Neuroendocrine system

Question 1

the neuroendocrine system

Answer 1

maintains homeostasis

Question 2

homeostasis

Answer 2

the condition of equilibrium (balance) in the body’s internal environment due to the constant interaction of the body’s many regulatory processes

Question 3

the nervous system

Answer 3

controls body actions through sending and receiving nerve impulses

Question 4

the endocrine system

Answer 4

controls body activities by releasing mediator molecules called hormones

Question 5

the neuroendocrine system functions

Answer 5

1. the nervous system causes muscles to contract or glands to secrete
2. the endocrine system affects virtually all tissues by
   - altering metabolism
   - regulating growth and development
   - influencing reproductive processes
3. parts of the nervous system stimulate or inhibit the release of hormones
4. hormones may promote or inhibit the generation of nerve impulses

Question 6

intro to nervous system

Answer 6

mass of two kg boy mass

one of the smallest yet most complex of the 11 body systems

Question 7

nervous tissue

Answer 7

two types:

1. neurons
2. neuroglia (glial cells)

Question 8

neurons

Answer 8

neurons = nerve cells

• excitable
• some are tiny (less than 1mm)
• longest cell sciatic nerve

Question 9

neuron structure

Answer 9

1. dendrites
2. cell body
3. axon

Question 10

dendrites

Answer 10

• the receiving portions of a neuron

- short and highly branched

Question 11

cell body

Answer 11

• contains nucleus and other organelles (lysosomes, mitochondria, golgi complex)
• receives nerve impulses

Question 12

axon

Answer 12

• arises at the axon hillock

- conducts nerve impulse away from cell body to axon terminals

Question 12

axon

Answer 12

• arises at the axon hillock

- conducts nerve impulse away from cell body to axon terminals

Question 13

axon - synaptic end bulbs

Answer 13

• at end of axon terminals
• contain vesicles filled with neurotransmitters
• neurotransmitters excite or inhibit other neurons or an effector (muscle fibres or gland cells)

Question 14

neuron - function

Answer 14

• single nerve cell (fibre) microscopic
• function: communication within the body by generation and conduction of nerve impulses
• functional unit of nervous system

Question 15

nerve

Answer 15

• bundle of axons, connective tissue and blood vessels

- macroscopic

Question 16

functional classification of neurons

Answer 16

sensory (afferent-towards) neurons
- transport sensory impulses (information) from skin, muscles, joint, sense organs and viscera - CNS
interneurons
- connect sensory to motor neurons
- 90% of neurons in the body
- integrate (process) sensory input and initiate responses
motor
- send motor impulses from CNS - muscles and glands

Question 17

neuroglia

Answer 17

• much smaller than neurons, but 5-25 times more numerous
• non-excitable - do not generate electrical impulses
• found in both the central nervous system (CNS) and the peripheral nervous system (PNS)
• provide neurons with structural and metabolic support

Question 18

types of neuroglia

Answer 18

central nervous system
1. astrocytes - largest, most numerous, BBB
2. oligodendrocytes - myelin sheath
3. microglia - phagocytes
4. ependymal - produce cerebrospinal fluid
peripheral nervous system
1. schwann cells - myelin sheath
2. satellite cells - structural support, regulate exchange of materials

Question 19

myelinated neurons

Answer 19

myelin sheath - structure

• a lipid / protein covering (white in colour) produced by:
• oligodendrocytes (CNS)
• schwann cells (PNS)

myelin sheath - function

• surrounds and electrically insulates most axons
• increases the speed of nerve impulse conduction (covered later in the nervous system lecture series)