A N A T O M Y 1 0 5

Unit 3

Nervous System

Receives info & responds to it.

Central Nervous System- brain & spinal chord

Peripheral Nervous System- nerves coming from brain & spinal chord.

Cranial Nerves- 12 pairs

Spinal Nerves- 31 pairs (named after vertibrae)

Sensory Neurons

Afferent- signal goes from sense organ to brain

Sensory Receptors

Photoreceptors- senses light

Thermoreceptors- responds to temperature

Chemoreceptors- senses pain, odors, tastes

Mechanoreceptors- Pacinian- pressure

Merkel’s Disks- touch

Meissner’s- touch

Chemoreceptors- potassium ions come from damaged cells, which causes bradykinins to be released (stimulates pain receptors)

Somatic Nervous System- controls voluntary movement

Autonomic Nervous System- controls involuntary movement, has 2 parts:

1. Sympathetic

2. Parasympathetic

Acts as a check & balance system.

Neurons- functional unit of the nervous system.

Cell body with nucleus.

Dendrites- bring info to cell body

Axon- takes message away from cell body

Myelin Sheath- makes it go faster (impulses)

Neurilemma Sheath- helps in healing

Sodium/Potassium Pump- electrical signals

Resting Neurons- outside is rich in sodium & poor in Potassium

Hydrocephalus- cerebrospinal fluid builds up in the head “water in the brain”

Spinal Chord & cauda equina- lots of nerves come off at the base of the spine; looks like a horse’s tail

Spina bifida- spinal chord doesn’t fully develop as a fetus

Human Brain

Encephalon

Average weight: 3 pounds

Hemispheres: left & right halves

Longitudal Fissure- big groove that halves the brain

Cerebrum- largest part of brain

Cerebellum- tiny brain. Small part, controls balance and muscle coordination.

Medulla Oblongata- brain stem, controls internal organs.

Corpus Callosum- thick bundle of nerves that cannectsthe two halves of the brain

Left brain- analytic thought, logic, language, science and math

Right brain- holistic thought, intuition, creativity, art & music

Thalamus- registers pain

Hypothalamus- tries to maintain homeostasis (temperature, thirst, appetite, sex drive, pituitary gland)

Amygdala- “primitive brain” raw emotions, rage, fear, pleasures, basic instincts

Hippocampus- long term memory

Brain Stem

Medulla- controls organs

Pons- controls breathing

Midbrain- reticular formation; survival & primitive emotions

Terms

EEG- electroencephalogram, registers brain waves Multiple Sclerosis- no known cause, disease of the nerves &

affects muscles, developed in 30’s & 40’s. Stroke- blood clot in the brain Migraines- terrible headaches Encephalitis- inflammation of the brain; caused by mosquito

bites, virus Ganglion- a bunch of nerves at a junction Phobias- irrational fears, some are warnings Schizophrenia- split from reality Multiple Personalities- lots of people in one Sleep- insomnia, narcolepsy, dreams IQ/Gifted- gifted characteristics: well rounded, well read

5 Senses

1. Hearing- not very dominant in humans. Damaged by 50 years old.

1) Pinna- outer ear lobe

2)Tympanium-ear drum, vibrates

3)Hammer, Anvil, Stirrup- vibrates because of #2

4)Cochlea- (blue) seachell; has many microscopic hairs, organ for hearing

5)Auditory Nerve- noise is processed

2. Taste- bitter, sour, salty, sweet

1)umami- “delicious” glutamate, MSG, artichoke, mushrooms

2)popillae- technical term for taste buds

3. Touch- Pacinian corpuscle- pressure

Merkel’s Disks- touch

Meissner Corpuscle- touch

4. Smell- olfaction, olfactory sense of smell wears out

Sight

Snellen Eye Chart Test

1. Cornea- clear outer layer

2. Aqueous humor- liquid behind cornea; gives shape

3. Pupil-hole which light goes through

4. Iris- muscle around pupil/ pigmented (makes pupil dilate)

5. Lens- focuses

6. Vitreous Liquid- filled with dark liquid to absorb light

7. Fovea- place on retina where image should fall

Sight continued

Rods- for light (photoreceptor)

Cones- for color (photoreceptor)

Cataracts- foggy lens

Glaucoma- tunnel vision

Myopia- nearsighted

Hyperopia- farsighted

Astigmatism- vision fades

Endocrine System

Works very closely with the nervous system.

Exocrine Glands- secretions exit the body; have ducts (tubes) to carry the secretion, Ex: mammary glands, sweat & oil glands, etc.

Endocrine Glands- produce hormones; have no ducts and travel through the bloodstream

Hormones

Proteins, controlled by negative feedback

Hypothalamus- main part of brain that starts everything

1. Pituitary Gland- aka Hypothesis or Master Gland

A. Stimulated by hypothalamus

B. Aka Hypothesis or Master Gland

C. Sella tercica- bony cup-like structure that protects it

D. Anterior section- Adenohypothesis (glandular)

E. Posterior section- Neurohypothesis (nervous tissue)

Pituitary Gland Only!!!!

Adenohypothesis

A. Somatotropin- growth hormone (HGH). Hyper secretion of Somatotropin results in Giantism. Hypo secretion of HGH results in Dwarfism.

