Hubs Flashcards
Structure and example of epithelial cells
Densely arranged cells with little extracellular matrix
Outer layer of skin
Lining of respiratory, digestive etc
Function of epithelial cells
Glandular activity
Covers and protects body surfaces
Lines cavities
Transports substances
Structure and example of connective tissue
Sparsely arranged cells Large proportion of matrix containing structural fibres Collegenous fibres loose, adipose, reticular, dense. Bones Cartilage Tendons Ligaments Blood
Function of connective tissue
Defend from microorganisms
Transport substances
Storage, movement, support
Structure and examples of muscle tissue
Long fiber-like
Skeletal Smooth cardiac
Heart, arm muscles, leg muscles, stomach muscles etc.
Function of muscle tissue
Body movements
heat
Structure and examples of nervous tissue
Mix of many cell types Axon transmit nerve impulses away Dendrites carry nerve impulses towards Tissue of brain Spinal chord Nerves Sensory organs
Define homeostasis
Homeostasis is the maintenance of realitivly constant condition in the internal environment in the face of external or internal change.
Function of nervous tissue
Communications between cells and organs
regulation/integration of body functions
Why is ECf regulated in multicellular organisms
To maintain the RMP
To retain homeostasis
Keep life processes going at optimal conditions
Normal range of Ca2+
2.1-2.6
Normal range of Na+
135-145
Normal range of Normal glucose
3.5-8
Normal range of fasting glucose
3.5-6
Normal range of K+
3.5-5
Passive transport mechanisms
Simple diffusion
Osmosis
Carrier mediated transport
Channel mediated transport
Why is it important to maintain sodium ECF?
Action potential in nerve and muscle tissue.
A high concentration of Na+ in ECF decreases the water content in the cells it surrounds, this causes the cell to shrink.
Active transport mechanisms
Ion pumps
Normal pumps
Exocytosis
Endocytosis
Define osmosis
Osmosis is the net movement across a partially permeable membrane down its own concentration gradient.
Water moves from areas of low solute concentration to areas of high solute concentration
Define osmolarity
Osmolarity is a measure of the total number of solute particles per solution. Normally 275-300
Define tonicity
Tonicity refers to the effect that a solution has on cell volume. Tonicity depends on type of solute.
Hypertonic= high solute concentration so cell shrinks
Hypotonic= low solute concentration so cell swells
Isotonic= normal/ the same concentration as the cell
Significance of RMP
Excitable tissue such as nerves and muscles must be able to change their RMP or else conditions such as cardiac arrhythmics may occur
Define RMP
The resting membrane potential is an electrical potential that exists across the cell membrane and is due to different concentrations of ions each side of the membrane and their respective permeabilities to it. approx. -70 mV
Process of creating RMP
Potassium ions diffuse out of the cell due to the concentration gradient, leaving behind a negative charge.
Potassium ions outside the cell are attracted to the negative charge on the inside so want to move back in
RMP created when these two forces equal/come to equilibrium
Define controlled variable
A controlled variable is an internal or external condition that must be kept constant in order for homeostasis
Define set point
The set pint is the value at which the variable is at optimum. Eg 37 degrees for body temperature
Define reference range
The acceptable limits for the variable
Why is there variability in control variable values between individuals?
Eg age. Blood pressure has a higher range of values in old people than in young people because more blood is needed to supply oxygen through degenerating capillaries.
Context must be taken into consideration when interpreting physiological measurements
Define negative feedback
Negative feedback control system works to stabilise physiological variables.
Define positive feedback
Positive feedback works to amplify the variable away from the set point. Eg childbirth
Define feed forward
Feed forward systems anticipate the effect of the stimulus before the variable changes.
Describe the physiological control systems for thermoregulation
Changed body temperature detected by hypothalamus
Compares to set point (37)
Sends nerve impulses to muscles to start shivering if cold
Sends nerve impulses to surface blood vessels to contract if cold
Sends nerve impulses to surface blood vessels to expand if warm
Sends nerve impulses to glands to start sweating is warm
Ways in which the body loses heat
Conduction
Convection
Radiation
Evaporation
Physiological example of positive feedback
Childbirth
Contractions and stretch detected by stretch receptors
Information via nerves to hypothalamus and pituitary gland
Release hormone oxytory which stimulates stronger, more frequent contractions
A cute symptoms of diabetes
Inability to synthase ATP so starves cell, causes degeneration of tissue
Urine has a high concentration of glucose so water moves out of cells osmotically, so dehydration
Liver breaks down glycogen and amino acids so blood glucose levels further increased.
Chronic symptoms of diabetes
Heart attack Stroke Renal failure Retinal damage Poor wound healing Peripheral nerve damage Susceptibility to infection
What is the sensor for positive feedback on childbirth?
Stretch receptors down there
What is the effector in positive feedback in childbirth?
Hormone oxytocin
Which ion contributes most to RMP?
Potassium
What is the interpreter for positive feedback in childbirth?
Hypothalamus and pituitary gland
Insulin is produced why which cells?
Beta cells in pancreatic islets
Why do potassium ions move out of cells?
Because of the concentration gradient
How is the resting membrane potential created?
When the amount of potassium ions moving out of the cell balances the force of attraction of potassium ions going towards the cell
What is the sodium potassium pump?
Active transport of Three sodium ions are exchanged for two potassium ions (potassium in)
What is not appropriate in the hubs lab?
Consuming food, drink, including gum and lozenges
Each lab has the potential to add how much to your final grade in hubs 191?
1%
Which of the following is NOT an example of homeostasis?
A. Sweating to cool the body
B. Excreting dilute urine to rid the body of excess water
C. Use of ADH to regulate water concentration in the blood
D. Using a thermometer to measure body temperature
E. Removing clothing to prevent an increase in core body temperature.
D
The term ‘negative feedback’ is defined as:
A. Predicting and preventing deviation of a variable from a set point value.
B. Predicting and increasing deviation of a variable from a set point value.
C. Detecting and increasing deviation of a variable from a set point value.
D. Detecting and correcting deviation of a variable from a set point value.
E. Detecting and maintaining deviation of a variable from a set point value.
D
The knee is (what) to the hip?
Distal
The movements of abduction and adduction are possible in which anatomical plane?
Coronal
A cell is placed into a solution and begins to shrink. This indicates that the solution is:
Hypertonic
What organelle is responsible for the production of ATP within cells?
Mitochondria
Which of the following is not one of the basic tissue types within the body?
A. Nervous.
B. Connective.
C. Muscle.
D. Epithelial.
E. Blood.
E
