In humans, the _____________ has a diminished importance compared to other vertebrates.
Olfactory receptors consist of neurons embedded in _____________ cells.
(T/F) You keep the same set of olfactory receptors throughout your entire life.
False. Olfactory receptors are replaced throughout one's lifetime.
Around ___ fiber bundles/side enter the skull via the cribriform plate of the ethmoid bone and terminate in the olfactory bulb .
20 fiber bundles/side
_________ cells are the principal neurons of the olfactory bulb.
The axons of ________ cells constitute the olfactory tract.
The olfactory tract follows the ventral surface of the frontal lobe and terminates in the ________________ and ______________ of the temporal lobe.
Anterior perforated substance and pyriform
Most axons within the olfactory system follow the lateral olfactory stria to end in the ipsilateral cortex near the ___________.
(T/F) Olfactory tracts terminate uncrossed.
(T/F) The olfactory tract projects first to the thalamus and then to the cerebral cortices.
False. The olfactory system terminates directly in the cortex.
Information from one olfactory bulb may be sent to the other via the ___________________ and the _________________.
Medial olfactory stria and the anterior commissure
___________ is used to refer to the leakage of CSF from the nose, typically following a fracture to the floor of the anterior cranial fossa which involves the cribriform plate.
___________ are tumors that may impinge upon the olfactory tracts after arising from the floor of the anterior cranial fossa. This is usually a unilateral impairment and each nostril must be tested for anosmia.
Epileptic discharges termed ______________ are characterized by olfactory hallucinations, usually of a disagreeable or offensive type such as the smell of burning rubber. They may also result in involuntary movements of the lips and tongue.
Uncinate fits result from compression of the _______________.
The limbic lobe consists of the:
- Cingulate gyrus
- Parahippocampal gyrus
The ______________ occupies the floor of the temporal horn of the lateral ventricle. It also bears resemblance to a C-shape in the sagittal plane and a seahorse-shape in the coronal plane.
The major outflow from the hippocampal formation is via a large fiber bundle that terminates in the mammillary bodies, known as the ___________.
The _____________ receives a considerable amount of input from the amygdala via the stria terminalis and diagonal band.
Septal region (septum)
The major limbic structures within the hypothalamus are the _______________.
The mammillary bodies receive a great deal of their input from the (ipsilateral/contralateral) fornix.
The mammillary bodies have a major efferent tract termed the ___________________ tract.
The mammillothalamic tract terminates in the __________ thalamic nucleus.
(T/F) The olfactory system projects to the amygdala without making use of the thalamus.
The major pathway to and from the amygdala is the ______________. It connects the amygdala with the septal region and hypothalamus.
The _____________ nuclei are involved with integrating information concerned with reproduction.
The septum projects to the habenular nuclei via the ______________.
One of the main functions of the hippocampus is the conversion of ____________ to _____________.
Short-term memory to long-term memory
(T/F) Bilateral lesions of small areas of the hippocampus are associated with profound impairment of recent events. Long-term memories are especially affected in these lesions.
False. Bilateral lesions of large areas of the hippocampus are associated with the profound impairment of recent events. Long-term memories are usually unimpaired.
Because the hippocampus is part of the limbic system, ____________ are associated with memories.
______________ is a psychosis thought to derive from a thiamine (B1) deficiency associated with chronic alcoholism. The lesions always involve the mammillary bodies, hippocampus, and dorsomedial thalamic nuclei. These patients can form no new memories.
________________ is a syndrome that results from massive bilateral lesions to the temporal lobe, including the amygdala, hippocampus, and parahippocampal gyrus. Patients have an absence of emotional responses so that fear, rage, and aggression cease to be displayed. Patients also exhibit a compulsion to be overly attentive to all sensory stimuli, as well as hypersexuality and visual agnosia in which objects are not recognized visually.
Electrical stimulation of the amygdala causes _________, _________, and ______________.
- Eating behavior
Stimulation of the __________ cortex will cause olfactory hallucinations.
Entorhinal (temporal lobe)
Areas of the septum and rostral hypothalamus can be described as ______________.
The _____________ has an essential role in regulating almost every autonomic reaction.
The hypothalamus controls (sympathetic/parasympathetic/both sympathetic and parasympathetic) responses.
Both sympathetic and parasympathetic
Parasympathetic responses may be evoked by stimulation of sites located in the (anterior/posterior) hypothalamic areas.
Sympathetic responses may be evoked by stimulation of sites located in the (anterior/posterior) hypothalamic areas.
