Lecture 17 Flashcards Preview

Anatomy and Physiology II > Lecture 17 > Flashcards

Flashcards in Lecture 17 Deck (44):
1

Role of the Respiratory Center:

Respiration controlled by neurons in pons & medulla

2

3 groups of neurons

medullary rhythmicity
pneumotaxic
apneustic centers

3

Medullary Rhythmicity Area:

Controls basic rhythm of respiration
Inspiration for 2 seconds, expiration for 3

4

Autorhythmic cells active for

2 seconds then inactive

5

Expiratory neurons:

inactive during most quiet breathing only active during high ventilation rates

6

Pneumotaxic Area

constant inhibitory impulses to inspiratory area

7

Apneustic Area

stimulatory signals to inspiratory area to prolong inspiration

8

Regulation of Respiratory Center: Cortical Influences

-voluntarily alter breathing patterns
-limitations are buildup of CO2 & H+ in blood
-inspiratory center is stimulated by increase in either

9

Central chemoreceptors in medulla:

-respond to changes in H+ or pCO2
-hypercapnia = slight increase in pCO2 is noticed

10

Peripheral chemoreceptors:

-respond to changes in H+ , pO2 or PCO2
-aortic body---in wall of aorta
-carotid bodies--in walls of common carotid arteries

11

hypoxia =

deficiency of O2

12

hypoxic hypoxia--

low pO2 in arterial blood

13

anemic hypoxia--

too little functioning Hb

14

ischemic hypoxia--

blood flow is too low

15

histotoxic hypoxia--

cyanide poisoning

16

Quick breathing rate response to exercise:

input from proprioceptors

17

Inflation Reflex (Hering-Breurer reflex):

big deep breath stretching receptors produces urge to exhale

18

Factors increasing breathing rate:

emotional anxiety, temperature increase or drop in blood pressure

19

Apnea or cessation of breathing:


by sudden plunge into cold water, sudden pain, irritation of airway

20

Smoker is easily “winded” with moderate exercise:

1. nicotine constricts terminal bronchioles
2. carbon monoxide in smoke binds to hemoglobin
3. irritants in smoke cause excess mucus secretion
4. irritants inhibit movements of cilia
5. in time destroys elastic fibers in lungs & leads to emphysema

21

Asthma:

is an inflammatory disorder of the airways, which causes attacks of wheezing, shortness of breath, chest tightness

22

Influenza:

viral infection that affects mainly the nose, throat, bronchi and, occasionally, lungs. High fever, aching muscles, headache and severe malaise, non-productive cough, sore throat and rhinitis

23

GI tract:

mouth
pharynx and esophagus
stomach
small and large intestine
rectum and anus

24

Mouth function:

bite, chew, swallow

25

function of Pharynx and esophagus----

transport

26

function of Stomach----

mechanical disruption; absorption of water & alcohol

27

function of Small intestine--

chemical & mechanical digestion & absorption

28

function of Large intestine----

absorb electrolytes & vitamins (B and K)

29

function of rectum and anus

defecation

30

Layers of the GI Tract:

1. Mucosal layer
2. Submucosal layer
3. Muscularis layer
4. Serosa layer

31

Mucosa:

1. Epithelium
2. Lamina propria
3. muscularis mucosae

32

Epithelium:

stratified squamous(in mouth,esophagus & anus) = tough
simple columnar in the rest

33

Lamina propria:

-thin layer of loose connective tissue
-contains BV and lymphatic tissue

34

Muscularis mucosae---

-thin layer of smooth muscle
-causes folds to form in mucosal layer
-increases local movements increasing absorption with exposure to “new” nutrients

35

Submucosa:

-Loose connective tissue:
containing BV, glands and lymphatic tissue
-Meissner’s plexus---

36

Meissner’s plexus---

parasympathetic
innervation

37

Skeletal muscle =

voluntary control
in mouth, pharynx , upper esophagus and anus
control over swallowing and defecation

38

Smooth muscle =

involuntary control
inner circular fibers & outer longitudinal fibers
mixes, crushes & propels food along by peristalsis

39

Auerbach’s plexus (myenteric)--

both parasympathetic & sympathetic innervation of circular and longitudinal smooth muscle layers

40

Serosa:

-An example of a serous membrane
-Covers all organs and walls of cavities
-Secretes slippery fluid
-Consists of connective tissue covered with simple squamous epithelium

41

Peritoneum:

-visceral layer covers organs
-parietal layer lines the walls of body cavity

42

Peritoneal cavity:

potential space containing a bit of serous fluid

43

Parts of the Peritoneum:

Mesentery
Mesocolon
Lesser omentum
Greater omentum

44

Peritonitis =

inflammation
trauma
rupture of GI tract
appendicitis
perforated ulcer