HB 2.3 - Intro to Human Body Flashcards
Define “Cell Division”
- Cells turning off certain genes permanently so that they only express genes that are related to its function -> “Committed”
Define “Stem Cells”
- Undifferentiated cells with no specialised function that can endlessly self-renew and differentiate into many types of tissues
Name the 2 types of stem cells and their potency
i. Embryonic Stem (ES) Cells
- Totipotent
ii. Adult Stem Cells
- Multipotent or Unipotent
Define “Totipotent” and give an example
- Able to give rise to all body tissue types
- Inner Cell Mass
Define “ Multipotent” & “Unipotent” and give an example
i. Multipotent
- Able to differentiate to >1 cell types or lineage
- Hematopoietic Stem Cells; Hair Follicle Stem Cells
ii. Unipotent
- Able to differentiate into x1 cell type
- Epidermal Stem Cells; Liver Stem Cells
What is the “Immortal Stand Hypothesis”
- The theory that stem cells undergo asymmetric division to endlessly self-renew
(Asymmetric division = Old DNA remains the same stem cell type; New replicated DNA differentiates into a more specialised cell
What are the 4 tissues categories?
i. Epithelial Tissue
ii. Connective Tissue
iii. Muscle Tissue
iv. Nervous Tissue
What is the function(s) of Epithelial Tissue? Where is it derived from?
- Derived from all x3 germ layers
- Function:
i. Sheets of cells that lines the external of body; internal body cavities; inside of lumen
ii. Form some glands
iii. Provide a dynamic barrier for import and export of molecules
What is the function(s) of Connective Tissue?
- Provides support and protection
- Connects organs and tissues
- Exist as matrix (extracellular material produced by connective tissue cells)
What are the types of connective tissue? List the categories of each types.
x3 types of connective tissue:
i. Connective Tissue Proper
- Loose Connective Tissue (Areolar; Adipose; Reticular)
- Dense Connective Tissue (Regular elastic; Irregular elastic)
ii. Supportive Connective Tissue
- Cartilage (Hyaline; Fibrocartilage; Elastic)
- Bone (Compact bone; Spongy bone)
iii. Fluid Connective Tissue
- Blood
- Lymph
List the 4 types of muscle tissues and their characteristics.
i. Skeletal Muscle Cell
- Striated
- Voluntary Movement
- Multi-nucleated on the boundaries
- Derived from mesoderm
ii. Cardiac Muscle Cell
- Striated (organised/ visible)
- Involuntary Movement
- Single-central-nucleated
- Derived from mesoderm
iii. Smooth Muscle Cell
- Non-striated
- Involuntary Movement
- Single-stretched-central-nucleated
- Derived from mesoderm
iv. Myoepithelial Cell (on epithelia: for iris muscle dilation; secretion of saliva, sweat, milk from glands)
- Non-striated
- Involuntary Movement
- Single-central-nucleated
- Derived from ectoderm
What is nervous tissue?
- Excitable cells
- Conducts electrochemical signals
List the types of nervous cells and their function.
i. Neurons
- Sends electrochemical signals
ii. Neuroglia
- Supports neurons, modulates information propagation
List the 2 types of tissue membrane.
i. Epithelial Membrane
- Epithelium that attaches to a layer of connective tissue
- Includes Mucous; Serous; Cutaneous membranes
ii. Connective Tissue Membrane
- Formed from connective tissue
- Enclose organs and line movable joints
Define “Compartmentalisation”
- A general principle that compartments of the body parts are separated by membranes that act as barriers.
Define “Homeostasis”
- Maintaining a dynamic stable internal environment that is within narrow limits to ensure cell survival. The overall unchanged variable is achieved without using energy.
List examples of factors that homeostasis regulates
- [Nutrient Molecules]
- [O2] & [CO2]
- [Waste Products]
- pH Level
- Amount of H2O, [Salt] & [Electrolytes]
- Volume & Pressure
- Temperature
Why do pH level have to be regulated?
- Different proteins can only work under certain pH range
What is the range and average arterial blood pH level?
- Range: 7.35 - 7.45
- Average: 7.40
What is acidemia?
pH level being too low
What is alkalemia?
pH level being too high
Name 4 types of acidemia
i. Ketoacidosis
- (eg. in type I diabetes) ↓ insulin -> Use fat as fuel -> Acidic ketone produced
ii. Latic Acidosis
- (eg. too much exercise; Heart failure) ↓[O2] -> ↑Latic acid produced
iii. Renal Tubular Acidosis
- Damaged kidneys can’t remove excess acid -> too much acid in blood
iv. Hyperchloremic Acidosis
- (eg. severe diarrhoea; kidney disnease) ↓[Bicarbonate] = Can’t buffer pH
Define “enzyme”
- A biological catalyst used to speed up and control rates of biochemical reactions by providing an alternative pathway with a lower activation energy
- ↑ reaction rate by up to 10^19
Define “isoenzyme”
Enzymes that have different amino acid sequences, kinetic/ physical/ chemical properties & tissue distributions but targets the same substrate and make the same product
Define “Vmax”
- Maximal rate of reaction
- Directly proportional to [total enzyme] thus = velocity with saturated substrate
Define “Km”
- The Michaelis Constant, shows the affinity of enzyme for substrate and shows the enzyme specificity
- ↑Tightly bind = ↑Affinity = ↓Km
- The amount of substrate that binds 1/2 of available enzyme, thus produces 1/2 of maximum velocity (Vmax)
