Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

Semester 2-MEH > Session 8-Hypothalamic Pituitary Axis And Growth Hormone > Flashcards

Session 8-Hypothalamic Pituitary Axis And Growth Hormone Flashcards

1
Q

Where does the pituitary gland sit?

A

Beneath hypothalamus in a socket of bone called the sella turcica

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

What is the embryological origin of the anterior pituitary gland?

A

Evagination of oral ectoderm (Rathke’s pouch) - primitive gut tissue

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

What is the embryological origin of the posterior pituitary gland?

A

Neuroectoderm - primitive brain tissue

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

Complete the sentence:

The posterior pituitary gland is physically connected to the hypothalamus since the hypothalamus drops down through the __________________ to form the posterior pituitary

A

Infundibulum

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

Where are oxytocin and antidiuretic hormone produced?

A

Neurosecretory cells in supraoptic and paraventricular nuclei of hypothalamus

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

What transports oxytocin and antidiuretic hormone to the posterior pituitary to be released?

A

Nerve cell axons

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

Where are hormones synthesised in the hypothalamus stored?

A

Median eminence before release into hypophyseal portal system

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

What do hormones synthesised in the hypothalamus stimulate/inhibit?

A

Target endocrine cells in anterior pituitary gland (neurocrine function)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

What transport functions do anterior pituitary hormones have?

A

Endocrine
Autocrine
Paracrine

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

Via which two distinct neurocrine pathways do hormones produced by nerve cells in the hypothalamus act?

A

1) direct effects on distant target tissues via oxytocin and antidiuretic hormone from posterior pituitary
2) tropic hormones secreted exclusively into hypophyseal portal system affect endocrine cells within anterior pituitary

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

What is another name for antidiuretic hormone?

A

Vasopressin

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

What do tropic hormones do?

A

Have direct effects on release of anterior pituitary hormones

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

Name the 6 tropic hormones produced in the hypothalamus

A

1) TRH (thyrotropin releasing hormone)
2) PIH (prolactin release-inhibiting hormone)
3) CRH (corticotropin releasing hormone)
4) GnRH (gonadotropin releasing hormone)
5) GHRH (growth hormone releasing hormone)
6) GHIH (growth hormone inhibiting hormone)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

Which hormones are produced by the anterior pituitary and what are their functions?

A

1) TSH - secretion of thyroid hormone from thyroid gland
2) ACTH (adrenocorticotropic hormone) - secretion of hormones from adrenal cortex
3) LH - ovulation and secretion of sex hormones
4) FSH - development of eggs and sperm
5) PRL (prolactin) - mammary gland development and milk secretion
6) GH (growth hormone) - growth and energy metabolism

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

What does oxytocin do?

A

Milk let down and uterus contractions during birth

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

What does antidiuretic hormone do?

A

Regulation of body water volume

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

Which hormone/s cause the anterior pituitary gland to release:

1) TSH
2) ACTH
3) prolactin
4) growth hormone
5) LH and FSH

A

1) TRH (thyrotropin releasing hormone)
2) CRH (corticotropin releasing hormone)
3) TRH and negative effect of PIH (prolactin release-inhibiting hormone)
4) GHRH and negative effect of GHIH
5) GnRH

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

What regulates the pathways by which hypothalamic and anterior pituitary hormones are produced?

A

Negative feedback

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

What is the most important endocrine regulator of postnatal growth?

A

Growth hormone

20
Q

Which factors influence growth?

A

Genetics
Nutrition
Environment
Hormones

21
Q

What inhibits the production of growth hormone?

A

Somatostatin (GHIH)

22
Q

How are growth-promoting effects mainly exerted?

A

Via insulin-like growth factors (somatomedins)

23
Q

Which cells produce and secrete insulin-like growth factors (IGFs) in response to growth hormone (GH)?

A

Liver cells

Skeletal muscle cells

24
Q

True or false: GH stimulates long bone growth

A

TRUE

25
Q

What do insulin-like growth factors (IGFs) stimulate?

A

Bone and cartilage growth

26
Q

What role do GH and IGFs have in adults?

A

Maintain muscle and bone mass and promote healing and tissue repair as well as modulating metabolism and body composition

27
Q

Which factors increase GH secretion?

A
  • stress (trauma, surgery)
  • exercise
  • decrease in glucose or fatty acids
  • fasting
28
Q

Which factors decrease GH secretion?

A
  • R.E.M. Sleep
  • increase in glucose or free fatty acids
  • obesity
29
Q

Describe the long loop negative feedback mechanism of GH secretion

A

Mediated by IGFs

  • inhibit release of GHRH from hypothalamus
  • stimulates release of somatostatin from hypothalamus
  • inhibit release of GH from anterior pituitary
30
Q

Describe the short loop negative feedback mechanism of GH secretion

A

Mediated by GH itself via stimulation of somatostatin release

31
Q

What does complete or partial GH deficiency in childhood lead to?

A

Pituitary dwarfism

32
Q

Which type of therapy is used to treat pituitary dwarfism?

A

GH therapy

33
Q

True or false: there is delayed or no sexual development during teen years in someone with pituitary dwarfism

A

TRUE

34
Q

What does an excess in GH lead to in childhood?

A

Gigantism (often caused by pituitary adenoma)

35
Q

What does an excess of GH lead to in adulthood?

A

Acromegaly - large extremities (hands, feet etc)

36
Q

How does GH exert its effects on cells?

A

1) GH binds to GH receptor
2) GH receptor activates Janus kinases (JAKs) by cross phosphorylation of JAK
3) phosphorylation of GH receptor
4) activation of signalling pathways
5) transcription factor activation and IGF production

37
Q

Which receptor family are Janus kinases in?

A

Tyrosine kinase

38
Q

Which mammalian IGF is mainly involved in foetal growth?

A

IGF2

39
Q

Which mammalian IGF is the major growth factor in adults?

A

IGF1

40
Q

What modulates the availability of IGFs?

A

Binding proteins

41
Q

True or false: actions of IGFs can only be paracrine

A

FALSE - can be autocrine and endocrine as well

42
Q

IGFs act through IGF receptors to modulate what?

A

1) hypertrophy
2) hyperplasia
3) increase in rate of protein synthesis
4) increase in rate of lipolysis in adipose tissue

43
Q

How does insulin influence growth?

A

Enhances somatic growth; interacts with IGF receptors

44
Q

How do thyroid hormones influence growth?

A

Promote CNS development and enhance GH secretion

45
Q

How do androgens influence growth?

A

Accelerate pubertal growth spurt
Increase muscle mass
Promote closer of epiphyseal plates

46
Q

How do estrogens influence growth?

A

Decrease somatic growth

Promote closure of epiphyseal plates

47
Q

How do glucocorticoids influence growth?

A

Inhibit somatic growth

Semester 2-MEH (21 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions