RESPIRATORY SYSTEM

Respiration- Ventilation or breathing (the movement of air into and out of the lungs; the exchange

of oxygen and carbon dioxide between air in the lungs and the blood; the transport of O2 and CO2 in the blood; and the exchange of O2 and CO2 between the blood and the tissues.

- a.k.a. cellular metabolism or cellular respiration

• Functions of the Respiratory System o For gas exchange

o Regulation of the blood Ph

o For voice production

o Olfaction

o Innate Immunity

o Ventilation

• Anatomy of the Respiratory System Upper Respiratory Tract

o External Nose

- Visible structure that forms a prominent feature of the faceo Nasal Cavity

- extends from the nares (external opening of the nose) to choane (opening into the pharynx)- Hard palate is considered as its roof

o Pharynx

- found within the throat- Common passageway for the respiratory and digestive system

Nasal Septum- Partition dividing the nasal cavity into right and left parts

Deviated Nasal Septum- Occurs when the septum bulges into one side

Hard Palate - Forms the floor of the nasal cavity

Conchae - Three prominent bony ridges- Present on the lateral walls on each side of the nasal cavity

Paranasal Sinuses- Air-filled spaces within bones- They include the maxillary, frontal, ethmoidal, and sphenoidal sinuses

Nasolacrimal ducts- Carry tears from the eyes, also open into the nasal cavity

Lower Respiratory Tract

PHARYNX - Common passageway for the digestive and respiratory systems

*Nasopharynx- The superior part of the pharynx- Located posterior to the choane and superior to the soft palate (incomplete muscle

and connective tissue partition)Uvula

- Grape-like, found in the posterior extension of the soft palatePharyngeal Tonsil

- Helps defend the body against infection*Oropharynx

- Extends from the uvula to the epiglottis, and the oral cavity opens into the oropharynx

- Lined with stratified squamous epithelium2 Sets of TonsilsPalatine Tonsil

- Located in the lateral walls near the border of the oral cavity and the oropharynxLingual Tonsil

- Located on the surface of the posterior part of the tongue

*Laryngopharynx- Passes posterior to the larynx and extends from the tip of the epiglottis to the

esophagus

LARYNX- located anterior to the throat and extends from the base of the tongue to the trachea

Thyroid Cartilage- Adam’s apple- Largest cartilage- Attached superiorly to the hyoid bone

Cricoid Cartilage- Forms the base of the larynx on which the cartilages rest

Epiglottis- Helps prevent swallowed materials from entering the larynx

Vestibular Folds- False vocal cords

Vocal Folds- True vocal cords- Source of voice production

TRACHEA- “windpipe”- Membranous tube attached to the larynx

BRONCHI- Divides from the trachea and connects to the lungs

LUNGS- Principal organ for respiration- Cone-shaped, base is resting on the diaphragm - Right lung has 3 lobes, Left lung has 2 lobes

Alveolar Ducts- Division of each respiratory bronchiole

Alveoli- Small air sacs where which acts as doorways for air

Alveolar Sacs- Chambers connected to two or more alveoli- 300million alveoli in the lungs

Respiratory Membrane- where gas exchange between air and blood takes place- very thin to facilitate diffusion of gases- consists of 6 layers

o fluid lining the alveolus

o alveolar epithelium

o basement membrane of the alveolar epithelium

o thin interstitial space

o basement membrane of the capillary endothelium

o capillary endothelium

Pleural Cavities

- lined with a serous membrane called the pleura; consists of Parietal pleura (lines the walls of thorax, diaphragm, and mediastinum) and visceral pleura (covers the surface of the lungs)

•Ventilation and Respiratory VolumesVentilation

- breathing, the process of moving air into and out of the lungs- Inspiration, inhalation

o Movement of air into the lungs

- Expiration, exhalationo movement of air out of the lungs

Diaphragm- large dome of skeletal muscle that separates the thoracic cavity from the abdominal

cavity

PRESSURE CHANGES AND AIR FLOW2 Principles of Air Flow:

1. Changes in volume result in changes in pressure- Ex. Volume of container increases, pressure in the container decreases.

