Kristof physiology 2

Function of C fibers (type IV fibers)

Pain fibers and autonomic postganglionic fibers

What is observed in the masseter reflex?

Masseter muscle is contracted, mouth is closed

List 8 proprioceptive reflexes

Masseter reflex, biceps reflex, triceps reflex, brachioradial reflex, brachioulnar reflex, abdominal muscle reflex, patellar reflex, achilles tendon reflex

Where do the fibers in DCML decussate?

Medial lemniscus (brainstem)

In which case do you get a contraction both when you switch on and off the stimulus?

Medium stimulus intensity (both cathode make and anode break excitations)

Which part of the adrenal gland is innervated by the autonomic system?

Medulla

Definition of the equilibrium membrane potential

Membrane potential at which there is no net movement of a certain ion across the membrane

Role of hippocampus

Memory formation

Last menstruation and after

Menopause

Type of dye used in a vaginal smear

Methylene blue

In which case can goiter be present in euthyroidism?

Mild iodine deficiency, TSH overproduction

What is rheobase?

Minimum electrical current required to excite the nerve or muscle when the duration of the stimulus is indefinitely long

What is chronaxie?

Minimum time required to excite the nerve or muscle when twice the rheobase is applied

Other names for the proprioceptive reflex

Monosynaptic, myotatic, deep reflex

Characteristics of Cushing's syndrome

Moon face, buffalo hump, obese trunk/head/neck, thin extremities, DM, osteoporosis

Length of smooth muscle AP

More than 300 ms

Functions of A-gamma fiber (type II fibers)

Motor fibers to muscle spindle

Functions of A-alpha fibers

Motor neurons (Ia) and primary endings of muscle spindle/ afferent/sensory fibers from proprioceptors (Ib)

Cathode is closer to the muscle, circuit is closed, open conduction between the two poles, low stimulus is on. What is observed?

Muscle contraction

Cathode is closer to the muscle, circuit is closed, open conduction between the two poles, strong stimulus is on. What is observed?

Muscle contraction

Cathode is closer to the muscle, circuit is open, open conduction between the two poles, post middle stimulus excitation. What is observed?

Muscle contraction (anode break excitation)

Cathode is closer to the muscle, circuit is closed, open conduction between the two poles, middle stimulus is on. What is observed?

Muscle contraction (cathode make excitation)

Cathode closer to the muscle, closed circuit, no conduction between the two poles. What is observed?

Muscle contracts because there is a depolarization around the cathode

Which receptors are affected by curare?

Muscle type nicotinic acetylcholine receptors

Movement of Na+, K+, and Cl- if membrane potential is between -85 mV and +55 mV

Na+: inflow K+: outflow Cl-: if under -60 outflow, if above -60 inflow

Movement of Na+, K+, and Cl- if membrane potential is 0 mV

Na+: inflow K+: outflow Cl-: inflow

Movement of Na+, K+, and Cl- if the membrane potential is +10 mV

Na+: inflow K+: outflow Cl-: inflow

Polarity of cathode

Negative

Location of GLUT3

Neuron

In which patient group can the Babinski reflex be physiological?

Newborns

Which substance inhibits nicotinic ach receptors?

Nicotine

Type of receptors on ganglia

Nicotinic acetylcholine receptors

What kind of receptors are on the adrenal medulla?

Nicotinic acetylcholine receptors

What is observed in the mamillary reflex?

Nipple erection

Do PSPs have a threshold?

No

Anode is closer to the muscle, circuit is closed, open conduction between the two poles, strong stimulus is on. What is observed?

No contraction

Cathode is closer to the muscle, circuit is open, open conduction between the two poles, post strong stimulus. What is observed?

No contraction (AP elicited around the anode cannot pass through the negative charge accumulation around the cathode)

Cathode is closer to the muscle, circuit is open, open conduction between the two poles, post low stimulus excitation. What is observed?

No muscle contraction

Can Post synaptic potentials (PSPs) be inhibited by TTX, why?

No, they do not use fast voltage gated Na+ channels.

Other name for DM2

Non-insulin dependent diabetes mellitus

What kind of hormone is the hPL?

Nonapeptide

Which enzymes are required for the synthesis of androgens/sex hormones from progesterone?

None

Effect of increased stimulus intensity on the amplitude of the contraction curve, above maximum threshold

None, all fibers have reached their threshold

What can be seen in a proestrus phase?

Nucleated epithelial cells

Typical body shape for DM2 patients

Obese/overweight

What is the dominant cell type in the diestrus/anestrus?

Only a few cells are present, mainly leukocytes

What causes the depolarization in the AP?

Opening of fast voltage gated Na+ channels causes Na+ influx

What causes repolarization in the AP?

Opening of voltage gated K+ channels causes K+ outflow

What is tested in the corneal reflex?

Ophthalmic nerve (afferent) and facial nerve (efferent)

Typical onset of DM2

Over 40 years old

Which hormones are produced by the hypothalamus?

Oxytocin, TRH, CRH, GnRH, GHRH, ADH

What stimulates calcitriol?

PTH

Parasympathetic or sympathetic fibers are longer, and why?

Parasympathetic, because the ganglia are located on the viscera and not close to the spinal cord

Types of sympathetic ganglia

Paravertebral (sympathetic trunk) and prevertebral

What is the Babinski reflex?

Pathological response to the plantar reflex, dorsal flexion

What factors increases the formation of GH?

Physical exercise, sleeping, and low blood glucose levels

Decreased levels og GH in childhood

Pituitary dwarfism

What is observed in the achilles tendon reflex?

Plantar flexion

What is observed in the plantar reflex?

