Brainscape's Knowledge GenomeTM

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


See full index

z basic sciences > pituitary gland > Flashcards

pituitary gland Flashcards

1
Q

hormone actions on whole body level

A

Regulation and integration of :

  • Ionic and fluid balance
  • Energy balance (metabolism)
  • Coping with the environment
  • Growth and development
  • Reproduction
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

hormone actions on cellular level :

A

Regulation of :

  • Cell division
  • Differentiation
  • Death (apoptosis)
  • Motility
  • Secretion
  • Nutrient uptake
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

hormone actions on molecluar level:

A

Hormone receptor is within the cell nucleus therefore effect on :

  • Regulation of
    • Gene transcription
    • Protein synthesis & degradation
    • Enzyme activity
    • Protein conformation
    • Protein:protein interactions
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

what are autocrine hormones

A

hormones that act on the same organ they are produced by

cell produces a hormone but is also influenced by that hormone

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

what are paracrine hormones?

A
  • adjacent or near to
  • hormone that has an effect on neighbouring cells
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

what are endocrine hormones?

A

hormones in circulation

act on far off organs

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

What is the significance of hormones which are bound to a plasma protein in circulation??

A
  • effective as the hormone is not immediately excreted
  • stays in circulation for longer
  • glomerulus does not allow large proteins to pass through
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

fill

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

how does endocrine feedback work?

A
  1. Sensory receptors gather external/internal information
  2. Integrated by neurons of CNS
  3. Hormone produced
  • nervous system and endocrine system are tightly integrated
    • hypothalamus bridges both systems
      • with anterior pituitary
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

location of pituitary gland

A

small structure at base of brain

  • lies inferior to the hypothalamus with the optic chiasm between

optic chiasm = crossing of optic nerves

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

what does the pituitary gland do

A
  • which releases hormones that, in turn,
    • controls the activity of the body’s other hormone glands
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

structure of the pituitary gland

A

Anterior lobe (pars distalis)

  • Portal blood vessels connect pituitary and hypothalamic capillary beds
  • Connected to hypothalamus by series of bleed vessels

Posterior lobe (pars nervosa)

  • Nerve fibres originate in the hypothalamus and transport hormones to posterior pituitary
  • Series of nerve fibres which transport hormone
  • Hormones travel within a nerve fibre
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

what hormones does the posterior pituitary release?

where are they produced?

A

oxytocin

vasopressin

both produced in hypothalamus

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

role of oxytocin

A
  • controls milk release from lactating breast
  • controls uterine contraction at onset of labour
    • essential for childbirth
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

role of vasopressin

A
  • anti-diuretic hormone (ADH)
  • acts on kidneys to reaborb water

Regulates blood osmolarity and urine output

Needed if dehydrated or haemorrhaging as we don’t want to lose plasma volume

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

when are hormones from the posterior pituitary gland released?

A

in response to nerve impulses

hormones come down nerve axons

action potentials release hormones into the capillary bed and out into circulation

17
Q

how does the interaction of oxytocin with its receptors lead to a response to the stimuli?

A
  • suckling -> nerve impulses
  • hypothalamus produces oxytocin
  • oxytocin released by posterior pituitary gland
  • binds to receptors
  • actives secondary messengers
  • raises level of intracellular calcium in myoepithelial cells of the mammary gland
  • myoepithelial cells contract forcing milk into ducts
18
Q

describe the neuro-endocrine reflex with vasopressin

A
  • increased plasma osmolarity stimulates osmoreceptors in hypothalamus
    • dehydration
  • hypothalamus and posterior pituitary release vasopressin
  • water selectively reabsorbed in distal tubules and collecting ducts of kidney
    • action of aquaporins
  • urine becomes more concentrated and urine volume decreases = decreased plasma osmolarity
19
Q

name an inhibitor of ADH from the posterior pituitary

A

alcohol

20
Q

what hormones does the anterior pituitary secrete?

what are their target organs?

A
  • Growth Hormone
  • Prolactin
  • Adenocorticotropic hormone (ACTH)
    • Stimulates the adrenal cortex
  • Thyroid stimulating hormone (TSH)
  • Follicle stimulating hormone (FSH)
    • Stimulates the ovaries & testes
  • Luteinising hormone (LH)
    • Stimulates the ovaries & testes
21
Q

what cells in the anterior pituitary release which hormones?

A
22
Q

What are ‘releasing hormones’?

A
  • Stay within private circulation of the hypothalamus and anterior pituitary
  • Stimulate release of anterior pituitary hormone
23
Q

what releasing hormones are able to stimulate or inhibit anterior pituitary hormones?

