Homeostasis And Response Flashcards
What is Homeostasis?
The process whereby your BODY maintains a STABLE
ENVIRONMENT by REGULATING conditions INSIDE the body in
response to INTERNAL and EXTERNAL stimuli
What is an example of Homeostasis?
-Body regulating temperatures
-Body regulating blood sugars
What do Automatic Control systems do?
-They DETECT when there is a CHANGE in OPTIMAL CONDITIONS
-They then SEND a SIGNAL in order to REVERSE that CHANGE
What are the three main Automatic Control Systems?
-Receptors
-Coordination Centres
-Effectors
What do Receptors do?
They DETECT any CHANGES in the environment (stimuli)
What do Coordination Centres do?
Receives and PROCESSES information from RECEPTORS around the body.
includes the BRAIN, PANCREAS and SPINAL CARD
What do Effectors do?
Effectors actually DO the RESPONSES.
they include MUSCLES and GLANDS
What is the Nervous System?
-
What does the Human Nervous System consist of?
-The Central Nervous System
-The Nervous System
What does a Neuron do?
Transmits electrical signals throughout the body
How role do Neurons play in the Central Nervous System?
What are the three main types of Neuron?
-Sensory Neuron
-Relay Neuron
-Motor Neuron
What does a Sensory Neuron do?
A Sensory Neuron DETECTS STIMULI and TRANSMITS that information to the BRAIN or the SPINAL CORD
What does a Relay Neuron do?
Relay neurons TRANSMIT INFORMATION between SENSORY and MOTOR neurons, PROCESSING signals WITHIN the CENTRAL NERVOUS SYSTEM
What does a Motor Neuron do?
Motor neurons TRANSMIT signals from the CENTRAL NERVOUS SYSTEM to MUSCLES and GLANDS, enabling movement.
How does information flow from Receptors to Effectors in the Nervous System?
(BLURT QUESTION)
Receptors -> Sensory Neurons -> CNS (Relay Neurons) -> Motor Neurons -> Effectors
What are some examples of Sense Organs and what do they sense?
Eyes – Detect light for vision.
Ears – Detect sound and help with balance.
Nose – Detects chemicals in the air for the sense of smell.
Tongue – Detects chemicals in food for taste.
Skin – Detects touch, temperature, and pain.
What are some examples of Effectors?
• Skeletal Muscles – Contract to produce voluntary movements
• Cardiac Muscle – Causes the heart to beat, pumping blood. • Salivary Glands – Release saliva to aid in digestion.
What is a Reflex Action?
An quick, AUTOMATIC RESPONSE to STIMULI as a way to PROTECT the BODY
What types of Neurons work together in a Reflex Response?
-Sensory Neurons
-Relay Neurons
-Motor Neurons
What do Reflex Actions do?
Protect the body by responding subconsciously to harmful stimuli such as heat.
Describe the Reflex Action sequence
(BLURT QUESTION)
The HARMFUL STIMULI is DETECTED by SENSORY NEURONS
They then TRANSMIT SIGNALS to RELAY NEURONS in the SPINAL CORD
The RELAY NEURONS are responsible for PROCESSING these SIGNALS and SENDING them to MOTOR NEURONS
The MOTOR NEURONS travel to EFFECTORS such as MUSCLES and GLANDS to stimulate a RESPONSE
What is the nerve pathway of a Reflex Action called?
Reflex Arc
What is a Synapse?
A GAP between the AXON TERMINAL of ONE NEUTRON and the DENDRITE of ANOTHER NEUTRON
What is the first stage of Neurotransmission?
-Electrical impulses TRAVEL along the first AXON of a NEURON
What happens during the second stage of Neurotransmission?
The NERVE ENDINGS of the NEURONS release NEUROTRANSMITTERS
What happens during the third stage of Neurotransmission?
NEUROTRANSMITTERS DIFFUSE across the SYNAPSE to RECEPTOR MOLECULES of the SECOND NEURON
What happens at the fourth stage of Neurotransmission?
