packet 17 Flashcards
Respiration controlled by
neurons in pons & medulla
ON TEST
where is respiratory center located
respiratory center
3 groups of neurons
medullary rhythmicity
pneumotaxic
apneustic centers
rhythm of breathing
medullary rythmicity
lung movement
pneumotaxic
come in to play when stop breathing
apneustic center
Controls basic rhythm of respiration
Inspiration for 2 seconds, expiration for 3
Autorhythmic cells active for 2 seconds then inactive
Expiratory neurons inactive during most quiet breathing only active during high ventilation rates
medulaary rthymicity area
constant inhibitory impulses to inspiratory area
neurons trying to turn off inspiration before lungs too expanded
Pneumotaxic Area
stimulatory signals to inspiratory area to prolong inspiration
Apneustic Area
voluntarily alter breathing patterns
limitations are buildup of CO2 & H+ in blood
inspiratory center is stimulated by increase in either
if you hold breathe until you faint—-breathing will resume
cortical influences–regulation of respiratory center
chemical regulation of respiration
central chemoreceptors in medulla
peripheral chemoreceptors
respond to changes in H+ or pCO2
hypercapnia = slight increase in pCO2 is noticed
Central chemoreceptors in medulla
respond to changes in H+ , pO2 or PCO2 aortic body---in wall of aorta nerves join vagus carotid bodies--in walls of common carotid arteries nerves join glossopharyngeal nerve
Peripheral chemoreceptors
MICRO ESSAY
name 2 conditions that will increase, decrease ventilation rate and depth
Increase 1. voluntary 2. increase body temp Decrease 1. lower temp 2. pain causes apnea
Deficiency of O2 at tissue level
hypoxia
low pO2 in arterial blood
high altitude, fluid in lungs & obstructions
hypoxic hypoxia-
too little functioning Hb
hemorrhage or anemia
anemic hypoxia-
blood flow is too low
ischemic hypoxia-
cyanide poisoning
blocks metabolic stages & O2 usage
histotoxic hypoxia-
Quick breathing rate response to exercise
input from proprioceptors
Inflation Reflex (Hering-Breurer reflex) big deep breath stretching receptors produces urge to exhale
Factors increasing breathing rate
emotional anxiety, temperature increase or drop in blood pressure
Apnea or cessation of breathing
by sudden plunge into cold water, sudden pain, irritation of airway
Respiratory Influences & Reflex Behaviors
Smoker is easily “winded” with moderate exercise
nicotine constricts terminal bronchioles
carbon monoxide in smoke binds to hemoglobin
irritants in smoke cause excess mucus secretion
irritants inhibit movements of cilia
in time destroys elastic fibers in lungs & leads to emphysema
trapping of air in alveoli & reduced gas exchange
smokers lowered respiratory efficiency
is an inflammatory disorder of the airways, which causes attacks of wheezing, shortness of breath, chest tightness Animals (pet hair or dander) Dust Changes in weather Chemicals in the air or in food Exercise Mold Pollen Strong emotions (stress) Smoke
asthma
Influenza is a 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
Easily carried from person to person via droplets and small particles produced when infected people cough or sneeze.
Recovery 1-2 weeks. However, in the very young, the elderly, and those with other serious medical conditions, infection can lead to severe complications of the underlying condition, pneumonia and death.
influenza
bite, chew, swallow
mouth
transport
Pharynx and esophagus-
mechanical disruption; absorption of water & alcohol
stomach
chemical & mechanical digestion & absorption
small intestine
absorb electrolytes & vitamins (B and K)
large intestine
defecation
rectum and anus
layers of GI tract
Mucosal layer
- Submucosal layer
- Muscularis layer
- Serosa layer
layers of mucosa
epithelium
lamina propria
muscularis mucosae
stratified squamous(in mouth,esophagus & anus) = tough
simple columnar in the rest
secretes enzymes and absorbs nutrients
specialized cells (goblet) secrete mucous onto cell surfaces
enteroendocrine cells—secrete hormones controlling organ function
epithelium
thin layer of loose connective tissue
contains BV and lymphatic tissue
lamina propria
thin layer of smooth muscle
causes folds to form in mucosal layer
increases local movements increasing absorption with exposure to “new” nutrients
muscularis mucosae
Loose connective tissue
containing BV, glands and lymphatic tissue
Meissner’s plexus--- parasympathetic innervation vasoconstriction local movement by muscularis mucosa smooth muscle
submucosa
types of muscularis
skeletal muscle
smooth muscle
auerbach’s plexus
voluntary control
in mouth, pharynx , upper esophagus and anus
control over swallowing and defecation
skeletal muscle
involuntary control
inner circular fibers & outer longitudinal fibers
mixes, crushes & propels food along by peristalsis
smooth muscle
both parasympathetic & sympathetic innervation of circular and longitudinal smooth muscle layers
Auerbach’s plexus (myenteric)–
An example of a serous membrane
Covers all organs and walls of cavities not open to the outside of the body
Secretes slippery fluid
Consists of connective tissue covered with simple squamous epithelium
serosa
visceral layer covers organs
parietal layer lines the walls of body cavity
peritoneum
potential space containing a bit of serous fluid
peritoneal cavity
parts of peritoneum
Mesentery
Mesocolon
Lesser omentum
Greater omentum
