PART 1 ALL CONTENT Flashcards
Levels of organisation
Chemical
Cellular
Tissue
Organ
Organ system
Organsim
Body cavities
spaces that enclose internal organs
Cells
the basic structural and functional units of the body
Classes of cells
Germ and somatic
Cell membrane function
- Maintains composition of inter and extra cellular fluid
- Determines movement of substances in and out of cell
- Communicates with other cells and organs
Phospholipid consists of what two things
Hydrophilic phosphate heads (water loving)
Hydrophobic lipid tails (water hating)
Simple diffusion molecules
Small, uncharged and lipid soluble
Facilitated diffusion molecules
Large or charged or water soluble
Simple diffusion
the movement of a molecule directly through the phospholipid bilayer from high to low concentration
Factors affecting rate of simple diffusion
concentration gradient
Facilitated diffusion
the movement of an ion or molecule from high to low concentration, via a channel or carrier protein
Factors affecting rate of facilitated diffusion
concentration gradient
Osmosis
movement of water
Water is water soluble: use a channel (aquaporin) to cross membrane
Move from high to low water concentration
Active transport
the movement of a molecule from an area of low to high concentration, via a channel or carrier protein
Factors affecting rate of active transport
Availability of ATP
Exocytosis
the release of fluids and/or solids from the cell via intracellular vesicles. ATP is required
Receptor-mediated transport
Target molecules bind to receptor proteins on the membrane surface triggering vesicle formation
Pinocytosis
Vesicles form at the membrane and bring fluids and small molecules into the cell
Phagocytosis
SOLID Vesicles form at the membrane to bring solid particles into the cell
Tonicity
the capability of a solution to modify the volume of cells by altering their water content
Vesicle
Membrane enclosed sac used to take in, transport and secrete substances in & out of cell
RER
protein synthesis
SER
metabolic processes, including synthesis of lipids and steroids, metabolism of carbohydrates
Golgi Apparatus
Storage, alteration and packing of secretory products and lysosomal enzymes
Direct communication
Physical contact
Gap junction
Indirect communication
No direct contact
Requires messanger molecule
Autocrine
Messenger molecule remains in interstitial fluid and act on the same cell
Paracrine
Messenger molecule remains in interstitial fluid and act on a different cell
Neurotransmission
Secretion of a neurotransmitter by a neuron to act on target cells
Endocrine
Endocrine signal (hormone) released into bloodstream and travels to target cell
Neurocrine
Neurocrine signal (hormone) released into bloodstream and travels to target cell
Neurotransmission characteristics
Neurotransmitter
Synapses
Onset of action in miliseconds
Duration of action is short
Neurosecretion characteristics
Neurohormone
Blood
Onset of action seconds to days
Duration of action is longer
Hormone roles in regulating
Metabolism and energy balance
Contraction of smooth and cardiac muscle cells
Immune system response
Target cell response to a hormone is based on
The hormone’s concentration in the blood
The number of hormone receptors on the target cell
DNA
Double stranded helix and has 4 bases
Coiled into histones and placed in chromosome
Ligand Receptors
Specific proteins that function when a specific molecule binds to the receptors
Chromosome
Long DNA molecule
Gene
Unit of heredity
Allele
Specific DNA sequence at a gene locus
- Two alleles per gene
- Homozygous: identical alleles
- Heterozygous: different alleles
Number of chromosomes mitosis and meiosis
Mitosis: 46
Meiosis: 23
Genetically identical mitosis and meiosis
Mitosis: yes
Meiosis: no
Transcription occurs where
Nucleus
Function mitosis and meiosis
Mitosis: replace body cells
Meiosis: make gametes
Number of daughter cells mitosis and meiosis
Mitosis: 2
Meiosis: 4
Transcription process
RNA polymerase connects RNA bases to the DNA
RNA bases bond together to form mRNA
Translation where
Cytoplasm
Translation process
MRNA attaches to a ribosome
TRNA’s anticodon pairs complementary codon on mRNA to go with amino acids
Mutations
Change in DNA sequence of a gene
Possible loss or gain of 1+ nucleotides
- Change in reading frame of gene
- Early stop codon
- Wrong protein produced
- Protein cant function
Glycolysis where
Cytosol
Mutation outcomes
- Functional protein produced (no change)
- Protein produced doesn’t work as well
- Protein cannot function or produce insufficient amount
Anabolism
small to big
Krebs where
Matrix of mitochondria
Krebs process
Acetyl coenzyme A -> CO2 and H2
Glycolysis process
Glycogen -> glucose -> pyruvic acid -> acetyl coenzyme A
ETC where
Inner mitochndrial matrix
ETC process
H2 + O2 -> H2O
End products: CO2 and H2O
Epithelial tissue characteristics
Avascular
Cells tightly packed
No extracellular matrix
Epithelial tissue functions
COVER
- Protection,
- Absorption
- Filtration
Connective tissue characteristics
Highly vascular
Few cells
Surrounded by extracellular matrix & contain ground substance
Connective tissue functions
SUPPORTS
- Support and bind other tissues
- Provide insulation and protection (organs)
Nervous tissue types
- Neurons (nerve cells)
- Neuroglia (support cells)
Nervous tissue function
Communication and control
Muscle tissue function
Contraction
Mucous membrane
Tracts
Open to outside of the body (moist membrane)
Supports absorption and secretion
Cutaneous membrane
Skin
Ground substance
Material between the cells
Serous membrane
Line body cavities
Efferent
Information flows away from the control centre
Synovial membrane
Line freely moveable joints
Homeostasis
Condition of equilibrium in the body’s internal environment due to the constant interaction of the body’s many regulatory processes
Afferent
Information flows towards the control centre
Parasympathetic
rest and digest
Sympathetic
fight and flight
Types of neuron cells
- Multipolar neuron (motor neuron & interneuron): most common
- Bipolar neuron (sensory neuron, eye and ear): rare
- Pseudo unipolar (sensory neuron): frequent in this neuron
RMP
The electrical potential difference across the plasma membrane when the cell is in a non-excited state
RMP depends on
- Permeability (anions such as protein can’t go through)
- Electrochemical gradients (e.g. charge and concentration of ions)
- Presence of Na+/K+ on the neuronal membrane.
Hyperpolarisation
1) Voltage gated potassium channels take time to close
2) K+ ions continue to leave the neuron
3) Membrane potential drops below the RMP (-70 mV) until it reaches around -90 mV
Repolarisation
1) Membrane reaches a certain potential (around +30 to 40 mV)
2) Voltage gated K+ channels open
3) Leads to the exit of K+ out of the cell (decrease membrane potential)
Depolarisation
1) Voltage gated sodium (Na+) channels open in the neuronal membrane
2) Sodium flows into the cell
3) This brings positive electrical charge (increases membrane potential)
Types of synapse
1) Electrical: gap junction (bidirectional): very fast connection present mainly in brain and heart
2) Chemical: (unidirectional) most common ones in mammals
Reflex
involuntary, fast and automatic response to a specific sensory stimulus
