hormonal coordination

give the name of the body's coordination system involving hormones

The endocrine system- uses hormones as chemical messenger

What is a hormone?

a chemical messenger that is secreted by a gland travels by blood to target organs where it causes a response

What is a gland?

an organ that secrete hormones into the bloodstream. maintains homeostasis and regulating bodily functions.

what is the pituitary gland

-referred to as the 'master gland,' -controls many other glands

Role of the pituitary gland

secreting human growth hormones-controls human growth stimulates the thyroid gland stimulates ovulation and the production of oestrogen in the ovaries stimulates the production of sperm and testosterone in the testes.

why is pitutiary gland called the master gland

it secretes a wider range of hormones some of which may stimulate other endocrine glands.

role of the thyroid gland in the endocrine system

secreting the hormone thyroxine- controls metabolism, heart rate, and body temperature.

Role of the pancreas

Secretes the hormone insulin - controls blood glucose levels.

Role of the adrenal gland

secretes adrenaline, a hormone that triggers the 'fight or flight' response in stressful situations.

Role of the ovaries

secrete estrogen, a hormone that coordinates the menstrual cycle and the development of female secondary sexual characteristics.

Role of the testes

secrete testosterone, a hormone that coordinates the production of sperm and the development of male secondary sexual characteristics.

what does the pancreas do

monitors and controls blood glucose concentration

how is blood glucose concentration controlled using negative feedback loop

When blood glucose concentrations rise or falls bellow the optimum, a hormone is secreted by the pancreas. -action of either hormone (Insulin or glucagon) helps bring back the concentration to the correct level

how does the pancreas respond when blood glucose levels are too high

-secretes the hormone insulin. -Insulin binds to receptors on the liver and muscles -causing excess glucose to be converted into glycogen and stored.

how does the pancreas respond when blood glucose levels are too low

-secretes the hormone glucagon -Glucagon binds to liver cells -causing glycogen to be converted into glucose and released into the blood.

What is type 1 diabetes?

an autoimmune disorder in which the pancreas does not produce sufficient insulin to control blood glucose concentration blood glucose levels are very high, leading to excessive urination, tiredness and weight loss.

How can type 1 diabetes be treated?

involves insulin injections before meals- allows glucose to be converted into glycogen -limiting carbohydrate intake attempts using pancreas and pancreatic cell transplants: investigation into genetic engineering of pancreatic cells.

what are Type 2 diabetes

a disorder in which the body's cells stop responding to insulin -leading to uncontrolled blood glucose concentration -linked with increasing age and obesity.

how can Type 2 diabetes be treated

following a carefully-controlled diet

• regular exercise, -weight loss

• medications that increase insulin production and effectiveness.

what is Osmosis

movement of water from a dilute solution to a concentrated solution through a partially permeable membrane.

in what ways is water lost from the body

sweating urine (some reabsorbed in the kidney) during exhalation via the lungs

in what ways are ions lost from the body

sweating and urine

How are excess amino acids excreted from the body?

deaminated in the liver to form ammonia. ammonia is toxic-converted into urea excreted from the body via sweat and urine.

how do the kidneys in maintain the balance of water and substance in the body

filter blood to remove waste products selectively reabsorb useful molecules

Full name of hormone ADH

Anti-diuretic hormone, which is responsible for regulating water reabsorption in the kidneys.

Location of ADH secretion

pituitary gland located in the brain.

how does ADH affect the reabsorption of water in the kidneys

● When the blood is too concentrated, the pituitary gland secretes more ADH. ● ADH travels in the bloodstream to the kidney and increases the permeability of kidney tubules to water. ● More water is reabsorbed in the kidneys, resulting in a smaller volume of more concentrated urine.

Danger of kidney failure

unable to filter blood properly leading to: a build-up of toxic molecules in the body uncontrolled ion and water balance and cell damage as a result of osmosis.

Two main ways of treating kidney failure

dialysis and transplant

What is kidney dialysis?

use of a specialist machine to carry out the function of kidneys. Dialysis fluid contains the same concentration of glucose and ions as healthy blood. As a result, only excess and waste molecules are lost from the blood, and glucose and ions remain.

what is the Function of reproductive hormones during puberty

males: causes the development of secondary sexual characteristics females: cause the development of secondary sexual characteristics and the maturation of eggs .

Main male reproductive hormone

Testosterone produced by the testes It controls sperm production

Main female reproductive hormone

Oestrogen -produced by the ovaries -It is involved in the menstrual cycle.

