homeostasis

Question 1

what is negative feedback?

Answer 1

its a one-step change like the thermostat
Aka dynamic equilibrium,

Question 2

How is negative feedback started?

Answer 2

This occurs by a receptor which is something that has the ability to make changes in the body
Then to an integrating/control centre that processes and “makes a decision”
Effector which is the cell/organ that makes the corrective action to restore homeostasis.

Question 3

what is positive feedback

Answer 3

its leaning into the problem more to create a larger change (its a loop)
Biggest one is either a heart attack or giving birth

Question 4

what kind of transmission is the nervous system?

Answer 4

sends electrical and chemical messages
It can be excitable and respond to stimulus
Conductive producing electrical signals that are quickly conducted to other cells.
Secretion of neurotransmitters.

Question 5

what are astrocytes?

Answer 5

Abundant glial cells
Connect to blood capillaries
Convert glucose to lactate
Secrete nerve growth
Communicate electrically
Absorb excess neurotransmitters and ions.

Question 6

what is the electrical potential?

Answer 6

Charged particles between two points

Question 7

What is an EPSP

Answer 7

this is an excitatory post synaptic potential. (Na, and K)

Question 8

what is an ipsp

Answer 8

this is an inhibitory post synaptic potential. (Cl, and K)

Question 9

what is the CNS

Answer 9

the central nervous system includes the brain and spinal cord

Question 10

what is the PNS

Answer 10

the peripheral nervous system which controls all other nerves except the brain and spinal cord.

Question 11

what is a leak channel?

Answer 11

constant permeability allowing free flowing of ions

Question 12

what is a voltage gated channel?

Answer 12

channels activated by changes in the charge on either side of the membrane.

Question 13

what is a ligand gated channel?

Answer 13

these open in response to an enzyme bonding to a spot on the channel causing it to open.

Question 14

what is a mechanically gated channel?

Answer 14

opens in response to pressure on the membrane.

Question 15

what is the role of ATPase pump?

Answer 15

this maintains the gradient on either side of the membrane keeping high concentration of sodium out and high conc of K inside.

Question 16

what is temporal summation?

Answer 16

this is when EPSPs cause an action potential to be pushed through the neuron.

Question 17

what is spatial summation?

Answer 17

this is where there is multiple depolarizations at the same time but in different spaces.

Question 18

what are oligodendrocytes

Answer 18

form myelin sheath

Question 19

what are ependymal cells

Answer 19

line internal cavities and secrete and circulate cerebral spinal fluid

Question 20

what are microglia

Answer 20

wander through CNS looking for damage and debris.

Question 21

what are the properties of local potentials

Answer 21

graded (vary with stimulus strength)
reversible
decremental (weaken as spread from point of stimulation)
excitatory or inhibitory

Question 22

action potential properties?

Answer 22

all or none (if threshold reached the neuron fires at maximum voltage)
non-graded
non-decremental
irreversible