PHL exam 4 wOOOoooOO

what are free nerve endings used for

what are free nerve endings used for

pain

what are enclosed nerve endings surrounded by layers of connective tissue used for

found on skin, creates graded response and sensitivity on larger regions

what are specialized receptors used for

sense organs, increase sensitivity

chemoreceptor

chemicals (PH, ATP, O2, Co2)

mechanoreceptor

mechanical (touch)

photoreceptor

photons (light)

thermoreceptor

cold and heat

nocireceptor

pain

what are proprioceptors used for

movement, sense of body position, fine motor control

where can you find proprioceptors

muscle spindles, joint receptors, golgi tendon organs

what are cutaneous receptors used for

touch, pressure, heat and cold, pain

special senses

sight, hearing, equilibrium, taste, smell

exteroceptors

respond to external stimuli, (sight, hearing)

interoceptors

respond to internal stimuli, (organs, tissues, mechanical and chemical)

how is a stimulus transduced into an electrical signal

signal transduction pathway, ion channel opens, change in membrane potential, signal to integrating center

what does graded potential determine

stimulus intensity and amount of action potential

where is electrical signal generated

receptor

what does receptor potential determine

stimulus intensity

what is frequency of action potentials proportional to

stimulus intensity

how high will the receptor potential be if the stimulus is long and stronger than average

higher than average

where does the receptor potential take place

transduction site

where is the receptor potential integrated

trigger zone

where does action potentials take place

between the myelinated axon

phasic receptor

fast-adapting mechanoreceptor (putting on a watch)

tonic receptors

slow adapting (smell)

meissners corpuscle function

sensing changes in texture (braille)

where is the meissners corpuscle found

just below layer of skin

ruffini endings function

skin stretch

free nerve ending funtcion

temperature, pain, touch

pacinain corpuscles function

sensing deep pressure

what has sensitive but dense receptive fields

hands, face, lips

what is lateral inhibition

disables spreading of action potential from excited neurons in the lateral direction (allows vision and sound to focus)

what has a less dense receptive field

thighs, forearm

what does it mean to have a small and dense receptive field

you can discriminate 2 points separately when they are closer together

where does fine touch pathway happen

dorsal column-medial lemniscus pathway (synapses in medulla)

where does the coarse touch pathway happen

spinothalamic tact (synapses in spinal cord)

does the fine touch go to the opposite side of the brain (contralateral)

yes

does the coarse touch go to the opposite side of the brain (contralateral)

no

functions of endocrine system

regulate development, growth, metabolism, maintain homeostasis, control digestive processes, control reproductive activity

major glands of endocrine system

pituitary, pineal, thyroid, parathyroid, adrenal gland

what is a endocrine gland

organ/tissue/cells that produce and secrete substance into the blood

what is a hormone

molecule secreted into the blood

what is a target organ

cells that have specific receptors for hormone

what is a receptor

proteins located on plasma membrane or within cell of target organ/tissue

what is a hormonal stimulation

release of a hormone is triggered by the release of another hormone

TSH (thyroid stimulating hormone) function

stimulates release of thyroid hormone from thyroid

what is a humeral stimulation

changes in blood level of nutrient or an ion trigger release of the hormone

what releases TSH

anterior pituitary

what triggers the release of insulin from pancreas

high blood glucose

what triggers release of glucagon from pancreas

low blood glucose

what organ is associated with humeral stimulation

pancreas

what is nervous system stimulation

simulation of the nervous system triggers the release of a hormone

what is an example of nervous system stimulation

sympathetic stimulation of adrenal medulla (leads to fight or flight)

what reflex mechanism is the adrenal medulla associated with

nerual

what do steroids hormones do

enter cell to bind to target tissue receptor

what kind of hormone is lipid-soluble and formed by cholesterol

steroid hormone

what are some examples of a steroid hormone

estrogen, progesterone, testosterone, cortisol, aldosterone

what hormone is water-soluble and derives from amino acids

biogenic amines

what do biogenic amines do

bind to receptor on cell membrane

biogenic amine examples

norepinephrine, epinephrine, thyroid hormone

what is a water-soluble amino acid

protein/glycoprotein

what is the most common type of hormone

proteins/glycoprotein

protein examples

antidiuretic hormone, insulin, glucagon, growth hormone

how are lipid-soluble hormones transported in blood

carrier molecule, loss in urine

what releases hormones

endocrine gland, directly into blood concentrations of hormone

how hormones are eliminated

degradation in liver, excretion in urine by kidneys, uptake by target cells

what organ are water-soluble carrier-proteins produced

liver

which classification of hormones does not require a carrier protein

water-soluble

what do water-soluble hormones do?

activate anabolic pathways, release cellular secretions, change membrane permeability, simulate muscle contractions

what hormone changes membrane permeability

epinephrine (opens Ca channels in heart)

what hormone stimulates muscle contractions

oxytocin

what hormones acts through second messenger systems

water-soluble

what is the first messenger in the 3 common messenger system

hormones

steps of 3 common messenger system

hormone binds to receptor, binding of receptor activates receptor, activated receptor triggers downstream response which amplifies first messenger signaling

what organ degrades hormones

liver

what is up-regulating

increase sensitivity

what is down-regulation

reduce sensitivity

what is the downstream effector of TSH

thyroid

what is the downstream effector of ACTH

adrenal gland

what is the downstream effector of FSH and Lh

testes and ovaries

what is the downstream effector of growth hormones

bones, muscle, adipose tissue, liver

what is the downstream effectors of prolactin

mammary gland

what nuclei controls release and production of oxytocin

paraventricular nucleus

what nuclei controls production and release of ADH

supraoptic nucleus

what part of the pituitary gland contain neural tissue

posterior pituitary

what does the posterior pituitary release

oxytocin and ADH

where are the releasing hormones produced

hypothalamus

which cell in the thyroid gland are the most numerous

follicular cells

what does the parathyroid gland do

regulates blood calcium

what are the effectors of parathyroid hormone

kidney and bone

GH and IGF act through negative feedback to regulate activity of what organs

hypothalamus

how often does the adrenal gland release epinephrine vs norepinephrine

epi 90 norepi 10

what are the functions of epinephrine and norepinephrine

increase heart rate and contraction, breaks down glycogen

zona glomersula

mineral coritcoids

zona fasiculata

glucorcorticoids

zona reticularis

sex steroids

what hormones does the anterior pituitary integrate

ACTH, epinephrine, norepinephrine

what endocrine gland helps regulate blood calcium

parathyroid

function of a-cells

glucagon 40%

function of b cells

insulin 50%