UNIT 4: LO5 (Control Systems) Flashcards
What is a stimuli?
A change in the environment.
What are receptors?
Organs which detect the stimuli.
What is the central nervous system (CNS) made up of?
- The brain
- The spinal cord (butterfly shape)
- Nerves
What does the CNS work together to give and how?
Voluntary and involuntary actions by sending electrical impulses to the brain.
What is the voluntary system made up of?
Peripheral nerves
What are the two types of peripheral nerves and their functions?
Sensory neurons:
- travel into spinal cord from body’s receptors
- involved with the eyes, ears, taste buds, skin, nose
Motor neurons:
- travel out of spinal cord to body’s effectors
- involved with the muscles (contract/movement) and glands (hormones)
What is a response?
An action taken to counteract the effect of the stimulus.
What is an effector?
A muscle movement or gland which will release a hormone to generate a response.
What is the autonomic nervous system and what are the nerves it controls?
Made up of nerves that control the body’s organs (involuntary control) and controls the sympathetic and parasympathetic nerves.
What are the roles of the sympathetic nerves?
- Speeds up organs e.g. heart rate increases
- Prepares body for survival
What are the roles of the parasympathetic nerves?
- Slows organs down e.g. decrease heart rate
- Keeps body in an efficient resting state
What is the structure of a neuron made up of?
Nucleus, cytoplasm, dendrites, axon, myelin sheath, nerve endings, nodes.
What is the role of the myelin sheath?
It is wrapped around axon for insulation and increases speed that impulse moves along axon.
What are the roles of the axon?
- Connects neurons to different parts of the body
- Carries electrical nerve impulses
What is the roles of the dendrites?
Receive incoming impulses from other neurons
What is the role of the nerve endings?
They connect to muscles and glands.
What is the role of the sensory neurons?
Carry information as electrical impulses from the receptor in the sense organs to the CNS.
What is the role of the relay neurons?
Carry electrical impulses from sensory neurones to motor neurones (found in the CNS).
What is the role of the motor neurons?
Carry electrical impulses from the CNS to the effectors .
What are reflex arcs?
Don’t involve the brain, they happen without us thinking (involuntary responses)
What is the order of the reflex arc?
Stimulus, receptor, sensory neuron, CNS, motor neuron, effector, response.
What is the endocrine system?
It is composed of glands which secrete hormones directly into the blood - hormones carried to target organ where it produces an effect but less targeted than nervous system and slower but long-lasting. Once hormone used is destroyed by liver.
What is the pituitary gland and its roles?
- Key part in endocrine system
- ‘Master gland’ because controls all other glands by allowing them to release other hormones
Where is the thyroid gland and what is the role of thyroxine?
At the front of the neck
Role:
- controls metabolism
Where is the adrenal gland and what are the roles of adrenalin?
On top of the kidneys
Roles:
- allows more glucose and oxygen to muscles (aerobic respiration can take place)
- triggers body’s ‘flight or fight’ response
What does the pancreas produce and what are the roles?
Insulin which decreases blood sugar levels and glucagon which increases blood sugar levels.
What is the cerebral hemisphere?
Folded with deep crevices that increase the size of the brain but allow it to fit inside of the cranium (skull).
What do the meninges do?
Protects the outside of the brain (triple layer of tough membranes).
What is the corpus collosum?
Bridge that joins the right and left cerebral hemispheres. Nerves from the right of the body connect with the left cerebral hemisphere and vice versa.
What is the cerebral cortex and its roles?
- Inner part of cerebrum
- Contains many areas where sensory information processed
- Most likely to be damaged in a head injury because of position
- Affected by stroke
- Responsible for consciousness, learning, memory and language
What is the cerebellum and its roles?
- Underneath the cerebral hemispheres at the back
- Neurons make it stimulate muscles so co-ordinates movements, balance and muscles memory
- Highly affected by alcohol
What is the hypothalamus and its roles?
- Detects changes in blood chemistry and temperature so involved in homeostasis
- Hypothalamus produces hormones - hormones co-ordinate sexual development, glucose and water regulation etc
What is the medulla and its roles?
- Swollen area at the base of the brain leading into the spinal cord
- Controls swallowing, heart rate, breathing rate (vital processes for life)
What are the lobes in the brain?
- Frontal
- Parietal
- Temporal
- Occipital
- Cerebellum
What activity is coordinated in the frontal lobe?
- Smell
- Speech
- Concentration, planning, problem solving
- Motor control
What activity is coordinated in the parietal lobe?
- Touch and pressure
- Taste
- Body awareness
What activity is coordinated in the temporal lobe?
- Hearing
- Facial recognition
What activity is coordinated in the occipital lobe?
Vision
What activity is coordinated in the cerebellum?
