Other #2 Hypothalamus, Emotional States Flashcards
Location of Hypothalamus
- Inferior to the hypothalamic sulcus
- Superior to the pituitary gland
- Caudal to lamina terminalis
What structure does Hypothalamus continuous with?
Pituitary Gland
Composition of Hypothalamus
- Preoptic Area - Rostral
- Zones - Caudal to preoptic area. Run Medial - Lateral (Periventricular, Medial, Lateral)
Fibers of the Hypothalamus
- Medial Forebrain Bundle
- Dorsal Longitudinal Fasciculus
Hypothalamus receives input from? (7 structures) (*Harry’s Hippo Saw Amy’s Brain Power Taking Risks)
- Hippocampus (memory)
- Septal nuclei (Pleasure / Addiction)
- Amygdaloid (Emotion)
- Brainstem (Physiologic systems)
- Prefrontal cortex (executive function)
- Thalamus (sensory)
- Retina (Sensory)
Hypothalamus projects to?
- Amygdaloid
- Brainstem
- Thalamus
- Spinal Cord
Hypothalamus has intrinsic connections with?
Pituitary gland
Pituitary gland is divided into?
anterior - adenohypophysis
posterior - neurohypophysis
Function of Hypothalamus
Integrate autonomic response and endocrine function with behavior (homeostasis & behavior)
Most of the connections in Hypothalamus are?
Reciprocal
Which 6 basic physiologic processes does the hypothalamus regulate?
- Blood pressure and electrolyte composition
- Body Temperature
- Energy Metabolism
- Reproduction
- Emergency Response to stress
- Sleep-wake cycle
What are the 3 physiological mechanisms Underlying function?
- Receives sensory and context information
- Compares sensory information to biological set points
- Activates responses to restore homeostasis
Hypothalamus can be divided in which two areas?
- Caudolateral
- Rostromedial
Caudolateral Area
- Consists of the posterior (Mamillary) region and lateral zone
- Anxiety
- Increased activity of sympathetic division
Rostromedial Area
- Consists of the remaining anterior (supraoptic) and tuberal regions
- Contentment
- Increase activity of Parasympathetic
Temperature regulation
- External temperature: thermoreceptors in the skin
- Internal temperature: Thermoreceptors in the hypothalamus
When blood temperature is below normal
Thermoreceptors in the hypothalamus activates heat conservation and heat production
- Heat conservation mediated by autonomic pathways
- Heat production mediated by reticulospinal pathways
For water balance, information about the osmolarity of the blood is monitored by?
Osmolarity sensitive neurons in the hypothalamus
Example: When blood osmolarity is high
- Osmolarity sensitive neurons in the hypothalamus stimulate ADH
- ADH increases water resorption
A lesion of the hypothalamus could result in?
specific autonomic, endocrine & memory deficits
A lesion of the pituitary gland could result in?
Specific endocrine deficits
Emotion state has which two componenets?
- Emotion
- Feeling
Emotion refers to?
physiological state - increased heart rate and respiration, dry mouth…
Emotion occurs?
Unconsciously, when the brain detects certain situations that have emotional competence
Emotion involves
cognitive, endocrine, autonomic, and MSK responses
Feeling
Cognitive state - happiness, surprise, anger
Conscious experience of cognitive and somatic responses
Theories
- Cognitive/ feelings second to Physiological / Emotion
- Emotional States at Amygdaloid, mediated by hypothalamus (emotions) and Cerebral cortex (feelings)
Two examples of physiological state (peripheral expression of emotion)
- Visceral Motor: increase HR & BP / Pupil dilation/hairs become erect
- Somatic Motor: Arching of back / extend claws/ snarling
Hypothalamus receives input from?
sense and ventro-medial forebrain
Hypothalamus projects to?
Brainstem (reticular formation)
What type of pathway is in Hypothalamus
Parallel pathways
Study of the hypothalamus
- Receptors in skin/face = input from senses
- Normal sensory input lead to normal motor output
- Emotion comes from our thought, it is sensory not motor
Function of the physiological state
- prepares the body for action
- Communicates our emotional state to other people
Cortical Representation of Feeling is associated with?
Cortex
What does the current theory say about feeling?
Unconsciously appraises something as being good/ bad, then conscious reflection
Both unconscious and conscious of emotional states involves?
Cerebral cortex
Example: Patients with prefrontal cortex or cingulate gyrus removed
- Pain is not felt as a powerful unpleasant experience
- Still perceive pain as a sensation but feelings to pain are diminished
What structure is associated with emotion (physiological state)?
Hypothalamus
What structure is associated with feelings (cognitive state)? play a role in emotional states
Limbic (prefrontal cortex, cingulate gyrus, insular cortex, amygdaloid)
Structures from the limbic system receive input from? project to?
- receives input from senses and amygdaloid
- projects to amygdaloid, hypothalamus, and brainstem
Function of the cortical regions in emotional states
- Memory & imagination can evoke feelings (stimulus of fear might not evoke the same feelings level in two people)
- Use emotional info in cognitive processing
- Conscious thought can suppress reflex emotional responses
Location of Amygdaloid
Internal to the uncus of the temporal cortex, Rostral to the hippocampus
Composition and connections of Amygdaloid
- Medial group: Olfactory bulb and olfactory cortex
- Central group: Hypothalamus
- Basal Lateral group: Cortices (cognitive expression/feelings)
Function of Amygdaloid
- Coordinate physiological and cognitive states of emotional states
- Mediates learned and unlearned emotional responses
- Invest sensory experience with emotional significance (give things emotional confidence)
- Influence selection and initiation of motivation
a large lesion of the limbic system could result in?
flattening of emotional states
Experience of an emotional state is responsible for?
- making rational decisions and judgements that guide social behavior
Frontal lobe lesions
inappropriate risky decisions when playing cards
Bilateral damage to the amygdaloid nuclei
- difficulty judging the trustworthiness of human faces
- inappropriately friendly behavior towards stranges
Emotionality is
Lateralized in the cerebral hemispheres
Right hemisphere is important for?
- expression and comprehension of affective aspects of speech
- negative emotion
Left hemisphere injury
incidence of depression is higher
Left hemisphere is involved in?
Positive emotion
