Fechar
Physiological adaptations
Homeostasis: The body's ability to maintain a relatively stable environment.
Internal environment: Tissue fluid, interstitial fluid.
External environment: Our surroundings.
Internal aspects of the body that need to be maintained at a steady state=
Blood glucose levels, temperature, blood pressure, insulin, cholesterol, pH, ions/salts, red & white blood cells, water.
The somatic nervous system:
*Controls skeletal muscles (movement)
*Instructions generally originate from the primary motor cortex of the brain.
*Controls voluntary movements.
Sensory neuron:
-Afferent neuron
-Detect stimuli and transmit to the CNS.
Inter neuron:
-Connecting neuron
-Transmits signal to motor neurons/ other parts of the CNS
Human endocrine system:
~Uses chemical substances called hormones to send messages all around the body.
~In response to a signal, hormones are released by specialised groups of cells called 'endocrine glands'.
Nervous system:
*Mode of transmission= Electrical and chemical
*Speed= Fast
*Travel to target= Direct via nerves
*Energy expenditure= High
*Duration of effect= Short
Afferent:
Afferent or sensory neurons receive information from the outside (sensory receptors) and sends them to other neurons so the body can produce a response.
Stimulus response system:
~Model of how a stimulus cases a change in the state or activity of a cell or organism (response).
~The system results in a changing of the stimulus effect.
~Stimulus may be internal or external.
~Our body's core temperature= 37*
~Our bodies heat comes from= Internal reactions, metabolism.
~Our body can detect temperature changes via= Thermoreceptors (Hot & cold receptors); Skin, internal (Blood vessels).
Too cool down:
~Reduce the amount of heat generation.
~Increase the amount of heat loss.
-->Behavioural: Remove clothing, spread out.
--> Sweating: Evaporation increases.
To warm up we can:
~Increase the amount of heat generated.
~Reduce the amount of heat lost.
--> Behavioural: Put on clothes, huddle, shiver (movement of muscles generates heat).
Control centre= Hypothalamus
ENDOTHERM: ~Mainly generates their own internal heat through metabolic reactions.
~Tend to have stable core body temperature.
Endotherms (Disadvantage):
~Energy intensive
~Need to eat to provide fuel to warm our body.
Endotherms (EXAMPLES):
~Eat a lot of food
~Metabolic processes
~Rely on panting to increase evaporation due to fur
~Avoid overheating
