Physio Lecture 24 (Final Exam)

Front 1

How are the endocrine and nervous system alike?

Back 1

1) They are both used to maintain homeostasis, 2) They use chemicals to signal other cells, 3) The other cells must have the appropriate receptors to respond to the chemicals, and 4) The signals must be able to be inactivated quickly.

Front 2

How are the endocrine and nervous system different?

Back 2

The endocrine system releases its chemical into the blood stream. The nervous system primarily releases its chemicals only to a neighboring cell (however, there are neurohormones such as epinephrine which combine both aspects of the endocrine and nervous system.)

Front 3

Do all hormones travel to their receptors via blood?

Back 3

yes

Front 4

Are hormones secreted at constant rates?

Back 4

No, they are typically pulsatile, which means that they are
released and then the release is stopped for a while and released again, etc.

Front 5

Do most hormones have
the same secretion pattern?

Back 5

No, each hormone has its own unique secretion pattern, ie melatonin from the pineal gland is released daily, whereas some gonadotropin type hormones are released monthly.

Front 6

Are all hormones the same type of molecule chemically?

Back 6

no

Front 7

What determines whether a hormone will influence a particular cell?

Back 7

The cell must have a receptor
for the hormone.

Front 8

What are target cells?

Back 8

Are any cells which have receptors for the hormone.

Front 9

What are the 3 chemical categories of hormones?

Are they all equally membrane permeable?

Back 9

Amines, peptides, and steroids.

No, the steroids and thyroids are quite permeable to cell membranes, the other amines and peptides, usually act via cell surface receptors only.

Front 10

Can the binding of a hormone to the surface of a cell trigger enzymatic activity within the cell?

Back 10

yes

Front 11

Can a hormone activate DNA transcription and protein synthesis?

Back 11

Yes, in fact, most do!

Front 12

What is the meaning of a “1st messenger”?

Back 12

The hormone itself is referred to as the 1st messenger.

Front 13

What is the meaning of a “2nd messenger”?

Name two common 2nd messengers

Back 13

Molecules which are released within the cytoplasma and cause responses in the
cells are referred to as 2nd messenger.

Any of these: cAMP,
cGMP, Ca++, DAG, IP3.

Front 14

Can a single cell have more than one kind of hormone receptor?

Back 14

Yes, cells typically have more than one kind of hormone receptor.

Front 15

What is a releasing hormone?

Back 15

Releasing hormones specifically refer to the hormones secreted into
the hypothalmic-hypophyseal portal from the hypothalmus, which will interact with the endocrine cells of the anterior pituitary to cause release of another hormone from the anterior pituitary.

Front 16

What is a tropic hormone?

Back 16

A tropic hormone is any hormone that causes the release of another hormone - so releasing hormones are a type of tropic hormone.

Front 17

What hormones are released from the anterior pituitary gland?

Back 17

ACTH (adrenocorticotrophic
hormone), PRL (prolactin), LH (luteinizing hormone), FSH (folicle stimulating hormone), TSH (thyroid stimulating hormone), GH (growth hormone).

Front 18

What hormones are released from the posterior pituitary gland?

Back 18

ADH, oxytocin

Front 19

What controls the release of anterior pituitary hormones?

Back 19

Direct stimulation of the hypothalmus

Front 20

How does negative feedback work with regard to the hypothalamus and anterior pituitary?

Back 20

The final hormones that are released, circulate back to both the hypothalmus and the anterior pituitary and cause the cessation of release of these hormones

Front 21

What are the target tissues of ACTH?

Back 21

The adrenal gland.

Front 22

What are the target tissues of TSH?

Back 22

The thyroid gland.

Front 23

What is the relationship between CRH, ACTH and cortisol? Where is each one produced?

Back 23

CRH (Corticotropin releasing hormone) is released from the hypothalmus and causes the anterior pituitary endocrine cells to release ACTH (adrenocorticotrophic hormone) which then stimulates the adrenal gland to secrete cortisol.

Front 24

What cells in the human body uptake iodine and for what purpose?

Back 24

The thyroid follicular cells.
They transport the iodine into the colloid space and will use the iodine to produce thyroxine (T4).

Front 25

What effect does TSH have on the thyroid gland?

Back 25

TSH causes the thyroid gland to release T4 (and the small amount of T3) into the blood stream.

Front 26

How does the blood level of TH affect the secretion of TRH and TSH?

Back 26

TH (thyroid hormone) will stop the release of TRH and TSH.

Front 27

What are the target cells of TH?

Back 27

Most cells in the body.

Front 28

What are the effects of TH in humans?

Back 28

In adults, TH primarily controls the basic metabolic rate (BMR).

Front 29

What other hormone action is
influenced by TH?

Back 29

Growth hormone (GH).

Front 30

What does hypersecretion refer to?

Back 30

Over production of a particular hormone.

