Ageing and nutrition Flashcards
Ageing
growing old or developing the characteristics related to old age - increased susceptibility to disease and a decline in physical vigour
When do you start to age
Mid 20s
Components making up nutritional status
Physical activity Basal metabolic rate Chronic disease Cognitive impairment Physiological changes
How do you determine BMR
How much energy you use each day
What is sarcopenia
Muscle wasting
Determinants of nutrition
Age Ethnicity grief Social status T2D Arthritis Osteoporosis Constipation
energy balance calculation
Energy in (nutrition) - energy out (metabolism, physical activity, thermogenesis)
Daily calorie recommendation for each sex
2500 men and 2000 women
What are micronutrients?
Vitamins and minerals etc
bones and micronutrients
- Vit D produced when cholesterol converted to pre-vitamin D3 by UV light, which gets activated by liver and kidney enzymes into vit D
- Vit D maintains blood concentration of calcium and phosphorus
- Prevents osteomalacia and muscle weakness
- With ageing = less sun = less vit D = weak bones
Define malnourishment
BMI <18.5
Unintentional weight loss greater than 10% over 3-6 months
factors to consider when looking at malnutrition
Diarrhoea Depression Dementia Dentition Dysfunction Dysphagia
Full bladder capacity
500ml
Which nervous system excretes urine
PS - s2-4
Which nerves stop you passing urine?
Sympathetic (T12-l2)
Supraspinal neural centre
pontine micturition centre in brainstem, a relay station for higher brain areas. Neurones are silent when bladder is empty but are activated when mechanoreceptors are stretched. They also relax external urethral sphincter whilst contracting detrusor muscle
Foetal urination
- Amniotic fluid made mostly from urine
- Urine in amniotic fluid gets more concentrated as pregnancy progresses
- Major output is baby swallowing the fluid
- Insufficient urine under-develops lungs (potentially fatal) and also can cause club foot
Lung development
- 7-17th week
- Formation of bronchial tree up to terminal bronchioles
- Broncho-pulmonary epithelium begins to make amniotic fluid
renal genesis
Indicated by lack of amnion fluid
not compatible with life
Autonomic bladder reflex in babies
- Bladder full
- Sensory nerves of PS stimulated by stretch receptors
- Spinal cord S2-4 passes to effector nerves
- Detrusor contracts and internal sphincter relaxes
Process of micturition
Bladder full
Sensory nerves of PS stimulated by stretch receptors
Spinal cord s2-4 passes to effector nerves
Detrusor contracts and internal sphincter releases
Potty training
Voluntary control begins to overrule autonomic
- Micturition centre in pons receives signals from stretch receptors
- If it is timely to urinate, pons returns signals to detrusor and internal urethral sphincter to empty. Signals from cerebrum inhibit sacral neurones that keep external sphincter closed - urine passes
- If it is untimely, signals from cerebrum keep external urethral sphincter contracted - urine remains in bladder
Function of bulbospongiosus in males
empty final bits of urine from urethra and bladder
Urinating during ejaculation
- S helps you urinate but also allow erection to proceed
- It is difficult to pass urine whilst having an erection - stops urination of urine into uterus during sex
- Pressure in corpus spongiosum compresses urethra
- Consider in priapism
Ejaculation
- Sympathetic not used in micturition but helps ejaculation
- Relaxes detrusor muscle
- Contracts internal urethral sphincter
- Pudendal nerve contracts bulbospongiosus
- Stops semen from going to bladder
Dementia control of urination
These factors impact micturition in people with dementia:
- Difficulty of cerebrum in interpreting micturition sensory info - they feel bladder is stretched but don’t relate this to going to toilet
- Loss of visuospatial abilities - can’t find a toilet
- Apraxia: difficulty of undressing and actually using toilet
- Locomotion problems - difficulty holding urine until they reach toilet seat
Muscles in defecation
- Internal anal sphincter (autonomic nervous system, S2-4 PS)
- External anal sphincter (voluntary, S2-4 pudendal nerve)
- Puborectalis - part of levator ani, pudendal nerve
- Puborectalis is like a sling and helps you tighten anal muscles - helps stop faeces
faeces vs flatulence
- Pressure receptors are on the three rectal valves hanging inwards
- Pressure receptors help you differentiate between faeces and flatulence
- Stretch and pressure = faeces
- Stretch and no pressure = flatulence
- No stretch and no pressure = empty rectum
descending pathways
- Cortical centres control voluntary control by inhibiting or exciting brainstem
- Frontal lobe decides about social context - implications in dementia
- Medial nucleus (pontine micturition centre) controls distal colon and rectum
- Lateral cell group controls external anal sphincter
- Spinal cord centre: descending neurones from LCG synapse in Onuf’s nucleus on motor neurones supplying external sphincter
- 2 pathways - intrinsic reflex connected to medial nucleus and lateral group
Spinal cord injuries
- araplegia or tetraplegia
- Lose cortical and brainstem control
- Inability to defecate when convenient
- Anorectal reflex: distended rectum, sensory and pressure to s1 defecation centre, encouraged peristalsis in sigmoid colon and rectum and relaxes internal anal sphincter
- Injury above S1 defecation centre: intact colorectal reflex but no voluntary control
- Injury below: deficient colorectal reflexes and voluntary control
Autism
impairments of language and behaviour - social emotion, social queues, developing relationships, restricted and repetitive behaviour, sx in early childhood and cause significant impact
Rett syndrome
- Language skill deficits - mute/non-verbal
- Coordination deficits
- Repetitive movements
- Slowed growth
- Microcephaly
- Complications = seizures, scoliosis and sleep disorders
- MECP2 gene mutation
Autism behavioural sx
Non-verbal communication impairment
Unaware of others and their emotions
No interest in pretend play with kids
Language sx autism
Audio-receptove impairment
Expressive impairment
Repeating
Words regulate environment
Asperger’s sx
- No language impairment - only behavioural
- less severe behavioural impairment
- Want to fit in but don’t know how
Definition of learning disability
Reduced IQ, globally impaired learning and intelligence
Dysgraphia
Disorder fo writing
Dyspraxia
Disorder of motor planning/execution
