Chapter 2: Physical Development And Sexuality Flashcards
What are programmed ageing theories
Based on the assumption that ageing and death are built into the genetic blueprint of organisms. It proposed that the length of life is programmed genetically and aging begins after reproductive ability ends.
Explain the genetic programming theory
One explanation is that cells of the body age in accordance with a master genetic programme innate to every specific species.
The second explanation regards cell division. A cell can divide a limited number of times. this means the cells ability to divide decrease whereby cells deteriorate until individual dies.
Telomeres: small tips of chromosomes play a major role and serve as a biological clock determining life span of the cell. Contains an enzyme called telomerase which is needed to replicate the telomeres and thus the cells. They are shortened with each division and eventually become so short and contain so little telomerase that cell division can’t continue.
What are error theories
Based on the assumption that ageing reflects unplanned changes in an organism over time. It explains ageing as a result of external or environmental factors that gradually damage the internal cells and organs.
State the wear and tear Theory
Argues that bodies age because of constant use. Decades of illness injury cause damage to the cells tissues and organs. The result is that the body becomes progressively less able to repair damaged and worn out components.
Describe the free radical theory
Nucleus of an atom is surrounded by a cloud of electrons which could be described as elementary particles but the nucleus can sometimes lose an electron leave atom with unpaired electrons the atom is then called a free radical.
These radicals attack structure of cell membranes causing cellular damaged and dysfunction. It also damages the DNA influencing ability to repair and when enough cells are damaged the organism dies.
Comment on the cross linking theory
Based on observations that with age many body tissues become less flexible and less functional. Skin becomes less elastic and takes on leathery appearance. Certain proteins cross link and produce molecules in a way that they make the body stiffer. These proteins are called collagen that cause stiffness in tissue.
What physical changes occur in the brain
Weight of brain begins to decline because of the deterioration and decrease in the number of neurons.
Blood flow to the brain starts decreasing. this means a decrease in O2 and glucose consumption with results that there’s often a decrease in cerebral metabolism and functioning.
What physical changes occur in the senses
A sense is the physiological capacity of organisms that provides info for perception or interpretation of the world.
Sight: Vision begins to deteriorate with onset of middle age due to gradual thickening of the lens loss of lens elasticity and increased lens density. There is a decline is accomodation which can lead to myopia (near sightedness) or presbyopia ( farsightedness).
Dark adaptation becomes slower.
Visual dysfunction include: #Glaucoma: group of eye diseases which results in damage to the optic nerve and vision lens. Develop due to increasing pressure of the ocular fluid inside the eye that doesn't drain normally causing visual defects. #Cataracts: the loss of the transparency of the lens of the eye where it becomes cloudy causing faded colour blurry vision and trouble with bright lights and seeing at night.
What physical changes occur in the senses
Hearing: presbycusis is the progressive and irreversible age related hearing loss resulting from the degeneration of structures in the inner ear or auditory nerves.
Symptoms include
Sounds or speech becoming dull muted or weakened
Need for increased volume of audio devices
Difficulty in understanding soft speech
Difficulty in speech discrimination against background noises.
Hyperacusis: sensitivity to certain volume and frequency of sound and tinnitus which is ringing buzzing hissing or other sounds in the ear when no external sound is present.
What physical changes occur in the senses
Taste: sense of taste become less sensitive with ageing due to loss in sensitivity of taste buds. Mouth produces less saliva.
Smell: ability of smell decreases significantly
Touch: people experience decline in ability to detect and discriminate touch stimuli like pressure vibration spatial acuity pain and temperature.
Functional impairment include
Speech articulation is effected due to diminished sensitivity and sense of vibration.
Hand grip requiring fine manipulation
Postural stability
Diminished sense of pain adds risk for serious injury.
What physical changes occur with muscle strength
May result in frailty a syndrome characterized by weakness weightloss exercise intolerance immobility and incontinence.
Reduction in muscle strength causes reduction in reaction speed which increase possibly of falling and hurting oneself.
How is a person’s stamina affected
Due to reduced muscle power and functioning of organs stamina also decreases. Less oxygen is available and heart disperses it at slower rate through bloodstream to muscle.
What changes take place in physical appearance
Wrinkled and lose skin.
Thinning and greying of hair
Slacking of breasts in women
Mask of ageing is where the external appearance changes with age the essential identity doesn’t.
What changes occur in height and weight
People lose approx 0.65-1.30cm every 10 years after 40/50 due to weakening of the muscles and resulting deterioration and compression of bones in the spine.
Adult weight seems to increase as many are inactive and there is a decrease in the rate that the body converts food into energy. In later adulthood weight loss decreases as people tend to eat less and muscle tissue is replaced with fat.
What changes occur in the internal organs as one ages
Cardiovascular and respiratory system:
Heart weight increases with increasing age and atrophy of the heart tissue takes place. The aorta loses elasticity. Hardening and shrinking of arteries restrict free blood flow in the body causing the heart to work harder.
The elasticity of lungs decline causing breathing to become more difficult over time. The loss of lung elasticity in called senile emphysema.
Other internal organs:
The capacity of the bladder is reduced and the bladder muscles also weaken causing frequently urinating.
Decline in the effectiveness of the immune system.