Plantar flexion

Characteristics of experimental setup for each of the polar excitement, Pflüger's law, and electrotonus examinations

Polar excitement: one stimulator, conduction between poles is blocked via NH4+ Pflügers law: one stimulator, free conduction between poles Electrotonus: two stimulators, free conduction between poles

Anode is closer to the muscle, circuit has just been opened, no conduction between the two poles. What is observed?

Polarities switch. There is a depolarization (accumulation of positive ions) around the anode, a contraction is observed.

Other names for exteroceptive reflex

Polysynaptic, skin, surface reflex

Symptoms of hyperglycemia

Polyuria, polydipsia, polyphagia, itchy skin

Which center is tested in the masseteric reflex?

Pons

Via what does GHRH reach the pituitary gland?

Portal vessels

Polarity of anode

Positive

Where do the two somatosensory systems terminate?

Postcentral gyrus

Which hormone increases after ovulation?

Progesterone

Steps of synthesis of corticosterone from progesterone

Progesterone -> 11-desoxyxorticosterone -> corticosterone

Which hormones increase towards the end of the pregnancy?

Progesterone, estradiol, hPL (human placenta lactogen)

Which hormone in the anterior pituitary is not affected if the portal circulation is blocked?

Prolactin

Two uterine phases

Proliferative and secretory

which phase in humans does the proestrus correspond to?

Proliferative phase (uterus), follicular phase (ovaries)

What causes iatrogenic Cushing's?

Prolonged glucocorticoid therapy

What are the two types of reflexes?

Proprioceptive and exteroceptive

In which form are thyroid hormones mostly found in?

Protein bound (thyroxin binding globulin)

Functions of A-delta fibers (type III fibers)

Protopathic sensation

Type of sensation carried by the spinothalamic system

Protopathic: pain, temperature, crude touch

Which factors can activate the stress-axis?

Psychological stress Physical stress: extreme exercise, pain, hypoglycemia

What can the babinski reflex indicate?

Pyramidal tract lesion

Location of GLUT 1

Red blood cells and blood brain barrier

Effect of TSH on thyroid gland

Release of T3 (tri-iodo-thyronine) and T4 (tetra-iodo-thyronine/thyroxin)

Effect of TRH on the anterior pituitary

Release of TSH

What is tested in the plantar reflex?

S1-S2

Which segments are tested in the achilles tendon reflex?

S1-S2

Why do levels of progesterone increase in the luteal phase?

Secreted by corpus luteum which grows in the luteal phase

Which phases in humans does the metestrus and diestrus correspond to?

Secretory phase/luteal phase

Typical body shape in individuals with DM1

Skinny, the cells of the body are not getting any glucose

Effect of increased corticsol on CNS

Sleepiness, depression

What causes hyperpolarization at the end of the neuron AP?

Slow closure of the K+ channels

Where do the fibers in the spinothalamic tract decussate?

Spinal cord, same level of corresponding DRG

Which hypothalamic nuclei produce oxytocin and ADH?

Supraoptic and paraventricular nuclei

What is tested in the mamillary reflex?

T4 segment

What is tested in the superficial abdominal reflex?

T7-T11 segments

Which segments are tested in the abdominal reflex?

T8-T12

Which hormones are present in a bigger concentration in the portal circulation than in the peripheral circulation?

TRH

In which case can goiter be present in hyperthyroidism?

TSH producing tumor, autoimmune disease (antibodies stimulate TSH release)

Which hormones are produced in the anterior pituitary?

TSH, ACTH, LH, FSH, GH, prolactin

Effect of LH on testis, and via which cells

Targets Leydig cells and increases production of testosterone

Effect of FSH on testis, and via which cells

Targets Sertoli cells, increases spermatogenesis and inhibin production

What does the equilibrium potential depend on (Nernst equation)?

Temperature, ion charge, intracellular and extracellular concentrations

How would the shape of the compound AP change when the recording electrodes are moved further away?

The AP becomes wider

How does the amplitude of the contraction curve change when the intensity of the stimulus is increased (from above threshold to higher), and why?

The amplitude is increased, more fibers are activated (each fiber has a different threshold). This is called a compound stimulus, where the APs of individual fibers are summated

How is the amplitude of the PSP different compared to the amplitude of the AP?

The amplitude of the AP is constant while that of the PSP decreases with time and distance

Relation between excitability and diameter of nerve fibers

The larger the diameter, the higher the excitability (lower threshold)

Cathode is closer to the muscle, circuit has just been opened, no conduction between the two poles. What is observed?

The polarities of the cathode and anode will switch. There will be a hyperpolarization (accumulation of negative charge) around the cathode, no contraction is elicited.

Why does 11-beta-hydroxylase deficiency cause non-salt losing form of androgenital-syndrome?

The production of 11-desoxycorticosterone and corticosterone is not inhibited since 21-beta-hydroxylase is present. 11-desoxycorticosterone and corticosterone have a sreduced but similar effect as aldosterone

Why do the levels of FSH regress during the follicular phase?

The rise in estrogen inhibits FSH secretion

Anode is closer to the muscle, closed circuit, no conduction between the two poles. What is observed?

There is a hyperpolarization around the anode (accumulation of negative ions), no contraction is elicited

Why is there no anode break excitation with a strong stimulus, cathode closer to the muscle?

There is a large accumulation of negative charge around the cathode, blocking the AP which was elicited around the anode from reaching the muscle

What is the cathode make excitation?

There is an accumulation of positive charge around the cathode, causing depolarization and increase in excitability. It is easier to elicit a contraction, lower threshold

Why are calcium channels important for signal transmission?

They cause exocytocis of the vesicles with neurotransmitters into the synapse where they can bind to the posynaptic membrane

Why do PSPs not have a refractory period?

They do not depend on fast voltage gated Na+ channels; no inactivation gate

How do glucocorticoids cause high blood pressure?

