Transcript Chapter 26- Chemical Regulation

Chapter 26- Chemical Regulation
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Adrenal cortex
Adrenal glands
Adrenal medulla
Adrenocorticotropic hormone (ACTH)
Androgens
Antagonistic hormones
Anterior pituitary
Calcitonin
Corticosteroids
Diabetes
Endocrine glands
Endocrine system
Endorphins
Epinephrine
Estrogen
Follicle-stimulating hormone (FSH)
Glucagon
Glucocorticoids
Goiter
Gonads
Growth hormone (GH)
Hormone
Hypoglycemia
Hypothalamus
Inhibiting hormones
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Insulin
Islet cells
Local regulators
Luteinizing hormone (LH)
Mineralocorticoids
Neurosecretory cell
Neurotransmitters
Norepinephrine
Pancreas
Parathyroid glands
Parathyroid hormone (PTH)
Pineal gland
Posterior pituitary
Progestins
Prolactin
Prostaglandins
Releasing hormones
Steroid hormones
Target cells
Testosterone
Thymus gland
Thyroid-stimulating hormone (TSH)
Thyroxine
Triiodothyronine
TSH-releasing hormone (TRH)
Hormones
• Regulatory chemicals that travel in blood from production
site and affect other sites in the body
– Coordinate activities in different parts of the body, enables organ
systems to function cooperatively
– Made and secreted by endocrine glands
– Target cells- cells that respond to specific hormone
– Neurosecretory cells- nerve cell that along with conducting nerve
signals, makes and secretes hormones
Endocrine system
• All hormone-secreting cells
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Often collaborates with nervous system
Both rely on chemical messages
Small amount of hormones can govern activities in many cells
Nervous system- chemicals- neurotransmitters- carry information
from one nerve cell to the other
• Local regulator- secreted into interstitial fluid and affects
nearby cells
• Ex: interleukins, prostaglandins
– Endocrine chemicals are transported in blood
Hormones affect target cells by 2 signaling
mechanisms
• Hormone attaches to receptor
protein on membrane
triggering a signal transduction
pathway to activate a protein
that carries out response
– Amine, peptide, protein
hormones
– Ex: glycogen to glucose
• Steroid hormones- binds to
receptors inside the cell (if it’s
a target cell- binds to receptor
and becomes and transcription
factor) – transcription and
translating of a gene follows
– Ex: testosterone, estrogen
– Lipids made from
cholesterol
Hypothalamus and Pituitary
• Connect Nervous system with Endocrine
system
– They have multiple functions
Hypothalamus
• Master control of endocrine system
• Sends signals to pituitary which secretes hormones to
body
• Secretes TRH (TSH-releasing hormone), TRH makes
anterior pituitary secrete TSH (thyroid stimulating
hormone), thyroid secretes thyroxine which increases
metabolism
Pituitary
• Posterior pituitary- composed of nervous tissue
(extension of hypothalamus), stores and secretes
hormones made in hypothalamus
• Anterior pituitary- glandular tissue- synthesizes
hormones
– Hypothalamus- regulates by secreting hormones into
blood
– Releasing hormones- make ant. pit. secrete
– Inhibiting hormones- make ant. pit. stop secreting
Thyroid
• Under voice box, affects many tissues
– T3 and T3 hormones- major role in development and maturation
– Maintain BP, heart rate, muscle tone, digestion and reproductive
functions
– Hyperthyroidism- too much T3 and T4
– Hypothyroidism- too little T3 and T4
– Goiter- defective gland or due to diet- thyroid enlargement
Parathyroid
• 4 on surface of thyroid
• Thyroid and parathyroidmaintains calcium
homeostasis
– Ca for nerve signals,
clotting, transport, bones
– Calcitonin and PTH
(parathyroid hormone)antagonistic hormoneselicit opposite effects
• Calcitonin lowers Ca in
blood, PTH raises Ca in
blood
Pancreas
• Hormones manage cellular fuel
– Insulin- protein hormone- produced by beta cells
– Glucagon- peptide hormone- produced in alpha cells
– Blood sugar increases- insulin secreted- body cells take up
glucose –it’s stored as glycogen and used for metabolic E
– Blood sugar decreases- glucagon secreted- liver cells
breakdown glycogen into glucose
– Antagonistic- negative feedback- controls glucose level
– Diabetes- hormonal disease, body cells are unable to absorb
glucose from blood
• Not enough insulin or cells don’t respond to insulin
• Type I- insulin dependent- autoimmune disease- WBC’s
attack beta cells
• Type II- noninsulin dependent- body cells don’t respond to
insulin –managed by controlled diet
• Hypoglycemia- too much insulin- blood glucose too low
Adrenal Glands
• Responses to stress- on top of kidneys
• 2 portions- adrenal medulla and cortex
– Medulla- flight or fight response
• Responds to nerve signals
• Amine hormones: epinephrine (Adrenaline) and norepinephrine
(noradrenaline)
• Liver cells release glucose, raise BP, raise breathing rate, metabolic
rate, change blood flow patterns
– Cortex- slower, longer lasting response
• Responds to endocrine glands
• ACTH- stimulates cortex to secrete steroid hormonescorticosteroids (2 types)
• Mineralcorticoids- mainly affect salt and water balance- makes
kidneys reabsorb = increase blood volume = increase BP
• Glucocorticoids- mobilize cellular fuel, reinforce glucagon effectpromote synthesis of glucose from protein and fat
• High levels can suppress body’s defenses ex: inflammation
Gonads
• Secrete steroid sex hormones along with producing
gametes
• 3 categories are produced
– Estrogens- higher in females- maintain female reproductive
system, promote secondary sex characteristics
– Progestins- higher in females- prepares uterus to support
embryo ex: progesterone
– Androgens- higher in males- maintain male reproductive system,
produce “maleness”, promote secondary sex characteristics ex:
testosterone