Thurs BIOL 319 Lec 4

Opiates

Narcotics, Hyperpolarize. Addictive because they play into reward pathways.

Hyperpolarize

Negative inside cell, may not be able to reach threshold here.

If dosage is not appropriate…

Medulla oblongata might be hyperpolarized.

Medulla Oblongata regulates…

RR, HR, BR

How can we prevent this?

By using an Antagonist drug that has a greater affinity for opioid receptors ( than opioid ).

Antagonist drug

Can dislodge the opiate & not cause any cellular action. Ex. Naxalone, Narcan.

Hypothalamus has…

Temperature regulation & satiety centers

Tissue

group of cells and/or fluids designed for a specific function.

What are the three types of fluids

Lymph, blood, interstitial fluid (inside the lymph)

The 4 types of tissue

Epithelial, Connective, Muscle, Nervous

Which ones don't do RMP only?

Muscle and Nervous, they also do A.P.

Which ones don’t do A.P. too?

Epithelial and Connective. They ONLY do RMP.

Biopsy

Removal of tissues for diagnostic purposes.

Pathologist

Examines biopsy to diagnose if Benign or Malignant.

Benign

Noncancerous

Malignant

Cancerous

How can a biopsy be obtained?

Colonoscopy

Autopsy

Examination of organs of a dead body to determine cause of death

How many embryonic germ layers do human embryos develop?

3, because we are triploblastic.

Embryonic germ layers

Forms early & gives rise to all tissues in body

Endoderm

Inner layer. Forms lining of digestive GI tract & derivatives.

Mesoderm

Middle layer. Forms tissues such as muscle, bone, blood vessels.

Ectoderm

Outer layer. Forms skin and neuroectoderm

Neuroectoderm

Forms nervous system & Neural crest

Neural crest

gives rise to peripheral nerves, skin pigment cells, medulla of adrenal glands, and face tissues.

Any cell or tissue layer must be within ____ cell lengths away

6-8 cell lengths

Why?

To be able to receive oxygen. More than 6-8 cell lengths away will eventually die

Endothelial cells

simple squamous endothelial cells that lie inside of blood & lymphatic vessel.

Capillaries are

only 1 endothelial cell thick → allows easy exchange of gases, nutrients, wastes & fluids.

Some cells (ex WBCs) can…

squeeze through capillary walls via amoeboid movement.

Epithelial Tissue

Thin & continuous layer of compactly packed cells with intracellular matrix.

[CHARACTERISTICS] Epithelial Tissue

Very little extracellular matrix. Covers body surface & forms glands. Distinct tissue surfaces. Cells connect to surrounding cells and extracellular matrix. Avascular. High regeneration capacity.

Distinct tissue surfaces

Free/apical, basal, and lateral surfaces & Basement membrane

Basement membrane

Has two layers, Basal lamina (Lamina lucida & Lamina densa) & Reticular lamia.

Basement membrane function

Supports & guides cell migration during tissue repair. Porous to allow movement with epithelial cells.

Basement membrane is made of…

Collagen, Glycoproteins, Proleoglans

Collagen

MOst abundant, made of fibrosis.

Collagen ISSUES

Osteogenesis Imperfecta (Bone creation, genetic), Marfan Syndrome, Rheumatoid Arthritis ( AUtoimmune disorder)

[FUNCTIONS] Epithelial Tissue

Protects underlying structures. Barrier. Permit passage of substances. Secreting & Absorbing substances. Carcinomas.

Goblet cells

Often responsible for secreting mucus.

Mucous glands =

DEFENSE

MCE

Mucociliary Escalator, Smokers cough

Carcinomas

Cancers of epithelial tissue.

[CLASSIFICATION] Epithelial Tissue

Based on Number of cell layers & Cell shape

Number of cell layers can be…

Simple, Stratified, Pseudo stratified columnar (looks stratified but is simple), Transitional

Transitional ex

Bladder

Urination=

Micturition

Cell shape

Squamous, Cuboidal, Columnar

Simple squamous epithelium FUNCTION

Diffusion, filtration, some secretion and protection against friction.