What is the menstrual cycle?

a monthly cycle of physiological changes the occur in females. It involves the shedding of the uterus lining and ovulation.

Events of the menstrual cells

the uterus lining thickens and eggs begin to mature in the ovaries an egg is released from on of the ovaries (ovulation)- uterus lining remains thick if the egg is fertilised, pregnancy may occur if not, the egg and the uterus lining are shed during menstruation

Ovulation

Ovulation is the release of a mature egg from the ovaries occurs every 28 days

Four main hormones involved in the menstrual cycle

oestrogen progesterone FSH (follicle-stimulating hormone) LH (luteinizing hormone).

Role of FSH in the menstrual cycle

FSH is screamed by the pituitary gland. controls the maturation of eggs within the ovaries (inside a follicle) triggers the production of oestrogen by the ovaries.

Role of estrogen in the menstrual cycle

oestrogen is produced by the ovaries and released due to the action of FSH- causes the re growth of the uterus lining. triggers the production of LH and restricts the release of more FSH

Role of LH in the menstrual cycle

LH is produced in the pituitary gland as a result of oestrogen. triggers ovulation the release of a mature egg from the ovaries.

Role of progesterone in menstrual cycle

-secreted from the follicle of the ovary -sustains the uterus lining -inhibits the production of FSH and LH.

what is Contraception

Contraception refers to methods used to prevent pregnancy.

what are Two types of oral contraceptives

● Combined contraceptive pill (contains oestrogen and progesterone). ● Mini pill (contains only progesterone).

how does the contraceptive pill prevent pregnancy

-inhibits the production of FSH-eggs do not mature, prevents the development of the uterus lining- eggs cannot implant increases the thickness of cervical mucus- immobilises sperm cells.

what is the contraceptive patch

-The contraceptive patch is a patch placed on the skin for 7 days at a time -contains both estrogen and progesterone.

what is a contraceptive implant

A small rod inserted under the skin which continuously releases the hormone progesterone - lasts for 3 years.

what is the contraceptive injection

injection contains progesterone lasts for approximately 3 months

what is the IUS

intrauterine system which is a small plastic device inserted in the uterus releases progesterone thickens cervical mucus and prevents build-up of uterine lining.

What is IUD? What does it do?

intrauterine device a small copper-containing device inserted into the uterus prevents embryo implantation.

Spermicide

a chemical that kills or immobilizes sperm cells not very effective work better when combined with barrier methods

what is a barrier method of contraception

Barrier methods of contraception involve physical separation between sperm and egg. e.g condoms- thin sheath worn the penis or inside the vagina (Protects against STIs but may break) diagrams-a thin cap placed over the cervix- prevent entry of sperm

What surgical methods of contraception are available?

Sterilisation - in males, the sperm ducts are tied (vasectomy) and in females, the oviducts are tied.

What is abstinence?

practice of not having sex avoids pregnancy. Some people abstain from sex around the time of ovulation - this is known as the rhythm method, but it is quite unreliable.

How do fertility drugs increase the chance of pregnancy?

Fertility drugs contain FSH and LH- which stimulate oestrogen production and maturation of eggs in the ovary also contain LH which triggers ovulation

what is IVF

IVF=vitro fertilisation mother is given FSH and LH- stimulates maturation of eggs and ovulation eggs are fertilise using sperm in a laboratory- develop into embryos 1 or 2 embryos are inserted into the mother's womb

what are the advantages of fertility treatment

● Allows infertile couples to have children ● Can store a woman's eggs for later

what are the disadvantages of fertility treatment

-can be expensive -has a low success rate increases the chance of multiple pregnancies- dangerous for mother and babies side effects due to the use of fertility drugs.

what is negative feedback

a type of control where the body responds to an increase or decrease in a factor by returning it to the optimum levels.

What is thyroxine?

a hormone released by the thyroid gland. its release is triggered by the THS (thyroid stimulating hormone) controls the metabolic rate, growth, and development of the body.

How is the release of thyroxine controlled by negative feedback?

levels of blood thyroxine falls- detected by receptors in brain . pituitary gland to release more THS more thyroxine produced and released by thyroid gland blood thyroxine level returns to normal

What is adrenaline?

is a hormone secreted by the adrenal gland in times of stress It is responsible for triggering the 'fight or flight' response

what are the effects of adrenaline

-increase in heart and breathing rate-delivers oxygen and glucose to the body -stored glycogen conversion to glucose dilation of pupils increased mental awareness blood diverted away from the digestive system to the muscles.