Lesson 1(Semi Final) Flashcards
Second controlling system of the body
Endocrine System
The fast control system
Nervous System
Uses chemical messengers( hormones) that are released into the blood.
Endocrine System
Hormones control several major processes;
Reproduction
Growth and development
Mobilization of body defenses
Maintenance of much of homeostasis
Regulation of metabolism
Is the scientific study of hormones and endocrine organs.
Endocrinology
Amino acids-based, which includes;
Proteins
Peptides
Amines
Made from cholesterol
Steroids
Made from highly active lipids that act as local hormones
Prostaglandins
Hormones affect only certain tissues or organs (Target cells or target organs)
Hormone action
Hormones act by two mechanisms;
Direct gene activation
Second-messenger system
Used by steroid hormones and thyroid hormone.
Direct gene activation
Used by protein and peptide hormones
Second-messenger system
The stimuli that activate endocrine glands fall into three major categories;
Hormonal
Humoral
Neural
Most common category of stimulus
Hormonal stimuli
Endocrine organs are activated by other hormones
Hormonal stimuli
Changing blood levels of certain ions and nutrients stimulate hormone release
Humoral stimuli
Indicates various body fluids, such as blood and bile
Humoral
Nerve fibers stimulate hormone release
Neural stimuli
Most are under the control of the sympathetic nervous system
Neural stimuli
The major endocrine organs;
Hypothalamus
Pituitary gland
Pineal gland
Thyroid gland
Parathyroid glands
Thymus
Adrenal glands
Pancreas
Gonads ( testes and ovaries)
Are ductless glands
Endocrine glands
Pea-sized that hangs by a stalk from the hypothalamus in the brain
Pituitary gland
Protected by the sella turcica of the sphenoid bone
Pituitary gland
Pituitary gland has two functional lobes;
Anterior pituitary
Posterior pituitary
Glandular tissue
Anterior pituitary
Nervous tissue
Posterior pituitary
Often called the “master endocrine gland”
Pituitary gland
Produces releasing hormones and inhibiting hormones
Hypothalamus
Hypothalamus also makes two hormones;
Oxytocin and antidiuretic hormone
Stimulates contractions of the uterus during labor, sexual relations and breastfeeding
Oxytocin
Causes milk ejection ( let-down reflex) in a breastfeeding woman
Oxytocin
Inhibits urine production (diuresis) by promoting water reabsorption by the kidneyy
Antidiuretic hormone (ADH)
The reason why ADH is known as?
Vasopressin
Six anterior pituitary hormone;
Growth hormone
Prolactin
Follicle stimulating hormone
Luteinizing hormone
Thyrotropic hormone
Adrenocorticotropic hormone
General metabolic hormone
Growth hormone (GH)
Major effects are directed to growth of skeletal muscles and long bones
Growth hormone
Plays a role in determining final body size
Growth hormone
Stimulates and maintains milk production following childbirth
Prolactin
Function in males is unknown
Prolactin
Regulate hormonal activity of the gonads
Gonadotropic hormones
Stimulates follicle development in ovaries
Follicle stimulating hormone
Stimulates sperm development in testes
Follicle stimulating hormone