B. Melanocyte Stimulating Hormone- produces melanin

C. Prolactin- produced during pregnancy to stimulate the mammary glands to produce milk.

D. Endorphins- natural pain killers

E. Thyroid Stimulating Hormone- stimulates thyroid to mature and release its hormones.

Pituitary Gland Only!!!! Continued…

F. Adrenocorticotropic Hormone (ACTH)- stimulates Adrenal Glands to mature and release hormones.

G. Follicle Stimulating Hormone (FSH)- stimulates the follicle to cause the egg to mature

H. Lutenizing Hormone (LH) (ICSH)- In females, LH causes ovulation to occur. In males, Interstitial Cell Stimulating Hormone causes cells in testicles to produce sperm. Also aids in spermatogenesis.

NeurohypophysisA. Oxytocin- causes labor & causes the milk to be releasedB. Vasopressin (ADH)- Antidiuretic Hormone causes your

body to retain water.

2. Pineal Body or Pineal Gland

1. Size of a grain of sand.

2. Produces Melatonin- regulates sleep cycles.

3. Regulates photoperiodic functions- seasonal or circadian cycle.

4. May regulate onset of puberty.

3. Thyroid Gland

1. Calcitonin- lowers calcium levels

2. Thyroxine- controls metabolism

Hyperthyroidism- too much Thyroxine is produced. Makes you hyper, irritable, usually thin.

Hypothyroidism- hyposecretion of Thyroxine. Tired, sluggish, sleep a lot, gain weight.

Cretinism- a retarded midget, tested at birth. Will start baby on Thyroxine if they don’t have any.

Goiter- when the thyroid swells. Caused by lack of iodine.

4. Parathyroid Glands

Usually 4 and they’re imbedded in the back of the thyroid.

1) Parathormone- raises calcium levels in blood.

5. Pancreas

Exocrine- produces pancreatic juices. (Digest foods) Travel through pancreatic duct.

Endocrine- produces 2 hormones that regulate blood glucose levels.

1. Insulin- reduces blood sugar levels.

2. Glucagon- increases blood sugar levels.

Diabetes

A major and growing health problem in the US.

1. Can’t produce or use glucose properly.

2. Leading cause of blindness, kidney disease, and amputations.

3. Brain cells live from glucose and low levels are bad! Can lead to seizures, coma, or death.

4. Most diabetics die from cardiovascular disease.

Type 1: mostly in kids and adolescents

Type 2: usually as an adult

Symptoms: frequent urination, always hungry, sudden weight loss, always thirsty.

6. Thymus Gland

Thymosine- helps body fight off disease.

Stimulates immune system.

Shrinks as you get older.

7. Ovaries

Estrogen- secondary sexual characteristics, important for menstrual cycle and pregnancy; produced by ovaries.

Progesterone- egg ruptures out of the follicle and causes uterine to be built up. Produced by the corpus luteum.

8. Testes

Testosterone- makes more hair on body, lower voice, and more muscles. Important during spermatogenesis.

9. Adrenal Glands (Suprarenals)

Located above the kidneys.

Adrenal cortex- outside layer.

1. Glucocorticoids- produced in times of stress; anti-inflammitory. Ex: Cortisol

2. Mineral Corticoids- regulates soduim levels (Na/K pump)

3. Sex Hormones- testosterone, some estrogens, steroids (from cholesterol)

Adrenal Medulla- middle layer

1. Produces adrenaline- fight or flight

2. Epinephrine- produced in response to stress.

Miscellaneous Hormones Produced

1. Kidneys- erythropoietin: stimulates red blood cells

-renin: keeps blood pressure in check (raises it)

2. Digestive Tract- Gastrin: causes HCL to be produced

3. Placenta- chorionic gonadotropin: helps baby growth, is detected in a pregnancy test

4. Prostaglandins- produced my cells throughout the body

Dirty Dozen Places to Pick Up Germs

1. Public Bathrooms2. Restaurants3. Your Workplace4. Airplanes5. Hotels/ Motels6. Swimming Pools7. Movie Theaters8. Day Care Centers9. Schools10. Your Home11. Your Doctor’s Office12. Hospitals

10 Most Important Drugs

1. Penicillin

2. Insulin

3. Smallpox Vaccine/ Polio Vaccine

4. Ether

5. Morphine

6. Aspirin

7. Salvarsan

8. Psychiatric Medications

9. Birth Control

10. Heart Medications

Other Important Drugs

L-dopa: Parkinson’s Disease

Steroids: Hydrocortisone and other legal ones.

Viagra

Cyclosporine: for transplant patients

HIV Drugs

I. Barriers

A. Skin- your first line of defense. Top layer is dead cells; it is a dry environment. We slough off these dead cells. Secretions from sweat and oil glands get rid of outer layer.

B. Mucus Membranes- traps germs. Lysosomes retard bacterial growth.

C. Stomach- acidic pH. HCl kills bacteria.

II. Nonspecific

Internal defenses attack a wide variety of microbes.A. Phagocytosis- most important ones doing this are

macrophages.B. Natural Killer Cells- most are white blood cells; attack

cells that have been invaded. Ex: cancerC. Inflammation- fluids rush to area, pus is also present

(white blood cells & bacterium that they kill) Damaged cells release chemicals called histamines. Histamines cause blood & fluids to race towards

wound. Would becomes swollen, red, & warm. Attracts macrophages to site & pus forms.