Simple squamous epithelium LOCATION

Serous membranes (Pleural, pericardial, peritoneal)

Simple cuboidal epithelium

Simple columnar epithelium FUNCTION

Movement of particles out of bronchioles of lungs by ciliated cells. Movement of oocytes through uterine tubes by ciliated cells. Secretion by cells of glands, stomach, intestine. Absorption by cells of intestines.

Actin

Microfilament; found in muscle and non-muscle cells

Cilia & Flagella

Made of microtubules

Metastasis

Spread of cancer cells from their original location to other tissues. Made of microtubules.

Diapedesis

Movement of cells out of vascular endothelium.

Vascular Endothelium

Simple squamous epithelium lining the inside of blood vessels

Pseudostratified columnar epithelium STRUCTURE

Goblet cells == Secrete mucus onto free surface

Stratified epithelium is lots of…

friction or mechanical agitation

Stratified squamous epithelium STRUCTURE

Keratinized keritinized KERITINIZED at outer layer of skin

Stratified cuboidal epithelium

Secretion vs EXCRETION (4). At sudor sweaatt.

Paradigm shift

New tech → new info → new analysis ⇒ NOT afraid to change our mind

Stratified columnar epithelium LOCATION

located in mammary gland ducts, larynx, and part of male urethra.

Ureter

Kidney → bladder; kidney stones can lodge here and cause pain.

Urethra

Bladder → outside; shorter in females → UTIs more prevalent.

Lithotripsy

Breaks kidney stones into smaller pieces to help them pass.

Female Urethra

Shorter than male urethra → UTIs more prevalent in females.

Transitional epithelium

Ureter and Urethra

Simple epithelium - Choroid plexus / CSF

Part of kidney tubules, glands and ducts

Stratified epithelium - Part of male urethra

Epididymides, ducts, deferens, mammary gland ducts

What are two of many free surfaces of epithelium

Smooth and Cilia

Smooth

Reduce friction. Called endothelium. Interstitium

Interstitium

space between cells

Cilia (microtubules)

move mucus across the surface of a cell.

Ex of cilia, Muscular escalator

Located in resp. Tree, trachea and bronchi. If GONE you will coughhhhh

Cell connections

Keep cells connected. At lateral & basal surfaces of cells.

C.A.M.s. (Cell adhesion molecules

how cells stay stuck together. Ex. Desmosomes & hemidesmosomes

Desmosomes

Spot welds cells to other cells

Hemidesmosomes

Spot welds cell to basement membrane

Gap junctions

Protein channels allow cells sharing ions & cytoplasm → intracellular communication & helps smooth and cardiac muscle (intercalated disc)

Gap junctions are…

Stage 1 of A.P., ⇒ therefore spontaneous depolarization occurs

Tight junctions

Cells held together for permeability barrier (no space between cells)

Tight junctions can be with…

GI tract - exocrine & endocrine

Exocrine

AWAY from blood. GI tract & skin

GI tract… is it really exocrine..?

Even if it is within an organism, it is technically exocrine because it is continuous with external environment

Endocrine

INTO blood. Blood, hormones.

Unicellular glands

Single cell

Goblet cells

secretes mucus as defense

Cystic fibrosis

Autosomal recessive disorder where a particular Cl-/H2O channel is defective ⇒ therefore mucus is built up

Where is the mucous built up?

Lungs, pancreas, sinus, bile ducts

What does this lead to?

Morbidity, a medical condition/disease

Moribund

dying, near death

The THREE modes of exocrine gland secretion

Merocrine/Eccrine secretion, Apocrine secretion, Holocrine

Merocrine/Eccrine secretion

Releases secretion by exocytosis. Most common type

Ex. of Merocrine/Eccrine secretion

sudoriferous glands

Apocrine secretion

top pinches off. Found at axillary region

Axillary regions

armpit and groin, has more oil.

Ex. of Apocrine secretion

Mammary gland

Holocrine

entire cells shed.

Ex of holocrine

Sebaceous oil glands of skin.