular domains
- Target protein binds with SH2 domain
- Activates signal transduction cascades
What are some protein hormone examples?
Growth hormone Parathyroid hormone Insulin Glucagon Prolactin
What are examples of amine hormones?
Thyroxine
Epinephrine
Dopamine
What are the essential properties of hormone receptors?
- Recognition: must bind with high affinity and selectivity
- Response: binding triggers signal transduction to have some deserved effect on cell
Which hormones oppose insulin?
Growth hormone
Glucagon
Cortisol
Epinephrine
What is the position of the pituitary gland?
In the middle cranial fossa, enclosed by the diaphragma sellae. Within the diencephalon, central core of brain.
What is the blood supply of the pituitary?
The cavernous part of the internal carotid artery. Also supplied by superior & inferior hypophyseal arteries
What is the relationship anatomically between the hypothalamus and pituitary?
Anatomic: both are within diencephalon. Hypothalamus lies above pituitary. Connected by stem/infundibulum
What is the physiological relationship between the hypothalamus and pituitary?
- Linked to posterior pituitary via neurons (carry ADH & oxytocin for release)
- Linked to anterior pituitary via portal system- signals are given through here.
Anatomic location of thyroid gland
Below the thyroid cartilage of the larynx, anterior to trachea
Anatomic location of parathyroid glands
Posterior aspect of thyroid gland
What hormones do the adrenal glands secrete?
Cortex: 1. Mineralcorticoids (ie aldosterone) 2. Glucocorticoids (ie. cortisol) 3. Sex hormones (testosterone,androgens) Medulla: 1. Catecholamines (epinephrine, norepinephrine, dopamine)
Glut4
Transports glucose into muscle and fat
Insulin induced
GLUT2
Transports glucose into liver and pancreas
LOW sensitivity so only does when HIGH glucose levels
GLUT1/GLUT3
Transports glucose into brain
HIGH sensitivity so maintains brain power supply
How does glucose get absorbed?
Via active transport into enterocytes using SGLT1 (sodium cotransporter)
How does glucose get into the bloodstream from gut?
Passive transport via GLUT2 transporters
What are the three fates of glucose once absorbed by cells?
- Metabolism to ATP (glycolysis, TCA, lactic acid fermentation, oxidative phosphorylation)
- Storage as glycogen
- Conversion to fatty acids via lipogenesis
What processes does insulin release affect?
- Expression of GLUT4 transporter on muscle and fat cells
- Upregulate glycogen formation
- Upregulate metabolism/ATP formation
- Upregulate protein formation
- Upregulate lipogenesis
