Bio 22 Post Lab Exam 3

POST-LABORATORY DISCUSSION FOR EXAMINATION 3

Respiratory, Digestive, Circulatory and Urogenital

DISCUSSION OUTLINE

• Exercise 14: Respiratory System

• Exercise 16: Digestive System

• Exercise 18: Circulatory System

• Exercise 20: Urogenital System

• Physiology of Respiration, Digestion and Circulation shall be taken cared of by the reporters

THE RESPIRATORY SYSTEM

• RESPIRATION: process by which gaseous exchange occurs between organism and its environment

• RESPIRATORY PROCESS: involves diffusion of gases through moist semi-permeable membranes

• simple organisms: simple diffusion via integument

• complex organisms: Respiratory System

RESPIRATORY SYSTEMS OF THE ANIMAL

KINGDOM

• Sponges and Jellyfish lack specialized organs for gas exchange and take in gases directly from the surrounding water

RESPIRATORY SYSTEMS OF THE ANIMAL

KINGDOM

• GILLS

• internal

• external

Gills greatly increase the surface area for gas exchange

Water flows over gills in one direction while blood flows in the opposite direction through gill capillaries

RESPIRATORY SYSTEMS OF THE

ANIMAL KINGDOM

• TRACHEA

• tubes that carry air directly to cells for gas exchange

• Spiracles: openings at the body surface that lead to tracheae (branch into smaller tubes known as tracheoles)

• LUNGS

LUNGS: birds• Birds depend on their respiratory system

for temperature control and to provide a tremendous amount of oxygen to support the production of energy needed during flight

• have evolved air sacs that extend off their lungs

• air sacs occupy space within the body cavity = help to reduce weight as well

• the air in the air sacs moves into the lungs when bird exhales = allows the lungs to be filled with large volumes air

• ROUTE: posterior air sac->lungs->anterior air sac->out of body

LUNGS : frogs• Gas exchange in frogs and toads is

through:

• cutaneous respiration (1/3)

• via skin

• pulmonary respiration (2/3)

• via lungs

• buccopharyngeal respiration (small amount)

• via mouth and lining of pharynx

HOW DO FROGS RESPIRE WHEN UNDERWATER

• SKIN: a uniform capillary network lies in a plane directly beneath the epidermis facilitates gas exchange between the capillary bed and the environment by both diffusion and convection (mucus layer aids in this gas exchange by dissolving respiratory gases)

• Internal Nares (nostrils): opening to allow air in helps frog breathe while floating on water

NEGATIVE vs POSITIVE PRESSURE BREATHING

• NEGATIVE: small throat pouch pulls down drawing air through the nostrils into the mouth

• POSITIVE: valves in the nostrils close and the throat pouch pushes upwards forcing the air into the lungs

• With the valves in the nostrils still closed, the throat pouch pulls down sucking the air from the lungs back into the mouth

• The valves in the nostrils open, the tongue blocks passage to the lungs, and the throat pouch pushes the air from the mouth back into the atmosphere

• A rich supply of blood vessels to its thin skin enables it to absorb large amounts of oxygen while under water

WHAT YOU NEED TO KNOW

• PARTS AND FUNCTION OF FROG RESPIRATORY SYSTEM

• COMPARE BREATHING IN FROG AND MAN

lungsGLOTTIS

VOCAL CORDS VS VOCAL SACS

• vocal cords: two muscular cords that run longitudinally along the larynx

• PURPOSE: croaking sound is produced by air passing over the vocal cords in the larynx of the throat, so it continues a true voice (loud call is produced usually by males during the breeding season)

• vocal sac: a flap of skin in the front of their throats which allows frogs to croak, trill and ribbit

• HOW: frog inhales = vocal sac filled with air = vocal sac stretch out like a balloon (with its mouth closed, frog forces air from this sac back and forth over its vocal cords, producing a loud, repetitive sound

RESPIRATION: IMPORTANT POINTS TO REMEMBER

• MOIST SEMIPERMEABLE MEMBRANE: moisture allows oxygen gas to dissolve and at the same time allow it to diffuse across the membrane

• RESPIRATION AND CIRCULATION: cardiovascular system carries exchanges gases with respiratory system for transport of important gases throughout the body

EXTERNAL AND INTERNAL RESPIRATION

• EXTERNAL RESPIRATION

• gas exchange

• between lungs (alveoli) and blood

• INTERNAL RESPIRATION

• gas transport

• between blood to tissues

EXTERNAL AND INTERNAL RESPIRATION

INHALATION & EXHALATION

THE DIGESTIVE SYSTEM

Ingestion and Mechanical Digestion

Chemical Digestion

Defecation

HOW DO ORGANISMS EAT?

• Modes of Nutrition

• Autotrophy

• Heterotrophy

• Types of Digestion

• Intracellular

• Extracellular

• Modes of feeding

• Filter feeding

• Fluid feeding

• Bulk feeding

DIGESTIVE SYSTEMS

• INCOMPLETE

• single opening

• both for input and output

• sponges, cnidarians, ctenophores, flatworms

• COMPLETE

• two openings

• one for input and the other for output

• nematodes, annelids, molluscs, arthropods, echinoderms and chordates

WHAT YOU NEED TO KNOW

•PARTS AND FUNCTION OF FROG DIGESTIVE TRACT (review!)

