Hist Exam 2

which cells are a part of both innate and adaptive immunity?

dendritic cells

what type of immunity protects against extracellular pathogens? intracellular/cancers?

humoral, cell-mediated

humoral immunity refers to what cells?

B cells

Cell mediated immunity refers to what cells?

T cells

Life of a B cell

originate and mature in bone marrow. only recognize one antigen which can activate it

activation causes it to differentiate into plasma cells or memory B cells

plasma cells vs memory B cells

Plasma cells make lots of antibodies

Memory B cells remain long term and respond rapidly upon future exposure

functions of adaptive humoral immunity

bacteria, toxins, viruses before entering cells

specific, memory, and long lasting protection (vaccines)

most B cells need help from…

Helper T cells (cytokines stimulate prolif and differentiation)

antibody functions

neutralize microbes, phagocytosis, complement activation, agglutinating pathogens together

Cell mediated immunity is good for what pathogens?

intracellular pathogens, viruses, fungi, protozoa, tumor/transplants, some bacteria

what are the primary organs of the lymphatic system? What cells live there?

thymus (T cells mature here), marrow (B and pre-T born here, B cells mature here)

what does MALT stand for?

mucosa-associated lymphoid tissue

lymphatic ducts drain into…

subclavian veins

lymph node immune function

dendritic cells migrate here via afferent lymphatic vessels, presents antigens to T lymphocytes

spleen fx

encapsulated bacteria like pneumococcus, meningococcus, hemophilus influenzae

which cells see the antigens in native form?

B cells (T cells see it after process by antigen presenting cell like dendritic cell)

small intestine lymphatics key points

lacteals in villi (collects pathogens as well as nutrients)

Peyer’s patch

M cells (holds dendritic cell)

what layer are the nodules in the MALT?

lamina propria

parts of a secondary nodule

germinal center and mantle

what forms the stroma (framework) of the lymph nodule?

reticular connective tissue and reticular cells

what type of collagen is reticular fibers?

III

what is inside the pocket of a M cell?

dendritic cell

lymphocyte

macrophages

Palatine tonsil key points

lots of secondary nodules

tonsillar crypts (can be stratifies squamous or respiratory epithelium)

partial capsule of dense connective tissue

HEV stands for…

high endothelial venules

HEVs are not found where?

spleen or primary lymphoid organs

layers of a HEV

tall/cuboidal endothelial cell, thick basal lamina, reticular fibroblast

lymph node key points

thin capsule of dense irregular connective tissue

afferent and efferent lymphatic vessels

medullary sinuses (also subscapular and trabecular)

T and B cells in the lymph node

T cells in the paracortex

B cells in the cortex

Where do most lymphocytes enter lymph node from?

HEVs (90%)

spleen key points

thick capsule

white pulp

PALS surrounds central arteriole

red pulp/splenic sinuses/splenic cords

PALS stands for what? contains what cells?

periarteriolar lymphatic sheath, T cells

what’s in the splenic cords and how does it affect the spleen function?

macrophages, dendritic cells, and lymphocytes

helps monitor blood during open splenic circulation

Immature T cells are called…

thymocytes

what is the first line of self-tolerance for autoreactive T cells?

negative selection- apoptosis of autoreactive cells (too strong) with self-MHC

positive selection- moderately binding to self-MHC is okay

CD4 vs CD8 cells

CD4- helper- T cells that recognize MHC class II and help activate other immune cells via cytokines

CD8- cytotoxic- T cells that recognize MHC class I and kill bad cells via cell lysis or apoptosis

thymus key points

thin connective tissue capsule

lobules from long trabeculae

dark cortex (immature) and a bit lighter medulla (mature)

light lacy thymic epithelium that becomes Hassal bodies/corpuscle

thymic epithelium forms a…

reticular epithelial network specialized to support thymocytes

function of the elastic arteries?

conduct blood, maintain pressure during diastole

functions of muscular arteries

distribute blood regulate flow to whole organs in response to activity, etc

functions of arterioles

peripheral resistance in an organ vascular bed

regulate blood pressure protecting capillaries and organs from high pressure

function of capillaries

exchange nutrients and waste

function of venules

collect blood from capillaries

functions of veins

transmit blood to large veins, reservoirs

function of large veins

receive lymph and return blood to heart, blood reservoir

layers of blood vessels

tunica intima

tunica media

tunica adventitia

tunica intima includes…

endothelium

basement membrane

some connective tissue

internal elastic lamina (arteries)

tunica media includes…

smooth muscle cells w circumferential elastic laminae

external elastic lamina (arteries)

tunica adventitia includes…

loose fibrillar connective tissue

fibroblasts/fibrocytes, macrophasges, major connective tissue cell types

vasa vasorum, nerves, lymph vessels (large vessels)

names of the elastic arteries

aorta, brachiocephalic, common carotid, subclavian, common iliac

elastic arteries key points

tunica intima is thick and not disinguished

tunica media is thickest layer and has a lot of elastic laminae (40-70)

tunica adventitia are <half the thickness and has vasa vasorum and nervi vascularis, fibroblasts and macrophages

muscular arteries key points

intima gets real thin, leaving only the internal elastic lamina which stains dark and is folded

media- smooth muscle with little bits of elastic fibers

adventitia can be very thin to very thick, lacks vasa vasorum

atherosclerosis progression

cholesterol-rich lipids accumulate in tunica intima, causing inflammation

monocytes enter and differentiate into scavenging macrophages

inflammation causes smooth muscle cells to enter intima and proliferate

macrophage fills up with lipids and becomes foam cells

plaque can break off and cause thrombosis causing heart attach or stroke

small arteries key points

intima- internal elastic lamina

arteriole key points

intima- usually no internal elastic lamina

media- 1-2 layers of smooth muscle

vasodilation factors? constriction?

