Exam 2 Part 2
cingulate cyrus
empathy and pain processing
Far away touch
no effect on action potential firing
Glycogensis
converting glucose to glycogen, using pancreas hormone insulin
aggression
Behavior intended to harm Two types: reactive and proactive Reactive - impulsive, emotional, provoked Proactive - emotionless, unprovoked Areas of brain in aggression: amygdala, hypothalamus, and septal area Murderers have higher activity in amygdala and hypothalamus
Chronic Stress
Causes issues with memory, appetite, sexual desire and performance. - Reduces energy and disrupts mood. - Unlike acute stress, it actually compromises the immune system. This is because the hormones released in chronic stress, suppress the immune system. - Increase in body inflammation.
locus coeruleus
known to secrete Norepinephrine. Responsible for emotional arousal, depression, pleasure, and stress.
ventromedial hypothalamus
lesions cause obesity
lateral hypothalamus
lesions will lead to the refusal of eating
Center receptive field
more firing of action potentials
Gluccorticoid Hormone
most common one is Cortisol
NYP/AgRP neurons
produce neuropeptide Y and agouti-related peptide: they stimulate appetite and lower metabolism (weight gain
POMC/CART nerouns
produce pro-opiomelanocortin and CART: inhibit appetite and raise metabolism (weight loss)
Cortisol
provides energy for the body to cope with the situation
Proactive agression
psychopathy, sociopathy ○ Impaired amygdala function and less autonomic response to stress
Murders
reactive aggressors have lower prefrontal cortex activity. ○ Less gray matter in PFC - antisocial personality disorder
Hypothalamus
responsible for Autonomic Nervous System reactions
Amygdala
responsible for aggression, emotional memory, and fear
Hippocampus
responsible for memory (different from emotional memory
adrenal medulla
secretes Epinephrine/Norepinephrine
tonic receptors
slow or no decline in AP frequency
Congential sensivity to pain
unable to perceive pain, mutated sodium channel in pain fibers in dorsal root ganglia
Lipids
for long-term storage, are fat tissue
adrenal cortex
secretes Cortisol (important stress hormone, that increase blood glucose + protein breakdown)
orbitofrontal cortex
Its' role is to inhibit any raw emotions from the amygdala - Prefrontal cortex split into Dorsolateral, and Orbitofrontal cortex.
prefrontal/orbitofrontal cortex
Makes decision before an action is taken. - Applies moral rules/values to daily functioning - Abnormalities here lead to an increase in aggression, depression, and Schizophrenia.
left hemisphere
Active in positive emotions.
Love
Right Caudate, VTA
Disgust
insula
Osmotic thirst
Is stimulated by high extracellular solute concentrated
Lust
Septal Area
Surrounding Receptive Field
decreased in firing of action potentials
Man on fire syndrome
- congenital hypersensitivity to pain, severe pain sensation triggered by an increase in temperature, heat, stress.
Epinephrine/Norepinephrine
: increase blood glucose and increase output from heart
synthesisa
A stimulus in one modality creates a sensation in another "This food tastes blue" LSD or posterior temporal lobe seizures can cause this problem
Stress
Activates the sympathetic nervous system (fight/flight response) - It is regulated/controlled by the hypothalamus - Effects on the body include increased heart rate, breathing rate, and blood flow - Adrenal Gland plays important role:
Fundamentals of sensory system
All sensory processing begins in receptor cells ● A stimulus produces graded potentials which can lead to action potentials ● Intensity of a stimulus can be coded ○ Changes in frequency of AP's can convey stimulus in a single neuron ○ Multiple neurons can act in parallel with more neurons actings in conjunction with a stronger stimulus ○ Range fractionation - different neurons respond to a specific range of stimuli
PTSD Brain changes
Amongst patients with PTSD, there is reduced frontal cortical and hippocampal volume ● In tortured victims, there is reduced cortical tissue ● Stress-induced brain damage is due to cortisol, possibly as a result of greater receptor sensitivity ○ Generally, PTSD patients have low serum cortisol while depressed patients have high serum cortisol. This does not necessarily hold true in all cases
Brain Control of Drinking
Circulating angiotensin II acts in the subfornical organ (SFO) to signal other brain sites to initiating drinking
Obesity treatment
Eat less/exercise: Combining those 2 together really helps Exercise (200 minutes per week) 2) Gastric bypass surgery (surgical creation of a tiny stomach) : reduces ghrelin and increases PYY and GLP-1, reducing hunger Reduces mortality and has many health benefits
Diets dont work
Energy expenditure is adjusted in response to nutrition At the beginning of a diet, the basal metabolic rate falls-to prevent losing weight Restricted food intake does promote longevity
Hunger Hormones
Fat cells produce leptin and secrete it into the bloodstream Defects in leptin production or sensitivity give a false low report of body fat, causing animals to overeat Obese people are leptin-resistant Overnutrition inflames the hypothalamus- obesity, diabetes, and heart disease
Homeostatic Controls
Homeostatic systems use our behavior to keep things balanced Negative feedback systems are the main homeostatic mechanisms if a desired set point is deviated from, compensatory action begins
Social Influence Hypothesis
Homesexual thoughts and actions stem from environmental factors, such as through early seduction
