BSC Physiology Flashcards
define homeostasis
maintenance of a relatively stable internal environment despite changing conditions of the external environment
what are the 5 regulated variable in the body?
1) [ ]s of nutrient molecules (glucose), O2 and CO2, and waste products (urea, creatine)
2) pH
3) Temp
4) blood volume and pressure
5) others- hormones, electrolytes, vitamins
how do hormones control feedback
they produce physiological responses that later inhibit secretion
why would homeostasis not occur
- organ/ organ system is being prevented from its job
- loss of negative feedback mechanisms
- organ/ organ systems reached their limits
what are 2 examples of when feedback does not occur
1) plasma osmolality. Diabetes insipidus, neurogenic- decreases ADH from posterior pituitary and nephrogenic, kidneys sensitive to ADH
2) MAP. limited by how much HR &CC increase b/c then we die
describe the variable, sensor, control center, and effector related to plasma osmolality
1) elevated PO > 285
2) osmoreceptors
3) hypothalamus synth and PP secretes ADH
4) kidney- retaining H20 increases, excreting H20 decreases
describe the variable, sensor, control center, and effector related to blood glucose
1) decreased blood glucose <70
2) pancreas alpha cells detect change
3) alpha cells secrete glucagon
4) hepatocytes convert glycogen to glucose
describe the variable, sensor, control center, and effector related to arterial pressure
1) decreased MAP <70
2) baroreceptors detect change in carotid arteries and aortic arch
3) brainstem activates SNS
4) increased heart rate and cardiac contractility, arteriolar vasoconstriction
describe the variable, sensor, control center, and effector related to contractions
1) increased stretch on uterine walls
2) stretch receptors in uterine walls detect
3) hypothalamus synth and PP secretes oxytocin
4) myometrial contractions stimulated
what are the 6 tools we use to see if a patient has moved from physiological to a pathological state
1) patient history and exam
2) blood tests and chemistry
3) urinalysis and other urine tests
4) radiology
5) histology/ cytology
6) miscellaneous
what are the blood tests and chemistry that are used to assess pathology vs physiology
ABG, CBC, thyroid panel, CMP
what radiology methods are used to assess pathology vs physiology
x-ray, CT, MRI, ultrasound
what are the histology methods used to assess pathology vs physiology
biopsy (fine needle and excisional) and pap smear
what are the miscellaneous tools that are used to assess pathology vs physiology
ECG, stress test, PFTs
what is a more complex feedback cycle and why is it more complex?
- low blood testosterone
- 3 different hormones, uses the endocrine axis
- multiple control centers and effectors
describe the variable, sensor, control center, and effector related to blood testosterone
- low blood testosterone
- hypothalamus secretes GnRH
- GnRH stimulates AP to secrete LH
- LH stimulates testosterone production by leydig cells
- increased blood testosterone, GnRH and LH secretion decline
who are the 2 major players of homeostasis
autonomic nervous system
endocrine system
list the types of spinal nerves and the amount of each in order from cranial to caudal
cervical nerves- 8
thoracic nerves- 12
lumbar nerves- 5
sacral nerves- 5
list the 12 brain and cranial nerves
1- fibers of olfactory nerve
2- optic
3- oculomotor
4- trochlear
5- trigeminal
6- abducens
7- facial
8- vestibulocochlear
9- glossopharyngeal
10- vagus
11- accessory
12- hypoglossal
what are the different sections of a neuron
- cell body/ soma
- dendrites
- axon
- axon hillock
- axon terminal
what is the pathway to the SNS and PNS
nervous systems -> central NS and peripheral nervous system* -> sensory and motor-> somatic and autonomic -> parasympathetic and sympathetic
what do the PNS and SNS do
PNS- conserve energy, rest and digest, feed and breed
SNS- mobilize body for activity, fight or flight, stress
what are the two types of neurotransmitters? list if there are subtypes of each
cholinergic and adrenergic, cholinergic has muscarinic and nicotinic
what are the MAIN parasympathetic actions for the eyes, parotid gland, heart, lungs, stomach/ intestines, and bladder
what is the neurotransmitter that attaches at the preganglionic end?
- pupil constriction, increased salivation, decreased HR and contractility, bronchoconstriction, increase all digestive activities, and increase urination
-Ach
what are the MAIN sympathetic actions for the eyes, parotid gland, heart, lungs, stomach/ intestines, and bladder
what is the neurotransmitter that attaches at the postganglionic end?
- pupil dilation, decreased salivation, increased HR and contractility, bronchodilation, decrease digestive activities, decrease urination
- ALL NE
- eyes alpha 1
- heart beta1
- lungs beta 2
- parotid alpha1B1B2
- stomach/int. alpha1, B1, B2
- bladder alpha 1, B1, B2
why would vision loss or damage to the optic nerve occur
pressure is too high on anterior chamber
which are the classic endocrine glands
pituitary, thyroid, parathyroid, adrenal, pancreas (islets of langerhaans), gonads (testes and ovaries), and placenta
what are the side job endocrine glands
brain, heart, liver, GI tract, kidneys, adipose tissue
what are the functions of homeostasis within the endocrine glands?
- maintains homeostasis
- cope w stress
- regulate cell metabolism and energy
- mood, growth, development, and reproduction regulation
what is the classic model for the endocrine system
messengers are synth. and secreted by endocrine glands ->
travel by blood ->
bind to receptor on target tissue
what are details to note on the endocrine model
- messengers are secreted in small quantities, can be paracrine or autocrine
- travelling thru blood may be with a hormone binding protein
- binding to receptor is specific and has high affinity, in cytoplasm or nuclei
how are endocrine messengers dealt with after use
- degraded by enzymes in target tissues, blood, kidneys, or liver
- metabolites excreted via urine/ bile
what are the 3 types of hormones?
1) peptidic- non steroid
2) AA derivatives/ tyrosine derivatives or biogenic amines- non steroid
3) steroid hormones
what are the characteristics of peptidic hormones
lipophobic and hydrophilic, no plasma protein carrier needed
what are the characteristics of AA derivative hormones? examples?
can show similarities to peptidic or steroids depending
ex: epinephrine and NE- lipophobic and hydrophilic
ex: thyroid, lipophilic and hydrophobic
what are characteristics of steroid hormones
lipids derived from cholesterol, differentiate by side chain
- lipophilic and hydrophobic, carried by plasma protein (albumin/ globulin, which can be specific)
what are 3 important features of hormone receptors
1) cells only respond to hormones they have receptors for
2) can be down or up regulated
3) can be manipulated pharmalogically w/ hormone agonists/ antagonists
how do you assess how to give hormones? what are examples of hormones?
by chemical nature of hormone
- birth control, levothyroxine, insulin, desmopressin (synth ADH, nasal spray), can be intranasally, subcutaneously or orally
where does endocrine disease most commonly develop? describe each
- develops on front and back ends
- front end: endocrine itself, can be hypo/ hyper secretion (ex: thyroidism and type I diabetes)
- back end: insensitive/ resistant receptors/ tissue (ex: type II diabetes)
what is the internal environment
inside body but outside cells, plasma and interstitial fluid = ECF