They increase the sensistivity of adrenergic receptors and increase water and salt retention

Which parts does proinsulin consist of?

Three amino acid chains: A, B and C. The C chain conects the A and B chains

Which cells release hCG?

Trophoblast cells

Way of action of dopamine on prolactin

Tuberoinfundibular dopaminergic system

Which parts does insulin consist of?

Two amino acid chains: A and B chain

Difference between type one and two Addison's disease

Type one causes hyperpigmentation, not the secondary type

Type of feedback by which TRH acts on itself

Ultrashort negative feedback

Effect of ADH on V1, V2, and V1-b receptors

V1: vasodilation V1-b: release of adrenocorticotrope hormone (ACTH) from the anterior pituitary V2: collecting tubules, water retention

How does adrenaline increase blood glucose levels?

Via beta 2 receptors in the liver, it stimulates the breakdown of glycogen. Via alpha receptors on beta cells, it inhibits the production and secretion of insulin.

Why do glucocorticoids cuase decreased calcium content in bones?

Via inhibition of osteoblasts

How does GnRH reach the anterior pituitary gland?

Via portal vessels

How does TRH reach the anterior pituitary gland?

Via portal vessels

Which vitamin is required for the production of steroid hormones from cholesterol?

Vitamin C

Other names for calcitriol

Vitamin D and 1,25 dihydroxycholecalciferol

where are the fast voltage gated sodium channels found in the neuron?

nodes of ranvier and axon hillock

Neurotransmitter released by sympathetic postganglionic fibers

norepinephrine

Where is calcitonin produced?

parafollicular cells of the thyroid gland (c-cells)

What kind of hormone is glucagon?

peptide hormone

What is the inner layer of the adrenal cortex?

Zona reticularis

Function of alpha cells

produce glucagon

Four phases of estrous cycle

proestrus, estrus, metestrus, diestrus

blood glucose in diabetes mellitus

above 7 mmol/L

Neurotransmitter released by preganglionic neurons

acetylcholine

Where are glucocorticoids produced?

adrenal cortex

Where is epinephrine produced?

adrenal medulla

Where is glucagon produced?

alpha cells of pancreas

Impaired fasting glucose (IFG)

an intermediate stage between normal glucose homeostasis and diabetes.

Where is growth hormone produced?

anterior pituitary gland

where is insulin produced?

beta cells of pancreas

effect of TTX (tetradotoxin)

blocks fast voltage gated sodium channels

effect of TEA (tetra ethyl ammonium)

blocks voltage gated potassium channels

How does glucagon increase blood glucose?

breaks down glycogen and stimulates gluconeogenesis

effect of inhibitory synapse on the post synaptic membrane

chloride and potassium channels open causing outflow of potassium and inflow of chloride, resulting in a hyperpolarization of the post synaptic membrane (making it harder to elicit an AP)

What kind of cells are in the adrenal medulla?

chromaffin cells which produce catecholamines (adrenaline, noradrenaline and dopamine)

What is myxedema?

condition caused by hypothyroidism where proteoglycans escape into the interstitial fluid and cause fluid retention (osmotically active)

Where is somatostatin produced?

delta cells of pancreas

What inhibits prolactin?

dopamine

What is goiter?

enlargement of the thyroid gland

Where does fertilization take place?

fallopian tubes

Two ovarian phases

follicular and luteal

what is GIP?

gastric inhibitory peptide, or glucose dependent insulinotrop peptide. It is secreted by the proximal part of the small intestine and inhibits gastric juice secretion and stimulates insulin production (promotes digestion).

which hormones increase blood glucose?

glucagon, adrenaline, noradrenaline, glucocorticoids (cortisol), growth hormone, thyroid hormones, and somatostatin

What does the zona fasciculata secrete?

glucocorticoids (cortisol) and androgens

which substances stimulate beta cells?

glucose, some amino acids, glucagon, parasympathetic nervous system (Ach), incretins (GIP, GLP-1)

Which neurotransmitters are found in the excitatory synapse?

glutamate and aspartate

What type of hormone is hCG?

glycoprotein hormone

function of aldosterone

increases Na+ reabsorption, K+ and H+ secretion

What is the end plate potential?

initial depolarization of motor end plate

which hormones decrease blood glucose?

insulin

What causes goiter?

iodine deficiency

role of somatostatin in blood glucose regulation

it raises blood glucose and inhibits beta cells in the pancreas

range of blood glucose in hypoglycemia

less than 3.5 mmol/L

normal OGTT

less than 7.8 mmol/l

what are the characteristics of GLUT2?

low affinity and high capacity for glucose

Effect of calcitonin of blood calcium

lowers blood calcium

1st menstruation

menarche

What is the adrenal medulla?

modified sympathetic ganglion

which blood glucose values in an OGTT are indicative of diabetes mellitus?

more than 11 mmol/l

Location of GLUT4

muscle and adipose tissue

type of axonal conduction of AP

saltatory

Location of GLUT5

small intestine

why do GLUT2 have low affinity for glucose?

so that glucose is only taken in when it is abundant in the blood, not when its scarce and needed for energy production

why do GLUT2 have high capacity for glucose?

so that high amount of glucose can be taken up and more insulin synthesised to regulated the blood glucose

effect of excitatory synapse on the post synaptic membrane

sodium and calcium channels open, causing inflow of sodium and calcium and depolarization of the post synaptic membrane

What is the resting membrane potential maintained by?

sodium potassium ATPase

which molecules inhibit beta cells?

somatostatin, adrenaline, and noradrenaline via alpha receptors.

Where is Norepinephrine produced?

sympathetic postganglionic fibers

how are beta cells stimulated? what is the result?

they are stimulated by glucose via GLUT2 and result in the production of insulin.

