Download Capítulo 45: Sistema Endocrino Hormona

Biol 3052 Capítulo 45 - Sistema Endocrino
Hormona
Capítulo 45:
Sistema Endocrino
Dr. Fernando J. Bird-Picó
Departamento de Biología
Recinto Universitario de Mayagüez
• Sustancia química (mensajero) que se
produce en una parte del cuerpo (glándula
o tejido) y viaja por la sangre o fluidos
intersticiales a ejecutar su función en otra
parte del cuerpo específica (tejido
“blanco”).
Figure 45.4
Figure 45.2
Major endocrine glands:
Hypothalamus
Blood
vessel
Response
(a) Endocrine signaling
Pineal gland
Pituitary gland
Thyroid gland
Response
(b) Paracrine signaling
Response
(c) Autocrine signaling
Synapse
Parathyroid glands
(behind thyroid)
Organs containing
endocrine cells:
Thymus
Heart
Liver
Adrenal glands
(atop kidneys)
Stomach
Pancreas
Kidneys
Ovaries (female)
Small
intestine
Neuron
Response
(d) Synaptic signaling
Testes (male)
Neurosecretory
cell
Blood
vessel
Response
(e) Neuroendocrine signaling
Dr. Fernando J. Bird-Picó Primavera 2016
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Biol 3052 Capítulo 45 - Sistema Endocrino
Table 45.1a
Table 45.1b
Figure 45.21
(b) Long-term stress response
and the adrenal cortex
(a) Short-term stress response
and the adrenal medulla
Stress
Spinal cord
(cross section)
Hypothalamus
Nerve
signals
Releasing
hormone
Nerve
cell
Anterior pituitary
Blood vessel
Adrenal medulla
secretes epinephrine
and norepinephrine.
Nerve cell
ACTH
Adrenal cortex
secretes mineralocorticoids and
glucocorticoids.
Adrenal
gland
Sistema de
retroalimentación
Kidney
Effects of epinephrine and norepinephrine:
• Glycogen broken down to glucose;
increased blood glucose
• Increased blood pressure
• Increased breathing rate
• Increased metabolic rate
• Change in blood flow patterns, leading to
increased alertness and decreased digestive,
excretory, and reproductive system activity
Effects of
mineralocorticoids:
Effects of
glucocorticoids:
• Retention of sodium
ions and water by
kidneys
• Proteins and fats broken
down and converted to
glucose, leading to
increased blood glucose
• Increased blood
volume and blood
pressure
Dr. Fernando J. Bird-Picó Primavera 2016
• Partial suppression of
immune system
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Biol 3052 Capítulo 45 - Sistema Endocrino
Acción de hormona esteroide
Figure 45.6-2
Modelo de mensajero
Figure 45.14
SECRETORY
CELL
Cerebrum
Pineal
gland
Lipidsoluble
hormone
Watersoluble
hormone
Thalamus
Hypothalamus
Cerebellum
Pituitary
gland
Spinal cord
VIA
BLOOD
Signal receptor
TARGET
CELL
Cytoplasmic
response
Transport
protein
OR
Gene
regulation
Signal
receptor
Cytoplasmic
response
NUCLEUS
(a)
Hypothalamus
Posterior
pituitary
Gene
regulation
Anterior
pituitary
(b)
Dr. Fernando J. Bird-Picó Primavera 2016
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Biol 3052 Capítulo 45 - Sistema Endocrino
Figure 45.15
Figure 45.16
Hypothalamus
Tropic effects only:
FSH
LH
TSH
ACTH
Neurosecretory
cells of the
hypothalamus
Neurosecretory
cells of the
hypothalamus
Nontropic effects only:
Prolactin
MSH
Neurohormone
Axons
Nontropic and tropic effects:
GH
Hypothalamic
releasing and
inhibiting
hormones
Posterior
pituitary
TARGET
ADH
Oxytocin
Kidney
tubules
Mammary glands,
uterine muscles
HORMONE
FSH and LH
TSH
ACTH
Prolactin
TARGET
Testes or
ovaries
Thyroid
Adrenal
cortex
Mammary
glands
Figure 45.13
Homeostasis
• Balance de la condición fisiológica del
organismo con su interior y su medio
ambiente
• Hormonas juegan papel importante en el
balance de electrolitos, glucosa, amino
ácidos y otros componentes en el torrente
sanguíneo
Blood glucose
level declines.
MSH
GH
Melanocytes Liver, bones,
other tissues
Insulin
Body cells
take up more
glucose.
Beta cells of
pancreas
release insulin
into the blood.
Liver takes
up glucose
and stores it
as glycogen.
STIMULUS:
Blood glucose level rises
(for instance, after eating a
carbohydrate-rich meal).
Homeostasis:
Blood glucose level
(70–110 mg/m100mL)
STIMULUS:
Blood glucose level
falls (for instance, after
skipping a meal).
Blood glucose
level rises.
Liver breaks
down glycogen
and releases
glucose into
the blood.
Dr. Fernando J. Bird-Picó Primavera 2016
Endocrine cells
of the anterior
pituitary
Pituitary
hormones
Posterior
pituitary
Anterior
pituitary
HORMONE
Portal vessels
Alpha cells of pancreas
release glucagon into
the blood.
Glucagon
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Biol 3052 Capítulo 45 - Sistema Endocrino
Figure 45.17
Example
Pathway
Stimulus
Cold
Sensory neuron
−
Hypothalamus
Neurosecretory cell
Hypothalamus secretes
thyrotropin-releasing
hormone (TRH ).
Releasing hormone
Blood vessel
Negative feedback
−
Anterior pituitary
Tropic hormone
Endocrine cell
Anterior pituitary secretes
thyroid-stimulating
hormone (TSH, also known
as thyrotropin ).
Thyroid gland secretes
thyroid hormone
(T3 and T4 ).
Hormone
Target
cells
Response
Body tissues
Increased cellular
metabolism
Dr. Fernando J. Bird-Picó Primavera 2016
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