Quiz 2 Flashcards
4 methods of cell-cell communication
Gap junctions, contact dependent signals, chemicals that diffuse, long-distance
What protein is involved in gap junctions
Connexins
What proteins are involved in contact dependent signaling
CAMs and integrins
What are some properties of granulosa cells
They release estrogen, have both autocrine and paracrine potential
What is involved in long distance cell-cell communication
Neurotransmitters
What is an example of a neurohormone
Oxytocin
Lipophobic =
Cannot pass through PM, hydrophilic, bind to extracellular receptors
Lipophilic =
Can pass through PM, hydrophobic
What can 2nd messengers do?
Alter gating of ion channels, increase intracellular Ca, and change enzyme activity
Tyrosine kinase
Receptor enzyme, insulin receptor, signal molecule binding causes TK to phosphorylate tyrosine
When G proteins are active they…
Open ion channels and alter enzyme activity in cytoplasm, bound to GTP
Adenylyl Cyclase-cAMP
GPCR amplifier enzyme pathway, converts ATP to CAMP
The Phospholipase C System
GPCR amplifier enzyme pathway, creates IP3 and DAG (DAG to PKC)
IP3 releases Ca stores and PKC phosphorylates proteins
How can Ca enter the cell
Through voltage gated ion channels or binding of ligand to mechanically gated channel
Hormones of the Ant Pituitary
TSH, ACTH, GH, PRL, HSH, FSH/LH
Hormones of the Post Pituitary
Vasopressin and oxytocin
Hypothyroidism causes…
Physical growth and development problems, impaired brain development, enlarged thyroid
Hyperthyroidism causes…
Graves disease, autoimmune disorder
Hormone classification by structure
Hydrophilic and lipophilic
Hydrophilic hormones
Water soluble, most are peptide or protein
ex. insulin and epinephrine
Lipophilic hormones
Ex. Thyroid hormones (aa derivative) and steroid (derived from cholesterol)
Hormone classification by function
Tropic, sex and anabolic
Precursors of hydrophilic hormones
Preprohormones
Examples of steroid hormones
Cortisol, aldosterone, estrogen, progesterone, testosterone
Protein hormones
Long folded chains
ex. insulin
Peptide hormones
Short chains of amino acids
ex. oxytocin and ADH
AA derivative hormones
ex. epinephrine and norepinephrine
Example of antagonism
Parathyroid (increases Ca) and calcitonin (decreases Ca)
Peptide/protein hormones are…
Hydrophilic/Lipophobic
5 secretory cells of the ant pit
Somatotrophs, corticotrophs, thyrotrophs, lactotrophs, gonadotrophs
How does GH affect blood glucose
It indirectly increases because it shifts energy use to lipid catabolism
Tropic hormones ex
TSH, ACTH, FSH, LH
How are hormones released from the ant pit
Neurons in hypothalamus secrete tropic hormones which enter the portal system and act on the hormone secreting cells in the ant pit
What happens when there are low levels of estrogen?
No positive feedback for the release of LH and GnRH
What are the 2 inhibiting hormones
Growth hormone (GHIH) and prolactin (PIH)
Glial cells of the CNS
Oligodendeocytes, microglia, astrocytes, ependymal cells
How does the BBB limit transport
Capillaries held together by tight junctions and astrocytes form tight sheaths
Microglia
Macrophages of the brain
Multiple sclerosis
Disorder of the oligodendrocytes, loss of myelin sheath
Glial cells of the PNS
Schwann cells, form myelin sheath
Inside the cell is…
Negative, lots of K
Outside the cell is…
Positive, lots of Na
How is a RMP maintained?
No channels for the exit of anionic proteins, and active transport of the Na/K pump
Saltatory conduction
Impulse regeneration jumps from node to node
Ex of chemical synapse
Neuromuscular junction
Opening of ion channels produces…
Post-synaptic potential (EPSP or IPSP)
4 chemical classes of neurotransmittera
Acetylcholine, amines, amino acids, other small molecules
Neuropeptides
Large-molecule neurotransmitters