The hypothalamus is intimately associated with the ________ gland.
The hypothalamus is connected to the pituitary gland via the ________________ tract.
The hypothalamus regulates the activity of the anterior pituitary gland by producing stimulatory or inhibitory factors that are released into the ___________________.
Hypophyseal portal system
The anterior boundary of the hypothalamus is the _____________.
The posterior boundary of the hypothalamus is the _____________.
Posterior edge of the mammillary body
The dorsal boundary of the hypothalamus is the _____________.
The lateral boundary of the hypothalamus is the _____________.
Fibers of the subthalamus and optic tracts
The ventral boundary of the hypothalamus is the _____________.
What are the three regions of the hypothalamus?
- Supraoptic or anterior
- Tuberal or middle
- Mammillary or posterior
Hormones of the anterior pituitary are released into the hypophyseal portal system that then coalesces and drains into the ______________, gaining access to the general circulation.
The (posterior/anterior) hypothalamus controls the body's heat loss function. Lesions of this region may cause dysregulation of body temperature and result in hyperthermia.
What hormones are released by the arcuate and paraventricular nuclei of the hypothalamus in order to regulate activity of the pituitary?
- Corticoptropin-releasing hormone (CRH or CRF)
- Growth-hormone releasing hormone (GHRH or GHRF)
- Thyrotropin-releasing hormone (TRH or TRF)
Destruction of the _______________ nucleus of the hypothalamus results in disruption of circadian rhythm of hormone release and sexual cycles.
The (posterior/anterior) hypothalamus is responsible for the body's heat conservation and serves in maintenance of the "set point" for body temperature.
(T/F) The anterior hypothalamus can increase body temperature by decreasing sweating and blood flow to the skin and by causing shivering.
False. The posterior thalamus is responsible for increasing body temperature and avoiding hypothermia.
The condition known as ______________ results if the anterior and posterior hypothalamus are both destroyed, causing body temperature to follow the temperature of the environment.
The _______________ and ______________ hypothalamic nuclei are involved in the regulation of food intake.
Medial - Satiety, emotion, endocrine (Ar)
Lateral - Hunger/feeding
The ______________ hypothalamic nucleus is a satiety center. Stimulation of this center causes hypophagia and a decrease in appetite.
The ______________ hypothalamic nucleus is a feeding and hunger center. Stimulation of this center causes hyperphagia and a marked increase in appetite.
The ______________ and _______________ nuclei are crucial to the appropriate control of fluid balance and blood pressure regulation via secretion of vasopressin (ADH).
Supraoptic nucleus (SON) and paraventricular nucleus (PVN)
A clinical state characterized by polyuria and polydipsia (excessive thirst) that can be brought about by destruction of the supraoptic and periventricular nuclei of the hypothalamus is known as _______________.
The (ventral/dorsal) longitudinal fasciculus connects the hypothalamus with the brainstem and spinal cord.
Dorsal longitudinal fasciculus
____________ is the arrest of menses.
Amenorrhea may be caused by insufficient release of _______________ or _____________.
Luteinizing-hormone releasing hormone (LHRH) or follicle stimulating hormone (FSH)
___________ may be caused by a lesion of the anterior hypothalamic nuclei, the tuberal hypothalamus, or the pituitary gland. It is associated with dysregulation of follicle stimulating hormone and luteinizing-hormone releasing hormone.
___________ is the excessive or spontaneous production of milk.
Galactorrhea is involved with an abnormality of the hormones ____________ and ______________.
Prolactin and oxytocin
______________ may be caused by a lesion of the arcuate nucleus, the anterior hypothalamus, median eminence, or pituitary stalk. It is associated with dysregulation of prolactin and oxytocin.
(T/F) Visual clues, such as bitemporal hemianopsia, may hint at the presence of a tumor located in the pituitary. The optic nucleus or optic chiasm often become compressed in these tumors, generating the visual abnormalities.
_____________ is a condition caused by hypersecretion of pituitary growth hormone after maturity and is characterized by the enlargement of the extremities of the skeleton.
Acromegaly may be caused by lesions in the (anterior/posterior) pituitary.
A disease marked by protein depletion, no change in cortisol levels between day and night, abnormal accumulation of fat in face, neck, and trunk, kyphosis, amenorrhea, hypertension, and muscular weakness is known as _________________. This condition is caused by the hypersecretion of adrenocorticotropic hormone (ACTH). This condition is most likely caused by the presence of a pituitary tumor.