Immunology Chapter 1 Flashcards
flora
community of microbes inhabiting a niche in the body
why do microbes infect humans?
to survive and replicate
commensal
aid in digestion
provide vitamins
prevent antibiotic resistance
pathogenic
opportunistic or not
4 kinds (bacteria, fungi, viruses and internal parasites)
constant interactions with hosts
endemic diseases
gradually changing, often not deadly
high mortality is only caused by
a new pathogen
antibiotic resistance
antibiotics kill commensal bacteria and allow pathogenic bacteria to gain a foothold
first line of defense
epithelial tissues
external: skin
internal: epithelia
epithelia
continuous with skin
very vulnerable tissues, covered by mucus
purpose of skin and mucosa
mechanical, chemical and microbiological barriers
protect internal tissues and organs
epithelial defenses
sebum in sebaceous glands
lysozyme acid in stomach
microbial flora
2 advantages of microorganisms
rapid reproduction
change characteristics much quicker and hosts
immune system
host cells dedicated to defense against microorganisms
distinguish between self and nonself
can mount an adaptive response
leukocytes
white blood cells
hematopoiesis
process of making hematopoietic cells (WBC and others)
progenitor cell of hematopoietic cells
pluripotent hematopoietic stem cell
pluripotent hematopoietic stem cell
capable of self renewal or maturation
located in yolk sac, fetal liver, spleen and bone marrow
hematopoiesis occurs all
through life because blood cells are short lived
3 hematopoietic lineages
lymphoid
myeloid
erythroid
erythroid cells
helps with clotting
erythrocytes and megakaryocytes
erythrocytes
RBC
carry oxygen
megakaryocytes
platelets
cells with giant nucleus
Myeloid
“of the bone marrow”
granulocytes, monocytes, macrophages, dendritic cells and mast cells
granulocytes
prominent granules, kill microorganisms in inflamed tissues
2-5 lobes in nuclei (polymorphonuclear leukocytes)