Biological structures Flashcards
Are some neurons different to others?
Yes, they can vary in size and shape.
How many neurones or nerve cells are in the average human nervous system?
100 billion
What is a neuron specialised for?
Communication to and from muscles/other organs in the body like the heart and stomach.
What is the function of the MOTOR neuron?
Carey information from the central nervous system to a muscle, causing the muscle to contract.
What is the function of the SENSORY neuron?
Receives messages from the outside world through our different senses then they are sent to the central nervous system.
What is the function of the INTERNEURON?
They connect neurons together. Found only in the central nervous system .
What is a cell body?
It contain the genetic material (chromosomes) of the cell.
What is an axon?
a long extension from the cell body
What is a myelin sheath?
It covers nearly all axons in the body. It helps to increase the speed of transmission of the nerve impulse down the axon.
What are terminal buttons?
These are at the end of the axon, they send signals to an adjacent cell
What are dendrites ?
Receives the impulse or signal from adjacent cell
(Neurotransmitter) what is a serotonin?
It regulates sleep and wakefulness and aggressive behaviour and is involved in pain.
(Neurotransmitter) what is endorphins?
A collection of neurotransmitters that affect mood and reduce feelings of pain, can be seen as the body’s painkiller chemical.
What’s the different between a motor and a sensory neuron?
Motor carries info from the inside whereas the sensory receives messages from the outside.
What is an action potential?
An electrical impulse that moves down the neuron and along the axon
What is the central nervous system made up of?
The spinal cord and brain.
What is the peripheral nervous system made up of?
Somatic nervous system, autonomic nervous system, sympathetic nervous system and parasympathetic.
What are the 3 main parts of the brain?
Brain stem, cerebellum & cerebral hemispheres.
What does the brain stem do?
Controls basic functions such as sleeping and waking & bodily functions such as breathing and heart rate
What is the cerebellum?
It is involved in regulating movement and sense of balance
What is the cerebral hemispheres?
These perform higher function concerned with hearing, vision and memory
What is the peripheral nervous system?
Made up of neurons that transmit messages or information to and from the central nervous system
What is Somatic?
It transmits info from our senses through receptors to the central nervous system
What is autonomic ?
Transmits info to and from internal bodily organs
What is the autonomic nervous system?
It works without conscious control
What does the sympathetic do?
Prepares the body for action in threatening situations
What does the parasympathetic do?
Supports normal body activity, considering and storing bodily energy.
Examples of what happens in the sympathetic ?
- dilates pupils
- increases heart rate
- sweat
Examples of what happens in the parasympathetic?
- contracts pupils
- decreases heart rate
- increases ruination by contracting the bladder
What is the endocrine system made up of?
A number of gland that secrete chemicals, called hormones in the bloodstream.
What are the main glands of the endocrine system?
Pineal gland, hypothalamus, parathyroid glands, pituitary gland, adrenal glands, pancreas , testes & ovaries.
Where is the pituitary gland located & what does it do?
Middle of the brain & it regulates and stimulates other glands.
Where is the hypothalamus & what does it do?
It’s a small structure in the brain, it controls the pituitary gland and hence the whole of the endocrine system
What does the parathyroid gland do?
Releases hormones
What are the testes and ovaries?
- Testes are in the male and release the male hormone testosterone.
- Ovaries are in the female and release their hormones oestrogen and progesterone.
Where are the adrenal glands located and what do they do?
Located immediately above the kidneys, they secrete a number of chemicals. Chemicals prepare the body in an emergency for fight or flight.
What is adrenalin?
Stress hormone
What is the fast chemical response?
Where the brain stimulated the sympathetic nervous system, this instructs the adrenal gland to release the hormone adrenalin, experienced in stress or high anxiety.
What is the slow chemical response?
Where hypothalamus stimulates the pituitary glands, then instructs the adrenal gland to release a hormone called cortisol into the brain, this inhibits reproductive functions and allows glucose the be release into bloodstream
What is the FIGHT OR FLIGHT response?
Where adrenalin or/and noradrenalin which are stress hormones get released into bloodstream. Stimulating the sympathetic and parasympathetic systems.
