L05 Control and Regulatory system Flashcards
Two main parts of the nervous system
Central nervous system
Peripheral nervous system
What is the PNS
branches of nerves from the CNS
What parts of the body are part of the CNS
Brain & spinal cord
Functions of the nervous system
Collect, process and respond to info
To coordinate the working of different organs
What are the 2 parts of the PNS?
autonomic and somatic
What are the 2 Parts of the ANS
Sympathetic & Parasympathetic
Role of the PNS
Transmits electrical impulses via neurones to and from the CNS
Role of the ANS
They govern viral functions in the body such as digestion (unconscious control)
Sympathetic & parasympathetic nervous system work antagonistically
Examples of what the sympathetic nervous system controls
fight or flight
Pupil dilation
Increased HR
Relax airways
Inhibit intestines
Examples of what the parasympathetic nervous system controls
Rest and digest
Constriction of pupils
Decrease HR
Constriction of airway
Stimulate intestines
Explain fight or flight
Anxiety and fear are important for survival to protect the body from stress & danger.
It happens due to epinephrine
After the threat has gone the parasympathetic NS brings conditions back to normal
Dendrites
Receive the nerve impulses from adjacent neurones
Axon
Where electrical impulses/ action potentials pass along, away from the cell body
Myelin Sheath
Insulation & Protection to the axon from external influences
Speed up electrical impulses - saltatory conduction
Function of motor neurones
Carries electrical impulses from the CNS to the effectors
Function of relay neurones
Transfer messages from sensory neurones to other relay or motor neurones
Function of sensory neurones
Carries electrical impulses from the PNS to the brain & spinal cord
Features of a reflex arc
Reacting unconsciously and quickly
Helps our survival
Is involuntary
Innate
Brain is bypassed
Why are only motor and sensory neurones utilised in reflex arcs
They are monosynaptic so it’s quicker
Autonomic reflex arc
Affects inner organs
Somatic reflex arc
Affects muscles
Explain the 5 steps that occur at a synpase
- Nerve impulses arrive at the axon terminal of the presynaptic neurone
- NT is released in the synapse from vesicles
- NT diffuses across the synapse
- MT binds to receptors on the post synaptic neurone
- Stimulation of the impulse in the post synaptic neurone
Cerebral Cortex
Involved in: memory, attention, perception, awareness, language
Has 2 hemispheres and 4 lobes
Has gyri and sulci which increase the surface area of grey matter (tightly packed neurones)
Frontal lobe
Carry out higher level mental processes like thinking, decision-making & planning
Parietal lobe
Controls the memory of objects and their uses.
Contains the sensory area which receives electrical impulses from sensory neurones
Occipital lobe
Nerve impulses from the eyes are received and turned into images
Temporal lobe
Controls hearing, speech and memory
Cerebellum
Controls and coordinates motor control and motor skills such as balance, walking and writing
Regulates the muscle activity ^
Corpus Callosum
Bridge of dense nerve tissues that connects the hemispheres enabling communication between them
Hypothalamus
Maintenance of body temp
Regulates appetite and thirst
Pituitary gland
Releases many types of hormone into the bloodstream
Medulla oblongata
Automatically carries out and regulates life sustaining functions such as breathing, swallowing & HR
Meninges
Three layers of protection surrounding the brain and the spinal cord. Defence against pathogens
Name the order of structures in the brain stem (top to bottom)
Pons
Medulla oblongata
Spinal cord
How are hormones transmitted?
In the blood
What does the endocrine system consist of?
Glands that produce hormones
What are hormones?
Chemical messengers that are released by glands and travel in the blood. They have target organs which have receptors on their membranes.
Endocrine glands
Hormones released straight into the blood
Do not have ducts
Exocrine glands
Hormones not released straight into blood because they have ducts
Peptide hormones
Not lipid soluble
Cannot diffuse into cells
Received by receptors (second messenger model)
Steroid hormones
Lipid soluble
Can pass through cell membranes
Act upon the DNA in the nucleus
Adrenal gland (hormone produced & action of hormones)
Adrenaline
Prepares body for action: high HR & BR
Pancreas (hormones produced and their function)
Insulin - promotes the uptake of glucose by cells so lowers blood glucose concentrations
Glucagon - raises blood glucose by converting stores of glycogen back into glucose
Thyroid (hormone produced and its function)
Thyroxine
Regulates cell metabolism
Pituitary gland (hormones produced and their roles)
ADH - triggers the uptake of water from urine in the kidney
LH & FSH - both involved in controlling the menstrual cycle
What type of hormone does the adrenal medulla produce? (& example)
Peptide
Adrenaline - fight or flight
What type of hormone does the adrenal cortex produce? (Examples)
Steroid
Mineralocorticoids (aldosterone) control the concentration of sodium and potassium in the blood
Glucocorticoids (cortisol) help to control the metabolism of carbs and proteins in the liver
In terms of adrenaline explain the second messenger model.
- Adrenaline receptor has a shape complementary to adrenaline
- Binding of adrenaline activates the enzyme adenyl cyclase
- Adenyl cycles converts ATP to cAMP, which can activate other enzymes in the cell.
What type of hormone is adrenaline?
Peptide
First v Second messengers
First messenger hormones transmit signals around the body and second messengers transmit signals inside cells
Calyx
Collects urine from collecting ducts & channels it into the renal pelvis
Nephron
Removes waste products like urea and absorbs nutrients like sodium and potassium when needed
Renal artery
Supplies blood (containing waste products) to the kidney from the aorta to be filtered and purified
Renal vein
Carries blood from the kidney to vena cava
Ureters
Carry urine from kidneys to bladder
Bladder
Storeys and releases urine
Urethra
Where urine exits the body
Where does ultrafiltration take place?
Golmerulus
Where does selective reabsorption happen?
Proximal convoluted tubules
Explain ultrafiltration
Blood is filtered at high pressures in the glomerulus
The glomerulus has pores so some molecules leave - such as urea - and enter the Bowman’s capsule
Blood cells and proteins should not leave as they are too big
Function of the loop of Henle and how this happens.
Osmoregulation - in the medulla
Loop of Henle is surrounded by salts to remove water from the nephron
Allows us to produce urine that is hypertonic to help blood
What does hypertonic mean
More concentrated
How does ADH effect the DCT
Causes it to become less permeable
Function of the kidney (removal of urea)
- We have more amino acids than needed so the liver deanimates them
- this forms ammonia which is converted to urea
- urea enters the blood ad travels to the kidneys
- Afferent arteriolar is wider than the efferent creating high pressure
- Blood enters the glomerulus
- ultrafiltration occurs
- Selective reabsorption in PCT
Roles of the liver: Deamination
Removal of surplus amino acids
Amino acids are converted to ammonia (toxic)
Ammonia is converted to urea
Urea taken to kidneys
Remaining amino acids are used in cellular respiration
Role of the liver: detoxification
Removes toxins like alcohol
If this does not happen then liver failure occurs
Function of the liver: production of bile
Bile allows the liver to remove poisonous by products
Liver cells break down and recycle RBCs
As the haemoglobin from RBC is recycled two poisonous chemicals are made (biliverdin and bilirubin)
Why are obstructions in the liver so dangerous?
They prevent toxic chemicals from being excreted by the bile so they travel in the blood instead causing jaundice
Symptoms of stroke
FACE: drooped on one side
ARMS: not being able to life both arms and keep them still
SPEECH: slurred
Dizziness, confusion, balance issues, difficulty swallowing, severe headache
Causes of stroke
High BP
Smoking
High fat diet
High sugar diet
Alcohol
Obesity
Being older than 65
Medication for strokes and what each one does
Aspirin: reduces chances of clots
Warfarin: blood thinner
Beta blockers: reduce BP
Statins: reduce cholesterol
What type of surgery removes blood clots following a stroke?