The RECEPTOR MOLECULES BIND to SPECIFIC, USEFUL NEUROTRANSMITTERS which triggers TRANSMISSION of the ELECTRICAL IMPULSE
-> receptor molecules, such as adrenaline receptors, only bind to neurotransmitters that are useful and “fit”
What is a Hormone?
A chemical messenger produced by the GLANDS in the ENDOCRINE SYSTEM
Where are Hormones carried?
The bloodstream
What is the function of Hormones?
**
ALTERS the ACTIVITY of a SPECIFIC TARGET ORGAN in order to MAINTAIN HOMEOSTASIS
What happens to a Hormone once it’s been used?
**
DEACTIVATED (by enzymes)
EXCRETED
RECYCLED
What is the main difference between Hormonal and Nervous System Control?
Hormonal Control is SLOWER but LASTS LONGER
Nervous System Control is FASTER but LASTS for a SHORTER period of time.
What type of signal do Hormones produce?
Chemical
How do the types of Effectors differ in the Nervous and Hormonal System?
**
Nervous System: Muscles and Glands
Hormonal System: Glands and Tissues
What is the Pituitary Gland also known as?
The Master Gland
Where is the Master Gland located?
The Brain
What does the Pituitary Gland do?
Releases SEVERAL HORMONES
Where is Insulin produced?
The PANCREAS
What does Insulin do?
It CONTROLS BLOOD SUGAR levels
Which organ does Insulin target?
The LIVER
What is the effect of Insulin?
INCREASES the CONVERSION RATE of GLUCOSE to GLYCOGEN for STORAGE
Where is Adrenaline produced?
**
The ADRENAL GLANDS
What is the role of Adrenaline?
**
To ACTIVATE the FLIGHT or FIGHT RESPONSE
What organs does Adrenaline target?
The RESPIRATORY and CIRCULATORY SYSTEMS
(several places)
What is ADH?
Anti-diuretic Hormone
Where is ADH produced?
The PITUITARY GLAND
What organ does ADH target?
The KIDNEYS
What is the role of ADH?
To CONTROL the WATER CONTENT of the BLOOD
What are the effects of ADH?
INCREASES the RATE of WATER REABSORPTION by COLLECTING DUCTS
What is a Negative Feedback Mechanism?
MECHANISM to LOWER RAISED LEVELS of something, and to RAISE REDUCED LEVELS of something in order to maintain HOMEOSTASIS
Describe on example of a Negative Feedback System
**
(BLURT QUESTION)
-A person LOSES a lot of WATER
-The KIDNEYS DETECT this CHANGE
-The PITUITARY GLAND produce ADH to STABILISE the WATER CONTENT of BLOOD molecules
-ADH INCREASES REABSORPTION through COLLECTING DUCTS
-This STABILISES WATER LEVELS in the BLOOD so the PITUITARY GLAND STOPS producing ADH
What is Thyroxine?
**
A hormone
Where is Thyroxine produced?
The Thyroid Gland
What does the Thyroid Gland do?
**
The Thyroid Gland STIMULATES the bodies BASAL METABOLIC RATE
What is the role of Thyroxine?
**
Thyroxine CONTROLS the RATE at which OXYGEN and FOOD PRODUCTS REACT to RELEASE ENERGY into the BODY
What kind of system controls Thyroxine levels?
A Negative Feedback System
What two parts of the brain control and detect Thyroxine levels?
**
The Pituitary Gland and the Hypothalamus
What hormone does the Hypothalamus produce?
TRH
-Thyrotropin Releasing Hormone
What hormone does the Pituitary Gland produce?
(In this instance)
TSH
-Thyroxine Stimulating Hormone
What happens when there are LOW THYROXINE LEVELS in the BLOODSTREAM?
The HYPOTHALAMUS releases TRH which SIGNALS for the PITUITARY GLAND to release TSH which causes the THYROID GLAND to RELEASE MORE THYROXINE
What happens when there are NORMAL THYROXINE LEVELS in the BLOODSTREAM?