biological hypothesis
Homosexuality is has biological origins. As a result, non-conformity is felt during early childhood (As early as ages 4-5) ○ Genetic origins can explain the 2-7 times increased detected homosexuality among siblings than the general population ○ Note: Both homosexual and heterosexual men have the same testosterone levels, meaning that hormonal influence is more likely to occur prenatally (before birth
Antigotensin Cascade
If blood volume decreases, kidneys release renin, which triggers formation of angiotensin II
Socialbility
Introverts with HIV are shown to have higher virus titers (concentration) than extroverts with HIV. This can be explained by an elevated level of norepinephrine in introverts, which suppresses the immune system ● Flu antibodies increase more following vaccinations in subjects who had higher activity in the left hemisphere, which is associated with positive emotions
Behavorial and Cognitive differences across genders
Most girls have better verbal ability than boys ● Most boys have better visual-spatial ability than girls ● Boys are more physically aggressive ● More boys are better at math but the overall ability is the same ● Note: Gender is a continuum, not a dichotomy. Many of these differences are extremes are there is mostly overlap between the abilities in girls and boy
Laughter
Orbitofrontal cortex
Osmotic Thirst Mechanisms
Osmosensory neurons in anterior hypothalamus (OVLT) respond to rise in blood osmotic pressure Their cell membranes shrink, opening mechanical-gated Na+ channels OVLT neurons respond to increased osmotic pressure by causing the pituitary to release antidiuretic hormone (ADH)
Chronic long lasting pain
Pain that persists long after injury and healing Pain signals remain active for many months or years Examples are neurogenic pain (nerve damage) and psychogenic pain (psychological pain, non visible damage
Four touch receptor classes
Pain ● Touch ● Vibration ● stretch
Bulimia
Recurrent binge eating Recurrent inappropriate compensatory behavior at least 2X a week for 3 months
anroexia nervosa
Refusal to maintain body weight - Fear of weight gain - Body image disturbance - Amenorrhea - Restricting or binge-eating/purging type Anorexia nervosa has the highest mortality rate of any psychiatric disorder Teenage girls with anorexia have Larger Insula: area active when you experience disgust Larger orbitofrontal cortex- area that tells you "you shouldnt do that
Ghrelin
Released by stomach endocrine cells- Appetite stimulant Rises during fasting; drops after eating Some obese people have elevated ghrelin levels
Receptive field
Sensory neuron responds to a specific stimulus. Each sensory neuron has its receptive field. Each receptive field is in different size and shape.
Gate control theory of pain
Spinal cord can block pain Increase in A fibers can close gate
ventral tegmental area
Substantia Nigra: known to secrete Dopamine. Responsible for the feeling of exhilaration/excitement.
Pain and tempature
Temperature receptors use the pain pathway Pain pathways involve two types of neurons ● Small, slow, unbeyinated c fibers, dull pain ● Large myelinated, fast A delta fibers, sharp pain
Sensory integration disorder
The brain has trouble integrating senses ● Hypersensitivity to touch - stimulus avoiders ○ Refuses to walk barefoot or have distress when washing hands or face ● Hyposensitivity to touch - stimulus seekers ○ May pinch or bite themselves
Hommoculus and Somatosensory cortex
This part of the brain is divided based on different body parts Cortical map - areas in the brain that are identified in performing specific tasks The somatosensory cortex can reorganize itself when one part of the body isn't used anymore (ex. arm amputation)
spinothalamic system
Transmits pain and temperature Periaqueductal gray- in the midbrain, involved in pain perception and usage of opioid receptors
Hypolvolmeic thirst mechanism
Triggered by loss of water volume- concentration is not changed Baroreceptors in blood vessels and heart detect the initial drop Brain activates thirst and salt craving Arteries constrict to raise BP Hypovolemia causes release of vasopressin (antidiuretic hormone) - Induces blood vessel constriction and so reduces blood flow to the bladder FYI: in diabetes insipidus vasopressin is not produced-kidneys send more urine to the bladder - This results in chronic thirst
phasaic receptors
adapt quickly by decreased frequency
Left frontal lobe
behavior approach. Emotions regulated: anger & joy.
Right frontal lobe
behavior withdrawal. Emotions regulated: fear & sadness. Active in negative emotions
Kluver-Bucy syndrome
increased aggression in 6 year old boy, behavior alternated between apathy and hyperactivity.
ATCH
is a hormone that is released by the anterior pituitary gland.
PTSD
is developed due to experiencing a stressful event that may have been threatening or catastrophic in nature. - Common symptoms include: flashbacks of re-experiencing the event, avoiding certain people or places that trigger memories, and hyperarousal symptoms such as panic. - Treatments: may include desensitization, propranolol (a beta blocker, essentially an anxiolytic drug), MDMA/Ectasy assisted therapy has shown promising results in trials (however there is a high chance for substance abuse)
Gloycgen
is glucose stored for short term in the liver
hypovolemic thirst
is stimulated by low extracellular/intravascular volume
Glucose
is the principal fuel for energy