Where is iodine stored?

thyroid gland

What is TRH and what does it do?

thyrotropin releasing hormone, it stimulates prolactin

where are voltage gated potassium channels found in the neuron?

under the myelin sheath

What is the middle layer of the adrenal cortex?

zona fasciculata

equilibrium membrane potential for Na+

+55 mV

Organs involved in the stress axis and their corresponding products

- Hypothalamus: corticotropin releasing hormone (CRH) - Anterior pituitary: adrenocorticotropic hormone (ACTH) - Adrenal cortex: cortisol(glucocorticoid)

Functions of GH

- growth processes - anabolic hormone; increases protein synthesis and increases muscle mass - increases blood glucose by decreaseing glucose uptake by cells - increases lipolysis

Range of membrane potential in which both the activation and inactivation gates of the fast voltage gated sodium channels are open

-20 to -40 mV

Membrane potential at which the inactivation gate of the voltage gated sodium channels is closed (also MP at which potassium channels open; peak of AP)

-30 mV

Equilibrium membrane potential for Cl-

-60 mV

Equilibrium membrane potential for K+

-85 mV

Reasons for a false positive pregnancy test with the immunological method

In males: testicular cancer In females: abnormally high FSH and LH levels caused by menopause, choliocarcinoma, wilms tumor, hydratidiform mole

where are the voltage dependent calcium channels found on the neuron?

In the axon terminal

Where are parasympathetic ganglia located?

In the wall of the innervated organ (intramural)

How do glucocorticoids increase blood glucose?

Increase gluconeogenesis and decrease glucose uptake

How does T3 and T4 increase blood glucose?

Increase glucose absorption from the small intestine

Functions of glucocorticoids (cortisol)

Increase of blood sugar via increasing gluconeogenesis, increasing glycogen synthesis, decreased glucose uptake of cells, increased proteolysis, amino acid release from skeletal muscle, lipolysis in limbs (central shift of adipose tissue), surfactant production by type II pneumocytes, increased sensitivity of adrenergic receptors, decreased calcium in bones, increased sensitivity of mineralocorticoid receptors (water and salt retention), inmmunosuppressiv effect, decreased WBC, decreased interleukin levels, decreased C-reactive protein levels

What is cathelectrotonus?

Increase of excitability around the cathode due to the accumulation of positive charge (depolarization)

Effect of amino acids on glucagon secretion

Increased

Effect of anelectrotonus on the threshold

Increased

Effect of catecholamins of glucagon secretion

Increased

Effect of gestational diabetes on chance of developing DM2

Increased by 50%

Effect of Cushing syndrome

Increased cortisol levels

Why does hyperthyroidism cause exophthalamus?

Increased proliferation of retrobulbar tissue

Effect of glucocorticoids on glucagon

Increased secretion

Effect of growth hormone on glucagon

Increased secretion

Effect of acidosis on concentration of free calcium

Increased, plasma proteins bind H+

Effect of glucagon on blood glucose

Increases

Effect of testosterone on spermatogenesis

Increases

Effect of PTH on calcium levels on blood calcium

Increases blood calcium

Effect of calcitriol on blood calcium

Increases blood calcium

How does GH increase blood glucose?

Increases glucose levels and decreases glucose uptake by the cells

How does adrenaline and noradrenaline increase blood glucose?

Increases glycogen break down in the liver via beta-2 receptors

Functions of TSH

Increases iodine uptake to thyroid gland Increases size of thyroid gland Increases all enzymes involved in T3 and T4 formation Increases thyroglobulin formation

Function of testosterone in females

Increases libido

Effect of kisspeptines

Inhibit GnRH during lactation

Effect of ACTH on CRH

Inhibition

Effect of T3 on TSH

Inhibition

Effect of TSH on TRH

Inhibition

Effect of cortisol on ACTH

Inhibition

Effect of cortisol on CRH

Inhibition

Effect of dopamine on prolactin

Inhibition

Effect of estradiol on LH (not the end of follicular phase)?

Inhibition

Effect of insulin on hormone sensitive lipase

Inhibition

Effect of insulin on lipolysis

Inhibition

Effect of insulin, somatostatin, and glucose on glucagon secretion

Inhibition

Effect of testosterone on LH and GnRH

Inhibition

Effect of LH and FSH on GnRH

Inhibition (negative feedback)

Types of post synaptic potentials

Inhibitory and excitatory

Effect of inhibin

Inhibits secretion of FSH and GnRH

Effect of progesterone on hypothalamus and anterior pituitary gland

Inhibits secretion of GnRH, LH, and FSH

Effect of increased sensitivity of adrenergic receptors

-Beta-1 receptors in the heart: increased HR, SV, CO, BP -alpha-1 receptors in the vessels: increased TPR and BP

Which factors activate adrenocorticotropic hormone?

-CRH (hypothalamus) -catecholamines (adrenaline, noradrenaline) -ADH/vasopressin (via V1-b receptors)

Causes of secondary Addison's disease

-CRH deficiency -> low ACTH -> low cortisol -ACTH deficiency -> low cortisol

Reasons for secondary Cushing syndrome

-CRH overproduction -> increased ATCH -> high cortisol -ACTH overproduction -> high cortisol

Effect of FSH and LH on ovaries

-Production of estradiol by theca interna cells and granulosa cells -Production of progesterone by corpus luteum

In which cases can postganglionic sympathetic fibers secrete acetylcholine

Innervation of sweat glands

Effect of hyperparathyroidism on urine

-decreased calcium concentration -increased phosphate concentration

Endocrine causes of hyperglycemia

-hyperthyroidism -giantism (GH, childhood) -acromegaly (GH, adult) -glucagonoma (glucagon producing tumor) -cushing-syndrome (cortisol overproduction) -pheocromocytoma (adrenal medulla tumor) -somatostatinoma

Effect of pheochromocytoma (adrenal medulla tumor)

-increased BP -hyperglycemia -mydriasis (pupil dilation) -piloerection -increased HR, BP, SV, CO, TPR -decreased blood flow to GI, urogenital tract, and skin -increased blood flow to skeletal muscle and coronary aa -decreased gastric motility and secretion of gastric juice -sphincter contriction -uterus and urinary bladder relaxation

How does PTH decrease plasma phosphate?

