Mock Exam

Primary function of the respiratory system

To exchange oxygen and carbon dioxide between the atmosphere and the blood

Difference between external and internal respiration

External respiration occurs between alveoli and blood while internal respiration occurs between blood and tissues

Correct airflow pathway

Nasal cavity → pharynx → larynx → trachea → bronchi → bronchioles → alveoli

Function of respiratory epithelium

Filters warms and humidifies incoming air while trapping particles in mucus

Purpose of the mucus elevator

Cilia move mucus and trapped pathogens upward toward the pharynx

Importance of turbulent airflow in nasal cavity

Improves air warming humidifying filtering and olfaction

Structure that prevents food from entering airway

Epiglottis

Reason tracheal cartilages are C-shaped

Allow esophagus expansion during swallowing while keeping airway open

Function of bronchioles

Regulate airflow resistance through smooth muscle contraction or relaxation

Type I alveolar cells

Thin cells specialized for gas exchange

Type II alveolar cells

Produce surfactant to reduce surface tension

Function of surfactant

Prevents alveolar collapse and increases lung compliance

Role of alveolar macrophages

Remove pathogens and debris from alveoli

Function of pleural membranes

Reduce friction and help lungs adhere to thoracic wall

Definition of pneumothorax

Air entering pleural cavity causing lung collapse

Tidal volume

Amount of air inhaled or exhaled during quiet breathing approximately 500 mL

Anatomical dead space

Air in conducting passages not involved in gas exchange approximately 150 mL

Boyle’s Law

Pressure and volume are inversely related

Why air enters lungs during inspiration

Intrapulmonary pressure becomes lower than atmospheric pressure

Primary muscles of inspiration

Diaphragm and external intercostals

Accessory muscles of inspiration

Sternocleidomastoid scalenes and pectoralis minor

Difference between hyperventilation and hyperpnea

Hyperventilation exceeds metabolic needs while hyperpnea matches increased metabolic demand

Definition of lung compliance

Ease with which lungs expand

Definition of elastance

Ability of lungs to recoil after stretching

Minute ventilation

Tidal volume multiplied by respiratory rate

Alveolar ventilation

(Tidal volume minus dead space) multiplied by respiratory rate

How oxygen is transported in blood

Mostly bound to hemoglobin

How carbon dioxide is transported in blood

Mostly as bicarbonate ions

Function of hemoglobin

Binds and transports oxygen in red blood cells

Right shift of oxygen dissociation curve

Hemoglobin releases oxygen more easily

Causes of right shift

Increased CO2 increased temperature and decreased pH

Function of carbonic anhydrase

Converts CO2 and water into carbonic acid

Chloride shift

Movement of chloride into RBCs as bicarbonate exits

Central chemoreceptors

Respond mainly to CO2 and pH changes in cerebrospinal fluid

Peripheral chemoreceptors

Respond to low oxygen high CO2 and low pH

Effect of COPD

Decreases airflow and impairs gas exchange

Function of DRG

Dorsal respiratory group controls quiet inspiration

Function of VRG

Ventral respiratory group assists forced breathing

Function of pontine centers

Smooth breathing rhythm and transition between inspiration and expiration

Normal atmospheric pressure at sea level

760 mmHg

Percentage of oxygen in atmosphere

Approximately 21 percent

Effect of altitude on gas exchange

Lower oxygen partial pressure reduces diffusion into blood

Primary functions of digestive system

Ingestion digestion absorption secretion motility and elimination

Function of saliva

Lubricates food and begins starch digestion

Function of salivary amylase

Breaks down starch into smaller carbohydrates

Function of tongue

Manipulates food assists swallowing and contains taste buds

Function of esophagus

Passageway moving food to stomach through peristalsis

Phases of swallowing

Oral voluntary phase followed by pharyngeal and esophageal involuntary phases

Definition of GERD

Backflow of stomach acid into esophagus causing irritation

Function of stomach

Stores mixes and chemically digests food into chyme

Special muscular layer in stomach

Oblique layer of muscularis externa

Parietal cell function

Secrete hydrochloric acid and intrinsic factor

Chief cell function

Secrete pepsinogen

Mucous cell function

Protect stomach lining with mucus

Function of pyloric sphincter

Controls movement of chyme into duodenum

Three sections of small intestine

Duodenum jejunum and ileum

Function of duodenum

Receives chyme bile and pancreatic enzymes for digestion

Function of jejunum

Major site of nutrient absorption

Function of ileum

Absorbs bile salts vitamin B12 and remaining nutrients

Function of villi

Increase surface area for absorption

Function of intestinal crypts

Produce intestinal secretions and new epithelial cells

Functions of large intestine

Absorbs water forms feces and eliminates waste

Definition of haustra

Pouches in large intestine aiding compaction

Haustral churning

Movement that slowly mixes fecal material

Function of appendix

Contains lymphoid tissue and supports immune function

Internal anal sphincter

Smooth muscle under involuntary control

External anal sphincter

Skeletal muscle under voluntary control

Function of liver

Produces bile processes nutrients detoxifies blood and stores glycogen

Role of bile in digestion

Emulsifies fats increasing surface area for enzymes

Function of gallbladder

Stores and concentrates bile

Function of pancreas in digestion

Produces digestive enzymes and bicarbonate

Endocrine pancreas function

Produces insulin and glucagon

Submucosa of GI tract

Contains blood vessels lymphatics and submucosal plexus

Muscularis externa function

Responsible for peristalsis and segmentation

Migrating motor complex

Clears digestive tract between meals

Enteric nervous system

Controls GI motility secretion and blood flow independently

Primary functions of kidneys

Filtration waste removal electrolyte balance pH regulation and blood pressure control

Pathway of urine

Kidney → ureter → bladder → urethra

Function of ureters

Transport urine from kidneys to bladder

Function of detrusor muscle

Smooth muscle that contracts during urination

Three portions of male urethra

Prostatic membranous and spongy urethra

Definition of micturition reflex

Neural reflex controlling urination

Functional unit of kidney

Nephron

Structures of renal corpuscle

Glomerulus and glomerular capsule

Function of afferent arteriole

Brings blood into glomerulus

Function of efferent arteriole

Carries blood away from glomerulus

Difference between cortical and juxtamedullary nephrons

Juxtamedullary nephrons have long loops of Henle for concentrating urine

Three nephron processes

Filtration reabsorption and secretion

Filtration

Movement of fluid from blood into nephron

Reabsorption

Movement of substances from filtrate back into blood

Secretion

Movement of substances from blood into filtrate

Three filtration barriers

Fenestrated endothelium basement membrane and filtration slits

Glomerular filtration rate GFR

Amount of filtrate formed by kidneys each minute

Myogenic regulation of GFR

Afferent arteriole constricts when stretched to maintain stable filtration

Tubuloglomerular feedback

Macula densa adjusts GFR based on filtrate flow

Role of peritubular capillaries

Receive reabsorbed water and solutes from nephron

Role of vasa recta

Maintain osmotic gradient in renal medulla

Countercurrent exchange

System that concentrates urine by maintaining medullary osmotic gradient

Function of ADH vasopressin

Increases water reabsorption in collecting ducts

Stimuli for ADH release

High osmolarity or low blood pressure