LO5 Flashcards
What is the axon?
long, thin part of the neuron which impulses are conducted away from the cell body to other cells
What is the cell body?
Part of the neuron that contains the nucleus
What are the dendrons?
short, branched part of the neuron that receives impulses from other neurons
What is the myelin sheath?
part of the neuron which surrounds the axon
- consists of schwann cells forming an insulting layer and enables electrical impulses to transmit quickly along the nerve cells
What is the node of Ranvier?
a gap between schwann cells that helps to speed up the nerve impulse
What is the function of the synapse?
transfers electrical activity (information) from one cell to another
What is a nuerotransmitter?
a chemical messenger that carries impulses between nerve cells, muscles and glands
What is the endocrine gland found in the neck called?
thyroid
What’s the type of chemical produced by endocrine glands called?
hormone
What is the structure and function of the spinal cord?
- has a hollow centre through which the spinal cord runs
- it transmits information to and from the brain and body through nerves
What is the function of the central nervous system?
- consists of the brain and spinal cord
- takes a main role in control and coordination of most body functions
What is the function of the autonomic nervous system?
- regulates body functions that are not consciously controlled such as breathing and heart rate
What is the function of the peripheral nervous system?
- consists of sensory and motor neurons that transmit nerve impulses to and from the brain and spinal cord
What is the function of sensory and motor neurons?
- sensory nerves transmit info from the senses (eyes, ears, etc) to the brain
- motor nerves transmit info to the muscles from the brain
- the sensory / motor nerve pathways work together, e.g when picking something up
What is the structure and function of the cerebral cortex?
- wrinkly outer layer of the brain which is responsible for processing sensory info from the body
- it is made up of 4 lobes - all responsible for processing different types of info
What is the structure and function of the cerebellum?
- positioned at the back of the skull
- co-ordinates and regulates muscle acitivty (walking and writing)
- also involved in the control of muscles to maintain balance
What is the function of fontal lobes?
- carry out higher level mental processes such as thinking, decision making and planning
What is the structure and function of the corpus callosum?
- a bridge of nerve tissue that connects the two halves of the brain
- enables communication between the two
What is the function of the hypothalamus?
- responsible for the maintenance of body temp
- also regulates appetite and thirst, letting us know when we need to eat or drink
What is the function of the medulla?
- automatically carries out and regulates life-sustaining functions such as breathing, swallowing and heart rate
What is the structure and function of the meninges?
- 3 layers of membranes surrounding the brain and spinal cord
- provide a barrier from the rest of the body and act as protection from infection
What is the structure of a myelin sheath?
- lined with fatty substance
- wrapped around the axon
- layer around schwann cells
What are some symptoms of a stroke?
- face may drop on one side
- may not be able to lift both arms up and keep them there
- slurred speech
- dizziness
- confusion
What is the biological explanation of an ischaemic stroke?
- blood clot blocks the flow of blood and oxygen to the brain
- clots form in areas where arteries are narrowed and blocked over time by plaques
What is the biological explanation of an haemorrhagic stroke?
- when a blood vessel in the skull bursts and bleeds into and around the brain
What is the main cause of a stroke?
high blood pressure which can weaken the arteries in the brain
What are some risk factors of a stroke?
- coronary heart disease
- high blood pressure
- stress
- family history and being aged over 65
What are some lifestyle factors that can lead to a stroke?
- smoking
- unhealthy diet
- lack of excerise
What are some treatments for someone who has had a stroke?
- medication to treat high blood pressure
- alteplase dissolves blood clots and restores blood flow
- statins if chlosterol levels are too high
- physiotherapy
How can someone be monitored after having a stroke?
- several sessions of physiotherapy a week
- exercises to improve muscle strength
What are some symptoms of MS?
- fatique
- difficulty walking
- muscle stiffness
What is the biological explanation of MS?
- the immune system attacks the myelin sheath in the brain and spinal cord
- this causes myelin sheath to become inflamed in pathes, which disrupts the messages travelling along the nerves
- this disruption leads to symptoms of MS
What are some possible causes of MS?
- related to someone with the condition
- smoking
- low vitamin D levels
What is the treatment for MS?
- there is no treatment
- however steriod medication is used to treat relapses
What are some care needs of an individual with MS?
- rely on a wheelchair
- recieving daily care:
- speech and language therapist, physiotherapist and a specialist MS team
What is the role of the pituitary gland?
- the master gland that regulates all other endocrine glands
What is the role of the pancreas?
- situated near the stomach that produces insulin
- insulin is needed to control glucose levels in the body
What is the role of the adrenal glands?
- two glands, one on top of each kidney
- produce adrenaline which is released as a response to threat and prepares the body to fight or run
What is the role of the thyroid gland?
- produces thyroxine which affects growth and sustains metabolism
What is the role of the ovaries and testes (reproductive glands)?
- testosterone in males affect sexual development, growth of facial hair and sperm production
- the ovaries produce oestrogen and progesterone as well as eggs which control breast growth, menstruation and pregnancy
What is deamination?
- occurs in the liver during protein metabolism (breakdown)
- it results in the production of ammonia - toxic waste
What are some functions of nephrons?
- excretion - waste products are removed from the blood by urine
ultrafiltration - occurs in Bowmans capsule - hydrostatic pressure forces plasma and dissolved products out of the blood
What is homeostasis?
the maintanence of a constant internal environment
What is detoxification?
- liver converts the ammonia produced by deamination into urea
- the urea is transported in the blood and removed by the kidney in urine
- liver breaks down alcohol and drugs such as paracetamol
What are some examples of homeostasis?
- the concentration of carbon dioxide in blood
- body temp maintained at 37 degrees
- blood sugar levels - controlled by release and storage of glucose, which is also controlled by insulin
What is negative feedback mechanisms?
- if the level of something rises, control systems reduce it again
- if the level of something falls, control systems raise it again
How do negative feedback mechanisms work?
- conditions in body change
- change detected
- corrective mechanisms activate
- conditions return to normal
- corrective mechanisms
What happens in a synapse?
- an electrical impulse travels along an axon
- this triggers the nerve-ending of a neuron to release neurotransmitters
- these chemicals diffuse across synapse and transmit signals
- they bind with receptor molecules on the membrane of the next neuron
How does the pancreas control blood sugar levels?
- insulin produced
- insulin released into blood
- insulin can lower blood sugar levels
What are some symptoms of diabetes?
- thirsty
- tired
- frequent urination
What are some possible impacts of diabetes on a person’s lifestyle?
- tired all of the time
- increased risk of infection
- vision loss
What are some functions of bile?
- breakdowns fat
- neutralises stomach acid
Which blood vessel carries blood from the body to the kidneys?
renal artery
What is the cortex?
- the outer layer of the kidney
What is the ureter?
a tube that carries urine from the kidney to the bladder
what is the calyx?
a chamber that collects urine
What is the urethra?
a tube that passes urine out of the body
What are some functions of the kidney nephrons?
- osmoregulation - regulates water balance in body
- excretion - waste products are removed from the blood, eg urea
