Cardiovascular system (see Chapter 9)

Heart increases in size.

There is an increased risk of thrombosis (clotting) and heart attack.

Fat is deposited in and around the heart muscle.

Varicose veins develop.

Heart valves thicken and stiffen.

There is a rise in blood pressure.

Resting and maximum heart rates decrease.

Pumping capacity declines.

Arteries decrease in diameter and lose elasticity.

Digestive system (see Chapter 11)

Teeth may be lost.

There is an increased risk of hiatal hernia, heartburn, peptic ulcers, constipation, hemorrhoids, and gallstones.

Peristalsis slows.

Rates of colon cancer and pancreatic cancer increase in the elderly.

Pouches form in the intestines (in a condition known as diverticulosis).

Liver requires more time to metabolize alcohol and drugs.

Endocrine system (see Chapter 8)

Glands shrink with age, decreasing hormone release.

Numerous homeostatic mechanisms are disrupted.

The metabolic rate decreases.

Lymphatic system (see Chapter 13)

Thymus gland shrinks with age.

Cancer risk increases.

Number and effectiveness of T lymphocytes decrease with age.

Infections are more common in elderly.

Autoimmune diseases (such as arthritis) increase.

Integumentary system (see Chapter 4)

Epidermal cells are replaced less frequently.

The skin loosens and wrinkles.

Adipose tissue in face and hands decreases.

Sensitivity to cold increases.

There is a loss and degeneration of fibers in dermis (collagen and elastin).

The body is less able to adjust to increased temperature.

Fewer blood vessels and sweat glands are present.

Hair grays and skin becomes paler.

Melanocytes decrease.

Hair thins.

Number of hair follicles decreases.

Muscular system (see Chapter 6)

Muscle tissue deteriorates and is replaced by connective tissue or fat.

The muscles lose strength.

Fewer mitochondria are in muscle cells.

Endurance decreases due to fewer mitochondria.

Neuromuscular junction degenerates.

There is a decrease in response and overall function.

Nervous system (see Chapter 7)

Brain cells die and are not replaced.

Learning, memory, and reasoning decrease.

Cerebral cortex of the brain shrinks.

Reflexes slow.

There is decreased production of neurotransmitters.

Alzheimer’s disease occurs in elderly people.

There is a loss of sensory input (smell, vision, hearing, and so on).

Reproductive system (see Chapter 14)

Females: Menopause occurs between 45 and 55 years of age and causes cessation of ovarian and uterine cycles, so eggs are no longer released, and hormones such as estrogen and progesterone are no longer produced.

Osteoporosis and wrinkling of skin occur, and there is an increased risk of heart attack.

Males: Possible decline in testosterone level after age 50; enlarged prostate gland; decreased sperm production.

Impotence and decreased sex drive occur.

Respiratory system (see Chapter 10)

Breathing capacity declines.

There is decreased efficiency of gas exchange.

Thickened capillaries, loss of elasticity in muscles of rib cage.

Risk of infections such as pneumonia increases.

Skeletal system (see Chapter 5)

Cartilage calcifies, becoming hard and brittle.

Bones become thinner and weaker.

Bone resorption occurs faster than creation of new bone (loss of bone matrix).

More time is required for bones to heal if they break.

Osteoporosis risk increases.

Urinary system (see Chapter 12)

Kidney size and function decrease.

Wastes build up in the blood.

There is decreased bladder capacity.

Incontinence occurs.

The prostate gland in men is enlarged.

The risk of kidney stones increases.

The urge to urinate is more frequent.

Urinary tract infections are more likely.