Interactions btwn cells and the extracellular environment pt 1

Intracellular compartment

• within the cells

• 67% of water

Extracellular Compartment

• space between blood vessels and the cells

• 33% of water

  • Blood vessels (20%) and interstitial space (13%) of that 33%

• collagen

• polysaccharides

• Integrins

What is found in interstitial space?

Edema

accumulation of fluid inside cells and interstitial space

Simple Diffusion

• form of passive transport

• ions move from high to low concentration

• no ATP needed

• concentration of ion

• permeability of membrane to to that ion

• diameter of substance

• structure of substance

Factors that affect simple diffusion?

• high oil/water concentration because it can easily pass through cell membrane (lipophilic)

• Decreased radius of substance

• decreased membrane thickness

• hydrophobic solutes have high permeability

HYDROPHILIC SOLUTES CANNOT PASS

Permeability increases with what?

Facilitated Diffusion

• first substance facilitates, second substance is transported to the target cell

  • Second substance CANNOT go to target cell without first substance help

Insulin helps glucose enter into the target cell

• Mechanism: insulin binds to receptor of target cell, activates GLUT4 channels inside cytoplasm; GLUT4 binds to cell membrane and acts as a channel for glucose entrance; glucose can then enter target cell where ATP is made

What is an example of facilitated diffusion?

Hyperglycemia

• condition caused by lack of insulin

• glucose accumulates in the blood

• target cell CANNOT receive glucose to make ATP

Type I

Continued hyperglycemia can cause what form of diabetes?

Primary Active Transport

• 2 different ions that require ATP to create a pump

  • ex:

    • Na+/K+ pump found in neuromuscular junction

    • Ca2+/ATPase/Calcium pump in neuromuscular junction

    • H+/K+ (proton pump) found in stomach; H+ (acid) released from parietal cells of stomach into its lumen

Gastrititis

• main issue is from primary active transport

• too much secretion of H+ from parietal cells to lumen of stomach resulting in inflammation of stomach or getting a gastric ulcer

Omeprazole

• inhibits proton pump to prevent over secretion of H+ from parietal into lumen of stomach

What is the cure for gastritis?

Secondary Active Transport

• 1 ion transports many ions

  • ex:

    • Na+ SYMPORTS (movement in same direction) phosphate, chloride, potassium, bicarbonate (HCO3-), amino acid, and glucose

    • Na+ also ANTIPORTS (opposite directions) H+ from blood into urine

Hyperosmostic

• chamber with more concentration/higher osmolarity

• higher osmotic pressure (more solute)

Hyposmotic

• chamber with less concentration/lower osmolarity

• lower osmotic pressure (less solute)

Osmolarity

• Chamber A with more concentration of solute will absorb the fluid (water) of Chamber B which has less concentration of solute

• Chamber A is thus diluted

• overtime concentration of both chambers becomes leveled which is called isosmotic

Chamber A: Blood vessels

Chamber B: Interstitial Space

• contains albumin and remains in blood vessels due to its large size; presence of albumin increases osmotic pressure; excess albumin leads to blood vessel absorbing extra fluid from interstitial/intracellular space

• Also helps prevent formation of Edema

Example of Osmolarity

Isosmotic

When the osmolarity of both chambers becomes leveled

Edema from accumulation of fluid inside interstitial space

Deficiency of albumin in the blood vessels leads to?

Cystic Fibrosis

• genetic disorder

• mutation of CFTR which controls the secretion of chloride from epithelial cells into lumen of organs

• leads to formation of mucus in lumen of different organs

• Modification of CFTR can lead to oversecretion of chloride and sodium into lumen

• attraction of white blood cells can then be followed by formation of UNCONTROLLABLE mucus

Organs:

• spermatic chord

• small/large intestines

• pancreas

• respiratory

Symptoms:

• infertility bc of spermatic cord

• diarrhea

• inflammation of small/large intestine

• endocrine hormone disorder in the pancreas

• respiratory Issues

• death/newborn death

What are the organs that can be affected from cystic fibrosis and what are the symptoms?

Cortisol for inflammation

NO CURE

Medicines to help alleviate symptoms of cystic fibrosis?

• vas deferens

• cremaster muscle (for ejaculation)

• sympathetic/parasympathetic nerve branches

• testicular artery

• pampiniform veins

Contents of spermatic cord?

• Infertility due to mucus formation in the lumen

• ovary would have infertility also

Obstruction of spermatic cord could result in?

• severe diarrhea

• dehydration

• protein deficiency

• vitamin deficiency

mucus formation in small/large intestines results in:

Blood Osmolarity

1. severe dehydration

2. blood concentration increases (increased blood osmolality)

3. increased osmotic pressure

4. stimulation of osmoreceptors (located in the walls of large BVs)

5. osmoreceptors in hypothalamus stimulate a tract of axons that terminate in the posterior pituitary

6. Posterior pituitary releases ADH into blood via the 2 nuclei in hypothalamus

7. Person drinks water

8. ADH acts on kidneys for water retention resulting in lowered urine volume

• Vagus nerve (X ten)

• Glossopharyngeal nerve (IX nine)

What nerves take info about blood osmolality to the hypothalamus?

• paraventricular

• supraoptic

What are the 2 osmoreceptors in the hypothalamus involved with blood osmolality?

280-303 milli-osmoles per kg

What is normal blood osmolality?

• pregnancy

• hypertension

• CV disorder

• renal disorder

• congenital issue of lymphatic system (responsible for reaccumulation of extra fluid and releases it into veinous system)

• viral,bacterial, fungi, and auto-immune diseases of lymphatic system (SEVERE EDEMA)

• destruction of capillaries

Causes of edema?