Front 31

What does Hyposecretionrefer to?

Back 31

Under production of a particular hormone.

Front 32

What is the difference between Primary Hypersecretion (or
Hyposecretion) and Secondary Hypersecretion (or Hyposecretion)?

Back 32

Primary Hypersecretion/
Hyposecretion means that the gland that produces the hormone is not functioning correctly and it is over or under producing the hormone that directly affects tissues; Secondary Hypersecretion/
Hyposecretion means that the problem is not associated with the gland that produces the hormone directly, rather the problem is with one of the glands that makes trophic hormones that are responsible for the ultimate release of the hormone.

Front 33

three types of hypersecretion, what are they and what gland are they associated with?

Back 33

Cushing’s syndrome –
adrenal cortex;
Reactive hypoglycemia – pancreas;
Graves’ disease – thyroid.

Front 34

three types of hyposecretion, what are they and what gland are they associated with? .

Back 34

Addison’s disease – adrenal cortex;
Diabetes Mellitus Type I (AKA Juvenile diabetes or IDDM) – pancreas;
Hashimoto’s disease – thyroid

Front 35

What are the symptoms of hypothyroidism? Causes?

Back 35

Low BMR, weight gain, lethargy, cold intolerance and
myxedema.
Hypothyroidism can be from a defective thyroid gland, or insufficient TRH or TSH, or insufficient amounts of iodine.

Front 36

What are the symptoms of Hyperthyroidism? Causes?

Back 36

Exopthalmos, weight loss, heat intolerance, irritability, high BMR.
Hyperthyroidism can be the result of hyper-secretion of either TRH, TSH, or an autoimmune disease (Graves' disease) see below.

Front 37

How is
the effect of hyperthyroidism different if its onset is from infancy rather than in adulthood?

Back 37

If hyperthyroidism occurs in infancy it will have profound effects on growth and development, especially of the nervous system, in infancy lack of thyroid hormone will affect myelination and synapse formation. In adulthood, consequences of hyperthyroidism do not neccesarily cause long
term complications, though do need to be controlled, if hyperthyroidism is left uncontrolled, an adult will have extreme weight loss, and high heart rate (about 150-180bpm) and will eventually start to cause bone to lose Ca++ and therefore the bones will become brittle. So hyperthyroidism does need to be controlled.

Front 38

What is a goiter?
3 circumstances when a person may develop a goiter?

Back 38

Goiter is an enlargement of the thyroid gland.
1) Not enough dietary iodine. 2) Hyper-secretion of TRH or TSH. 3) Graves' disease, which is an autoimmune disease in which thyroid stimulating immunoglobulins (TSI) over stimulate the thyroid gland to hyper-secrete TH.

Front 39

Endocrine Gland

Back 39

Ductless glands that secrete hormones into the blood

Front 40

Hormone

Back 40

A long distance chemical mediator that is secreted by an endocrine gland into the blood which transports it to its target cells that contain a receptor for it

Front 41

Neurohormone

Back 41

Hormones released into the blood by neurosecretory neurons, Norepinephrine

Front 42

Prehormones

Back 42

Precursors of prohormones, e.g. preproinsulin

Front 43

Prohormones

Back 43

Precursors of hormones e.g. proinsulin

Front 44

Half-life

Back 44

Time that half the drug is cleared from the body, Time required for blood level to be reduced by half, ranges from minutes to hours for most (days for thyroid hormone)

Front 45

Upregulation

Back 45

Priming Effect, occurs when a hormone induces more of its own receptors in target cell, results in GREATER RESPONSE in target cell

Front 46

Downregulation

Back 46

Desensitization, occurs after long exposure to high levels of polypeptide hormone, subsequent exposure to this hormone produces a LESSER RESPONSE, due to decrease in number of receptors on targets, most of these peptide hormones have a pulsatile secretion in which prevents downregulation from occurringe.g. Type II diabetes,

Front 47

Pulsatile Secretion

Back 47

A secretion on peptide hormones that prevent downregulation (desensitization) from occurring, which acts like an “on-off” switch to help prevention of desensitization

Front 48

Posterior Pituitary

Back 48

Stores and releases hormones made in hypothalamus, Vasopressin (ADH) and Oxytocin

Front 49

Anterior Pituitary

Back 49

Produces own hormones, controlled by hypothalamus that is signaled by neurohormone, 6 different cells and each can produce different hormone

Front 50

Infundibulum

Back 50

Connects pituitary gland to hypothalamus and helps in protection of cells between the two

Front 51

Hypothalamus (Hypophyseal portal system)

Front 52

GH (Growth Hormone)

Back 52

Promotes growth, protein synthesis, and movement of amino acids into cells

Front 53

TSH (Thyroid Stimulating Hormone)

