Control And Communication and reproduction Flashcards
Organs that make up CNS
Brain
Spinal cord
Describe brain structure in terms of different parts
Cerebrum is the largest part and is on top of the brain
The cerebellum is at the back of the brain
The medulla is connected to the spinal cord
The function of the cerebrum
Enables conscious thought, memory and intelligence
Function of cerebellum
Controls balance and muscular coordination
Function of medulla
Controls breathing and heart rate
Describe the function of a neurone
Transport electrical impulses from the sense organ to the effector
Define a reflex action
Reflex actions prevent the body from damage
A rapid action from a muscle e.g. Limb withdrawal
Slower response from a gland e.g. The release of a hormone
Describe a reflex are
The neural pathway that controls a reflex action involves 3 types of neurone
Sensory neurone carries impulse from sense organ to the relay neurone in the spinal cord
Relay neurone carries impulse from sensory neurone to the motor neurone
Motor neurone carries impulse from the relay neurone in the spinal cord to the effector
And the gap that occurs between neurones
Synapse a tiny gap occurs between neurones
Describe how electrical impulses are maintained through the synapse
Chemicals diffuse across this space captured by receptors
Triggers off an impulse in the receiving neurone
Describe the function of the endocrine system
Endocrine glands release hormones into the blood stream.
Hormones are chemical messengers.
They are slower than electrical impulses
Target cells have receptor proteins for hormones so only some tissues are affected by specific
Pituitary gland
Release growth hormone
Target tissues are bones, muscles and liver
Hormone stimulates growth during development.
Ovary gland
Releases oestrogen
Target tissues are the uterus and pituitary gland
Hormone repairs uterus lining, regulates menstrual cycle and stimulates pituitary gland to make utenising hormone
Islets of langerhans in pancreas
Produces insulin hormone
Target tissues are liver
Hormone controls conversion of excess glucose in the bloodstream to glycogen
Describe how glucose concentration is regulated in the body
After eating a big meal = high blood glucose level therefore pancreas produces more insulin than glucagon, glucose is converted to glycogen, glycogen is stored in the liver and blood glucose levels return to normal.
If not eaten in a while = low blood glucose level therefore pancreas produces more glucagon than insulin, glycogen in liver is converted back to glucose therefore glucose is released into the bloodstream and blood glucose levels return to normal
Causes, symptoms and treatments of type 1 diabetes
Causes :
Genetics, environmental and auto immune factors
Symptoms:
Urine rich in glucose
Produces excessive volumes of urine
Persistent thirst
Treatment:
Daily insulin injections and a careful diet
Causes, symptoms and treatments of type 2 diabetes
Causes :
Unhealthy diet leading to obesity, physical inactivity and genetics.
Symptoms:
Urine rich in glucose
Produces excessive volumes of urine
Persistent thirst
Treatment:
Exercise, weight loss, diet control and additional insulin in some cases
Suggest reasons why diabetes is continuing to increase in Scotland?
Increasing obesity rates in Scotland are causing this
High fat diet
Drinking excessive levels of alcohol regularly
Lack of exercise
What is diabetes?
Diabetes is a condition where the sufferer are unable to control their blood glucose level
Diabetes is an example of a failed ‘internal communication’ pathway between different cells in the body.
Define reproduction
Reproduction is the process by which members of a species produce offspring
Explain why it is important for organisms to reproduce
To increase variety in a species
To prevent the species from going extinct
Define the terms of diploid and haploid chromosomes
Diploid cells have the normal number of pairs of chromosomes
E.g. Humans have 46 chromosomes
Haploid cells only have
E.g. Humans had 23
Give examples of diploid cells
Liver cells
Any body cells
Bone cells
Skin cells
Give examples of haploid cells
Sperm cells
Egg cells
Describe the structure of sperm and egg cells
Egg:
Microscopic but very large compared to sperm cell
Cytoplasm contains yolk which will nourish the embryo before implantation
Also had nucleus and later of jelly
Haploid cell
Sperm: microscopic and haploid
Long tail for swimming
Head contains chemicals to help penetrate the egg + also contains enzymes and nucleus
Male reproductive system
Penis
Testes
Sperm duct
Female reproductive system
Oviduct
Ovary
Uterus
Vagina
Female site of gamete reproduction
Ovaries
Make sure of gamete production
Testes
Site of fertilisation
Oviduct
Site of embryo development
Uterus
Male reproductive parts of a flower
Anther and filament = stamen
Female reproductive parts of a flower
Stigma, style and ovary = carpel
Site of gamete production if. Flowering plants
Male gamete: found inside pollen (pollen grains)
Site of production: anther
Female gamete: ovules
Site of production: ovary
describe the process of pollination
The transfer of pollen front the anther to the stigma
Pollen grain lands on stigma, a pollen tube grows down the style towards the ovary.
The male gamete travels down the pollen tube towards the ovary. Inside the ovary the male gamete it fertilises the egg cell to create a zygote. A seed is formed containing the embryonic plant
Describe fertilisation
Fertilisation is the fusion of the nuclei of the two haploid gametes to produce a diploid zygote (fertilised egg cells)
