THE LIMBIC SYSTEM Flashcards
It is considered the brain’s emotional center and plays a crucial role in forming and retrieving memories, particularly those tied to emotional experiences.
LIMBIC SYSTEM
It plays a role in evaluating sensory information and determining the appropriate emotional response, particularly in
threat detection and survival-related behaviors.
AMYGDALA
Dysfunction in the amygdala has been linked to
ANXIETY DISORDERS, AGGRESSION
is essential for forming new long-term memories and is particularly involved in the consolidation of
declarative memory (facts and events).
It is also involved in spatial navigation and the organization of memories.
HIPPOCAMPUS
Damage to the hippocampus can lead to
difficulties in forming new memories (anterograde amnesia)
This structure is involved in regulating emotions and pain. It plays a role in linking behavioral outcomes to motivation,
which is crucial for learning from positive and negative experiences.
CINGULATE GYRUS
anterior cingulate cortex is helping the cingulate gyrus to
decision-making and emotional regulation.
it acts as a relay station
for sensory information before it reaches the cerebral cortex.
It processes information and contributes to emotional and sensory experiences.
thalamus
is a key regulatory center for various autonomic functions, including emotional responses, hunger,
thirst, and circadian rhythms. It plays a role in the limbic system by regulating emotional responses and interacting with
the pituitary gland to release hormones.
hypothalamus
The limbic system is central to generating emotional
responses, including fear, anger, pleasure, and arousal.
emotion
The hippocampus, in particular, is vital for encoding
memories, especially emotional and episodic memories.
memories
It links emotions and motivations to specific actions, particularly those related to survival, such as eating and reproduction.
Motivation and Behavior
The limbic system is also involved in the sense of
smell, with certain smells having strong emotional
connections.
olfaction
Main Function: Stimulates the release of adrenocorticotropic hormone (ACTH) from the anterior pituitary.
Role: Regulates the body’s response to stress by promoting the release of cortisol from the adrenal glands.
Corticotropin-Releasing Hormone (CRH)
Main Function: Stimulates the release of thyroid-stimulating hormone (TSH) from the anterior pituitary.
Role: Controls metabolism by promoting the production of thyroid hormones (T3 and T4) in the thyroid
gland.
Thyrotropin-Releasing Hormone (TRH)
Main Function: Stimulates the release of luteinizing hormone (LH) and follicle-stimulating hormone (FSH)
from the anterior pituitary.
Role: Regulates reproductive processes, including ovulation and sperm production.
Gonadotropin-Releasing Hormone (GnRH)
Main Function: Stimulates the release of growth hormone (GH) from the anterior pituitary.
Role: Promotes growth, cell repair, and metabolism.
Growth Hormone-Releasing Hormone (GHRH)
Main Function: Inhibits the release of growth hormone (GH) and thyroid-stimulating hormone (TSH).
Role: Acts as a regulatory brake on growth and metabolism.
Somatostatin (Growth Hormone-Inhibiting Hormone)
Main Function: Inhibits the release of prolactin from the anterior pituitary.
Role: Prevents excess milk production in females and regulates reproductive health.
Prolactin-Inhibiting Hormone (Dopamine)
(also known as the “master gland”) is a pea-sized structure located at the base of the brain,
directly connected to the hypothalamus.
pituitary gland
receives signals from the hypothalamus in the form of releasing and inhibiting hormones
that are delivered through the hypophyseal portal system.
ANTERIOR PITUITARY
Promotes growth, especially during childhood, and regulates metabolism.
Growth Hormone (GH)
Stimulates the thyroid gland to produce thyroid hormones, which
regulate metabolism.
Thyroid-Stimulating Hormone
Stimulates the adrenal glands to produce cortisol, which helps the
body respond to stress.
Adrenocorticotropic Hormone (ACTH)
Regulates milk production in breastfeeding mothers.
PROLACTIN
Regulate reproductive processes,
including ovulation and sperm production.
Luteinizing Hormone (LH) and Follicle-Stimulating Hormone (FSH)
pituitary stores and releases hormones produced by the hypothalamus
POSTERIOR PITUITARY
Regulates water balance by acting on the kidneys to conserve water, thereby
increasing blood volume and pressure.
Antidiuretic Hormone (ADH)
Plays a role in childbirth, breastfeeding, and social bonding. It stimulates uterine contractions
during labor and milk ejection during breastfeeding. Oxytocin is also associated with feelings of attachment
and emotional bonding.
OXYTOCIN
is a small but crucial structure in the brain responsible for maintaining homeostasis. It controls many bodily
functions, including temperature regulation, hunger, thirst, sleep, and emotional activity.
HYPOTHALAMUS
The hypothalamus receives feedback from hormone levels in the bloodstream and adjusts its signals
to maintain balance (homeostasis).
Negative Feedback Loop
Produces and releases hormones.
Anterior Pituitary (adenohypophysis)
Stores and releases hormones produced by the hypothalamus.
Posterior Pituitary (neurohypophysis)
The hypothalamus sends chemical signals, called releasing or inhibiting hormones, to the anterior pituitary through a special blood vessel system called the hypophyseal portal system.
Releasing and Inhibiting Hormones
The hypothalamus produces hormones that are stored in the posterior pituitary and released directly
into the bloodstream.
Direct Hormone Release
Involved in childbirth, lactation, and emotional bonding.
OXYTOCIN
Regulates water balance in the body by affecting kidney function.
Antidiuretic Hormone (ADH)
The hypothalamus communicates
with the pituitary gland via neurohormones. It sends electrical
signals that trigger hormone release in the posterior pituitary and
chemical signals (hormones) to control the anterior pituitary.
Neuroendocrine Communication
The hormones released by the pituitary
(stimulated by the hypothalamus) affect other endocrine glands,
such as the thyroid, adrenal glands, and reproductive organs, which helps regulate
Endocrine Control
This is a fast response. The hypothalamus
stimulates the adrenal medulla (via nerve fibers) to release adrenaline (epinephrine) and
norepinephrine. These hormones increase heart rate, blood pressure, and energy levels to
prepare the body for immediate action.
Sympathetic-Adrenal-Medullary (SAM) System
This is a slower, longer-lasting response that
involves the release of stress hormones from the adrenal cortex.
Hypothalamic-Pituitary-Adrenal (HPA) Axis
helps maintain prolonged alertness and energy during stressful situations, increases glucose
availability, and suppresses non-essential functions like immune responses.
CORTISOL
ACTH travels to the adrenal glands (located above the kidneys), which in turn release cortisol, a key
stress hormone.
Adrenal Glands
This feedback helps reduce the release of CRH and ACTH, thereby reducing cortisol production. The system then returns
to its baseline state.
FEEDBACK REGULATION
It plays a key role in the “fight-or-flight” response.
Sympathetic-Adrenal-Medullary (SAM) system
The brain, particularly the hypothalamus, detects a threat or stressor.
Perception of stress
The sympathetic nervous system is triggered,
which is responsible for the body’s rapid involuntary response to stress.
Activation of the sympathetic nervous system
The adrenal medulla (part of the adrenal glands) releases
adrenaline and noradrenaline into the bloodstream.
Adrenal medulla response