2. Air flows from an area of higher concentration to and area of lower pressure

Alveolar Pressure- Air pressure within the alveoli

Atmospheric Pressure- Air pressure outside the body

LUNG RECOIL- Tendency of an expanded lung to decrease in size

- Happens during quite expiration - Occur because the connective tissue of the lungs contain elastic fibers and because

the film of fluid lining the alveoli has surface tension

SURFACTANT- Surface acting agent- A mixture of lipoprotein molecules produced by secretory cells of the alveolar

epithelium

DIGESTIVE SYSTEM

Digestive system- Where food is broken into smaller and smaller particles

• Functions of the Digestive System 1. Ingestion of Food

2. Digestion of Food3. Absorption of Nutrients4. Elimination of Wastes

• Oral Cavity, Pharynx and Esophagus

ORAL CAVITY- Mouth, first part of the digestive tract

Lips - Muscular structures formed mostly by the orbicularis oris muscle

Tongue- Large, muscular organ that occupies most of the oral cavity- Frenulum – thin fold of tissue

Teeth- Adult – 32- Child – 20 - Composed of incisors, canine, premolars, molars, and wisdom teeth- Consists of crown, neck and root

- Pulp cavity – center of the tooth – filled with blood vessels, nerves, and connective tissue (pulp)

- Dentin – living, cellular, bonelike tissue- Enamel – extremely hard, acellular substance

Salivary Glands- Three major pairs: parotid, submandibular, sublingual glands- Produces saliva that contains enzymes that break down food- Saliva – helps keep the oral cavity moist

PHARYNX- Throat- Connects the mouth with esophagus- Consists of 3parts: nasopharynx, oropharynx and laryngopharynx

ESOPHAGUS- Gullet- Muscular tube, lined with moist stratified squamous epithelium, that extends from the

pharynx to the stomach- About 25cm long- Sphincters: Esophageal and Cardiac

Swallowing- deglutition

• Stomach- enlarged segment of the digestive tract in the left superior part of the abdomen

Gastroesophageal opening- opening form the esophagus into the stomach

Fundus- superior part of the stomach

Pyloric- opening from the stomach to the small intestine

Rugae- large folds of the stomach- “wrinkles”

Chyme- Semifluid mixture that forms when food begins to be broken down

• Small Intestine

- About 6meters long- Major absorptive organ- Consists of 3 parts: Duodenum, Jejunum and the Ileum

Duodenum- About 25cm long- Contains bile and pancreatic ducts

Jejunum- 2.5m long and makes up two-fifths of the total length of the small intestine- Absorbs nutrients

Ileum- 3.5m long, three-fifths of the small intestine

• Large Intestine- Absorb water from indigestible food- Consists of the cecum, colon and anal canal

Cecum- Proximal end of the large intestine where it joins with the small intestine at the

ileocecal junction- About 6cm- Appendix – 9cm long – attached to the cecum

Colon- 1.5-1.8m long- Consists of ascending, transverse, descending and sigmoid colon

Rectum- Straight, muscular tube that begins at the termination of the sigmoid colon and ends

at the anal canalAnal Canal

- Last 2-3cm of the digestive tract- Begins at the inferior end of the rectum and ends at the anus

• Liver and Pancreas

Liver- weighs about 1.36kg (3lbs)- located at the right upper quadrant of the abdomen

Functions:o Digestion

o Excretion

o Nutrient Storage

o Nutrient Conversion

o Detoxification of harmful chemicals

o Synthesis of new molecules

*Bile - has an important role in digestion by diluting and neutralizing stomach acid and

increasing the efficiency of fat digestion

Pancreas- Posterior to the stomach in the inferior part of the left upper quadrant- Head is near the midline of the body while the tail extends to the left where it touches

the spleen- Pancreatic Islets/Islets of Langerhans – produce the hormones insulin and

glucagon

EXCRETORY/URINARY SYSTEM

Urinary System- Consists of:

o 2 kidneys

o 2 ureters

o A urinary bladder

o A urethra

•Functions of the Urinary System1. Excretion2. Regulation of blood volume and pressure3. Regulation of the concentration of solutes in the blood4. Regulation of extracellular fluid Ph5. Regulation of red blood cell synthesis6. Regulation of Vit.D synthesis

•Kidneys- Bean-shaped organs, about the size of a tightly clenched fist- Lie on the posterior abdominal wall

Retroperitoneal- Structures that are behind the peritoneum

Renal Capsule- Layer of connective tissue that surround the kidney

Hilum

- Renal artery and nerves enter and where the renal vein, ureter and lymphatic vessels exit

- IndentationRenal Sinus

- Contains blood vessels, part of the system for collecting urine and adipose tissueRenal Cortex

- Outer portionRenal Medulla

- Inner portionRenal Pyramid

- Boundary between the cortex and the medulla- Tips project towards the center of the kidney