It inhibits the Na+/PO4 2- cotransportes in the proximal convoluted tubule

Other examples of glycoprotein hormone

LH, FSH, TSH (released by anterior pituitary)

glycoprotein hormones

LH, FSH, TSH, hCG

What is diabetes mellitus type 1 caused by?

Lack of insulin, viral infection, autoimmune disease where antibodies are produced against beta cells of the pancreas

Decreased levels IGF-1 in childhood

Laron's dwarfism

Duration of AP in neuron

Less than 4 ms

What is the dominant cell type in the metaestrus?

Leukocytes

What type of receptors are on the post synaptic membrane?

Ligand gated ion channels

Acute stress reactions

-increased blood glucose via B2-receptors on the liver -increased FFA via B3 receptors in adipose tissue -pupil dilation via A1 receptors on dilator pupil m. -piloerection via A1 receptors on erector pili -increased HR, SV, CO, BP via B1-receptors in the heart -increased TPR via A1-receptors on vessels (vasoconstriction) -decreased blood flow to GI, urogenital tract, skin via A1-receptors -increased blood flow to skeletal muscle and coronary aa via B2-receptors -decreased gastric motility and gastric juice production -sphincter constriction via A receptors -uterus and urinary bladder relaxation via B2-receptors

Which part of the body has the finest two point discrimnation?

Lip

Effect of hyperparathyroidism on plasma

-increased calcium concentration -decreased phosphate concentration

Effect of insulin on skeletal muscle

-increased glucose uptake via GLUT4 -increased glycogen synthesis -increased protein synthesis -increased amino acid uptake -decreased proteolysis -decreased amino acid release -increased potassium uptake

Effect of insulin on adipose tissue

-increased glucose uptake via GLUT4 -increased lipid synthesis -increased lipid uptake via stimulation of lipoprotein lipase -decreased lipolysis via inhibition of the hormone sensitive lipase -decreased free fatty acid release -decreased ketone body formation

Functions of glucagon

-increased glycogenolysis -increased gluconeogenesis -glucose release from the liver -increased proteolysis -amino acid release from skeletal muscle -increased lipolysis

How does calcitriol increase blooc calcium?

-increases calcium ansorption from the GI -increases calcium reabsorption in the kidneys

Effect of PTH

-increases calcium reabsorption in the distal convoluted tubule -increases osteoclast activity -decreases concentration of plasma phosphate

Effect of prolactin

-milk production -surfactant production -stimulates kisspeptines

Function of testosterone in males

-promotion of spermatogenesis -increases protein synthesis (anabolic steroid hormone) -responsible for primary and secondary male features

Function of oxytocin

-uterine contraction -milk ejection -orgasm -prosocial hormone -pair bonding -maternal behavior

how is an oral glucose tolerance test performed?

1 g/bwkg is dissolved in 300 ml of water and consumed within 10 minutes. The blood glucose is measured 2 hours later

Conduction velocity of C fibers

1 m/s

Diameter of C fibers

1 micron

Extracellular concentration of free calcium ions

1,1-1,4 mmol/l

Effect of insulin on liver (enough glucose)

1- increased glycogen synthesis 2- decreased glycogenolysis 3- decreased gluconeogenesis 4- increased lipid formation from glucose (lipogenesis) 5- increased glycolysis 6- decreased ketone body formation

How long is the refractory period in a neuron?

1-2 ms

Length of neuron AP

1-2 ms (less than 4 ms)

Typical onset of DM1

10-24 years old

Enzyme required for synthesis of aldosterone from corticosterone

11-beta hydroxylase

Conduction velocity of A-delta neurons

12-30 m/s

Diameter of A-alpha fibers

15 microns

Conduction velocity of A-gamma neurons

15-30 m/s

Which enzymes are present in the zona fasicularis and reticularis?

17-alpha-hydroxylase

Which enzyme in the glomerular zone of the glomerular zone of the adrenal cortex is responsible for the production of aldosterone?

18-aldehyde oxygenase enzyme

Total concentration of extracellular calcium

2,2-2,8 mmol/l

Length of AP in pacemaker cells

200-300 ms

Causes of androgenital syndrome/virilism (androgen overproduction)?

21-beta-hydroxilase deficiency, 11-beta-hydroxilase deficiency, androgen producing tumor, hyperactivation of reticular zone

Enzyme required for synthesis of corticosterone from progesterone

21-beta-hydroxylase

Which enzymes are required for the synthesis of glucocorticoids (cortisol) from progesterone?

21-beta-hydroxylase and 11-beta-hydroxylase

Enzymes required for the synthesis of aldosterone from progesterone

21-beta-hydroxylase, 11-beta-hydroxylase

How long is the normal female cycle?

28 days

Diameter of A-delta fibers

3 microns

Diameter of B fibers

3 microns

Conduction velocity of B fibers

3-15 m/s

Conduction velocity of A-beta neurons

30-70 m/s

How long is the rat cycle?

4-5 days

Normal fasting blood glucose

4-5.5 mmol/L

Average weight of fetus in pregnancy with gestational diabetes

4-6 kg

Length of AP in skeletal muscle

4-6 ms

Diameter of A-gamma fibers

5 microns

When does implantation take place?

