1.1 The Pituitary Gland and the Hypothalamus Flashcards
What is the name of the Hollow in which the Pituitary gland is found?
The Sella Turcica
Which bone is the Sella Turcica in?
The Sphenoid Bone
How is the Pituitary related to the Optic Chiasm?
Directly Superior
What is the Clinical Significance of the close relation of the Pituitary Gland to the Optic Chiasm?
Enlargement of the Gland can result in the Nasal Fibers, which cross over at the Optic Chiasm, being impinged. This can lead to a Reduced Visual Field Deficit, known as Bitemporal Hemianopia
What connects the Pituitary Gland to the Hypothalamus?
The Pituitary Stalk
What does the Pituitary Gland consist of?
- An Anterior Lobe of the Pituitary
- Posterior Lobe of the Pituitary
- Pars Intermedialis
What are the names of the Anterior Lobe of the Pituitary?
- Pars Anterior
- Pars Distalis
- Adenohypophysis
What are the names of the Posterior Lobe of the Pituitary?
- Pars Posterior
- Pars Nervosa
- Neurohypophysis
What is the Anterior Lobe of the Pituitary Gland’s part of the Pituitary Stalk called?
Pars Tuberalis
What is the Posterior Lobe of the Pituitary Gland’s part of the Pituitary Stalk called?
Infundibulum
Which of the 2 Lobes of the Pituitary Gland is Larger?
Anterior Lobe (Adenohypophysis) = 2/3 Posterior Lobe (Neurohypophysis) = 1/3
Which of the 2 Lobes of the Pituitary Gland is Glandular, and Manufactures numerous Hormones?
The Anterior Lobe
True Endocrine
Which of the 2 Lobes of the Pituitary Gland releases Hormones after having a input from the Nervous System?
The Posterior Lobe
Neuroendocrine
What is secreted from the Posterior Pituitary Gland?
Neurohormones Produced in the Hypothalamus
Does the Anterior Lobe of the Pituitary stain Dark or Light?
Dark
Does the Posterior Lobe of the Pituitary stain Dark or Light?
Light
What are the 3 types of Cells in the Anterior Pituitary?
- Acidophilic
- Basophilic
- Chromophilic (Not looked at in great detail)
What colour do Acidophilic Cells stain?
Pink
What colour do Basophilic Cells stain?
Purple
What colour do Chromophilic Cells stain?
Pale - due to them not taking up much stain
What are the 2 Classes of Acidophils?
- Somatotrophs
2. Mammotrophs
What are the 3 Classes of Basophils?
- Corticotrophs
- Thyrotrophs
- Gonadotrophs
What is the Secretory Product of Somatotrophs (An Acidophil)?
Somatotrophin (aka Growth Hormone)
What is the Secretory Product of Mammotrophs (An Acidophil)?
Prolactin
What are the 2 Secretory Product of Corticotrophs (A Basophil)?
- Adrenocorticotrophic Hormone (ACTH)
2. Melanocyte Stimulating Hormone (MSH)
What is the Secretory Product of Thyrotrophs (A Basophil)?
Thyroid Stimulating Hormone (TSH)
What are the 2 Secretory Product of Gonadotrophs (A Basophil)?
- Follicle Stimulating Hormone (FSH)
2. Luteinizing Hormone (LH)
What are the Target Organs of the Somatotrophin (aka Growth Hormone), produced by the Somatotrophs? And what are it’s actions?
- The Liver
- The Adipose Tissue
Where the Protein, Lipid, and Carbohydrate Metabolism will be controlled
What is the Target Organ of the Prolactin, produced by the Mammotrophs? And what are it’s actions?
The Mammary Glands, where Milk production is Stimulated
What is the Target Organ of the ACTH, produced by the Corticotrophs? And what are it’s actions?
The Adrenal Cortex, which then causes Glucocorticoid Secretions (Cortisol from the Zona Fasciculata)
What is the Target Organ of the MSH, produced by the Corticotrophs? And what are it’s actions?
The Melanocytes of the Skin, which then causes Pigmentation to occur
What is the Target Organ of the TSH, produced by the Thyrotrophs? And what are it’s actions?
The Thyroid, where Thyroid Hormones Thyroxine (T3) and Triiodothyronine (T4) production / secretion is stimulated
What is the Target Organ of the FSH / LH, produced by the Gonadotrophs? And what are it’s actions?
The Ovaries / Testes, and these control reproductive function - will be covered in the Reproduction Block
What are the main secretory bodies of the Posterior Pituitary?
Neurosecretory Bodies (Herring Bodies)
What are the 2 Hormones secreted from the Posterior Pituitary?
- Anti-Diuretic Hormon (ADH) (aka Vasopressin)
2. Oxytocin
What is the Target Organ of the ADH, released from the Posterior Pituitary? And what are it’s actions?
The Kidneys, where the conservation of Body Water is stimulated
What is the Target Organ of the Oxytocin, released from the Posterior Pituitary? And what are it’s actions?
To the Ovaries which will stimulate Milk Ejection, and Uterine Contractions
What is the Arterial Blood Supply to the Pituitary Gland?
- The Superior Hypophysial Artery
2. The Inferior Hypophysial Artery
Where do the 2 Arteries which supply the Pituitary Gland arise from?
They are a Branch of the Internal Carotid Artery
Which of the 2 Arteries which supply the Pituitary Gland, enters into the Hypothalamus?
The Superior Hypophysial Artery
What does the Superior Hypophysial Artery do once entered into the Hypothalamus?
It breaks up into capillaries
Where do the Capillaries, formed in the Hypothalamus then travel?
To the Anterior Pituitary
What is formed by:
a) The Superior Hypophysial Artery breaking up into Capillaries in the Hypothalamus
b) These Capillaries being transported directly to the Anterior Pituitary?
The Hypothalamo-Hypophysial Portal System
Which Artery supplies the Posterior Pituitary Gland?
The Inferior Hypophsial Artery
How does the Hypothalmus communicate with the Anterior Pituitary?
Through the Releasing and Inhibiting of Hormones into the Hypothalamo-Hypophysial Portal System making it a True Endocrine System
How does the Hypothalmus communicate with the Posterior Pituitary?
Through the Neurosecretory Cells, via the Infundibulum
What is the Venous Drainage of the Pituitary Gland?
Through the Hypophsial Veins to the Cavernous Sinus