Endocrine System Prerecording 2 Flashcards
A single Pituitary gland sits in the bony ____ _____
A single Pituitary gland sits in the bony Sella Turcica
The pituitary gland is connected to the hypothalamus by a thin stem of blood vessels and nerve cell projections called the _______
The pituitary gland is connected to the brain by a thin stem of blood vessels and nerve cell projections called the infundibulum (Pituitary stalk)
What are the two regions of the pituitary gland and their origins?
- Anterior Lobe (Adenohypophysis): came from Embryonic tissue known as ectoderm
- Posterior Lobe (Neurohypophysis): came from the brain (Extension of brain tissue)
Pituitary gland histology:
The anterior lobe (adenohypophysis) contains ______ _____\_cells typical of an endocrine gland.
The Posterior lobe (neurohypophysis) contains ______ _____\_
Pituitary gland histology:
The anterior lobe (adenohypophysis) contains Cuboidal Epithelial cells typical of an endocrine gland.
The Posterior lobe (neurohypophysis) contains Nerve Terminals
Which lobe of the pituitary gland contains cuboidal epithelial cells typical of an endocrine gland?
The anterior (adenohypophysis) lobe
What 7 hormones are released by the Anterior (adenohypophysis) lobe of the pituitary gland?
From the Pars Distallis:
- Thyroid-stimulating hormone (TSH)
- Adrenocorticotropic hormone (ACTH)
- Growth Hormone (GH)
- Prolactin (PRL)
- Follicle-stimulating hormone (FSH)
- Luteinizing Hormone (LH)
From the Pars Intermedia:
- Melanocyte-stimulating hormone (MSH)
Which two hormones are released from the posterior (neurohypophysis) lobe of the pituitary gland?
- Antidiuretic Hormone (ADH)
- Oxytocin (OXT)
Label the Hypothalamic-Hypophyseal Portal System
(hypothalamic-hypophyseal portal system = system of blood vessels connecting the hypothalamus with the anterior pituitary)
Which hormone stimulates body growth and metabolism?
Is it an anterior or posterior pituitary hormone?
Human Growth Hormone (hGH)
Anterior Pituitary Hormone
Which hormone controls thyroid gland function?
Is it an Anterior or posterior pituitary hormone?
Thyroid Stimulating Hormone (TSH)
Anterior Pituitary Hormone
Which two hormones control the secretion of sex hormones and the production of gametes (and as such are very important in terms of the reproductive system and are key for the menstrual cycle)
Follicle-stimulating hormone (FSH) and luteinizing hormone (LH)
These are anterior pituitary hormones
Which hormone stimulates milk production?
Is it an anterior or posterior pituitary hormone?
Prolactin (Prl)
Anterior Pituitary Hormone
Which hormone controls hormone secretion by the adrenal cortex?
Is this an anterior or posterior pituitary hormone?
Adrenocorticotropic Hormone (ACTH)
Anterior pituitary hormone
Which hormone stimulates melanin secretion?
Is this an anterior or posterior pituitary hormone?
Melanocyte stimulating hormone (MSH)
Anterior pituitary hormone
The posterior lobe bypasses what area between the hypothalamus and the pituitary?
Primary capillary plexus
The ___________ runs from the hypothalamus to the neurohypophysis pituitary gland
The hypothalamohypophyseal tract runs from the hypothalamus to the neurohypophysis pituitary gland
The neurosecretory cells of the supraoptic and periventricular nuclei of the hypothalamus have axons that extend from the hypothalamus to the ________ and bypasses the _______
The neurosecretory cells of the supraoptic and periventricular nuclei of the hypothalamus have axons that extend from the hypothalamus to the capillary plexus of neurohypophysis and bypasses the primary capillary plexus
What hormone
- regulates the concentration of urine
- functions in regulation of blood pressure
Vasopressin (aka Antiduretic Hormone ADH)
What produces vasopressin (Antidiuretic hormone)?
By neurons of the supraoptic nucleus
What hormone has the following functions:
- stimulates uterine contraction during childbirth
- stimulates release of milk from mammary glands
love and labor
Oxytocin
What produces oxytocin?
