Ch. 49/50 Flashcards Preview

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Flashcards in Ch. 49/50 Deck (33):
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Spinal cord

31 pairs spinal neurons
Each nerve contains neurons which carry sensory info in and motor info out

1

resting potential

electric potential across the cell membrane of a nerve cell or muscle cell when the cell is not active

2

Peripheral nervous system

Neurons not included in CNS
Afferent- info towards the day
Efferent- info away from the brain

2

Brain stem

Links cerebrum to spinal cord
maintains necessary functions of the body

5

Meninges

Protects CNS
3 types- dura master, arachnoid layer, piña mater

6

endocrine system

transmits hormons into blood stream
slower acting than nervous system
regulates processes over days or even months

7

motor neurons

carry info from CNS to muscles and glands

8

hypothalamus

helps maintain homeostasis
directly and indirectly controls much of body's hormone production
coordinates many activities of nervous and endocrine system

9

sympathetic divisoin

part of autonomic nervous system
speeds up, uses energy
redirects blood when stressed or threatend

11

parasympathetic division

part of autonomic nervous system
slows down, less energy
controls internal environment during routine conditions

12

reflexes

involuntary, self- protective movements

13

synapses

special junctions at which neurons and cells communicate

14

refractory period

short period of time after the stimulation of a nerve during which the nerve cannot be stimulated

15

hormones

substances secreted by cells that act to regulate the activity of other cells in body
influence activity of distant target cells
steroid hormones-amino acid based hormones

16

neurotransmitters

chemical substance that transmits nerve impulses across a synapses

17

endocrine vs. exocrine system

endocrine- ductless, transmits hormones
exocrine- has ducts, secrete non-hormonal chemicals

18

amino acid based hormones vs. steroid hormones

amino acid- mostly water soluble,
steroid- fat soluble, can diffuse across membrane

19

target cells

specific cell to which a hormone is directed to produce a specific effect

20

ex. of negative feedback loops

lutenizing hormone (LH) in females stimulates estrogen production

21

types of receptors

mechanoreceptors- movement, pressure, tension
photoreceptors- variations in light
chemoreceptors- chemicals
thermoreceptors- changes in temp.
pain receptors- tissue damage

22

Central nervous system

Brain and spinal cord
control flow of info into the body

23

thyroid gland

two lobes located near lower larynx
produces and secretes the hormones thyroxine and triiodothyronine
regulates aspects of metabolism and mineral balance

24

Cerebellum

posterior portion of brain
Receives info from sensory neurons, uses info for coordination of muscles

24

action potential

sudden change in the polarity of the membrane of a neuron, gland cell, or muscle fiber that facilitates the transmission of electrical impulses

25

adrenal glands (adrenal medulla)

located above each kidney
causes body's reaction to stress

26

gonads

ovaries and testes
gamete-producing organs that also produce steroid sex hormones

27

thymus

located beneath sternum
helps development of immune system
stimulates formation of T cells

28

pituitary gland

located at base of brain
secretes hormones that affect other glands and organs
regulated by hypothalamus
posterior and anterior pituitary

29

growth hormone

regulates development of muscles and bones

30

insulin

lowers blood sugar by stimulating body cells to take in and store glucose

31

glucagon

increase blood sugar level by stimulating body cells to release glucose

32

Cerebrum

-2 hemispheres connected by corpus callosum
-four lobes
-groved surface increases surface area
-receives sensation and controls movement

33

pancreas

produce insulin and glucagon