5-6 days after fertilization

how many amino acids does insulin have?

51

range of blood glucose in IFG

6-7 mmol/L

impaired glucose tolerance blood glucose range

7.8-11 mmol/l

Conduction velocity of A-alpha neurons

70-120 m/s

Diameter of A-beta fibers

8 microns

How many amino acids does proinsulin consist of?

86

Why does iodine deficiency cause goiter?

A deficiency prevents the synthesis of T3 and T4 which means that there are no thyroid hormones synthesized. Thus, no negative feedback on TSH which will increase in production and cause the enlargement of the thyroid gland.

Which are the fastest and slowest fibers?

A-alpha are the fastest, C fibers are the slowest

Which fibers innervate the extrafusal fibers of the muscle spindle?

A-alpha motor neurons

Which fibers are characteristic of the DCML?

A-beta fibers

Which fibers are characteristic of the spinothalamic tract?

A-delta fibers and C fibers

Which motor/efferent fibers innervate the intrafusal fibers of the muscle spindle?

A-gamma motor neurons

Which hormones are secreted by the posterior pituitary?

ADH and oxytocin

Neurotransmitter released by parasympathetic postganglionic fibers

Acetylcholine

Describe the process from the release of acetylcholine to the generation of AP in the skeletal muscle

Ach binds to acetylcholine receptors on the muscle cell membrane (sarcolemma) which causes opening of ligand gated Na+ channels, and Na+ will flow into the cell. This will cause a depolarization (EPP) of the sarcolemma and activate the fast voltage gated Na+ channels. This causes further inflow of Na+ and the generation of the AP (overshoot).

Where is prolactin produced?

Acidophilic cells of the anterior pituitary gland

Increased levels of GH in adulthood

Acromegaly

Which requires more energy to be evoked, action potential or PSP?

Action potential, requires activation of fast voltage gated Na+ channels

Causes of primary Addison's disease

Adrenal cortex failure

Which hormones can increase blood glucose?

Adrenalin, noradrenaline, glucagon, growth hormone, glucocorticoids, thyroid hormones, somatostatin (by inhibiting insulin)

Which hormones does proopiomelanocortin gene produce?

Adrenocorticotrope hormone (ACTH), melanocyte stimulating hormone (MSH), lipoprotein hormone (LPH), and beta-endorphin hormone

Why can menopause result in a false positive hCG test?

After menopause, estradiol and progesterone levels decrease. There is no negative feedback on FSH and LH, which will increase. The high levels of FSH and LH can cross-react with hCG and give a positive test.

Which molecules can be synthesized from cholesterol?

Aldosterone/mineralocorticoids, cortisol/glucocorticoids, and androgens/sex steriods

Maximum threshold in compound AP

All axons are activated

Effect of alpha 1 receptors and beta 2 receptors in vessels (both adrenergic)

Alpha 1: vasoconstriction Beta 2: vasodilation

Components of hCG

Alpha and beta subunit

What subunits are glycoprotein hormones composed of?

Alpha and beta subunits

What are the two main characteristics of muscle stimulus?

Amplitude and duration (pulse width) of stimulus

How is the antagonist muscle in the monosynaptic reflex relaxed?

An inhibitory interneuron can move in between the segments and inhibit the alpha motor neuron for the antagonist muscle.

Effect of 21-beta-hydroxylase enzyme deficiency on the synthesis of mineralocorticoids (aldosterone) and glucocorticoids (cortisol)

Androgenital syndrom (virilism), salt-losing form

Effect of 11-beta-hydroxylase enzyme deficiency

Androgenital syndrome, non-salt-losing form

Which molecules are synthesized in the case of 21-beta-hydroxylase deficiency?

Androgens/sex steroids

What stimulates the production of aldosterone?

Angiotensin II, hyperkalemia, hyponatremia, ACTH (adrenocorticotroph hormone)

Which antibody is used in the immunological method (pregnancy test)?

Anti beta hCG antibodies

What can be seen in an estrus phase?

Anucleated epithelial cells

Minimum threshold in compound AP

At least 1 axon is activated

Function of B fibers (type III fibers)

Autonomic preganglionic fibers

Where are the fast voltage gated Na+ channels located in C fibers?

Axon hillock and whole axon

Way of transport of hPL from hypothalamus to posterior pituitary gland

Axonal transport

Why does 21-beta hydroxylase deficiency result in salt-losing form of virilism?

Because no aldosterone is produced and therefore less Na+ is reabsorbed

Why is the concentration of glucose low in the ejaculate?

Because sperm cells consume glucose

Location of GLUT2

Beta cells of pancreas, liver, kidneys, and small intestine

Which subunit differentiates the glycoprotein hormones (FSH, LH, TSH, hCG)?

Beta subunit

Which subunit in glycoproteins is different?

Beta subunit

Effect of decreased corticsol on CNS

Brain malfunctions

How are catecholamines metabolized?

By MAO-A (monoamino oxydase), MAO-B, and COMPT (cathecolamine ortho-methyl transferase)

How will alpha receptor blockers affect blood glucose levels and how?

By blocking alpha receptors, adrenaline cannot bind and will not inhibit the production and secretion of insulin. Insulin will be produced and the blood glucose levels will decrease.

Where is the hPL produced?

By the supraoptic and paraventricular nuclei of the hypothalamus

Which segments are tested in the biceps reflex?

C5-C6

Which segments are tested in the brachioradialis reflex?

C5-C6

Which segments are tested in the triceps reflex?

C6-C8

Which segments are tested in the brachioulnaris reflex?