A
  • GH has a inhibitory and stimulatory hormone from the hypothalamus
    • SS and SHRH
  • Prolactin
    • Has no stimulatory but has inhibitory
    • DA
  • E.g. if not breastfeeding
    • Has high levels of dopamine in circulation to suppress prolactin (milk production)
    • Dopamine antagonists
      • Suppress dopamine function
      • Will produce milk
24
Q

differences between the posterior and anterior lobe of the pituitary gland

A

Posterior lobe

  • Connects hypothalamus by nerve fibres
  • 2 hormones

Anterior lobe

  • Releasing hormones produced in hypothalamus
  • Travel through private network of vessels
  • Stimulate release of anterior pituitary hormones
25
Q

When is growth hormone necessary for normal growth?

what occurs when there is insufficient growth hormone during these times?

A
  • from ages 2-11
  • during puberty
  • short stature
26
Q

extent of growth also depends on other hormones :

how do they affect growth?

A

Thyroxine

  • (lack inhibits growth)

Cortisol

  • (excess inhibits growth)

Insulin

  • (excess stimulates growth)
27
Q

direct metabolic effects of growth hormone:

A
  • Anabolic
    • Conserve glucose for CNS
      • Stops cells taking up glucose
    • Glucose sparing with an anti-insulin action
  • Muscle
    • Decreases glucose uptake
    • Stimulates aa uptake/protein synthesis
    • Inhibits protein breakdown
      • = increased muscle mass
  • Adipose tissue
    • Decreases glucose uptake
    • Increases lipolysis
      • = Decrease in fat deposits
  • Liver
    • Increases gluconeogenesis
    • Increases protein synthesis
      • Simulates IGF production
        • Insulin like growth factor
  • GH protects against hypoglycaemia
    • Stops fat and muscle up-taking glucose in circulation and conserves it for the CNS
28
Q

indirect effects of growth hormone

A

stimulates liver to release insulin like growth factor (IGF-1,IGF-2) –>

  • Skeletal growth
    • Cartilage formation
      • Increase chondrocyte mitosis & matrix production
    • Bone deposition
      • Lengthening and thickening of long bones
  • Soft tissue growth
    • Protein synthesis
    • Cell proliferation
  • Growth promoting
    • Bone response to GH ceases when growth plates fuse
    • Occurs at 18/19 years old
29
Q

what is somatopause

what occurs due to it

A

Natural decline in growth hormone with age

  • Decrease in lean body mass
  • Decline in bone mineral density
  • Increase in body fat
  • Sleep disturbance
30
Q

draw endocrine feedback for growth hormone release and action

A
31
Q

how do growth hormone disorders usually occur

A

usually due to pituitary tumour secreting growth hormone

32
Q

what is gigantism and how does it occur

A
  • Gigantism refers to abnormally high linear growth due to excessive action of IGF while the epiphyseal growth plates are open during (children)
    • Usually in children who have pituitary tumour secreting excess GH
      • Therefore high IGF in circulation too
      • Therefore individuals are taller
  • Normal body proportions as soft tissues are also affected
33
Q

what is acromegaly and how is it caused.

what symptoms?

A
  • Increased growth hormone later in life after fusion of epiphyses
  • Effect on skeletal elements which don’t grow by endochondral ossification
  • Has effect on soft tissues as well
  • Acromegaly
    • course facial features
    • enlarged hands and feet
    • protruding jaw and separation of teeth
    • enlarged tongue and thickened lips
    • deep voice
    • cardiomegaly
    • Diabetes
      • Excess glucose in circulation as cells do not uptake it
  • Usually due to pituitary tumour
34
Q

what is the consequences of a growth hormone insufficiency in adults?

A

no major symptoms

somatopause

35
Q

what is the consequences of a growth hormone insufficiency in children?

A

= pituitary dwarfism

  • Slow growth rate below 3rd centile on age/height or bone chart
  • Normal body proportions
    • Characteristic
    • Result of slow growth / slow rate of GH production
  • Poor muscle development, excess subcutaneous fat
36
Q

Growth hormone disorders in oral cavity

A
  • Hypo- and hyper-pituitarism
  • Decreased facial and cranial base growth
  • Gaps, delayed eruption, incomplete root formation.
  • Overgrown gum tissue
  • Missing teeth

Dental professionals can be the first see the signs and symptoms of these growth disorders and can correctly diagnose the serious underlying disease

z basic sciences (21 decks)

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