Sem 1 ICA: Foundation Concepts

inspiratory capacity

all the air that can be inspired at rest

IC equation

VT + IRV

Functional residual capacity

air remaining in lungs after normal expiration

FRC equation

ERV + RV

vital capacity

all the air you're capable of moving

VC equation

TV + IRV + ERV

total lung capacity

all air in the lungs after maximal inspiration

TLC equation

TV + IRV + ERV + RV

Functions of the respiratory system

1) Gas exchange between atmosphere and blood

2)Homeostatic regulation of pH

3)Protection against inspired pathogens/irritating substances

4)Vocalization

5)Metabolic functions

Conducting zone function

Brings air in/out. Before it reaches gas exchange area, it's warmed, humidified & filtered

Respiratory zone function

Gas exchange

Respiratory zone

Respiratory bronchioles, alveolar ducts & alveolar sacs

Ventilation requirements

1)Hollow conducting system

2)Pump (respiratory muscles)

3) Volume change

4)Pressure difference

5)Air flow

Boyle's Law

Pressure that a gas exerts in a container is inversely proportional to the volume of the container

What is Pb at sea level

760 mmHg

Tidal volume

1)Volume of air flowing into lungs during inspiration

2)Volume of air flowing into lungs during expiration in a normal resting respiratory cycle

Minute volume (total pulmonary ventilation)

Total volume of air that enters/exits the respiratory system per minute

Dalton's Law

Total pressure exerted by a mixture of non-reactive gases = sum of the partial pressures

Pressure gradient for oxygen

60 mmHg

Pressure gradient for carbon dioxide

6 mmHg

The driving force for diffusion in gas exchange

partial pressure difference

Parenchyma cells

responsible for the organ's specialized functions

Stroma cells

Cells that have a supporting role in the organ

Where is simple squamous found

alveoli, endothelium and mesothelium

Where is simple cuboidal found

Tubules of kidney, ovary, bile duct and thyroid gland

where is non-ciliated simple columnar found

digestive tract (stomach, gallbladder, collecting ducts of kidneys)

Where is keratinized stratified squamous epithelium found?

epidermis and anal canal

Where is non-keratinized stratified squamous epithelium found?

oral cavity, pharynx, oesophagus, ectocervix, vagina, urethra, upper part of anal canal

Where is stratified cuboidal found?

Ducts of salivary glands

What is the function of stratified columnar?

secretion and protection

Where is non-ciliated pseudostratified columnar found?

In the male gonad

Where is ciliated pseudostratified columnar found?

In the trachea (mucociliary escalator)

What does the surface of distended/non-distended transitional look like?

Distended: scalloped. Non-distended: flattened

Epithelial metaplasia

Reversible conversion of one differentiated epithelial cell type to another differentiated epithelial cell type within the same tissue/organ

What are the stimuli of epithelial metaplasia?

Irritation/inflammation, environmental changes and nutritional

Barrett's oesophagus

Chronic GERD= inflammation

Distal oesophagus: Stratified squamous epithelia replaced by simple columnar with goblet cells

What are the 4 intercellular junctions found

1)gap junctions

2)hemidesmosomes

3) adhering junction (belt, desmosome)

4) tight junction

What junction is attacked in food poisoning and asthma attacks?

tight junction

What happens when viruses, bacteria, pathogens attack junctions?

Destruction of junctional complexes between epithelial cells =protective functions compromised

What is the function of serous cells?

enzymatic action

Where are simple tubular glands found?

small intestine and colon

Where are simple coiled tubular glands found?

sweat glands

Where are simple branched tubular glands found?

stomach

Where are simple acinar glands found?

penile urethra

Where are simple branched acinar glands found?

sebaceous glands of the skin

Which glands are involved with acne vulgaris?

simple branched acinar glands

Acne vulgaris

At puberty: upsurge of testosterone = excessive holocrine secretion of sebum & keratin = blockage of glandular ducts = localized inflammation

Where are compound branched tubular glands found?

Duodenum

What is the function of compound exocrine glands?

Secretion

Where are compound acinar glands found?

Pancreas, mammary glands

Where are compound tubulo-acinar glands found?

Salivary/prostate glands

Difference between FRC and RV

RV: # air that cannot be expelled from the lungs at the end of a forced expiration

Where does cell exfoliation occur?

1)Skin epidermis & skin appendages

2)Surfaces of internal cavities & passages

3)Major exocrine glands & glandular ducts

Epimysium

surrounds all the fascicles in a muscle

Perimysium

surrounds a fascicle (a bundle of muscle cells/myocytes)

Endomysium

surrounds a myocyte

Myocytes

composed of longitudinally-arranged myofibrils

Myofibril

a sub-unit of myocytes. Composed of a bundle of myofilaments

What does a triad contain?

2 terminal cisternae and 1 T tubule

How many triads per sarcomere? (# of terminal cisterns)

2

Triad function

ECC

Myofibril structure

Why are myosin heads in opposite directions?

To form cross-bridges

Relxed sarcomere

H zone and I band are relatively wide

Where is slow twitch type I found?

back

Where is fast twitch type IIA found?

major muscles of leg

Where is fast twitch type IIB found?

extra-ocular muscles, limb-digit muscles

Muscle atrophy

muscle mass decreases in size

How many diads per sarcomere? (# of terminal cisterns)

1

Transverse intercalated disc

Has desmosomes and fascia adherens

Lateral intercalated disc

Has gap junctions

What happens to cardiomyocytes in an MI?

They're replaced by scar tissue

SR in triads/diads

triad: complex,abundant

Location of T tubules in triads/diads

Triads: A-I junction

Diads: Z disk

Smooth muscle cell

Calveolae

invaginations

Dense bodies

Allows smooth muscle to generate intracellular contractile tension; analogous to z-line

Contractile protein of smooth muscle

calmodulin

Multi-unit smooth muscle

Stimulated independently, but function as a single unit

Where is multi unit smooth muscle tissue found?

iris and epididymis

Single-unit smooth muscle

Smooth muscle with gap junctions linking the cells together so they function as a unit

Where is single unit smooth muscle found?

hollow organs

Leiomyomas

Benign tumors of smooth muscle fibers.

Possible causes of leiomyomas

1) Pregnancy

2) Family history

3) Hormonal changes

primary microcephaly

AR, missense mutation of CDK6

Synapsis

Pairing of homologous chromosomes

Cell loss disorders

AIDS, MI

Cell accumulation disorders

Cancer, viral infections

Necrosis

inable to maintain homeostasis. Membrane not maintained.

Apoptosis

normal physiological condition. Cell membrane maintained.

Embryonic stem cell

totipotent

Cystic fibrosis transmembrane conductance regulator (CFTR) protein

a channel across the membrane. Helps maintain the balance of salt and water on surface.

Significance of membranes

compartmentalization, increase efficiency

Non-membranous organelles

cytoskeleton, proteasome, ribosomes, inclusions

Cytoskeleton function

stability & movement

Alzheimer's disease

Changes in neurofilaments. Produces neurofibrillary tangles & aggregations

Acidic cytokeratin (intermediate filament involved with AlZheimers)

Epithelial. Skin-blistering disorders

Basic cytokeratin (intermediate filament involved with AlZheimers)

Epithelial. Keratoderma, corneal dystrophy

Lamins (intermediate filament involved with AlZheimers)

Cardiomyopathy, muscular dystrophies, progeria

Heterochromatin staining

dark