Diencephalon Flashcards
The diencephalon is the ____ part of the forebrain/ ______ that occupies the ____ region of the brain.
Caudal
Prosencephalon
Central
Subdivisions of the diencephalon:
•Epithalamus
•Subthalamus(Ventral thalamus)
•Thalamus(Dorsal thalamus)
•Hypothalamus
•Metathalamus
Subthalamus is also known as
Ventral thalamus
Epithalamus is the most ____ part of the diencephalon; It forms a _____ covering over the _____
Dorsal
Caplike
Thalamus
_______ is the smallest and oldest part of the diencephalon.
Epithalamus
Epithalamus consists of:
Pineal body
Posterior commissure
Habenular commissure
Habenular nuclei
The Epithalamus is functionally and anatomically linked to the _____; implicated in a number of ______ namely
Limbic system
Autonomic system
Respiratory ,Cardiovascular ,Endocrine (thyroid functions) and Reproductive( mating behavior; responsible for postpartum maternal behavior)
The pineal gland is a ___, _____ gland located within the brain
Small
Endocrine
The pineal gland’s main secretion is _____ which performs the function of _____
Melatonin
Regulating the body’s circadian rhythm
The pineal gland is also thought to produce hormones that _____ the action of other _____ glands in the body
Inhibit
Endocrine
The pineal gland is a small ______ body approximately ____ long. It is shaped like a ____ from which it’s name is derived.
Glandular
6mm
Pine cone
How many type of cells are found in the gland?
The types of cells present within the glands are:
Two
Pinealocytes
Glial cells
The pinealocytes are _____
Glial cells are ____
Hormone secreting cells
Supporting cells
The pineal gland is a ____ structure located between _____. It is attached to the ____ wall of the ____. In close proximity to the gland are the ______ of the _____
Midline
Two cerebral hemispheres
Posterior
3rd ventricle
Superior collinuli
Midbrain
The stalk/peduncle divides into two ____ separated by ____
Laminae
Pineal recess of the 3rd ventricle
The superior lamina of the stalk contains ______
The inferior lamina of the stalk contains
______
Habenular commissure(HC)
Posterior commissure (PC)
Pineal body also secretes a number of ________ but their functions are poorly understood . The hormones of the pineal gland are ______; they influence the activity of other _____ glands e.g …..
Polypeptide hormones
Regulatory
Endocrine
Parathyroid, endocrine pancreas, pituitary, adrenal glands, gonads
The effect of the polypeptide hormones of the pineal glands
on endocrine glands are ______.
Explain how they carry out this effect.
Inhibitory
They do so by reducing the synthesis and release of the hormones produced by the endocrine glands.
Explain how the pineal gland regulates sex hormones.
Pineal gland inhibits the pituitary gland from secreting sex hormones: FSH and LH which aid in the proper development and functioning of ovaries and testes.
Therefore , plays a role in regulating the onset of puberty while it also inhibits the maturation of genitals until puberty.
Hormones of the pineal gland reach the pituitary gland through the ______ and _____
Blood stream
Cerebrospinal fluid (CSF)
With increasing age,the pineal glands become ____ and form ____ / ____
Calcified
Corpora arenacea or Brain sand
The main arterial supply to the pineal gland is via the ____.
posterior choroidal arteries (arise from the posterior cerebral artery)
Pineal gland function and melatonin secretion can be impaired due to____
Disease or injury to the pineal gland
Pineal gland dysfunction can be caused by:
Pineal tumors
Craniopharyngiomas (rare type of non-cancerous or benign brain tumors that starts near the pituitary gland and can also affect to nearby structures in the brain)
Injuries affecting the sympathetic innervation of the pineal gland
Rare congenital disorders that alter melatonin secretion
The most prominent manifestation of pineal gland dysfunction is ____
Change in circadian rhythm
Production of melatonin by the pineal gland can be impaired on a smaller scale by factors such as
Unnatural timing of light exposure
Delayed bedtime and rise time (jet lag syndrome)
Hypothalamus is located _____ the dorsal thalamus and ____ to the Subthalamus.
Below
Medial
