Study Guide 1113/ study 2

 

Integument – skin and its derivatives

 

Epidermis – outer layer of skin, innervated, not vascularized

Dermis – lower layer, innervated and vascularized

Subcutaneous tissue – layer under the skin

Keratinocytes – produce keratin

Keratin – protective protein on outer layer of skin

Melanocytes – produce melanin

Melanin – dark pigment

 

Epidermis gets its nutrition by diffusion. This is why the outer layer is dead.  It runs out of nutrients.  The outer layer protects the inner layers

 

Why are baby’s that are healthy sometimes orange?  

 

Why do very fair skinned people sometimes look pink?

 

Cyanosis – dark blue color of skin or mucous membranes when the hemoglobin is not well oxygenated

 

Why do people stink an hour or so after they sweat? 

 

Pili – hair

Alopecia – hair loss

 

List functions of the integument

 

Basal cell carcinoma – most common type of skin cancer, high cure rate if caught early

Squamous cell carcinoma – grows rapidly, high cure rate if caught early

Malignant melanoma – most deadly type of skin cancer.  Dark in color.

 

1st degree burn – redness and swelling

2nd degree burn – blisters

3rd degree burn – full thickness.  Not painful because nerves are dead

 

Dermatitis – skin inflammation

Albinism – inherited condition, recessive gene, melanocytes do not produce pigment

Bone

 Diaphysis – shaft of long bone

 Epiphysis – end of long bone

 Epiphyseal plate – disc of hyaline cartilage where bone grows in length

Periosteum – outer covering of bone

Osteoblasts – bone building cells

Osteoclasts – cells that break down bone

Endosteum – inner lining of bone

Hematopoetic tissue in bone – red marrow, blood cells are made here

Osteogenic cells – differentiate into other bone cells

Osteocyte – mature bone cell

Osteon – structural unit of bone.   Also called Haversian system

Osteoid – organic matrix of bone

Hydroxyapatites – inorganic part of bone

Ossification – forming bone

Hyaline cartilage – tissue that bone forms from

 

Bone grows in length at the epiphyseal plate

Bone grows in width at the periosteum

 

Bone growth is stimulated by growth hormone

Excessive growth hormone – gigantism

Deficit of growth hormone – dwarfism

Epiphyseal plate closure is caused by sex hormones

 

 

Regulation of blood calcium levels

Parathyroid hormone – when calcium level is too low, PTH causes osteoclasts to resorb bone and release calcium into the blood.

Calcitonin – inhibits bone resorption when calcium levels are too high.

 

If calcium levels drop too low – neuromuscular problems, death

If calcium levels are too high – deposits of calcium in blood vessels, kidneys, other soft tissues.

 

Osteomalacia – bones are not adequately mineralized.  (adults)

Rickets – bones are not properly mineralized (children)

Causes of osteomalacia and rickets

            1.  calcium deficiency

            2.  lack of vitamin D

            3.  lack of sunshine (vitamin D)

            4.  Calcium/phosphorus imbalance in diet

 

Osteoporosis -  know what it is, who it effects, what is thought to cause it.

 

Joints

 Articular cartilage – hyaline cartilage that covers the opposing bone surfaces

Synovial fluid – fluid that fills the joint cavity

Articular capsule – joint capsule

Menisci – articular discs

Bursae – flattened fibrous sacs lined with synovial membrane and filled with synovial fluid

Bursitis – inflammation of bursa

Tendon sheath – elongated bursa around a tendon

Ligament – connects bone to bone

Tendon – connects muscle to bone

Origin – muscle’s attachment to the immovable bone

Insertion – muscle’s attachment to the movable bone

 

Flexion – decrease angle of joint

Extension – increases angle of joint

Abduction – move limb away from body

Adduction – move limb toward body

Supination – turn hand up

Pronation – turn hand down

 

Arthritis – inflammation or degeneration of joint

Osteoarthritis – “wear and tear” arthritis

Rheumatoid arthritis – arthritis due to an autoimmune reaction/ crippling

Gout – inflammation due to deposits of uric acid.  Affects big toe.   Made worse by alcohol, or eating sardines, liver, and kidneys.

Lyme disease – inflammatory disease, spread by ticks, caused by Borrelia burgdorferi,  a spirochete bacteria

 

 

Muscles

 

Prefixes that refer to muscle – myo, mys,. Sarco

 

Skeletal muscle – voluntary, striated

Cardiac muscle – involuntary, striated, has intercalated discs

Smooth muscle -  visceral, nonstriated, involuntary

 

4 muscle functions-

1. produce movement

2. maintain posture

3. stabilizing joints

4.  generating heat

 

Endomysium – sheath around individual muscle fiber

Perimysium – wraps around fascicles

Fascicle – bundle of muscle fibers

Epimysium – wraps around entire muscle

Sarcolemma – plasma membrane of muscle fiber

Myoglobin – red pigment in muscle

Sarcomere – smallest contractile unit of muscle fiber

Actin and myosin – proteins that cause actual contraction

Action potential – electrical current

Acetylcholine – neurotransmitter at neuromuscular junction

Acetylcholinesterase – enzyme that breaks down acetylcholine when it is used up

 

Steps in muscle contraction:

Nerve impulse cause release of acetylcholine

This opens Na and K channels

Depolarization

Action potential spread across sarcolemma

Action potential causes release of stored calcium from the sarcoplasmic reticulum

Calcium allows muscle contraction (actin and myocin change their binding sites to that the cell is now shorter and thicker)

Calcium is pumped into the cell's sarcoplasmic reticulum where it is stored by active transport (requires ATP)

(Without ATP, the cell stays in a state of contraction.) See rigor mortis below.

 

Questions:

1.   What neurotransmitter causes depolarization of the sarcolemma?    (acetylcholine)

2.    What chemical actually directly causes muscle contraction? (calcium)

 

Rigor mortis is caused by a net inflow of calcium to the cell due to lack of ATP to pump it out.  This causes actin and myosin to bind.

 

Motor unit -  a motor neuron and all the muscle fibers it supplies

 

When muscles work in beyond their ability to supply enough oxygen for normal cellular respiration, they must get energy from anaerobic glycolysis.   Lactic acid is the by product of this reaction.

 

What chemical makes overworked muscles sore?

 

 

Aerobic or endurance exercise – causes increase in blood supply and mitochondria for cells

 

Resistance training – causes muscle hypertrophy

 

Disuse atrophy – degeneration and loss of muscle mass due to disuse

 

Peristalsis – gut movements

Borborigmus  - gut sounds

Fibromyalgia – chronic inflammation of muscles, tendons, and joints

Myalgia – muscle pain

Myopathy – muscle disease