Transcript By Mital Patel

Olga Vajnerová
2. LF UK Praha
Hypothalamus, a major control
headquarters for the limbic system
• Hypothalamus
• Cortex
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Thalamus
Temporal lobe
Basal ganglia
Septum
Paraolfactory area
cingulate gyrus
Parahippocampal gyrus
Orbitofrontal cortex
Anterior nuclei
Hippocampus
Amygdala
Functions of hypothalamus
Neurosecretion – oxytocin, ADH
Statins, liberins
Temperature control
Homeostasis
Biorhythms
Transmission of emotions
Hunger, thirst
Functions of hypothalamus
Relation to autonomic function
Parasympathetic responses
Urinary bladder contraction
Sympathetic responses
Increased adrenal medullary secretion
Vasoconstriction
Stress – fight or flight
Cardiovascular regulation
Arterial pressure
Heart rate
Specific cardiovascular control centres are in….
Reticular regions of the pons and medulla
Cardioexcitatory area
Cardioinhibitory area
Vasomotor area
Via Sympathetic and Parasympathetic nerves
Influence on respiratory and gastointestinal reflexes
Olfactory stimulus – from paleocortex
Signals to visceromotor centres i medulla – nausea, vomiting
Transmission of emotions from limbic system
Rage, anxiety and fear, joy, sadness
Is connected with visceromotor and somatomotor reaction
Hear rate, breathig rate, vasomotor reaction – pale or red skin,
sweat glands, gastrointestinal motility and secretion, smooth
muscle in skin, shivering
Biological rhythms
Suprachiasmaticus nuclei – retinohypothalamic tract
Pacemaker of circadian rhythms
Sleep – wake cycle
ACTH secretion
Melatonin secretion
Body temperature rhythm
Activity patterns of animals
Regulation of body water
1. Thirst center
Lateral hypothalamus
Osmoreceptors – when the EF is too concetrated – develops intense desire to
drink water
2. Antidiuretic hormone
Gastrointestinal and feeding regulation
Hunger
Lateral hypothalamic area,
stimulation – extreme hunger, appetite,
desire to search for food
Damage to this area – lethal starvation
Satiety
Ventromedial nuclei
Stimulation – stop eating
Destruction – hunger centers overactive, obesity
Regulation of body temperature
Temperature
regulating centers
1. Peripheral
Temperature receptors
Skin receptors (cold and warm)
Deep body temperature receptors
Spinal cord, abdominal viscera and great veins
2. Central
Temperature detectors in hypothalamus
Heat sensitive neurons, cold sensitiv neurons
Praeoptic area
Posterior hypothalamus integrates the central
and peripheral temperature sensory signals
Control
Heat-producing
Heat- conserving reaction of the body
Set point – crucial temperature level
37.1ºC
Feedback gain for body temperature control
Temperature-decreasing mechanisms
Vasodilation of skin blood vessels
Inhibition of the sympathetic centers in the posterior
hypothalamus
Sweating
Praeoptic area, via autonomic pathways to the spinal cord
Sympathetic but cholinergic
Decrease in heat production
Inhibition of shivering and thermogenesis
Temperature-decreasing
mechanisms
Vasodilation of skin blood vessels
Inhibition of the sympathetic centers in the posterior
hypothalamus
Sweating
Praeoptic area, via autonomic pathways to the spinal cord
Sympathetic but cholinergic
Decrease in heat production
Inhibition of shivering and thermogenesis
Temperature-decreasing
mechanisms
Vasodilation of skin blood vessels
Inhibition of the sympathetic centers in the posterior
hypothalamus
Sweating
Praeoptic area, via autonomic pathways to the spinal cord
Sympathetic but cholinergic
Decrease in heat
production
Inhibition of shivering
and thermogenesis
Temperature-increasing mechanisms
When the body is too cold
1. Vasoconstriction of skin blood vessels
Stimulation of the sympathetic centers in the posterior
hypothalamus
2. Piloerection
via autonomic pathways to the spinal cord
Sympathetic stimulation causes
arrector pili muscles to contract
3. Increase in heat production, thermogenesis
Shivering, sympathetic excitation of heat production,
Thyroxin secretion
3. Increase in heat production, thermogenesis
Shivering
Primary motor center for shivering in the dorsomedial portion of the posterior
hypothalamus
Excited by cold signals from the skin and spinal cord
Tr hypothalamoreticularis, hypothalamospinalis to spinal motoneurons
Non rhytmical signals, increase the tone of the skeletal muscles
Probably feedback oscillation of the muscle spindle stretch reflex
Sympathetic excitation of heat production
Chemical thermogenesis, E and NE uncouple oxidative phosphorylation, energy
in the form of heat but do not cause ATP to be formed
Thyroxin secretion
Sympathetic excitation of heat production
Chemical thermogenesis, E and NE uncouple oxidative
phosphorylation, energy in the form of heat but do not cause ATP to be
formed
Thyroxin secretion
Olga Vajnerová
using Mital Patel presentation
Structure of hypothalamus and pituitary gland
• The pituitary gland together with the hypothalamus provide endocrine control
of many major physiological function
Hypothalamus:
• Located below the thalamus just above
the brain stem
• Subdivided into a number of nuclei =
paraventricular, supraoptic, arcuate,
Pituitary gland:
• Located inside skull below
hypothalamus
•Has 3 divisions = Adenohypophysis
(ant), Neurohypophysis (post) and the
pars intermedia
Adenohypophysis
• Linked to hypothalamus via
hypophyseal-portal system in the
infundibulum
• Connection allows hypothalamus to
stimulate/inhibit 5 distinct pituitary cell
types:
1. somatotropes -human growth hormone
2. corticotropes - adrenocortictropin
3. Thyrotropes - TSH
4. Gonadotropes – LH and FSH
5. Lactotropes - Prolactin
Negative feedback (autoregulation)
Hypothalamic hormones
Adenohypophysis
Blue – peptides
yellow - steroids
Light blue – glycoproteins
orange – tyrosine derivates
Neurohypophysis
• Connected to the hypothalamus
via infundibulum
• Hormones made in nerve cell
bodies in the hypothalamus, are
transported down the nerve to
the neurohypophysis
• Secretes two peptide hormones:
oxytocin – from paraventricular
nucles
ADH – from supraoptic nucleus
• Axons reach terminal on inf
hypophyseal artery to enter
general circulation
Hypothalamic hormones
Neurohypophysis
QUESTION
• PATIENT :
– EXTREME THIRST
– EXCESSIVE DILUTED URINATION DAY
AND NIGHT
– DEHYDRATION
WHATS THE DIAGNOSIS?
QUESTION
• PATIENT :
– EXTREME THIRST
– EXCESSIVE DILUTED URINATION DAY
AND NIGHT
– DEHYDRATION
DIABETES
INSIPIDUS
WHATS THE DIAGNOSIS?
ADH
DEFICIENCY