Biomed I: Infectious Diseases

Mucus

provides an additional layer of protection
has a thinner epithelium layer because it is in the nose, gut, and respiratory tract
if the epithelium was not thinner than normal, these could not function
works with the cilia

Intestinal Epithelium

One layer thick
similar to mucus
cells are sealed together tightly

What are 2 microbial factors?

versatility- pathogens that can be transmitted through multiple routes
infectious dose- number of organisms required to infect a host

B cells

attack invading cells on the outside of the cell
produce antibodies

Tears

have enzymes that break down bacteria
can flush out bacteria
lubricate the eye

Stomach Acid

has a pH level of 1.5 to 3.5
lowers the chance of pathogens getting into the intestines

Hypodermis

the bottom layer of the skin

What layer are fingerprints found on?

(answer to question)
fingerprints also called "friction ridges" are found in the dermis (specifically the papillary layer)

Adipose tissue

the seams of fat that make up the hypodermis
they provide cushioning and insulation

Epithelium

an external barrier that separates the inside and outside of the body
made of several thick layers
few pathogens can get in
bottom is sterile

Defensins

chemicals that keep unwanted microbes in check and support symbiotic commensal bacteria (good bacteria)

Antibodies

proteins that recognize specific invading microbes and mark them for destruction

T Cells

attack invading pathogens inside the cell
coordinate immune responses
kill infected host cells
can recognise invaders even if they are well camouflaged

Fungi

unicellular eukaryotic organisms with chitinous cell walls

Spanish Flu

A pandemic that killed 50-100 million people
was a strand of either pig or bird flu
mainly affected people from ages 20-40
most devastating pandemic ever (not including COVID)

Vector

an insect or small animal carrying a disease

Virus

noncellular particles made of genetic material protected by a protein shell and sometimes and envelope

Pathogens

the name for microbial agents that can cause disease

infectious diseases can be transmitted through...

(answer to a question)
the air, physical contact, and surfaces

Infectious disease

a clinically clear illness with symptoms resulting from the presence of microbial agents (must be transmissible)

Infectious agents

pathogens, microbes, viruses, protozoa, parasites, etc.

Bacteria

single celled prokaryotic cells

Microbes

organisms invisible to the naked eye

Disease

an impairment of overall health

Protozoa

eukaryotic microbes that aren't fungi

Strains

different mutations of a pathogen

Commensal microbiota

non-pathogenic (can't get you sick) microbes that occupy our skin, respiratory, digestive, and urogenital tracts and protect us from other pathogens by competing for space

Immune status

the system's ability to defend itself

Internal tissue damage

injuries of the muscles, tendons, and ligaments
causes you to be more exposed to microbes

pandemic

a disease that spreads across continents (worldwide)

CDC

Center for Disease Control and Prevention
protects the public by giving medical advice

Cross-protection

protection conferred on a host by vaccination with one strain of a microorganism that later protects against a slightly different strand

Dose

the number of microbes the host has been exposed to

Peristalsis

relaxation and contraction of muscles in the small intestine that propels food through the digestive system

Route of transmission

the path a microbe takes to travel from an infected host to an uninfected one

Transmission

the passing of a communicable disease from an infected host to an uninfected host

How can microbes get in the body?

(answer to question)
under the skin;
cuts
burns
wounds
transplants
needles
vectors

Columbus and his plagues

smallpox and measles were carried from Europe to the Americas by the Spanish
Columbus took Syphilis back to Europe from the Americas
Bioterrorism began (the English would throw blankets with smallpox on it on the Native Americans)

Capsule

protects the bacterium from the physical stress
helps it camouflage

Cell wall

protects the plasma membrane

Spores

helps the bacteria survive in difficult conditions or when dormant

Pili

how the bacteria stick to surfaces

Nucleoid

the area in the cytoplasm of a bacteria that the DNA is found
makes cell division more efficient

How many bacterial cells are in one eukaryotic cell?

(answer to question)
around 1,000 bacterial cells can fit in one eukaryotic cell

How many viral cells can fit in one bacterial cell?

Around 8,000 viruses can fit in one bacteria

Epidermis

the outmost layer of skin

Dermis

the middle layer of skin
where the epithelium gets its oxygen and nutrients

Epidemic

the unusual rapid spread of an infectious disease to a large number of people in a given population within a short period of time

Epithelia

what forms the protective layer of the skin and mucosal membranes

How can microbes get to the mucosal membranes?

(answer to question)
mouth
nose
ears
genitourinary tract
mother to child

envelope

protects the capsid when present
composed of lipids and proteins
contains receptor proteins needed to attach to host cells

Gram negative cell wall

have less murein (polysaccharide) and have an outer membrane
LPS is a major lipid found here
the slightest trace of LPS can be identified as foreign
makes you SUPER SUPER sick

Measles

a highly contagious disease caused by a virus that spreads through the air
about 1/3 of the people who get it develop complications such as:
pneumonia
ear infections
diarrhea
brain inflammation
miscarriage

Bubonic plague

one of the worst plagues
killed half of Europe's population
started in Central Asia, then expanded to Crimea
the people knew it was transmitted by rats but did not know it was the fleas

Antonine plague

was either a smallpox or measles variation
one of the first plagues recorded
hit Rome and slowed the expansion of the Roman Empire
was an epidemic

Complement

chemicals produced by the liver that kill bacteria in other invading cells by punching holes in their cell membranes

Phagocytes

identify invading microbes using receptors
eat microbes

Non-sterile body parts

(answer to question)
skin
mouth
stomach
intestines
upper respiratory tract

Smallpox

a viral disease with very high mortality rate of about 30-35%
the last smallpox case that occurred naturally was 1977
the only human infectious disease to be completely eradicated form the planet
samples still exist in labs in the US and Russia

Sterile body parts

(answer to question)
brain
spinal fluid
heart
liver
blood
muscles

Apocrine sweat glands

less abundant sweat glands (only 2000 of them)
found in the groin and armpits
don't start functioning until puberty

Eccrine sweat glands

more abundant sweat glands
found in palms, forehead, and soles of feet

Genome

where the gene of a virus are located
inside the capsid
can be DNA or RNA
codes for viral protein

Capsid

a protein that covers the genome
protects the genome
composed of protein
contains enzymes needed for replication

Plasmid

a circular piece of DNA found in a prokaryotic cell
are not critical to life but can produce toxins (ex: botulism)
can make bacteria resistant to antibiotics
transfer easily through sex pili

Gram positive cell wall

cell wall made of multiple layers of murein
murein helps it survive in low or high salt concentration
murein and LTA (major lipid) are recognized as foreign