Physiology S1 Y1 Flashcards
What are muscle cells specialised to do?
Generate mechanical force
Are skeletal, cardiac and smooth muscles voluntary or involuntary?
Skeletal = voluntary
Cardiac and smooth = involuntary
What are neurons specialised to do?
Initiate, integrate and conduct electrical signals
- neuron to neuron = passing on electrical signals
- neuron to gland = secreting electrical signals
- neuron to muscle = contraction
What are epithelial cells specialised to do?
The selective secretion and absorption of ions and organic molecules
- different sides of cell can have different functions
What are connective cells specialised to do?
Connecting, anchoring and supporting of bodily structures
- can be loose connective tissue, dense connective tissue, bone, cartilage, adipose and blood
2 types of protein fibres?
- Collagen fibres (ropelike)
- Elastin fibres (rubberband like)
- What is extracellular fluid?
- Intertitial fluid? - What is the space containing it?
- Fluid in blood + surrounding cells
- Extracellular fluid around + between cells - interstitium
What is homeostasis?
“State of reasonably stable balance between physiological variables” they are not constant but are in a predictable range
- regulated by dynamic constancy
What is pathophysiology?
Alterations to homeostasis out of the normal range
- How are conditions in the body maintained at their set point?
- Can set points be changed and why?
- Continuous adding of energy and feedback mechanisms
- They can be reset so important conditions can be maintained if the environment changes e.g. in the presence of a pathogen body temp. increases
How does negative feedback get used in homeostasis?
Prevents compensatory responses to a loss of homeostasis and oppose a stimulus e.g. if body temp. increases, this is opposed and brought down
How does positive feedback get used in homeostasis?
Accelerates a process such as blood clotting to seal a wound
What is feedforward regulation?
Regulated variables changing are anticipated and the body is prepared for this before it occurs through use of external/internal environmental detectors and learning
What are afferent and efferent nerve pathways?
Nerves that connect receptors to the integrating center and the integrating center to effectors
What other mechanism can act as a reflex component?
Hormones
2 major effectors?
- Muscles (contract)
- Glands (secrete hormones)
4 substances that allow cells to communicate?
- Hormones - target cells in one or more places in body
- Neurotransmitters - allows neurons or effector cells to recieve/transmit signals
- Paracrine substances - target cells in close proximity of release
- Autocrine substances - act on the same cell that secreted it
What is adaptation?
Characteristic that favours the survival of an individual in a specific environment or conditions
What is acclimatization?
Adaptation due to prolonged exposure to an environmental change
Why are biological rhythms useful?
Allow homeostatic mechanisms to be used immediately as there is an anticipatory component added to the homeostatic control system (a feedforward system)
What is the pool?
The readily available quantity of a substance
What are electrolytes?
Ionic forms of mineral elements
Difference between polar and non-polar bonds?
Polar bonds have uneven distribution of electrons (creates areas of positive and negative charge) and they are hydrophilic
Non-polar bonds have equal sharing of electrons and are hydrophobic
Lipids:
- Why are they not very soluble?
- What are the four subclasses?
- Non-polar covalent bonds
- Fatty acids (saturated or unsaturated)
- Triglycerides (part of membranes)
- Phospholipids
- Steroids (4 carbon rings, not water soluble)