Introduction
What is Anatomy? and examples
What is Physiology? and examples
Anatomy is the study of structures in the body
Examples: Gross anatomy, microscopic anatomy
Physiology is the study of how those structures work
Examples: Cell physiology, System physiology, Pathophysiology
Cellular polarity: where are the basal, lateral, and apical located?
Basal: Bottom
Lateral: Side
Apical: Top
Gap Junctions
- Channel between cells so cytoplasms are continuous (allows communication)
- Made up of connexons (interlocking transmembrane channel proteins)
-Example: ciliated epithelium
Transitional
- Cuboidal until stretched into Squamous shape
- Has scalloped edges to allow for expansion
- Example: Bladder
What is one Unicelluar Gland? List specific characteristics
- Goblet Cells
- single-secreting cells interspersed with non-secreting cells
- have microvilli
- can be a result of metaplasia (irritants stimulate irreversible cell differentiation, ie smoking)
Cytology Vs Histology? What are they?
Cytology: Study of cells
Histology: Study of tissues including epithelial
tissue, connective tissue, nervous tissue,
and muscular tissue
What are the 4 functions of Epithelial Tissue?
1. Physical Protection
2. Permeability Layer (selective permeability)
3. Sensory (neuroepithelium)
4. Produce secretions (glandular epithelium)
Simple Squamous
- Very thin and delicate
- Example: serous membranes
Simple Columnar
- Specialized for absorption/secretion
- Often has microvilli
- Example: Intestinal Epithelium
Shape: -Tubular -Acinar (Aveolar)
Number of Ducts: -Simple -compound
Branching: -Many glandular areas share one duct
What is Homeostasis?
Maintenance of a stable internal environment
Describe the specialized apical structures: Microvilli, Cilia, Stereocilia.
Microvilli: Increase surface area for absorption/ secretion.
Cilia: For movement of particles across the surface.
Stereocilia: For sensing movement.
Stratified Squamous
- thicker, stronger than simple squamous
- may be keratinized for waterproofing
- Example: Epidermis
Stratified Columnar
- Very thick, RARE (never more than a few layers)
- Example: Conjunctiva
Merocrine
- Vesicles migrate apically, released via exocytosis
- Example: sweat glands
What is Autoregulation? List 1 example
Autoregulation is when the cell essentially "fixes" and regulates itself with no nervous or endocrine input.
Example: When a cell is experiencing hypoxia (low oxygen) and regulates chemicals or ions to vasodilate capillaries, allowing more oxygen to enter the cell
Tight Junctions
- very impermeable
- transmembrane proteins extend from each cell and interlock
- found on lateral surface
- Example: intestinal epithelium
Simple Cuboidal
- Specialized for secretion/absorption
- Example: Renal Tubules
Pseudostratified Columnar
- Only ONE layer, but nuclei are at different levels, so appears to be more
- Usually ciliated
- Example: Respiratory epithelium
Apocrine
- Vesicles migrate apically, apical end is shed
- example: ceruminous glands
What is Extrinsic regulation? List both kinds and examples.
Extrinsic regulation is when the nervous and/or endocrine system helps maintain a stable internal environment.
Negative Feedback: The system works to oppose the initial stimulus
Example: When blood glucose levels drop, a hormone is released to release stored energy from fat cells. Then blood glucose rises as a result.
Positive Feedback: The system works to increase the initial stimulus
Example: Childbirth begins, putting pressure on the. cervix. Oxytocin is released to increase uterine contractions. This causes even more pressure on the cervix, causing the release of more oxytocin
Example when it goes WRONG: Profuse bleeding causes a drop in blood pressure. Heart speeds up in an attempt to raise the blood pressure. This causes even more bleeding, causing the blood pressure to decrease even more.
Desmosomes
- Strong to resist mechanical stress (microfilaments attached to cytoskeleton)
- made up of CAMS (Cellular Adhesion Molecules) and proteoglycans
- Button Desmosomes: found on lateral side
-Hemidesmosomes: found on basal side
-Example: Epithelium of skin
Stratified Cuboidal
- very thick, RARE (never more than a few layers)
- Example: Salivary Glands
What are the two multicellular glands, and what does the second one secrete?
1. Endocrine Glands: secrete into the intestinal fluid
2. Exocrine Glands: secrete onto surface of epithelium using ducts. Secretions inlude:
- Serous: thin, watery fluid (Ex. serous membranes)
- Mucus: thicker secretion containing mucins ((viscous colloid with lysozomes) antiseptic enzyme) (Ex. submucosal glands in small intestine)
- Mixed: both serous and mucus secretions (Ex. Submandibular salivary glands)
Holocrine
- Vesicles are interspersed throughout cell, cell explodes
- Example: sebaceous glands