Calyx- Funnel shaped structure- Surround the tip of each renal pyramid

Renal Pelvis- Larger funnel where calyces from all the renal pyramids join

Nephron- Functional unit of the kidney- 1.3million in each kidney- Renal Corpuscle – structure that contains a Bowman’s capsule and a glomerulus- Bowman’s Capsule – enlarged end of the nephron; consists of specialized cells

called Podocytes (wrap around the glomerular capillaries)- Glomerulus – tuft of capillaries that lies within the indentation of the Bowman’s

capsule

Filtration Membrane- Formed by the endothelium of the glomerular capillaries, the podocytes and the

basement membranes - Found in the renal corpuscle

Filtrate- Fluid that passes across the filtration membrane

Proximal Tubule- Area where the filtrate passes through first

Loop of Henle- it contains both descending and ascending loops- water and solutes passes through the loop of henle’s thin wall by the process of

diffusionDistal Tubule

- structure found between the loop of henle and the collecting ductCollecting Duct

- empties into the calyces- It carries fluid from the renal cortex through the renal medulla

• Ureters, Urinary Bladder and Urethra

Ureters- These are small tube that carry urine from the renal pelvis of the kidney into the

bladderUrinary Bladder

- Found in the pelvic cavity- Stores urine (maximum of 1000ml)

Urethra- Tube that exits the urinary bladder- Carries urine and other waste materials from the urinary bladder to the outside of the

body

REPRODUCTIVE SYSTEM

• Functions of the Reproductive Organ1. Production of Gametes2. Fertilization3. Development and nourishment of a new individual4. Production of reproductive hormones

• Male Reproductive Organ- Consists of the testes, a series of ducts, accessory glands and supporting structure.

Scrotum- Saclike structure containing the testes- Layer of loose connective tissue and a layer of smooth muscle (Dartos Muscle)- Cremaster Muscles – extensions of abdominal muscles in the scrotum

Testes- Male gonads, primary male reproductive organ- Oval organs, about 4-5cm long, within the scrotum- Seminiferous Tubules – where sperm cells develop- Interstitial Cells – produces testosterone- Germ Cells- Sustentacular Cells – give nourishment to the germ cells

Epididymis- Tightly coiled series of threadlike tubules that form a comma-shaped structure on the

posterior side of the testes- It is where the seminiferous tubules empty a new sperm and where they continue to

mature and develop the ability to swim and bind to oocytes

Ductus Deferens- “vas deferens”- Emerges from the epididymis and ascends along the posterior side of the testes to

become associated with the blood vessels and nerves that supply the testes

Urethra- Extends from the urinary bladder to the distal end of the penis- The passageway of both urine and male reproductive fluid

Penis- Male organ of copulation and functions in the transfer of sperm cells from the male to

the female- 3 columns of erectile tissue, with blood causes the penis to enlarge and become firm

(Erection):o Corporus Cavernosum

o Corpus Spongiosum

o Spongy Urethra

- Also a passageway of urine

Glands- Seminal Vesicles – glands consisting of many saclike structures located next to the

ampulla of the ductus deferens; about 5cm long- Prostate Gland – consists of both glandular and muscular tissue and is about the

size and shape of a walnut- Bulbourethral Gland – Cowper glands; pair of small, mucus secreting glands

located near the base of the penis

Secretions- Semen – mixture of sperm cells and secretions from the male reproductive organ

• Female Reproductive Organ

Ovaries - Small organs suspended in the pelvic cavity- Suspensory Ligament – extends from each ovary to the lateral wall- Ovarian Ligament – attaches the ovary to the superior margin of the uterus- Ovarian Follicle – contains an oocyte (female sex cell)

Uterine Tubes- Fallopian tubes, Oviduct- Extends from the area of the ovaries to the uterus

- Receives the secondary oocyte- Fimbriae – thin processes on the opening of each uterine tubes

Uterus- As big as a medium-sized pear- Oriented in the pelvic cavity- Main part: body, narrower part: cervix- 3 Layers:

o Perimetrium/Serous – outermost

o Myometrium/Muscular – consists of smooth muscle, quite thick, bulk of the

uterine wallo Endometrium – simple columnar epithelial cells with an underlying

connective tissue

Vagina- Female organ of copulation- Receives the penis during intercourse- Also allows menstrual flow and childbirth

External Female Genitalia- Vulva/Pudendum – external female genitalia; consist of vestibule and its

surrounding structures- Vestibule – space into which the vagina and urethra open- Labia Minora – thin, longitudinal skin folds- Clitoris – small, erectile structure

- Pepuce – fold of skin where the 2 labia minora unite over the clitoris- Labia Majora – lateral to the labia minora; 2 prominent, rounded folds of skin