Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

PHGY 210 > digestion - lecture 2 > Flashcards

digestion - lecture 2 Flashcards

1
Q

what are target cells for excitatory and inhibitory enteric neurons

A

smooth muscle cell or secretory cell

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

describe ans modulation of ens

A

cns = parasym (excitatory - vagal nerve ach onto nicotinic receptors) and symp (inhibitory release noradrenaline)
sensory afferent fibers to cns = send info to cns to activate and ans = feedback on system

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

describe activation of ans

A

Sensory afferents –> parasym = medulla pregang and ans efferents have effect
sensory afferents –> sympa = spinal chord postgang - sympathetic chain of ganglia

efferent sends through vagal nerve

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

describe things that effect cns

A

afferent neurons with info from chemoreceptors, osomoreceptors and mechanoreceptors
sight, smell and taste of foods = activates directly salivation and also secretion in stomach
emotional state = if anxious = not induce saliva as usual
also cortical pathways
happens outside gut wall = efferent autonomic neuron’s synapse on enteric neurons

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

what doe ans modulation of ens allow for

A

integrated activity over longer distances along git
long extrinsic reflexes
ps = excites - can excite inhibitory neurons
s = inhibits - can inhibit inhibitory neurons

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

what is neural control of integration by

A

ens and ans

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

what are non git hormones

A

may influence growth and development of git

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

what are git hormones

A

may influence activities outside git

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

what do git hormones do

A

regulates activities inside git

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

describe hypothalamic feeding center - stimulates hunger

A

increase appetite
ghrelin released by glands in stomach during fasting

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

describe hypothalamic feeding center - induces satiety

A

decrease appetite
leptin released by fat cells with overeating

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

what is des

A

diffuse endocrine system
scattered among other cells in mucosa
largest most diverse endocrine system in body

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

name 5 most important gi hormones

A

gastrin
cck
secretin
gip
vip

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

name 3 modes of hormonal reg and describe briefly

A

autocrine = own cell
paracrine = on nearby cell
endocrine = through blood stream capillary and the effects target tissues

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

what type of hormones are git regulatory hormones

A

mostly peptides

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

describe how git hormones get to target cell

A

released from mucosa inton portal blood (hepatic portal vein) and goes to liver then to heart then to systemic circ and then to target tissues (tissues of gut)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

do git hormone have only one target

A

nooooooooo
multiple targets = diff effects like inhibitory or excitatory

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

what do git hormones interact with

A

each other and with neurotransmitters
synergistically = potentiate each other so net effect larger then alone
antagonistically = inhibits

19
Q

what does propulsion - flow - in git rely on

A

gradients of pressure deltaP
Variations in resistance 1/R

20
Q

describe pressure - propulsion in git

A

muscles produce coordinated contractions of muscular elements in git wall = creates gradient of pressure
circular muscles activated in diff parts = segmentation
activate in each region = peristalsis

21
Q

describe resistance - propulsion in git

A

normally little to no resistance
sphincters closed at rest
= prevents movement, high resistance but open at right time
stomach acid moves up lower esophageal sphincter = heart burn and damage

22
Q

describe normal flow in git

A

aboral - away from mouth
meets little to no resistance

23
Q

what are the phases of deglutition - swallowing

A

oral - voluntary
Pharyngeal
esophageal
gastric

24
Q

Describe pharynx

A

conveys food from mouth to eso through process known as deglutition = swallowing
connected to nasal passages and to mouth and eso and trachea

25
Q

describe esophagus

A

transports food into stomach
requires relaxation of 2 sphincters = ues and les

26
Q

describe oral phase - mouth–> pharynx

A

voluntary control
can chew or spit out
lips closed and use tongue
bolus = food in mouth, one sticky mass
once choose to swallow = involuntary

27
Q

describe oral phase - anterior mouth –> pharynx

A

push food up against hard palate
bolus moves to back of tongue and soft palate comes up and closes off nose
bolus moves to pharynx and epiglottis closes off trachea

28
Q

describe cortical vs medullary centers

A

Cortical = voluntary, ability to initiate
deglutition center = involuntary reflexes driven by coordinate movements- as soon as make decision to swallow - in medulla

29
Q

oral phase definition

A

transport of bolus (masticated insalivated mass of food) from anterior to posterior of mouth

30
Q

define deglutition center

A

series of reflexes coordinated in deglutition center in medulla oblongata

31
Q

name and describe 2 important aspects of oral phase

A

ability to initiate = voluntary –> cortex
coordinated movements = reflex involuntary –> medulla

32
Q

describe pharyngeal phase - gen

A

stretch of pharyngeal receptors once food at back of throat
larynx moves close to glottis to protect airways

33
Q

what is pharynx and describe

A

region where respiratory and digestive tracks cross
must be controlled by reflexes if not = food moves into airways and bacteria can lead to infections in lungs, ppl who have stroke have trouble swallowing

34
Q

name and describe 4 important aspects of pharyngeal involuntary phase

A

1 - passages to nose, mouth and trachea blocked
2 - apnea = stop breathing to decrease chance you pull in air when you swallow
3 - ues relaxes
4 - pharynx muscles contract and push bolus into eso
must happen in correct order

35
Q

describe path of air and food

A

respiratory tract for air going into trachea and git for bolus going to eso both tracts cross in pharynx

36
Q

describe deglutition reflexes - gen

A

a series of protective reflexes
initiated by stimulation of afferent fibers in pharnyx
Organized in deglutition center
closing off nasal, oral and laryngeal cavities = prevents misdirection of bolus
respiration briefly inhibited

37
Q

what is deglutition

A

swallowing of food

38
Q

describe deglutition reflexes - specific

A

Pharyngeal receptors send afferents to cns –> deglutition center in medulla - send efferents to do =
protective reactions
Deglutition apnea
relax ues
contract pharyngeal constrictor muscles

39
Q

describe upper esophageal sphincter - closure

A

impulses originate in cns
mediated by vagus nerve
releases ach (consTANTly) causing muscle contraction
striated muscle uper 1/3 eso and smooth muscle lower 2/3 eso

40
Q

describe upper esophageal sphincter - during deglutition

A

relaxation = impulses stop and muscles relax no ach
cricopharyngeus = striated muscle = where ues is

41
Q

describe pharyngeal phase - 4 aspects

A

involuntary
rapid = 1/5th of sec
stereotyped = reflex driven same sequence each time
temporospatial coordination = same sequence so wont choke, at right time and order

42
Q

describe esophageal phase

A

gradient of pressure moves down eso
vagus somatic = synapses on striated muscle
vagus autonomic = synapses on ens then smooth muscle
body of eso = in thoracic cavity
recall neg pressure in thoracic cavity = -5mmhg - -10mmhg
sphincters must be closed all the time

43
Q

describe whole of pharyngeal phase

A

bolus in pharnyx = reflexes cause it to move downwards
as moves down = presses on epiglottis and covers the glottis = secondary effect
reflexive contraction of vocal chords = larynx moves upwards and forwards to fit under base of tongue
glottis closes and protects lower airways = epiglottis and movement of larynx = deglutition reflex
ues relaxes and pharyngeal muscle contracts = push bolus across the released ues into eso

PHGY 210 (36 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions