Brainscape's Knowledge GenomeTM

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


See full index

Block 3: Brain and Behaviour > Guided learning: Neuroendocrinology > Flashcards

Guided learning: Neuroendocrinology Flashcards

You may prefer our related Brainscape-certified flashcards:
The Brain flashcards
1
Q

What is the key function of the neuroendocrine system?

Which two regions are connected by the neuroendocrine system?

A

1) maintain homeostasis
2) hypothalamus and pituitary gland

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

What homeostatic processes are controlled by the neuroendocrine system?

A
  • metabolism and energy homeostasis (intake vs usage)
  • blood pressure
  • fluid balance
  • circadian rhythm
  • reproduction
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

Where is the hypothalamus located?

What does it form the base of?

How complete is the BBB in this region? What is the function of this?

A
  • Hypothalamus is located under the thalamus and forms the floor and walls of the third ventricle
  • The blood brain barrier is incomplete here, allowing contact between circulating CSF and the cells of the hypothalamus surrounding the ventricle, makes it ideal for its role in maintaining homeostasis.
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

Which division of the NS does the hypothalamus form part of?

What other structures are included in this?

A
  • Hypothalamus is part of the diencephalon
  • Hypothalamus, thalamus and epithalamus all form the diencephalon
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

The hypothalamus interacts with 4 main systems to maintain endocrine and autonomic setpoints, allowing the body to function optimally.

What are these 4 main systems?

A

Mnemonic HEAL

Homeostatic

Endocrine

Autonomic

Limbic

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

How does the hypothalamus control the activity of your internal organs?

What is the feedback pathway?

A
  • Hypothalamus integrates sensory information about the internal environment of the body from the nervous system and via circulating substances in the blood and CSF
  • It transmits these signals to the brainstem and spinal cord which controls the activity of the internal organs —> drives fight or flight response
  • Connections to frontal cortex and limbic system allows higher functions eg mood and memory to influence homeostasis.
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

describe the grouping of the nuclei of the hypothalamus

A
  • Hypothalamus contains 13 nuclei, grouped according to their proximity to the ventricles:
    • periventricular nuclei
    • medial nuclei
    • lateral nuclei
    • Anatomical relation often links to their function for example:
      • Suprachiasmatic nucleus is involved in integrating light into the circadian rhythm
      • Arcuate nucleus at the floor of the hypothalamus is close to the 3rd ventricle where the BBB is less complete, enables it to sample blood borne factors such as glucose and control glucose/energy balance.
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

What is the medial forebrain bundle?

What are the mamillary bodies made up of?

A
  • There are many medial nuclei of the hypothalamus
  • The medial forebrain bundle of the hypothalamus connects the hypothalamus to many cortical regions and passes through the lateral nuclei.
  • Mamillary bodies comprise multiple subnuclei (medial/ intermediate/ lateral).
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

What are the 4 regions of the hypothalamus?

Label the image shown

A
  • Preoptic region
  • Anterior/ supraoptic nuclei –> primarily controls parasympathetic function*
  • Middle/ tuberal nuclei –> controlling thirst and feeding behaviours
  • Posterior/ mamillary nuclei –> controlling sympathetic functon*

* be aware this is generalised approach, sympathetic function also done by the anterior nuclei, paraticularly the PVN involved in stress response. Parasympathetic can be found in the posterior too.

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

In the anterior and preoptic region of the hypothalamus what are the nuclei?

Can you name their principal functions?

A
  • Preoptic –> medial preoptic nucleus:
    • BP, Sex, Arousal
  • Anterior:
    • Supraoptic nucleus (SON) –> osmoregulation
    • Suprachiasmatic nucleus (SCN) –> diurnal rhythm
    • Paraventricular nucleus (PVN) –> stress response, autonomic control, appetite
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

In the middle/ tuberal region of the hypothalamus what are the nuclei and some of their functions?

A
  • Arcuate nucleus (ARC) –> appetite and growth
  • Dorsomedial (DMN) -> CV, GI function
  • Ventromedial (VMN) –> appetite and mood
  • Lateral nucleus (LH) –> thirst and mood
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

In the posterior region of the hypothalamus what are some of the nuclei and what are their functions?

A
  • Mamillary bodies –> memory
  • Tuberomamillary –> sleep/ wake cycle
  • Posterior nucleus –> BP and thermoregulation
  • dorsal nucleus –> diurnal rhythm
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

Fill out the functions of the nuclei

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

Why is the pituitary gland known as the master gland?

A
  • Pituitary gland releases endocrine hormones into the blood stream
  • These control peripheral targets/ organs
  • Pituitary gland contorls the activity of all the other organs in the body
  • Controls metabolism, growth, reproduction
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

Label the image shown

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

Label the image shown

A
17
Q

What connects the hypothalamus to the pituitary gland?

What is it made up of?

What do hypothalamic inputs have to travel through to reach the hypothalamus?

A
  • Hypothalamus connected to pituitary gland via infundibulum
  • Infundibulum stalk is made up of fibres connecting the two regions
  • R and L hypothalamic inputs have to travel through the median eminence before going via the infundibulum
  • median eminence contains a capillary bed that connects the hypothalamus to the anterior pituitary via long portal veins
18
Q

What are the two divisions of the pituitary gland?

What type of neurones communicate to these regions and via what system?

A
  • Pituitary gland split into anterior and posterior:
    • anterior pituitary gland contains glandular cells that release hormones directly into the blood after stimulation by a hormone carried in the hypophyseal portal system
    • Hormone released from parvocellular neurones
    • posterior pituitary contains the axon terminals of the large magnocellular neurons, which synthesise the hormone for release in the cell body and carry it down the axon terminal for release.
19
Q

What are the two main pathways of communication of the hypothalamus to the pituitary gland?

A
  1. Tuberohypophyseal / Tuberoinfundibular –> innervates the anterior pituitary veins to control hormonal release
    • Release of releasing hormone from parvocellular neurons in hypoT, into hypophyseal portal system.
    • Carried to 2nd capillary bed in anterior pituitary, reaches secretory granular cells
    • Release hormone into venule, carried into general circulation via cavernous sinus
  2. Hypothalamohypophyseal –> magnocellular neurons connecting from hypoT to posterior pituitary.
20
Q

The hypothalamus controls the posterior pituitary in a direct way.

Describe this. What hypothalamic nuclei are involved?

What hormones are released?

What are the actions of these hormones?

A
  • Axonal projections from magnocellular neurones situated in paraventricular and supraoptic nuclei directly project to the posterior pituitary
  • Release vasopressin (ADH) and oxytocin directly into the systemic circulation
  • ADH controls water uptake and therefore BP
  • Oxytocin is involved in reproduction. Causes SMC contraction of uterus (birth) , mammary glands (lactation), and vas deferens/ prostate. Also controls bonding between mother and baby.
21
Q

How does the hypothalamus control hormonal release from the anterior pituitary?

What hormones are released by the anterior pituitary?

A
  • Parvocellular neurones from the hypothalamus send projections to the hypothalamic portal system and secrete hormones into the hypophyseal portal system.
  • They synthesise both releasing hormones and inhibitory hormones, either stimulating anterior pit. release or inhibiting it.
  • Within the infundibulum is the bridge of capillaries that connects the hypothalamus to the anterior pituitary - the hypophyseal portal system.
  • Once the hypothalamic releasing/ inhibitory hormone reaches the glandular cells in the anterior pit. they are either stimulated or inhibited to release their hormone.
  • Anterior pituitary produces 6 hormones (that we need to know): GH, TSH, ACTH, FSH, LH, Prolactin
22
Q

What pathway inhibits prolactin production?

Why can antipsychotics interrupt this pathway? what are the symptoms?

A
  • The hypothalamic arcuate nucleus is connected to the anterior pituitary by the dopaminergic tuberohypophyseal/ tuberoinfundibular pathway.
  • This inhibits prolactin production.
  • Antipsychotics act by inhibiting the dopamine pathway, hence they can cause prolactin release which stimulates the mammary glands to produce milk and breast growth.
23
Q

What are the three major hypothalamic axes?

A
  • Hypothalamic pituitary adrenal (HPA) –> regulated stress response
  • Hypothalamic pituitary thyroid (HPT) –> regulates general metabolic rate
  • Hypothalamic pituitary gonadal (HPG) –> controls reproduction
24
Q

What hormones are released by the hypoT / Pituitary in the HPA axis?

A
  • CRH –> corticotropin releasing hormone is secreted from the HypoT (influenced by stress/ time of day/ serum cortisol)
  • CRH travels in blood binds to receptors in anterior pituitary gland
  • Causes increased production adrenocorticotropic hormone (ACTH)
  • ACTH released and travels to adrenal glands
  • ACTH binds to adrenal cortex which releases cortisol, enabling body to cope with stress in more effective manner
  • Increased cortisol inhibits production of CRH and ACTH via negative feedback.
  • Note release of NA and adrenaline is from the adrenal medulla. This is under direct control of the SympNS, causes the fight or flight response.
25
Q

What are the hormones released by the hypothalamus and pituitary in the Hypothalmic pituitary thyroid (HPT) axis?

A
  • Thyrotropin releasing hormone (TRH) is released from the hypoT
  • This stimulates release of TSH from the anterior pituitary
  • TSH then acts on the Thyroid gland which produces T3/ T4 in response
  • T3/T4 negatively feedback on both the HypoT and Ant. Pituitary to regulate further release of TRH and TSH.
26
Q

Which hormones are released by the HypoT and Pit in the Hypothalmic Pituitary Gonadal axis?

A
  • Hypothalamus releases Gonadotropin releasing hormone (GnRH)
  • This stimulates the pituitary gland to release Follicle stimulating hormone (FSH) and Luteinizing hormone (LH).
  • This act on the gonads (ovaries and testes) which in turn produce sex steroid hormones:
    • testosterone
    • oestrogen
    • progesteron
    • inhibin
27
Q

What division of the NS does the hypothalamus control to maintain homeostasis?

Which descending tracts are involved?

A
  • Autonomic NS via reticulospinal tract
28
Q

Name the hypothalamic nuclei involved in the following functions

A
29
Q

Why could a pituitary tumour cause visual deficits? What is the most typical deficit seen with pituitary tumours?

A

Pituitary gland sits adjacent to optic chiasm, tumour growth can compress the chiasm. Most commonly causes bitemporal hemianopia, loss of the temporal visual fields

30
Q

Clinical case:

  • 36-year old woman visits the GP complaining about problems with her bladder function
  • significant increase in the amount of water she was drinking and felt thirsty for most of the day.
  • increased frequency of urination and was passing large quantities of pale urine.
  • Six months prior to the visit she had been involved in a car crash, where she sustained a severe head injury, but had recovered well and was released with no residual signs or symptoms.

What type of diabetes does she have?

What brain regions could be damaged?

What hormone is inhibited?

How can this be treated pharmacologically?

A
  • Diabetes insipidus
  • Supraoptic nuclei (SON) of the hypothalamus or the posterior lobe of the pituitary. SON damage more likely as post. pit damage would not inhibit release of ADH from hypoT.
  • Hormone inhibited is ADH/ Vasopressin
  • Treated with synthetic ADH –> Desmopressin (nasa spray/ tablet).

Block 3: Brain and Behaviour (14 decks)

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