***r
TRH and TSH release are INHIBITED
What happens when there are HIGH THYROXINE LEVELS in the BLOODSTREAM?
The rate of TRH and TSH is REDUCED
Why is Adrenaline NOT controlled by a Negative Feedback Mechanism?
**
Adrenaline is only used in TIMES of DANGER and so does not need to be CONSTANTLY MAINTAINED for HOMEOSTASIS
Why is glucose needed in the body?
Respiration
What does the pancreas do when blood sugars are high?
**
Releases insulin
What does the liver do when blood sugars are high?
**
Converts glucose to glycogen
What does the liver do when blood sugars are too low?
**
Breaks down glycogen into glucose
What is Diabetes?
**
A medical condition where the body CANNOT CONTROL BLOOD SUGAR LEVELS
What is the difference between Type 1 and Type 2 Diabetes?
**
Type 1 Diabetes: The PANCREAS does NOT PRODUCE ENOUGH INSULIN, so BSL are TOO HIGH
Type 2 Diabetes: The body becomes RESISTANT to INSULIN which is why BSL are TOO HIGH
How is Type 1 Diabetes treated?
Insulin injections and Diet and Exercise Maintenance
How is Type 2 Diabetes treated?
Medication and Diet and Exercise Maintenance
Why does increasing exercise help to treat Type 1 Diabetes?
-Bodily cells become MORE SENSITIVE to INSULIN
-REDUCES the LEVELS of BLOOD SUGAR through INCREASED RESPIRATION
Why does exercise help to treat people with Type 2 Diabetes?
-Bodily cells become MORE SENSITIVE to INSULIN
-REDUCES the LEVELS of BLOOD SUGAR through INCREASED RESPIRATION
-Promotes BETTER CIRCULATION which is OFTEN a RISK with TYPE 2 DIABETES
-LOWERS BLOOD PRESSURE which DECREASES the RISK of a HEART ATTACK
What is the main correlation of rising cases of Type 2 Diabetes?
Obesity
Why is there a positive correlation between rising Type 2 Diabetes and Obesity levels?
OBESITY leads to INSULIN RESISTANCE due to EXCESS FATTY ACIDS which LIMIT the EFFECTIVENESS of INSULIN
Between what ages does puberty occur generally?
**
10-16
What two hormones cause bodily changes?
Oestrogen and Testosterone
What is Testosterone produced by?
The Testes (for men)
The Ovaries (for women)
What is Oestrogen produced by?
The Ovaries
What does Testosterone do?
Controls the DEVELOPMENT of MALE SECONDARY SEXUAL CHARACTERISTICS
What does Oestrogen do?
Controls the DEVELOPMENT of FEMALE SECONDARY SEXUAL CHARACTER
Restate the definition of a Hormone
A chemical produced by the glands
Name the 6 Organs which produce Hormones
(BLURT QUESTION)
-The Adrenal Glands
-The Thyroid Gland
-The Pituitary Gland
-The Hypothalamus
-Pancreas
-Testes
-Ovaries
What happens during Menstruation?
The UTERUS LINING BREAKS DOWN and is SHED through the vagina as BLOOD.
What four hormones are involved in Menstruation?
-FSH
-> The Follicle Stimulating Hormone
-Oestrogen
-LH
-> Luteinising Hormone
-Progesterone
Where is the Follicle Stimulating Hormone produced?
The Pituitary Gland
What does the Follicle Stimulating Hormone do?
Stimulates the GROWTH and MATURATION of EGGS in the OVARIES
Causes the OVARIES to RELEASE OESTROGEN
Where is Oestrogen produced?
**
The Ovaries
What is the role of Oestrogen?
STOPS FSH from being PRODUCED
THICKENS the UTERUS LINING
Causes the PITUITARY GLAND to RELEASE LH
Where is the Luteinising Hormone produced?
The Pituitary Gland
What is the role of the Luteinising Hormone?
Triggers Ovulation
Where is Progesterone produced?