Neurons of paraventricular nucleus
Pituitary to the Adrenal glands is called the:
Hypothalamic-Pituitary-Adrenal-Axis
Describe the Hypothalamic-pituitary-adrenal Axis:
Use the fill-in-the-blanks ONLY until you are comfortable recalling 100%
In the hypothalamic-pituitary-adrenal Axis, some of the neurosecretory cells produce ________ and release it into the primary capillary plexus. It travels through the ______ veins into the secondary capillary plexus where it stimulates some of the glandular cells to produce ______ which travels out through the efferent veins into the circulatory system and makes its way to the _____\_ glands
In the hypothalamic-pituitary-adrenal Axis, some of the neurosecretory cells produce corticotropin-releasing hormone (CRH) released into the primary capillary plexus, travels through the portal veins into the secondary capillary plexus where it stimulates some of the glandular cells to produce Adrenocorticotropic Hormone (ACTH) which travels out through the efferent veins into the circulatory system and makes its way to the Adrenal glands
There is a layer of _____ between the adrenal glands and the Kidneys
Fascia
The cortex of the adrenal glands stores ______ and _____
The cortex of the adrenal glands stores cholesterol and fatty acids
Why does the cortex of the adrenal gland store cholesterol and fatty acid?
To use in the synthesis of >24 steroid hormones (corticosteroids)
-steroid hormones are derived from cholesterol
What are the 3 layers of the Adrenal Cortex of the Adrenal Gland?
From most superficial to deepest:
- Zona Glomerulosa
- Zona Fasciculata (fibrous/fascicles)
- Zona Reticularis (“network”)
The ACTH (adrenocorticotropic hormone) produced in the anterior pituitary has what effect in the Adrenal Cortex?
ACTH stimulates cells in the Zona fasciculata - produces the GLUCOCORTICOIDS
Cells of the Zona Fasciculata of the Adrenal Cortex produce ______ after being stimulated by ______
Cells of the Zona Fasciculata of the Adrenal Cortex produce Glucocorticoids after being stimulated by ACTH (from the anterior pituitary)
What is the function of glucocorticoids?
Where are they produced?
Provide an example of a glucocorticoid.
Glucocorticoids control a number of physiological functions for both resting homeostasis and in response to stress (eg glucose metabolism)
- also used for immunosuppressive and anti-inflammatory properties (some drugs are derivatives of glucocorticoids)
Produced by the Zona Fasciculata (middle layer of Adrenal cortex)
Eg: Cortisol
The zona Glomerulosa of the adrenal cortex produces which class of steroid hormones?
Mineralcorticoids
What are the mineralocorticoid hormones important for?
Where are they produced?
Provide an example.
- Mineralocorticoids control electrolyte balance
- increases renal absorption of Na+ and H2O
- Decreases renal absorption of K+
- Produced by cells of the Zona Glomerulosa of the Adrenal Cortex
- Eg: Aldosterone
What class of steroid hormones are produced by the Zona reticularis of the Adrenal Cortex?
Androgens
What are Androgens important for?
Where are they produced?
- Androgens are sex hormones
- stimulate hair growth in axillary and pubic regions
- The zona reticularis is an important source of androgens in adult females
- Produced by cells of the zona reticularis of the adrenal cortex
Post-ganglionic neurons of the sympathetic nervous system that act on the adrenal medulla are essentially what?
The Chromaffin cells of the adrenal medulla
What type of cells are the Chromaffin cells of the adrenal medulla?
What are they equivalent to?
Neuroendocrine cells
- equivalent to postganglionic sympathetic neurons
The chromaffin cells of the adrenal medulla release ______/______ (_____/______) into the blood providing a ______ response to _____
The chromaffin cells of the adrenal medulla release adrenaline/noradrenaline (epinephrine/norepinephrine) into the blood providing a FAST response to stress
What are epinephrine and norepinephrine important for?
From where are they released?
- Important functions in fight or flight (sympathetic response)
- Increase cardiac output
- increase blood pressure
- increase blood glucose
- effect release of lipids from adipose tissue
- Released by Chromaffin cells in the Adrenal Medulla
In terms of the hypothalamic-pituitary-adrenal Axis, what produces a fast response to stress and what produces a chronic (prolonged) response to stress?
- Nerve impulse from hypothalamus to spinal cord synapses on cell body of preganglionic neuron - preganglionic sympathetic fibres carry response to adrenal medulla - stimulates Chromaffin Cells (neurosecretory cells) of Adrenal Medulla to release Epinephrine/Norepinephrine into the blood = Fast Response
- Hypothalamic neurosecretory cells release corticotropin-releasing hormone into the primary capillary plexus -> portal vein -> Secondary capillary plexus of anterior pituitary -> stimulates release of ACTH into the blood.
- ACTH travels to the Adrenal Cortex where it stimulates cells of the zona fasciculata to release glucocorticoids = CHRONIC STRESS RESPONSE