C7-C8

Functions of thyroid hormones

CNS development in childhood and growth processes Increase metabolic rate Increase cell metabolism Increase number and function of mitochondria Increase blood glucose levels via increasing glucose uptake from the GI Increase heat production Increase sensitivity of adrenergic receptors

Which is stronger from cathode make excitation and anode break excitation?

Cathode make excitation

Where is PTH produced?

Chief cells of parathyroid gland

How is aldosterone synthesized from cholesterol?

Cholesterol -> pregonolon -> progesterone -> 11-desoxy-corticosterone -> corticosterone -> aldosterone

Where in the spinal cord is the spinothalamic tract located?

Contralaterally in the lateral and anterior columns

List 7 exteroceptive reflexes

Corneal reflex, pharyngeal reflex, mamillary reflex, superficial abdominal reflex, creamster reflex, plantar reflex, anal reflex

Why does adrenal cortex cause hyperpigmentation?

Corticsol inhibits ACTH, without it the levels of ACTH will increase. This causes increased transcription of propriomelanocortin gene which stimulates MSH, causing hyperpigmentation

Which hormone is affected by addison's disease and in what way?

Cortisol levels are decreased

Reasons for primary Cushing syndrome

Cortisol overproduction

Where do the 1st neurons of the DCML synapse?

Cuneate or gracile nucleus

Endocrine reasons for diabetes mellitus

Cushing syndrome, giantism/acromegaly, pheocromocytoma, glucagonoma, somatostatinoma, hyperthyroidism

When can fertilization take place?

Day 12-16

Effect of cathelectrotonus on the threshold

Decreased

Effect of lidocaine and ether on the conduction velocity of nerve fibers

Decreased

Effect of decreased temperature on conduction velocity

Decreased conduction velocity

Symptoms of hypothyroidism

Decreased metabolic rate, overweight, myxedema, low HR and BP

Effect of increased amino acid release from skeletal muscle as a result of glucocorticoid exposure

Decreased muscle mass and increased gluconeogenesis

What is anelectrotonus?

Decreased of excitability around the anode due to accumulation of negative charge (hyperpolarization)

Effect of alkalosis on concentration of free calcium

Decreased, plasma proteins release H+ and bind calcium

In a closed circuit, what happens around the cathode?

Depolarization (accumulation of positive ions)

What is gestation diabetes?

Diabetes developed during pregnancy

Relation between diameter of fibers and conduction velocity

Directly proportional, the wider the faster

Determination of nerve conductance velocity

Distance between the two recording electrodes (mm) divided by the time delay between the peaks on the two contraction curves (ms)

Two types of somatosensory systems

Dorsal column meidal lemniscus and spinothalamic system

Where do the 1st neurons of the spinothalamic tract synapse?

Dorsal horn of the spinal cord

Why does LH and FSH increase towards the end of the luteal phase?

Due to the decrease in estradiol and progesterone which inhibit LH and FSH

Why does adrenal cortex cause low BP?

Due to unresponsiveness of catecholamines, water and electrolyte imbalance

Which organs produce calcitriol?

Liver, kidneys, skin

Characteristics of GLUT2

Low affinity (blood glucose should be higer than normal) and high capacity (a lot of glucose molecules can be taken up to produce adequate amount of insulin)

Which gradient works against the concentration gradient across the cell membrane?

Electrical gradient

Functions of A-beta fibers (type II fibers)

Epicritic sentation and secondary endings of muscle spindle/sensory fibers from proprioceptors

Type of sensation carried by the DCML

Epicritic: fine touch (two point disrimination, graphesthesia), vibration

Which hormone of the menstrual cycle is characterized by two peaks?

Estradiol

What is observed in the brachioulnar reflex?

Extension

What is observed in the patellar reflex?

Extension at the knee joint

What is observed in the triceps reflex?

Extension in the elbow

What is observed in the corneal reflex?

Eye blink after touching the cornea

Which hormone is characterized by a small peak before ovulation?

FSH

What is observed in the brachioradial reflex?

Flexion and supination

What is observed in the biceps reflex?

Flexion and supination in the elbow

Which form of thyroid hormones is active?

Free form

neurotransmitters in inhibitory synapse

GABA and glycine

What do acidophil cells in the anterior pituitary release?

GH and prolactin

Effect of GHRH on the anterior pituitary gland

GH release

What stimulates alpha cells?

GH, glucocorticoids, catecholamines, arginine

which glucose transporter is insulin independent?

GLUT2

Which type of glucose transporter is insulin dependent?

GLUT4

What is observed in the pharyngeal reflex?

Gagging

Increased levels of GH in childhood

Gigantism

In which zone of the adrenal cortex are mineralocorticoids produced?

Glomerular zone (outer layer)

What is tested in the pharyngeal reflex?

Glossopharyngeal and vagus nerves

Dominating hormone during post-absorptive phase

Glucagon

what is GLP-1?

Glucagon like peptide-1 (GLP-1): Secreted from L-cells of the ileum and colon (as well as neurons of the solitary tract) this hormone/neurotransmitter has a half-life of only 1-2 minutes, but has receptors in the brain, gut and pancreas. It stimulates insulin secretion by B-cells of the pancreas and suppresses appetite in the brain. GLP-1 analogs are now used in treatment of obesity in type 2 diabetes.

Describe the cellular mechanism of insulin production in beta cells

Glucose 6-P is produced from glucose and activates the preproinsulin gene. The preproinsulin gene codes for proinsulin which will differentiate into insulin and C peptide

Describe the cellular mechanism of insulin secretion in beta cells

Glucose is taken up by GLUT2 in the pancreatic beta cells. Glucose is phosphorylated into G6-P which undergoes glycolysis, TCA, and oxidative phosphorylation, producing ATP. ATP inhibits the ATP sensitive potassium channels, causing a depolarization of the cell membrane. The increase of the membrane potential activates the voltage gated calcium channels. The inflow of calcium ions causes a hypopolarization of the cell membrane which stimulates the exocytosis of vesicles containing C-peptide and insulin.