Coordination
What is haemorrhagic stroke?
Happens when a blood vessel inside the skull bursts and bleeds into and around the brain - caused by high blood pressure which weakens arteries in the brain so they split or rupture.
What is ischaemic stroke?
Happens when blood clot blocks flow of blood and oxygen to brain - form in areas where arteries been narrowed or blocked by plaque.
How can strokes be diagnosed and monitored?
- Blood tests
- Brain scans
- Swallow test
- Heart and blood vessel tests
- Echocardiogram (images of heart and blood vessels)
What are treatments of ischemic stoke?
- Thrombolysis - dissolves blood clots
- Thrombectomy - removes blood clots
- Anticoagulants - prevent clotting
- Aspirin - blood thinner
What are treatments of haemorrhagic stroke?
- Low blood pressure medicine
- Surgery - removes blood from brain
What are symptoms of multiple sclerosis (MS)?
- Difficulty walking
- Numbness in body
- Muscle stiffness
- Balance and coordination problems
What is the cause of multiple sclerosis (MS)?
Autoimmune condition when the immune system mistakenly attacks healthy part of body - attacks myelin sheath (becomes inflamed in small patches) which damages and scars it meaning messages travelling along nerves become slowed or disrupted.
How is multiple sclerosis treated?
- Physio
- Speech and language therapy
- Stem cell therapy
- Painkillers
- Depressants
What is urea?
Poisonous waste product resulting from breakdown of proteins.
What do the ovaries release and their function?
- Oestrogen which thickens the uterus lining
- Progesterone which maintains the uterus thickness
What do the testes release and what is its function?
Testosterone which makes/releases sperm cells.
What are the external structures of the kidneys and their functions?
- Renal artery - brings ‘dirty blood’ into kidney
- Renal vein - takes ‘clean blood’ away from kidney to vena cava
- Ureter - small tube where urine drains from each kidney into bladder
What are the internal structures of the kidneys and their functions?
- Cortex -outer layer
- Medulla - inner layer
- Renal pelvis - collects all waste substances and water before drains into ureter
- Calyx - fibrous white region in centre of kidney which collects urine from nephrons to pass onto ureter
What are nephrons?
- Working units of kidney that filter blood
- Regulate water, salt, PH and blood pressure levels
- Remove urea from blood
What is detoxification?
The process of breaking down and removing toxic substances in the body.
What is deamination?
When amino acids are turned into ammonia.
What is the structure of the nephron?
Glomerulus, Bowman’s capsule, proximal convoluted tubule, loop of Henle, distil convoluted tubule, collecting duct.
What is ultrafiltration and where does it happen in the nephron?
Where the blood gets filtered in the glomerulus because blood pressure is high here so substances are pushed put and form filtrate.
What is selective reabsorption and where does it happen in the nephron?
When all substances are filtered out and useful substances are reabsorbed, while toxic/unwanted substances are not in the proximal convoluted tubule.
What happens in the loop of Henle?
Reabsorption of water into blood and tissues.
What happens to toxic substances in the kidney?
Water, urea and other toxic waste is removed in urine which drains down the collecting duct into the renal pelvis of the kidney.
What is nephrotic syndrome?
It is an autoimmune condition in both the kidneys where the body’s immune system attacks the glomerulus, causing it to become damaged and blood proteins (albumin, antibodies) and blood clotting proteins escape into filtrate.
What are the consequences of nephrotic syndrome?
- Fluid builds up and swelling caused which puts a strain on heart and lungs because without albumin tissue fluid cant be reabsorbed
- Bruise easier (blood clotting proteins lost)
How is nephrotic syndrome monitored?
- Urine tests - see protein present
- Blood test
- Kidney biopsy
What are the treatments for nephrotic syndrome?
- Steroid medication (reduce inflammation)
- Diuretics - urinate more so less strain on kidneys
- Dietary changes
- Kidney transplant
- Antibiotics for infections
What are the roles of the liver?
- Makes bile for digestion
- Stores vitamins, minerals and glucose
- Deamination
- Detoxification
- Break down and recycle red blood cells – produces two poisonous chemicals (biliverdin and bilirubin) which pass out the body through bile
When does assimilation happen in the liver?
After food digested, glucose removed from blood and converted into glycogen which is stored in cells.
What is cirrhosis?
Scarring of the liver caused by continuous long-term liver damage, scar tissue replaces healthy tissue in the liver and prevents the liver working properly
What are symptoms of cirrhosis?
- Jaundice
- Itchy
- Swelling
- Fatigue
- Infection
- Bruising easily
How is cirrhosis diagnosed?
- Blood test
- Imaging tests
- Liver biopsy
- Endoscopy
What is homeostasis?
The maintenance of a constant, stable internal environment in the human body so conditions are ideal for life.
