Physiology, Digestion, Life on earth! Flashcards
What are the three levels in the hierarchy of structural order in terms of the aspects of life?
- Organisms: organs, systems and communication tissues 2. Cells: organelles - structure and function 3. Molecules: DNA/RNA, signalling molecules, enzymes, proteins, carbs, fats etc
Define cell differentiation
The development of cells with specialised structure and function from unspecialised precursor cells.
Describe an Amoeba
A protist that lives in fresh water and moves by ameboid movement.
Define a tissue
Groups of cells with a common structure and function
What are the four catagories of tissues?
Epithelium, connective, muscle and nerve.
Where would you find Stratified squamous epithelium?
The tongue and oesophagus.
Where would you find Pseudostratified columnar epithelium?
Larger respiratory airways of the nasal cavity, trachea and bronchi
Where would you find simple squamous epithelium?
The lungs
Where would you find simple columnar epithelium?
Large and small intestine, the stomach
Where would you find Cuboidal epithelium?
Surface of the ovaries
Name two examples of occluding junctions?
Tight and anchoring junctions
What is a function of gap junctions?
They allow molecules to pass through from one cell to the other
What two sides do typical epithelia have and what does this mean in terms of their locations?
They have a Basel and Apical side. Basel = closely interacting with other cells. Apical = This side is exposed to the lumen.
Describe collagen, elastic and reticular fibres found in connective tissues
Collagen = strong and non-elastic, elastic = made of elastin, and reticular = thin and highly branched reticular fibres which serve to join connective tissue to adjacent tissues.
What does adipose tissue store?
Fat droplets
What does the Equality act aim to ensure?
The elimination of unlawful discrimination, harassment and victimisation, and to foster good relations between those who share protected characteristics.
In terms of location, structure, control and power, describe skeletal muscle.
Found in the limbs, has a striated structure, is voluntarily controlled, and has high power.
In terms of location, structure, control and power, describe cardiac muscle.
Located in the heart, has a striated structure, is involuntarily controlled, and has high power.
In terms of location, structure, control and power, describe smooth muscle.
Is located in the gut and blood vessels, has a non-striated structure, is involuntarily controlled, and has low power.
Describe the parts that make up muscles from smallest to largest.
Sarcomeres –> myofibrils –> myofibers –> Muscles
What two protein fibres are sarcomeres made up of? Which is thick and which is thin?
Actin (thin) and myosin (thick)
describe the stages of muscle contraction.
- Myosin head hydrolyses ATP 2. Myosin head binds to actin forming a cross bridge 3. the release of ADP and Pi causes a power stroke which slides the thin filament along the myosin 4. Binding of a new ATP releases the myosin head
What is muscle contraction a result of?
Interactions between actin and myosin filaments
What is the sliding filament model?
When thin filaments slide over thick filaments without changing length.
What is the function of sensory nerves?
To carry an electrical signal from sense organs to the CNS - they respond to stimuli.
What is the function of motor nerves?
To carry an electrical signal from the CNS to the muscles - activate contraction.
What cells produce myelin?
Schwann cells in motor neurons
What is concentrated at the nodes of Ranvier?
Sodium channels
define convergent evolution
A mechanism which has evolved to have the same function but differs in the details
Name a consequence of demyelination
Degenerative diseases such as multiple sclerosis
Briefly describe how a signal is transmitted in an electrical synapse
Ions flow through gap junctions located in the synapse. Allows for much faster transmission
How are signals communicated between motor neurons and muscles
Signal is passed through a neuromuscular junction from the neuron to the muscle
What conversion makes blood clotting possible?
The conversion of fibrinogen to fibrin
What is the function of fibroblasts?
To secrete a matrix and proteins
What is the function of mesenteries?
To hold the internal organs in place
What is adipose tissue regulated by? How does this tissue type help blood vessels?
Hormones. Gives protection to the blood vessels
How does adipose tissue differ in marine animals?
Known as blubber, and has adapted to become more vascularised and help with: Energy, insulation, buoyancy and protection.
What type of protein is collagen?
Glycoprotein
What are the functions of ligaments and joints?
Ligaments = link joints. Tendons = attach muscles to bones.
What is bone made of?
Mineralised matrix of collagen fibres impregnated with salts
What cells secrete the building blocks of bones?
Osteoblasts
What do the compact and spongy parts of bone offer?
Spongy = keeps the weight manageable. Compact = provides the bone strength
What terms refers to bones being able to handle lots of force?
Compliance