Why does the long-term release of glucocorticoids cause an increase in glycogen synthesis?

Glycogen is synthesized in preparation for acute stress and the increased need for glucose this requires.

Which hormones are transported from the hypothalamus to the anterior pituitary via the portal circulation?

GnRH, GHRH, TRH, CRH

Reasons for a false negative pregnancy test with the immunological method

HCG levels are not high enough

What is a cholicarcinoma?

HCG producing tumor

Complications of diabetes mellitus

Heart failure, kidney failure, retinopathy, vasculopathy, neuropathy, stroke, delayed wound healing

Which hormone is increased after implantation?

Human chorionic gonatotropin (hCG)

Symptoms of hypoglycemia

Hunger, pale skin, sweating, tachycardia, irritability

What stimulates the production of calcitonin?

Hypercalcemia

Side effects of increased glucocorticoids

Hyperglycemia (steroid DM), muscle loss, central shift of adipose tissue, osteoporosis, high blood pressure, gastric ulcer, weak immune system

What is characteristic of DM2 at the start?

Hyperinsulinaemia

What stimulates PTH?

Hypocalcemia

Effect of adrenal cortex failure (no glucocorticoids/mineralocorticoids)

Hypoglycemia, low blood pressure, inadequate stress response, hyperpigmentation

Where is tRH released from?

Hypothalamus

Where is the gonadotrope releasing hormone (GnRH) released?

Hypothalamus

Where is GHRH produced?

Hypothalamus (arcuate nucleus)

Which sensory/afferent fibers innervate the intrafusal fibers of the muscle spindle?

Ia (A-alpha) and II (A-beta) fibers

Which fibers innervate the golgi tendon organ?

Ib fibers (A-alpha)

What is the anode break excitation?

Immediately after the circuit is opened, there is an accumulation of positive charge around the anode. This causes a depolarization which can travel towards the muscle when there is an open conduction between the two poles. This is only observed in medium stimulus with the cathode closer to the muscle

Main difference between compund AP and individual AP

In individual AP, the all or nothing law applies. An increase in stimulus intensity has no effect on the amplitude

What is observed in the anal reflex?

Constriction of the anal sphincter

Anode is closer to the muscle, circuit is open, open conduction between the two poles, post strong stimulus. What is observed?

Contraction (anode break excitation)

What is observed in the abdominal reflex?

Contraction of the abdominal muscle

What is observed in the cremaster reflex?

Contraction of the ipsilateral cremasteric muscle

What is observed in the superficial abdominal reflex?

Contraction of the ipsilateral muscle

Which hormone increases at the beginning of pregnancy until week 10 and then decreases?

Human chorionic gonadotropin hormone (hCG)

Where in the spinal cord is the CDML located?

Ipsilaterally in the dorsal column

In Brown sequard syndrome, which functions are lost below the level of injury and on which side?

Ipsilaterally: motor function and epicritic sensation Contralaterally: protopathic sensation

In Brown sequard syndrome, which functions are preserved below the level of injury and on which side?

Ipsilaterally: protopathic sentation Contralaterally: motor functions and epicritic sensation

How does calcitonin act?

It acticated osteoblasts and calcium is absorbed into the bone

Effect of Conn-syndrome (hyperaldosteronism)

High BP, hypokalemia, high blood pH (metabolic alkalosis), low levels of free calcium

What can inhibit nicotinic acetylcholine receptors

High dose of nicotine

Dominating hormone during nutrient absorption phase

Insulin

Other name for DM1

Insulin dependent diabetes mellitus

Causes of diabetes mellitus type 2

Insulin resistance, decreased sensitivity of insulin receptors, genes, lifestyle

What inhibits alpha cells?

Insulin, somatostatin, and glucose

Why is the amplitude of the AP constant?

It is restored at the nodes of Ranvier via fast voltage activated Na+ channels

Target organs of aldosterone

Kidneys (collecting ducts), salivary glands, sweat glands, colon, and gallbladder

What is tested in the cremaster reflex?

L1-L2 segments

Which segments are tested in the patellar reflex?

L2-L4

Which hormone of the menstrual cycle is characterized by a big peak before ovulation (day-14)?

LH

Why can high levels of LH give a false positive hCG test?

LH and hCG have the same beta subunit, they have very similar structures

Effect of GnRH from hypothalamus on anterior pituitary gland

Stimulates release oof FSH and LH

Which organ does GH affect and how?

Stimulates the release of somatomedin from the liver (e.g IGF-1)

Effect of LH on GnRH in late follicular phase when estradiol is high

Stimulation

Effect of insulin on lipoprotein lipase

Stimulation

What kind of innervation do blood vessels have?

Sympathetic

Innervation of adrenal medulla

Sympathetic preganglionic fibers (Ach)

What causes pale skin, sweating, and tachycardia in hypoglycemia?

Symphathetic activation

Difference in experimental setup between investigation of polar excitement and Pflüger's law

The conduction between the anode and cathode is not blocked in the Pflüger investigation; no NH4+ block.

Why do levels of estradiol and progesterone decrease at the end of the luteal phase?

The corpus luteum dies (becomes corpus albican which does not secrete progesterone or estrogen)

What causes the refractory period in neurons?

The fast voltage gated sodium dependent channels have an inactivation gate that needs to be reset after an AP. The time taken for the inactivation gate to reset back into the activation gate is the refractory period within which no AP can be elicited.

Symptoms of hyperthyroidism

Weight loss, exophtalamus, high HR, high systolic BP and blood glucose