Nervous & Endocrine

Question 1

Glial Cells “Nerve Glue”

Answer 1

Support neurons physically and metabolically (4 types)

Question 2

Membrane Potential

Answer 2

When a neuron is a rest

Question 3

Resting Membrane Potential

Answer 3

Potential difference in a resting membrane : -70 mv in a resting neuron
membrane is polarized
Ion pumps help maintain resting potentiall
Maintaining Ion balance is expensive energetically even at rest

Question 4

Electrical Signals: What are the two types?

Answer 4

1. Graded potential

2. Action potential

Question 5

What is a graded potential

Answer 5

If a cell is not stimulated the it is graded: signal not large enough to cause action potential.

Act as signals over very short distances
Important in initiating action potentials.

Question 6

What is a action potential?

Answer 6

If you can feel anything that is an action. Enough stimuli are carried through to cause transfer of signal through neuron to cause an action.

Stimulus causes depolarization signal, action potential, then repolarization, then depolarized, follow by return to resting state

Question 7

Structure of Neuron

Answer 7

Dendrites

Synapse
cell body
axon hillock
axon

Question 8

Hormonal Signalling structure

Answer 8

Endocrine cell

Hormone receptors

Question 9

Differences between Nervous and Endocrine system

Answer 9

Nervous
Electrical impulse along defined path 
Receptors on postsynaptic cell
Rapid signals (<1 sec) 
Short acting

Endocrine
Hormones in blood stream
Receptors on target tissues
Long duration
Slow signals (secs to hrs)

Question 10

Similarities in Nervous and Endocrine

Answer 10

Both:
Rely on release of chemicals
Primarily regulated by negative feedback
Regulate activities of cells, tissues, organs, organ systems
in response to challenges to homeostasis
Initiated with a stimulus
Whole‐animal integration

Question 11

Neuron four parts what are their function?

Answer 11

1. Dendrites: receive input signal from other neurons.
   2 Cell body: site of integration of synaptic potentials
2. Axon: Conduction component, propages action potentials
3. Presynaptic terminals: Output (secretion of neurotransmitter.

Question 12

Action potentials. what influences singling speed?

Answer 12

Axon diameter, larger axon faster at conducting signal

Degree of myelination-insulation

Question 13

Myelination

Answer 13

Myelin is the sheath of the axon which increased the rate of propagation
it acts as an insulator

Question 14

What is the synapse

Answer 14

Point of contact of a neuron with another neuron or an effector

Question 15

Synaptic Transmission

Answer 15

Presynaptic signal (action potential) effects postynapic cell:
Rapid
excitatory or inhibitory
usually chemicals, but can be electrical

Question 16

What is the difference between graded and action potentials?

Answer 16

Graded potentials:

• localized (polarized ) signals that do no propagate enough trigger action potentials down he neuron chain.
• Cell is not stimulated

Action potential:
-If you can feel anything that is an action. -Enough stimuli are carried through to cause transfer of signal through neuron to cause an action.

-Stimulus causes depolarization signal (graded) and if it is large enough-> action potential is triggered, then repolarization occurs and then is depolarized, follow by return to resting state.

Question 17

Vertebrate Nervous System:

What are the two major parts?

Answer 17

Central: (CNS)

Peripheral Nervous System: (PNS)

Question 18

Central nervous system: (CNS)

Answer 18

Brain and Spinal cord

Neurons interact to achieve integrative functions

Question 19

Peripheral Nervous System: (PNS)

Answer 19

All process and cell bodies outside of CNS

Question 20

Types of neurons: 3

Answer 20

Sensory neurons
• Convey information to CNS

Motor neurons
• Convey information CNS ->
effectors (i.e. muscles)

Interneuron
• Found completely
within the CNS
• Link between
sensory & motor
neurons

Question 21

Peripheral nervous system: Types

Answer 21

Somatic

Autonomic

Question 22

Somatic: Outside body

Answer 22

Controls skeletal muscle
locomotion

Somatic sensory receptors:
Touch, hearing, vision, taste, olfaction

Question 23

Autonomic: Inside body

Answer 23

Unobservable and Inate (ex breathing heartbeat)
Enteric-gut
Sympathetic: (ex: fight or flight response)
Parasympathetic (Rest)

Question 24

Sympathetic Vs parasympathetic?

Answer 24

Sympathetc: (prepares body for action) Prepares body for action (heart rate, fight or flight, release of norepinephrine)

parasympathetic: (prepares body for rest and digestion)
- release of acetylcholine

Question 25

Sympathetic Vs parasympathetic in regards to dive response

Autonomic conflict?

Answer 25

Decrease in hear rate–> parasympathetic (rest) Vagus nerve rules in diving although sympathetic action still occurs. Bradycardia controls.

Vasoconstriction, tachycardia–> sympathetic (action)

Conflict heart rate fluctuation at depth is risky (susceptibility to diving injuries). Actually not dangerous: change is action of perfusing at surface.

Parasympathetic (rest)- Vagus nerve rules in diving although sympathetic action still occurs.

benign arrhythmias are common

Question 26

What are hormones and what are some effects of hormones?

Answer 26

Hormones are chemical messengers with regulatory effects in cells or organs.

Some affect multiple organs and some are specific to just a few targeted tissues.

Multiple: Growth hormone, Thyroid, insulin.,

Specific areas targeted: adrenocorticotropic (ACTH)
thyroid-stimulating hormone (TSH)

Question 27

Pituitary Gland

Answer 27

“master gland”- Communicates with other gland in body

releases hormones that affect other glands
Two pieces: anterior and posterior pituitary
Controlled by hypothalamus (brain)

Question 28

Adrenal glands structure

Answer 28

Two glands on top of kidneys: Have external cortex and internal Medulla

Question 29

Adrenal gland function

Answer 29

Fight or flight hormones: adrenaline and nonradenalin

increases blood glucose and heart rate

Divert blood from non-essential organs

Emidiate response

Question 30

Adrenal hormones produced: 3

Answer 30

Glucocorticoids: Cortisol- for metabolism
Mineralocorticoids: Aldosterone- mineral balance
Gonadocorticoids: Androgen and estrogen: small amounts

Question 31

The main hormone form the adrenal medulla also functions as a neurotransmitter int he sympathetic nervous system. What is the name of this hormone?

Answer 31

Norepinephrine

Question 32

What three categories of hormones are released by the adrenal cortex?

Answer 32

Glucocorticoids: Cortisol- for metabolism

Mineralocorticoids: Aldosterone- mineral balance

Gonadocorticoids: Androgen and estrogen: small amounts

Question 33

What are Islets of Langerhans

Answer 33

Specialized pancreas cells that secrete:
Insulin: lowers blood sugar, stimulates protein production, amino acids

Glucagon: increased blood sugar

Question 34

Diabetes Mellitus: Types and what they are:

Answer 34

Type 1: less common. Destruction of beta cells, do not release insulin-no glucose regulation.
Type 2: common (lifestyle). Insulin resistance–> beta cells still work but targeting cells are less sensitive
Gestational diabetes:
-usually disappears after childbirth.

Question 35

What is stress? lol

Answer 35

Stressor:

• stimulus that threatens homeostasis
• physical and psychological

Stress response:
-achieving stability through change

Question 36

Stages of stress:

Answer 36

Immediate:
- sympathetic (seconds):fight or flight

-sympathetic-adrenomedullary(Sam)( 20-30 seconds) takes a little longer: stimulates rapid mobilization of metabolic resources (ex. increase in o2 stores for fight or flight, redirecting of blood to important organs.

Prolonged:
-HPA-axis–>. its, hrs, wks
regulate metabolism, immune response and general homeostasis