B10 and B11 - The Human Nervous System and Hormonal Coordination Flashcards
Homeostasis
Maintaining a stable state despite environmental changes around you, detecting issues involves Automatic Control Systems
Internal Condition (Controlled by Homeostasis)
- Blood Glucose Concentration
- Body Temperature
- Bodily Water Content
Any of these can be on any scale e.g. Putting your hand over a hot object can react a Receptor
Automatic Control Systems Cycle
Receptor Cells - detect stimuli, change in environment, changes internally/externally, sense movement
Coordination Centre - Process information given from Receptors and passes it on to the Effector
Effector - Carries out the response, to restore normal levels
Coordination Centre Examples
- Brain
- Spinal Cord
- Pancreas
Effector Examples
- Muscle
- Glands
Nervous System (Homeostasis)
- Purpose it to react to surroundings
- Made of 2 parts (CNS which is Brain and Spinal Cord), and other nerves, moving back and forth
- Receptor sends stimulus down Sensory Neurons (Nerve Cells) to the CNS which sends the Neurons on other multiple paths to the Effectors
- Response carried out, either Muscle contracting or a Gland secreting hormones
Reflex Arc (e.g. Burns)
- Receptor detects heat, sending electrical impulses travels along Sensory Neurone (connected to Receptors) to the CNS
- End of Sensory Neurone is a Synapse, releasing a chemical travelling along a Relay Neurone to the CNS, electrical impulse occurs, causing another Synapse, causing an electrical impulse in a Motor Neurone to an effector (muscle), contracting away from the heat
Reflexes
Automatic and fast, brain doesn’t consciously react
Endocrine System
- It is a control system made if glands that secrete Chemicals called Hormones in the bloodstream
- The Blood carries the Hormones to targeted Organ
Hormones
- Take a while to get to targeted Organ, however the effect lasts longer, provide Coordination
- Rapid Response Hormones include Insulin and Adrenaline
- Long Response Hormones include Growth and Sex Hormones
Pituitary Gland (Master Gland)
- Secretes Thyroid stimulating hormones, controlling amount of Thyroxine is created
Hormones released in different Environment
ADH - Effects Kidney function
Growth Hormones - Controls Growth in Chiildren
Hormones Stimulating other Endocrine Glands
Follicle Stimulating Hormones (FSH) - Stimulate Ovaries to make Oestrogen in female
TSH - Stimulate Thyroid Gland to make Thyroxine to control Metabolism rate
Pancreas Hormone (Endocrine Gland)
Controls Level on Glucose in Blood
Adrenaline (Endocrine Gland)
Prepares body for Stressful Situations
Thyroid Gland (Endocrine Gland)
Controls Rate of Metabolism
Ovaries (Endocrine Gland)
Control development of female secondary features: Enlarge Beasts, Erection from Nipples
- Involved in Menstrual Cycle
Testes (Endocrine Gland)
Control development of male secondary features: Facial Hair, Deeper Voice, Heavier Bone Structure
Controlling Blood Glucose Concentration
- Glucose is received by meals, having too much is bad therefore the Pancreas monitors/changes Glucose in blood using Insulin
- Pancreas can convert between Glucose and Glycogen
Insulin
- Draws Glucose away from Blood, storing in at Glycogen in Liver/Muscles
- Insulin reacts to Glucose/Glycogen in a negative feedback cycle
Type 1 Diabetes
- Can’t produce much Insulin therefore keeps Blood Glucose Concentration high
- Controlled by injecting Insulin to replace Hormones that aren’t made in the body
- Pancreas Transplant, few donors
- Pancreatic Cell transplant, low success
Type 2 Diabetes
- Body stops responding/rejects Insulin, linked to Obesity
- Treated by Carbohydrate controlled diet
- Regular Exercise, loose energy
- Loosing Weights
Master Glands
Secretes many Hormones into blood due to changes in body conditions
- Hormones stimulate other Glands to release other Hormones
Negative Feedback
Bodily System tries to maintain stable state
Thyroid
- Uses Iodine from body to make Thyroxine
- Controls rate of Metabolism and brain/bodily growth
Underactive Thyroid
- When Gland cant produce enough Hormones due to Immune System rejecting/attacking it
- May be inherited by genetic information targeting wrong organ.
- Symptoms are depression, tiredness
Sexual Reproduction
Where both sexes produce offspring with games (egg/sperm) by Meiosis
Primary Sexual Characteristics
- Features when you were born
Female Secondary Sexual Characteristics
- Features developed through puberty
- Female: Growth Spurt, Breasts Enlarge, Periods occur
Male Secondary Sexual Characteristics
- Features developed through puberty
- Male: Growth Spurt, Bodily Hair, Testes more active
Menstrual Cycle
- Females that go through puberty, Ovulation occurs when an Egg Matures and drops along with a thick line of Uterus, blood, over the course of 2-7 days
- Occurs when Pituitary Gland secretes FSH and LH
Hormones During Menstrual Cycle
Follicle Stimulating Hormone (FSH) - Matures the Eggs and stimulates Ovary to produce Oestrogen Luteinising Hormone (LH) - Stimulates dropping of Egg, Ovulation Oestrogen - Stimulates Build up of Uterus Lining
Stimulate
Raises Nervous Activity
Fertility
- Age 45-55 Menopause occurs, less fertile and children after that may have genetic problems
- Zygote occurs (fertilised egg), Line of Uterus provides protection/food for embryo
Menstrual Hormone Production
Oestrogen - Secreted in Ovaries in response to FSH
FSH and LH - Secreted by Pituitary Gland to stimulate the Ovaries to produce Oestrogen, triggering Ovulation
Progesterone - Maintains line of Uterus after Ovulation, allows 1 Ovulation at a time
Contraception
A way to stop pregnancy
Infertility
- Infertility may occur due to lack of sperm/female Hormones or Obesity and Age
Infertility Treatment
- FSH Fertility Drugs Ovulates more, higher chance of pregnancy
- IVF used if Oviduct (Tube letting Eggs pass) is damaged, eggs from women treated with Fertility Drugs and Sperm fertilises the eggs in a lab, becoming Embryos inserted back into Mother’s Uterus
Fertilisation during a Period
- Sperm fertilises with the egg during a period, lasting 2-7 days
- Uterus is food for the Zygote