ACh and NO

Ang II, norep, endothelin

Alzheimer’s is relate to

cerebral blood flow

capillary key points

endothelial cells very flat, can form tight and gap junctions

pericytes contracts vessel

basement membrane surrounds outside

what do pericytes react to?

metabolic and autonomic system cues

types of capillaries and functions

continuous- gases pass freely, regulates fluids and proteins

fenestrated- fluids and proteins relativey free

sinusoidal- blood cells can pass through

locations of continuous, fenestrated and sinusoidal capillaries

continuous- nervous tissue, muscle, connective tissue, exocrine glands, lungs

fenestrated- endocrine glands, intestine, pancreas, glomeruli

sinusoidal- liver, spleen, bone marrow, lymph nodes, adrenal cortex

blood-brain barrier key points

continuous, pinocytotic vesicles

tight junctions

pericytes

astrocyte endfeet surrounds smooth muscle layer (glial)

selective nutrient transport

venule key points

bigger lumen than corresponding arteriole

intima- endothelial cells only, no internal elastic lamina

media- 1-2 muscle cell layers

adventitia- thickest layer

venule role in inflammatory response? arteriole?

damage causes mast cells to release histamine

venule cells get sticky for and contract

WBCs migrate out (diapedesis) and fluid leadks out (edema)

arteriole reaction to histamine causes warmth and redness

how to treat pathological diapedesis

glycocorticoids to stiffen endothelial junctions

layers of the heart

endocardium- simple squamous and connective tissue

subendocardial (connective tissue that includes nerves and Purkinje fibers)

myocardium,

epicardium (includes mesothelium, and vessels, nerves, fat)

purkinje fibers key points

faster inherent rhythm of depolarization compared to regular myocardium

fewer myofibrils (stains lighter)

membrane depolarization of the heart

sinoatrial node on atrium

AV node closer to ventricle

Purkinje fibers in ventricle wall

cardiomyocytes to cardiomyocytes via gap junctions

types of epithelium for each part of airway

bronchus to bronchiole- pseudostratified ciliated columnar

terminal to respiratory bronchiole- cuboidal

alveolus- squamous epithelium

where do the goblet cells and glands stop showing up in lower respiratory tract? ciliated cells?

not in terminal bronchiole and smaller

ciliated cells- phased out in respiratory bronchioles

hyaline cartilage stop showing up where?

not in bronchioles and smaller

where do smooth muscles stop showing up?

alveolar duct

asthma is a dysfx of what?

smooth muscle contraction too reactive in bronchi and larger bronchioles

cell types of the conducting division’s respiratory epithelium

pseudostratified ciliated columnar epithelium

goblet cells

basal cells- progenitor cells of epithelium

neuroendocrine cells- look like basal cells, secrete polypeptide hormones, effectors of secretory processes

brush cells- chemosensory cells with tufts of microvilli

what cells give rise to small cell carcinoma of lung?

neuroendocrine cells

brush cells function

senses bitter/acrid compounds

release ACh basally to activate sensory nerve endings

slows respiratory rate (CNS reflex pathway)

increases mucus production by nearby goblet cells (paracrine hormone release)

what is the muscle connecting the C shaped ring od cartilage in trachea?

trachealis

what is the name of mucosa of respiratory epithelium?

lamina propria

layers of trachea

mucosa (lamina propria)

submucosa

hyaline cartilage

adventitia

what layer are sero-mucosal glands in the the trachea?

submucosa

special cell in terminal bronchioles? function?

club cells

progenitor cell for other club cells and ciliated cells (prolif with toxic injury)

secrete secretoglobins that protect bronchioles

detoxify/metabolize harmful substances

bronchiole diseases

viruses like measles and adenovirus

bronchiolitis over time

alveolar cell types

type I pneumocytes

type II pneumocytes (makes surfactant)

alveolar macrophages

what is the pore between the alveoli called

pore of Kohn

types of respiratory system disfx

obstructive (COPD)- can’t expel

restrictive- can’t stretch out

vascular- edema/embolism/pHTN)

infectious/other- destruction of airway

examples of obstructive diseases

emphysema, asthma, bronchitis

examples of restrictive disease

pulmonary fibrosis, sarcoidosis, alveolar damage

chronic bronchitis vs emphysema

bronchitis is squamous metaplasia in conducting division (esp bronchioles)

emphysema is in the respiratory division (elastase too active, loss of alveolar vascularity and septa)

inhaling particulates and cystic fibrosis leads to chronic bronchitis and…

bronchiectasis (thickened mucus and dilations and herniations of scarred bronchi)

types of bones

long, short, flat, irregular

bone composition

hydroxyapatite (calcium phosphate)

organic matrix (90% type I coll, 10% GAGs and other proteins)

water

examples of bone composition pathologies

osteogenesis imperfecta- (brittle bone disease) no type I coll

osteomalacia/rickets- (no hydroxyapatite)

long bone basic parts

epiphysis, metaphysis, diaphysis

inside and outside stuff of the bone

cortical/compact

cancellous/trabecular

osteon is the collection of _____ around a _____ in a _____

haversian lamellae, blood vessel, Haversian canal

a canal going perpendicular to a Haversian canal is…

Volkmann’s Canal

Periosteum is made up of…

outer fibrous layer and inner osteogenic layer

osteogenic layer also called…

Sharpey’s Fibers

bone cells originate from…

hematopoietic stem cell (osteoclast)

mesenchymal stem cell (osteoblast, cartillage)

4 main bone cells

osteoblasts, osteoclasts, osteocytes, bone lining cells

osteoclast function

solubilize bone (hydrogen ions for mineral, proteases for organic)