Homeostasis

Front 1

Homeostasis

Back 1

Body's attempt to adjust to fluctuating environment to return to the norm

Front 2

Three components of control system

Back 2

Monitor, coordinating center, regulator

Front 3

Negative feedback system

Back 3

Mechanisms that make adjustments to restore homeostasis, prevent small changes from becoming large. Example. Carbon dioxide levels rise, sensors are stimulated, control center relays info to brain, regulator sends impulse to muscles to increase depth and rate of breathing

Front 4

Positive feedback system

Back 4

Process where controlled variable is moved away from homeostasis. Allows physiological event to be accomplished rapidly for example labour

Front 5

Thermoregulation

Back 5

Negative feedback mechanism. Stimulus is the skin, control centre is hypothalamus, receptor is skin.

Front 6

Vasodilation

Back 6

When body is too hot blood vessels at the surface of the skin dilate and blood moves to surface, so heat is radiated away from the body.

Front 7

Vasoconstriction

Back 7

Surface blood vessels constrict when temperature is low, keeps blood close to core.

Front 8

Function of the CNS

Back 8

Central nervous system acts as a coordinating center

Front 9

Function of PNS

Back 9

Peripheral nervous system carries info to and from CNS

Front 10

Parts of the PNS

Back 10

Somatic and Autonomic

Front 11

Parts of the nerve cell

Back 11

Dendrites, Schwann cell, node of ranvier, sensory neuron, cell body, nucleus, motor neuron, axon,myelin sheild

Front 12

Glial

Back 12

Neurological cells, non conducting support structure

Front 13

Neuron groups

Back 13

Sensory, interneurons, motor neurons

Front 14

Sensory neurons

Back 14

Sense and relay info from environment to CNS. Located in clusters called Ganglia

Front 15

Interneurons

Back 15

Link neurons within the body. Integrate and interpret sensory information and connect neurons to motor neurons

Front 16

Motor neurons

Back 16

Relay information to effectors

Front 17

Effectors

Back 17

Muscles, organs, glands, effectors as they produce responses

Front 18

How is the neuron signal relayed

Back 18

Message moved from dendrite, through nerve body to axon. Travels through the mylein sheath, jumping between the nodes of ranvierm

Front 19

Anatomy of the neuron

Back 19

Front 20

Nervous system that surrounds nerve fibers

Back 20

Neurilemma

Front 21

Function of neurilemma

Back 21

Promotes regeneration of damaged axons

Front 22

Difference between white matter and grey matter

Back 22

White matter contains mylein and neurilemma, grey matter does not.

Front 23

What is MS a disease of?

Back 23

Destruction of myelin sheath

Front 24

Mylelin sheath

Back 24

Insulting fatty later that speeds transmission

Front 25

Axon

Back 25

The conducting fiber

Front 26

Schwann Cells

Back 26

They make myelin

Front 27

Dendrites

Back 27

Receivers

Front 28

Axon terminals

Back 28

Transmitters

Front 29

5 components of a reflex arch

Back 29

Receptor (senses something)

Neuron (sends signal to the CNS)

Interneuron (registers signal)

Motor neuron (sends response back)

Effector (carries out the action)

Front 30

What is membrane potential

Back 30

The cytoplasmic side of the membrane (inside the cell) is negative to the extracellular side. This charge separation is a form of potential energy.

Front 31

What is resting membrane potential

Back 31

Potential difference across a membrane in a resting neuron (-70 mV) provides energy for generating a nerve impulse. The process of generating a resting membrane potential of -70mV is called polarization

Front 32

Process of the Sodium-Potassium Pump

Back 32

1. Carrier protein has a shape that allows it to take up 3 sodium ions from the inside of the cell

2. ATP is split and a phosphate group is transfered to the carrier protein changing its shape, which allows it to release the sodium ions and take in two potassium ions.

3.The phosphate group is released which changes the shape once more allowing the potassium to be released.

Front 33

What is depolarization and how does it occur?

Back 33

Depolarization is when membrane potential is reduced to less than -70mV. During depolarization the inside of the cell becomes less negative relative to the outside of the cells. Depolarization occurs because of an action potential

Front 34

What is action potential?

Back 34

Action potential is the movement of an electrical impulse along the plasma membrane of an axon.

Front 35

What is threshold potential?

Back 35

The level an axon must depolarize for an action potential to occur. Close to -50mV

Front 36

Path of action potential

Back 36

Front 37

Step 1 of Action Potential

Back 37

An action potential is triggered when the threshold potential is reached

Front 38

Step 2 of Action Potential

Back 38

Voltage gated sodium channels open when the threshold potential is reached. Sodium ions move down their concentration gradient and rush into the axon and depolarize the membrane. +40mV

Front 39

Step 3 of action potential

Back 39

Voltage gated sodium channels close due to change in membrane potential. Voltage gated potassium channels open. Potassium ions move down their concentration gradient and exit the axon. -90mV

Front 40

Step 4 of action potential

Back 40

Voltage gated potassium channels close. The sodium potassium pump and naturally occurring diffusion restore the resting membrane of -70mV. The membrane is repolarized.

Front 41

What is the refractory period?

Back 41

The period after action potential occurs where the membrane cannot be stimulated.

Front 42

Signal transmission across a synpase step 1

Back 42

The nerve impulse travels to the synaptic terminal

Front 43

Signal transmission across a synpase step 2

Back 43

Synaptic vesicles containing neurotransmitters move toward and fuse with the presynaptic membrane.

Front 44

Signal transmission across a synpase step 3

Back 44

Synaptic vesicles release neurotransmitters into the synaptic cleft by exocytosis. Neurotransmitters diffuse across the synapse to reach the post synaptic neuron or the cell membrane of an effector

Front 45

Signal transmission across a synpase step 4

Back 45

Neurotransmitters bind to specific receptor proteins on the postsynaptic membrane the receptor protein trigger ion channels to open. Depolarization of the post synpatic membrane occurs and an action potential is initiated if the threshold potential is reached.

Front 46

Function of serotonin

Back 46

Regulated temperature and sensory perception. Is involved with mood control.

Front 47

Function of endorphins

Back 47

Act as natural painkillers, also emotional areas of the brain

Front 48

What are the glands in the endocrine system?

Back 48

Front 49

Steriod hormone action

Back 49

1. Hormone diffuses from cell into blood

2. Diffuses into the cells of target tissue

3. Attached to receptor molecule in cytoplasm

4. Hormone receptor complex enters nucleus

5. Hormone complex activayes transcription of a particular gene to induce hormone effect

Front 50

Peptide hormone action

Back 50

1. Hormone released from cell vesicles into blood

2. Attached to a receptor on the exterior of the cell and membrane of target cells

3. HR complex triggers production of cAMP

4. cAMP triggers a specific enzyme cascade to induce hormone effect