Thrombectomy
Supportive treatments for strokes
Feeding tubes
Mobility aids
Physiotherapy
Biological explanation for ischaemic strokes
Blood clot blocks the flow of blood and oxygen to the brain. Forms where arteries are narrowed over time by plaque
Biological explanation for haemorrhagic strokes
When a blood vessel in the skull bursts and bleeds into and around the brain
Biological explanation for MS
AUTOIMMUNE
Immune system attacks the myelin sheath and causes inflammation - this distrust messaged travelling along nerves
Scarring is left on the myelin sheath
Symptoms of MS
Fatigue
Difficulty walking
Numbness and tingling
Muscle stiffness
Balance issues
Difficulty controlling the bladder
Blurred vision
Monitoring & Treatment of MS
Steroids
Physiotherapy
Speech and language therapy
Impacts of MS
Pain meaning activities can’t happen
Loss of independence
Causes of MS
Genetics
Smoking
Viral infections
Low vitamin D
Biological explanation for type 1 diabetes
AUTOIMMUNE
Immune system attacks and destroys cells that produce insulin so glucose concentrations cannot return to normal
Biological explanation for type 2 diabetes
Body doesn’t produce enough insulin to control glucose levels so glucose stays in the blood resulting in organ damage
Symptoms and effects of diabetes
Increased thirst
Tiredness
Increased urination
Unexplained weight loss
Slow healing wounds
Impacts on lifestyle with diabetes
Regular check ups
Dietary changes
Feeling tired
Monitoring and treatment of diabetes
Checking blood glucose levels with blood tests
Diabetic eye screening
Healthy diet and regular exercise
Biological explanation of nephrotic syndrome
Kidneys do not work properly and large amounts of protein enter the urine.
Loss of protein is due to an increase in permeability of the glomerulus
Water is drawn into soft tissues causing oedema
Symptoms & Effects
- Swelling of body tissues
- High levels of urine passed
- A greater chance of of catching infection due to reduced protein antibodies
- Blood clots
Nephrotic syndrome: impact on lifestyle
Side effects of medication
Regular check up
Waiting for transplants
Recovering from surgery
Stress about treatment
Causes of nephrotic syndrome
Infections such as HIV or hepatitis
Certain types of cancer
Genes
What is dialysis?
The removal of waste products and toxic substances from blood with a specialised machine
Monitoring an treating nephrotic syndrome
Steroids
Blood tests
Biopsies
Reduce salt intake
Vaccines
Urine monitoring with dipstick
Removal of kidneys
Dialysis
Biological explanation for alcohol related liver cirrhosis
Scarring of liver caused by long term damage. Scar tissue replaces healthy tissue and prevents the liver from working properly
Biological explanation for haemochromatosis liver cirrhosis
Faulty gene which allows excess absorption of iron. Iron is deposited in liver, pancreas, joints and heart
Biological plantation for nonalcoholic fatty liver disease (liver cirrhosis)
Buildup of fat causing inflammation. Scar tissue forms around the liver and near by blood vessels
Symptoms of liver cirrhosis
Nausea
Weight loss
Vomiting blood
Loss of appetite
Jaundice
Itchy skin
Confusion
Impact on lifestyle: liver cirrhosis
Withdrawal symptoms
Recovering from surgery
Healthy eating
Causes of liver cirrhosis
Alcohol misuse
Long term infection of hepatitis C
Obesity
How are symptoms managed for liver cirrhosis
Stop drinking alcohol
Maintain a healthy weight
Transplants
Describe how negative feedback / homeostasis controls temperature
Hypothalamus detects the change in temp
If too hot
Sweating - the sweat evaporating cools the blood
Vasodilation
If too cold
Shivering
Vasoconstriction
Hairs rise to trap heat
Describe how negative feedback / homeostasis controls water levels
Nephron - loop of Henle
Pituitary gland releases ADH when water concentration is too low to make the loop of Henle more permeable
When water content is too high, ADH is reduced to make the loop of Henle less permeable
Describe how negative feedback / homeostasis controls blood glucose
Monitored by islets of Lamgerhans in pancreas
High glucose = insulin released = glycogen in liver + muscle
Low glucose = glucagon released = glycogen converted back to glucose
