Biological 6-10 Flashcards
Hormones
Enable communication between cells through the blood (endocrine system)
Similarities between neural and endocrine systems
- production of chemicals stored for later release
- some chemicals are hormones and neurotransmitters
- stimulated to release chemicals
- each react with specific receptors
Differences between neural and endocrine systems
- Neural communication is fixed between channels to precise locations; hormonal signalling is more generalised
- Neural messages are very rapid; hormonal communication is slower and more prolonged
- Neural messages either fire or dont; hormones require more for greater effect
- Some neural communication is under voluntary control; hormone release is not
Hormonal Classification and action
- PROTEIN hormones made up of amino acids- BIG so bind with receptors on membrane
- STEROID hormones made up of cholesterol-SMALLER so pass through membrane and bind with receptors on the cytoplasm
Location of Major Endocrine Glands (7)
- Hypothalamus
- Pituitary Gland
- Pineal gland
- Thyroid Gland
- Thymus
- Adrenal Gland
- Pancreas
- Ovary (women)
- Testis (men)
What does the Pineal gland produce?
Melatonin
affects sleep and light
Job of the hypothalamus in relation to pituitary gland
Makes Hypothalamic Releasing Hormones that stimulate or inhibit release from the pituitary gland
Job of the pituitary gland
releases tropic hormones which influences release of hormones from other glands
What controls the Anterior Pituitary Gland?
Hypothalamic Releasing Hormones
What controls the Posterior Pituitary Gland?
Nerve stimulation from hypothalamus
What does the Posterior Pituitary Gland produce?
Anti-diuretic hormone (ADH/Vaporessin)
Oxytocin
What is the job of Anti-diuretic hormone? (secreted by the pituitary gland)
- stimulates the re-absorption of water by kidneys
- stimulates vasoconstriction
What is the job of oxytocin? (secreted by the posterior pituitary gland)
- causes muscle contraction in uterus (childbirth)
- stimulates ejection of breast milk
Why is oxytocin known as the tend and befriend
- levels respond to social stimulation (inhibits stress)
- elevated levels during sexual arousal and orgasm
What does the Anterior Pituitary Gland produce?
- growth hormones
- thyroid stimulating hormones
- gonadotrophins (sex hormone release)
- Adrenocorticotropic Hormone (ACTH)
- Prolactin
What is the job of the growth hormones? (Anterior pituitary glands)
-regulates GROWTH rates (not enough growth hormones causes pituitary dwarfism; too much causes gigantism)
What is the job of thyroid stimulating hormones? (Anterior pituitary glands)
-stimulates THYROXINE by the thyroid gland. if thyroid can’t produce enough thyroxine, it swells up
What is the job of Gonadotrophins? (Anterior Pituitary Glands)
- Luteinizing Hormone- production of PROGESTERONE and TESTOSTERONE (ovaries and testes and adrenal cortex
- Follicle Stimulating Hormone- production of ESTROGEN ad SPERM (ovaries and testes)
What is the job of PROLACTIN?
- tissue development in breasts during pregnancy
- stimulates milk production after birth
- sexual desire: more prolactin after orgasms reducing sexual desire)
Structure of the Adrenal Gland
- Sits on top of the kidneys
- Made up of Medulla (inside),NERVE IMPLUSES and Cortex (outside), ACTH from anterior pituitary
Job of the Adrenal Medulla (Fight, Flight, F**k Hormones
-Secretes Adrenaline and Noradrenaline which regulates heart rate, glucose release and peripheral blood vessels
Job of the Adrenal Cortex
- SEX HORMONES (Adrogens and Estrogens(testes/ovaries)
- MINERALOCORTICOIDS (Aldosterone-kidneys retain sodium and excrete potassium, maintains blood pressure, maintains salt and water in the body
- CORTICOSTEROIDS (stress hormones-Cortisol)
Job of the Pancreas
-secretes insulin (takes up excess glucose) and glucagon (releases glucose)
Job of the testes
-secretes androgens–> Testosterone (begins in prenatal development to determining sex, then bursts in puberty)
Job of testosterone in puberty? (male hormone)
- growth and development of the male reproductive structures
- increased skeletal muscle growth
- enlargement f the larynx (voice changes)
- increased body hair
- sexual drive
Job of the Ovaries
-secretes female sex hormones (estrogen)
What is the job of Estradiol (female hormone)
-breast development
distribution of fat
-maturation of uterus and vagina
What is the job of Progestrone (female hormone)
-thickens the lining of uterus in pregnancy
What is the job of Estradiol and Progestrone?
- stimulates changes in uterus during the menstrual cycle
- influences sexual behaviour
Describe the link between the colour red and testosterone
Those who prefer the colour red had higher levels of testosterone and were viewed as more aggressive.
What is the job of Adrenocorticotropic Hormone?
Stress Hormone Release-stimulates release of stress hormones from adrenal cortex
Name the two pathways in which stress enters the body
Sympathetic Adrenal Medullary (SAM) Axis Hypothalamic Pituitary (HPA) Axis
What are the roles of Adrenaline and Noradrenaline in the SAM Axis?
increased
- heart rate
- blood pressure
- redirection of blood muscle/organs
What is the role of cortsol in the short term?
Increased
- sensitivity of cells to adrenaline and noradrenaline
- blood sugar levels
- mental alertness
What is the role of cortisol on the long term processes?
switches off
- immune system
- growth and repair
- digestion
- reproduction
- regulation of sleep patterns
Describe stress going through the SAM Axis
Stressor is detected in the HYPOTHALAMUS and is communicated to the SYMPATHETIC NERVOUS SYSTEM which communicates to the ADRENAL MEDULLA (inside) and secretes ADRENALINE or NORADRENALINE
Describe stress going through the HPA Axis
Stressor is detected in the HYPOTHALAMUS and is communicated to the PITUITARY GLAND which releases ADRENOCORTICOTROPIC HORMONE (ACTH) through the blood which communicates to the ADRENAL CORTEX which secretes CORTISOL
How do we measure adrenaline and noradrenaline in the body?
blood samples, heart rates/blood pressure
How do we measure cortisol in the body?
cotton swab collects saliva
What are the effects of long term stress i.e continuous cortisol in the body
SYSTEMS SWITCH OFF
- immune system=increased risk of ILL-HEALTH
- growth and repair=INABILITY to health wounds
- digestion=increased risk of PEPTIC ULCERS
- reproduction=FERTILITY PROBLEMS
- regulation of sleep patterns=INSOMNIA
How could measure stress in the real world?
- exam periods
- caregiving
- stressful living conditions
- excessive lifestyles
- high stress jobs
- major life events
How could we measure stress in the lab?
- public speaking tasks
- mental arithmetic
- mirror-tracing
- injections
- cold pressor
- noise
- mutli-tasking
- strooptask
What is the link between ecstasy users and cortisol?
- impaired memory
- sleep problems
- depression and anxiety
- impaired immunity
- ill-health
Name the 2 systems under the NERVOUS SYSTEM
CENTRAL nervous system
PERIPHERAL nervous system
Name the 2 systems under the CENTRAL NERVOUS SYSTEM
BRAIN
SPINAL CORD