**
Ovaries
What is the Role of Progesterone?
To MAINTAIN UTERUS LINING
What does the Placenta do during Pregnancy?
**
Produces PROGESTERONE to THICKEN the UTERUS LINING for PREGNANCY and STOPS MENSTRUATION
Describe the relationship between different Hormones during the course of the Menstrual Cycle.
(BLURT QUESTION)
FSH -> Oestrogen -> LH -> Progesterone
-FSH causes EGGS to GROW and DEVELOP
-FSH causes the OVARIES to RELEASE OESTROGEN
-Oestrogen THICKENS the UTERUS LINING
-Oestrogen STOPS FSH from being RELEASED
-Oestrogens TRIGGERS the RELEASE of LH from the PITUITARY GLAND
-LH TRIGGERS OVULATION (the release of the egg)
-LH triggers for the OVARIES to RELEASE PROGESTERONE
-Progesterone THICKENS and MAINTAINS UTERUS LINING through CONTROLLING OESTROGEN LEVELS so that the EGG is SAFE
What is Human Fertility controlled by?
**
Hormones
What two hormones does the Birth Control Pill usually contain?
-Oestrogen
-Progesterone
How do Oestrogen and Progesterone act as contraceptives?
**
INHIBITS the PRODUCTION of FSH so EGGS CANNOT DEVELOP
What are some Benefits of Hormonal Contraception?
**
Very Effective
What are some Risks or Side Effects of Hormonal Contraception?
**
Changes in Weight and Mood
What are three examples of Non-hormonal Contraception?
-Barrier Protection
-Abstinence
-Surgical Contraception
What are some benefits of Condoms?
Very Effective
Cheap
Painless
What are some Risks of Condoms?
-Might break
What are some benefits of Surgical Contraception?
**
-Removes risk of conception completely
What are some risks of Surgical Contraception ?
**
Cannot be reversed
Can be painful
What are some benefits of Abstinence?
Can be highly successful
What are some risks of Abstinence?
If the timings aren’t accurate the risk of pregnancy is high
Why do some biological reasons couples struggle to get Pregnant?
**
Not enough semen in sperm (men)
Not enough FSH produced by the Pituitary Gland (women)
What two hormones are present in Fertility Treatments?
-FSH
-LH
How do the Luteinising and Follicle Stimulating Hormone increase a woman’s chance of becoming Pregnant?
They STIMULATE EGG PRODUCTION in the OVARIES
Why might the treatment NOT work?
(BLURT QUESTION)
-Because the treatment INCREASES the amount of MATURE EGGS PRODUCED it INCREASES the CHANCE of TWINS or TRIPLETS which INCREASE the CHANCE of a MISCARRIAGE
What happens during the first stage of IVF?
The MOTHER is GIVEN FSH and LH
What happens during the second stage of IVF?
The EGGS are COLLECTED from the MOTHER and FERTILISED by SPERM from the FATHER in a DISH in a LABORATORY
What happens during the third stage of IVF?
The FERTILISED EGGS DEVELOP into EMBRYOS
What happens during the fourth stage of IVF?
At the STAGE where they have ACCUMULATED into TINY BALLS of CELLS they are INSERTED into the MOTHER’S WOMB
The development in what has allowed IVF to develop further?
Microscopic Techniques
What are some advantages of IVF?
UNUSED EGGS can be DONATED
EMBRYOS can be SCREENED for GENETIC DISEASES
Very SAFE
What are some disadvantages of IVF?
Side effects such as HOT FLUSHES and SEVERE HEADACHES
Why does the NHS choose who gets IVF?
**
OLDER WOMEN have a VERY LOW CHANCE of PREGNANCY
What ethical concerns are associated with IVF?
**
-UNUSED EMBRYOS may be DESTROYED -> the pro-life movement
-Fear that COUPLES may want DESIGNER BABIES which some might consider UNNATURAL or UNETHICAL
Why are Embryos allowed to develop before being implanted in the Uterus?
**
To ensure they MATURE
