Biology Flashcards 3 - CNS, Endocrine system, Reproduction, Cells
What are sense organs called?
Receptor cells
What is an electrical impulse?
Signal that is sent along the neurone cells giving us information about the changes in our environment
What is a motor neurone
Sends electrical impulses away from the central nervous system
What is a reflex action?
A fast, automatic response.
This is not conscious.
What is the endocrine system (Three)
- Made up of glands
- Glands release hormones that travel through the bloodstream
- The blood carries the hormone to the target organ
What hormones give a fast response? (Two)
- Adrenaline
- Insulin
What is the endocrine gland in the brain called?
Pituitary
What does the thyroid do/control?
Controls the metabolic rate
What does the pancreas do/control?
Controls blood glucose levels
What is the function of the testes?
Controls development of male secondary sexual characteristics and is involved in the production of sperm
What does the pituitary gland control/do? (Four - inc. difference in males and females)
- Controls growth
- Stimulates thyroid gland to make thyroxine (controls metabolism)
- in Females: stimulates ovaries to produce and release eggs
- Males: Stimulates testes to produce sperm
What does the Adrenal gland do?
Prepares the body for stressful situations
What is oestrogen and where is it made? (Three)
- Made in the ovaries
- Causes lining of the uterus to develop
- Stops production of FSH and stimulates LH production
What is FSH and where is it made? (Three)
- Made in the pituitary gland, found below the brain
- Triggers oestrogen production
- Matures egg in the uterus
What is a receptor?
A specialised cell that detects a stimulus and converts into an electrical impulse
How does information cross a synapse? (Two)
- Chemicals (neurotransmitters) are released ad they diffuse across the gap.
- This triggers an electrical impulse in the next neurone.
What do the ovaries do?(Two)
- Controls development of female secondary sexual characteristics involved in the menstrual cycle.
- Produces the hormone oestrogen.
How does information travel along a neurone?
An electrical impulse
What is the name of the neurone that carries info from CNS to an effector?
Motor neurone
What type of neurone carries information from the receptor to the CNS
Sensory neurone
What neurone is found between the sensory & motor neurone to allow them to communicate?
Relay neurone
What are effectors?
These are muscles and glands and they bring about changes so that we respond to changes in our environment.
What happens to the muscle when it receives an impulse from a motor neurone? (Two)
- The muscle contracts
- This minimises any damage to the body from potentially harmful conditions
What is the endocrine system made of? What does this lead to?
- Made up of glands that release chemicals called hormones into the blood.
- The blood carries the hormone to the target organ. The target organ has receptors on the cell membrane.
How are muscles different to hormonal effects? (Two)
- Hormonal effects are slower but longer lasting.
- Some hormones can give a faster response E.g. insulin controls blood glucose levels
What is LH and where is it made? (Two)
- It is made in the pituitary gland
- Triggers the release of the egg
What is progesterone and where is it made?
- Maintains lining of the uterus, inhabits FSH and LH
- Made in the empty egg
How does the contraceptive pill work?
- Mixed pill contains low doses of oestrogen along with some progesterone. The hormones inhibit the production and release of FSH by the pituitary gland, affecting the ovaries, so no eggs mature
Pros and cons of the contraceptive pill? (Two each)
Pros:
- Highly effective
- Easy to take
Cons:
- Side effects
- Doesn’t protect against STD’s
What is meiosis?
Meiosis is a type of cell division that results in sex cells called gametes
What HAPPENS in meiosis? (Five)
- Chromosomes duplicate
- identical chromosomes line up along equator
- Chromosomes separate
- Cells split in 2, halving chromosomes
- Chromosomes separate again
Five differences between meiosis and mitosis?
MITOSIS:
- The chromosome number is 1/2
- Produces 2 daughter cells
- Daughter cells are genetically identical
- The chromosome number is daughter cell is same as parent cells
- Daughter cells are not genetically identical
MEIOSIS:
- Produces gametes
- This cell divides twice
- The cell divides once
- Produces 4 daughter cells
- Used for growth and repair, and asexual reproduction