Nervous System and Hormones Flashcards
What is a stimulus?
A change in the environment
What is a receptor
a group of specialized cells that detect a stimulus
found in sensory organs
Expand CNS
Central Nervous System
What is a co-ordinator
Links a receptor to an effector
What is an effector
part of the body which responds to the stimulus
What is a response?
A response is a reaction to the stimulus
What are nerves also called as?
Neurons
Explain neurons
carry information in small electrical signals called impulses
often grouped in large bundles called nerves
How does a stimulus result in a response?
Stimulus —> Receptor —> CNS/Co-Ordinator—>Effectors—>Response
What is the CNS made up of?
Brain and Spinal Cord
Explain some features of the nervous system
Acts all over the body
Short term
Very fast response
Communicates to the body through electrical impulses via neutrons
Explain some features of Hormones
Slow response
Long Term
Acts on a target organ
Communicates to the body via blood
How are neurons adapted to their function
Branched structures at each end to allow electrical signals to pass
Explain Synapses
The small gap between neurons which impulses jump across
Describe Voluntary Actions
When the brain is involved in thinking about an action
Involves conscious thought
slower response
Describe Reflex Actions
Automatic and fast response to the stimuli, does not involve the brain or conscious thought
Involves the spinal cord
What are the two types of Effectors?
Muscles and Glands
What is a reflex arc?
The pathway of neurons in a reflex action is described as reflex arc
What is a Sensory Neuron?
Carries impulses from the receptor to the spinal cord
What is Motor Neuron?
Carries nerve impulses from spinal cord to the effector
What is a association neuron?
Joins the sensory and motor neuron
What are Hormones?
Hormones are chemical messengers, produced by glands that travel in the blood to bring about a response in a target organ
What is Insulin
Insulin is the hormone that lowers blood glucose concentrations
Explain the steps of The Action of Insulin
1) Blood Glucose Level Normal
2) Meal containing carbohydrate
3) Blood Glucose Lebel Increases
4)Pancreas Produce More Insulin
5) More respiration, More uptake of glucose, glucose converted into glycogen
6)Blood Glucose Level Decrease
7)Blood Glucose Level Normal
What is diabetes
Diabetes is a life long condition in which the body does not produce enough insilin
Symptoms of Diabetes
High blood glucose concentration
Lethargy
Thirst
Name two types of Diabetes
Type 1
Type 2
Main effect of Type 1 Diabetes
Insulin is not produced by pancreas
Treatment for Type 1
Insulin injections for life and controlled diet
Preventive measures for Type 1
None- not caused by lifestyle
Cant prevent it
Age of First Occurrence for Type 1
Childhood
Main Effect of Type 2
Insulin is produced but stops working properly or doesn’t produce enough insulin
Treatment for Type 2
Controlled diet
Insulin injections
Preventive measures for Type 2 Diabetes
Exercise
Reduced sugar intake
avoid obesity
Age of First Occurrence of Type 2
Usually as an adult
Long Term effects of Diabetes
Eye damage/blindness
Heart disease
Strokes
Kidney damage
What is osmoregulation
Controlling the water balance in the body
Role of kidney in our body
Excretion
Osmoregulation
Cortex
Outer part of the kidney
Renal vein
Returns filtered blood to the vena cava
Medula
Middle part of the kidney
Ureter
Drains urine from the kidneys
Bladder
Stores urine
Urethra
Takes urine out of the body
Sphincter muscle
Holds urine in the bladder
Renal artery
Carries blood to the kidney for filtering
Explain the excretory system
The kidney filters blood and excretes waste product
Most of blood is filtered out of the blood vessels, only useful material(water, glucose)is absorbed back to the blood. This takes place is CORTEX
What does the excretory system do to waste materials?
They are drained into the pelvis, before emptying into the ureters for excretion
Explain Homeostatis
Maintaining constant internal environment in the body for proper functioning of cells and enzymes in response to internal and external change
How does body gain water?
Drinking liquids
In food
Water produced in respiration
How does the body loose water
Sweat
Breathing out water vapor
urination
What is an example of homeostatic control
The control of blood glucose
Which organs controls water balance?
Kidney
Osmoregulation when blood is too dilute?(too much water in blood)
1)Blood Concentration Normal
2)Large Drink of Liquid
3)Blood too Dilute
4)Kidney reabsorbs less water back into the blood and more urine is produced
5)Blood Concentration level normal
Osmoregulation when blood is too concentration
1) Blood Concentration Normal
2)Lots of water lost as swear during exercise
3)Blood too Concentrated
4) Kidney Reabsorbs more water into the blood and less urine is produced
Expand ADH
Antidiuretic hormone
What does ADH do
Controls the amount of water reabsorbed
Explain ADH
If blood is too concentrated more ADH is produced=more water absorption=less urine
If blood is too dilute=less ADH produced=less water absorption=more urine
