More Physiology Stuff Again

Electrical Transmission (not chemical)

Two neurons are connected via gap junctions so ions can conduct directly.

Ionotropic receptors

Increase permeability of ions when neurotransmitter binds

Metabotropic receptors

Are g-protein coupled receptors that activate a signaling cascade when neurotransmitter binds.

EPSP is caused by?

Acetylcholine and Glutamate

IPSP is caused by?

Glycine and GABA

Temporal vs spatial summation

Temporal = same stimulus multiple times, Spatial = different stimuluses at once.

Agonist

Ligand that binds to another ligand’s receptor and DOES exhibit an effect (Derivatives of opioids)

Antagonist

Ligand that binds to the receptor and exerts no effect (Narcan)

Nicotinic ACh receptors

Bind to ACh to let both Na and K flow

Sensitization

Basically, interrupting habituation

How does Sensitization happen?

An interneuron does a g-receptor response to inactivate K channels and activate more Ca channels.

Long-term potentiation

Basically, classical conditioning

Cerebrum

The forebrain (Higher)

Cerebellum

Hindbrain (Lower)

Adrenal Medulla

Releases norepinephrine into blood

Neurosecretory Transmission

Neurons release neurotransmitters to blood stream

Paracriine transmission

Cell releases signals to neighboring cells 

Steroid Hormones are secreted by what?

Gonads and adrenal cortex

Where do steroids bind?

Intracellularly

Are steroids stored?

No, only synthesized as needed

Are peptide hormones stored?

Yes, in secretory granules released by oxytocin.

Insulin is what type of hormone?

Peptide hormone

Epithelial endocrine cells

Stimulated to release hormones by other hormones

Neurosecretory Cells

Hormone secreting cells stimulated by neurons

Where is the pituitary gland located

hypothalamus

ADH is?

Antidueretic Hormone, retains water in kidneys,vasoconstrictor.

Oxytocin is?

Uterus contraction for birth, lactation, mother stuff

What secretes ADH and Oxytocin?

POSTERIOR pituitary gland

Growth hormones do what?

Literally influence growth and metabolism

ACTH does what?

Adrenocorticotropic hormone stimulates production of other hormones (androgens specifically) like cortisol and testosterone.

What releases ACTH and growth hormones?

ANTERIOR pituitary gland

What stimulates the anterior pituitary gland?

Hypothalamo-hypophysical portal system

Release hormones

Stimulate release of anterior pituitary hormones

Inhibiting hormones

Inhibit release of anterior pituitary hormones 

What are tropic hormones?

Hormones that cause other glands to release hormones

Who releases tropic hormones?

Anterior pituitaryh gland

What is the sequence of endocrine control called?

An axis

Does the posterior pituitary make hormones?

No, it only stores them and releases them when the hypothalamus neurons tell it to.

How does the hypothalamus make the anterior pituitary secrete its hormones?

By releasing its own hormones in the blood stream.

ACTH makes what again?

Cortisol via adrenal glands (stress response) and can also ask to make testosterone.

What hormone does the hypothalamus secrete to release ACTH via anterior pituitary?

CRH

Reminder, what is ADH?

A vasopressin to cause kidneys to retain fluid. Decreases BP

What is aldosterone?

Causes kidney to retain Na+, so it retains fluids.

What does ADH do at low blood volume?

Adds aquaporins

What is renin?

Something secreted at low blood pressure to secrete aldosterone.

What system conserves sodium?

Renin-angiotension--aldosterone system.

How does Aldesterone work?

Increases Sodium potassium pump activity to conserve Na so it isn’t flushed from urine.

Glucagon does what?

Increases blood sugar levels (opposite of insulin)

What causes insulin to be released chemically?

Ca+ channels open due to depolarization due to excessive ATP

Muscle organization?

sacromeres —> Myofibrils —> Myofibers

What is the thick, red filament in a sacromere?

Myosin

What is the thin filament?

Actin

What is the thin filament composition?

Blobs of actin with 2 strands of tropomyosin and small troponin molecules attached to tropomyosin.

What is on a myosin filament?

Actin binding site and ATP binding site

Basically, who actually moves the muscle?

Myosin

When does it actually move in the moving cycle?

When phosphate detaches from adp

What does ATP initially do?

Dissociate the rigored myosin and actin from eachother, attaches itself to the myosin and does its thing.

Where does Ca bind?

Troponin, which causes tropomyosin to move tf out the way.

RyR and DHPR channels?

When positively charged, let calcium down to sacromere.

Tonic muscles?

No action potnetial, for posture.

How are insect muscles stopped?

Calcium

Smooth muscle has no?

Sacromere and therebyt no troponin

How do smooth muscle contract?

Caveolae squeezes them