Back 53

Stimulates thyroid to produce and secrete T4 and T3, trophic hormone

Front 54

ACTH

Back 54

Stimulates adrenal cortex to secrete cortisol, trophic hormone

Front 55

FSH (Follicle Stimulating Hormone

Back 55

Stimulates growth of ovarian follicles and sperm production trophic hormone

Front 56

LH (Lutienizing Hormone)

Back 56

Causes ovulation and secretion of testosterone in tests, reproductive system, trophic hormone

Front 57

PRL (Prolactin)

Back 57

Stimulates milk production in mammary glands

Front 58

RH (Releasing Hormone)

Back 58

A hypothalamic hormone that stimulates the secretion of a particular anterior pituitary hormone

Front 59

Cortisol

Back 59

Adrenocortical hormone, steroid, glucocorticoid Secreted by cortex controlled by ACTH secreted from adrenal glands which inhibits glucose utilization and stimulates gluconeogenesis

Front 60

Sex Steroids

Back 60

Secreted by cortex controlled by ACTH and are considered androgens

Front 61

Mineralocorticoids

Back 61

Aldosterone, secreted from adrenal cortex which is controlled by ACTH, aldosterone stimulates kidneys to reabsorb Na and secrete K

Front 62

Glucocorticoids

Back 62

Cortisol, which inhibits glucose utilization and stimulates gluconeogenesis

Front 63

Thyroid Gland

Back 63

Located below larynx, secretes T4 and T3 which set BMR and are needed for growth and development, consists of thyroid follicles (made up of follicle cells filled with colloid)

Front 64

Follicle Cells

Back 64

Out layer of thyroid follicles, synthesize T4

Front 65

Thyroxine (T4)

Back 65

Tyrosine made up of four iodine groups, usually broken down into T3, set BMR and are needed for growth and development

Front 66

Triiodothyronine (T3)

Back 66

Tyrosine made up of three iodine groups, set BMR and are needed for growth and development,

Front 67

Hypersecretion

Back 67

Endocrine pathology where an exaggeration of a hormone’s effects can produce side effects, can be due to benign tumors or cancerous tumors of endocrine glands, creates large amounts of hormones

Front 68

Hyposecretion

Back 68

Endocrine pathology where a hormone’s effects are diminished or eliminated, can be due to destruction of the gland such as an autoimmune attack,

Front 69

Hashimoto’s Disease (Hypothyroidism)

Back 69

Thyroid Endocrine disorder due to Hyposecretion of thyroid due to destruction of thyroid gland, inadequate levels of T4 and T3, low BMR, weight gain, lethargy, cold intolerance, a puffy face hands and feet, low BMR rate because not able to make ATP

Front 70

Grave’s Disease (Hyperthyroidism)

Back 70

Thyroid Endocrine disorder due to Hypersecretion of thyroid due to autoantibodies that bind to and activate the TSH receptor, bind to receptor to produce too much thyroid gland, can produce goiters (enlarged gland due to too much production), autoimmune disease where antibodies act like TSH and stimulate thyroid gland to grow and over secrete causing Exopthalmos (weight loss, heart intolerance, irritability, high BMR)

Front 71

Cushing’s Syndrome

Back 71

Adrenal cortex endocrine disorder where there is a hypersecretion of cortisol

Front 72

Addison’s Disease

Back 72

Adrenal cortex endocrine disorder where there is hyposecretion of cortisol

Front 73

Diabetes Mellitus (Type I Juvenile Diabetes)

Back 73

Pancreatic endocrine disorder where there is a hyposecretion of insulin

Front 74

Reactive Hypoglycemia

Back 74

Pancreatic endocrine disorder where there is hypersecretion of insulin

Front 75

Myxedema

Back 75

Hypothyroidism, Puffy face, hands and feet due to inadequate levels of T4 and T3

Front 76

Cretenism

Back 76

Hypothyroidism, Severe mental retardation due to inadequate levels of T4 and T3

Front 77

Expothalmos

Back 77

Caused by hyperthyroidism where an excess of thyroid is produced and results in weight loss, heat intolerance, irritability, and high BMR, a lot of thyroid will result in high BMR from excess ATP so energy source isn’t stored and is lost

Front 78

GH (Growth Hormone)

Back 78

Promotes growth, protein synthesis, and movement of amino acids into cells

Front 79

TSH (Thyroid Stimulating Hormone)

Back 79

Stimulates thyroid to produce and secrete T4 and T3, trophic hormone

Back 80

Stimulates adrenal cortex to secrete cortisol, trophic hormone

Front 81

FSH (Follicle Stimulating Hormone)

Back 81

Stimulates growth of ovarian follicles and sperm production trophic hormone

Front 82

LH (Lutienizing Hormone)

Back 82

Causes ovulation and secretion of testosterone in tests, reproductive system, trophic hormone

Front 83

PRL (Prolactin)

Back 83

Stimulates milk production in mammary glands