• DIGESTIVE GLANDS AND THEIR FUNCTION

• HISTOLOGY: HOW THEY RELATE WITH THEIR FUNCTION

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IMPORTANT DIGESTION FACTS YOU NEED TO

KNOW

• SUSPENSORY STRUCTURES AND FUNCTION

• PYLORIC SPHINCTERS AND FUNCTION

• MICROVILLI AND FUNCTION

• GOBLET CELLS AND FUNCTION

• ACINAR CELLS AND CRYPTS OF LIEBERKUHN AND FUNCTION

SUSPENSORY STRUCTURES

• mesogastrium

• membrane suspending the stomach

• mesenterium

• membrane suspending the small intestines

• mesorectum

• membrane suspending the large intestines

SUSPENSORY STRUCTURES

•gastroduodenal omentum

•connects duodenum to the stomach

•hepatoduodenal omentum

•connects liver to duodenum

Mesentery: organ to body wall

Omentum: organ to organ

HISTOLOGY IN RELATION TO FUNCTION: STOMACH

RUGAE

• tunica serosa

• tunica muscularis

• submucosa

• tunica mucosa

• muscularis mucosa

• lamina propria

• simple columnar epithelium

• tunica mucosa

• muscularis mucsa

• lamina propria

• simple columnar epithelium

HISTOLOGY IN RELATION TO FUNCTION: SMALL INTESTINE VILLI

• tunica serosa

• tunica muscularis

• tela submucosa

• tunica mucosa

• lamina propria

• simple columnar epithelium

• goblet cells

• crypts of Lieberkuhn

• BRUSH BORDER/MICROVILLI: increase area for absorption

• GOBLET CELLS: secretes mucus which protects the digestive organs digest themselves; eases passage of food

• CRYPTS OF LIEBERKUHN: secretes sucrase, maltase, endopeptidase and exopeptidase

HISTOLOGY IN RELATION TO FUNCTION: LIVER

HEPATIC TRINITY

• hepatic trinity/triad

• bile duct

• hepatic artery

• hepatic vein

HISTOLOGY IN RELATION TO FUNCTION: PANCREAS

ACINAR CELLS

• acinar cells (exocrine)

• zymogen granules: secretory vesicles

• islets of Langerhans (endocrine)

• release insulin and glucagon to regulate blood glucose level

CIRCULATORY SYSTEMS

• OPEN:

• Circulatory medium directly bathes peripheral tissues

• Blood is conveyed directly to organs

• Less readily regulated blood distributed

• Usually a low pressure system

• Sustained pressure is possible (due to small body size)

• Return to heart is often slow

• CLOSED:

• Circulatory medium in vessels; tissues are not bathed in CM

• Blood is conveyed directly to organs

• Well-regulated blood distribution (via the sphincters, valves and hormones)

• Usually high pressure system

• Hydraulic pressure sustained

• requires high peripheral resistance (provided by arteries’ elastic vessels)

THE FROG’S HEART

• PARTS: pericardial cavity; pericardium; ventricle; atria/auricle; conus arteriosus; sinus venosus

• HEART: pumps blood to different parts of the body

• VALVES: prevents back flow of blood

• spiral valves: prevents mixing of deoxygenated and oxygenated blood

THE BLOOD VESSELS: ARTERY, VEIN AND

CAPILLARIES

FROG ARTERIAL AND VENOUS SYSTEM

CHALLENGE: Can you trace the path of blood?

UROGENITAL SYSTEM

• EXCRETORY

• elimination of metabolic wastes

• Example: urea, uric acid, ammonia

• REPRODUCTIVE

• production of sex cells or gametes

EXCRETION BY ANIMALS

Many invertebrates such as flatworms use a nephridium as their excretory organ. At the end of each blind tubule of the nephridium is a ciliated flame cell. As fluid passes down the tubule, solutes are reabsorbed and returned to the body fluids.

Excretory system of an earthworm: metanephridium

Body fluids are drawn into the Malphigian tubules by osmosis due to large concentrations of potassium inside the tubule. Body fluids pass back into the body, nitrogenous wastes empty into the insect's gut. Water is reabsorbed and waste is expelled from the insect.

Paired Kidneys of Vertebrates

URINE FORMATION IN VERTEBRATES

1

2

3

4

5Urine Production

1. Filtration in the glomerulus and nephron capsule.

2. Reabsorption in the proximal tubule.

3. Tubular secretion in the Loop of Henle.

KIDNEYS: histology

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Glomerulus: simple cuboidal epithelium

REPRODUCTIVE SYSTEMS

• MALE

• TESTIS/TESTES

• FEMALE

• OVARY

• OVIDUCT

MALE: histology

• spermatocysts

• seminiferous tubules

• spermatogonia

• primary spermatocytes

• secondary spermatocytes

• spermatids

• spermatozoa

• leydig cells: synthesis of testosterone

• sertoli cells: nourishment of the spermatogenic cells

FEMALE: histology

•oogonium:

•oocyte:

•nucleolus:

•follicle cells:

IMPORTANT POINTS• arrangement of cells in seminiferous tubules: man vs frog

IMPORTANT POINTS

• SPERMATOGENESIS: male form of gametogenesis; results in the formation of spermatocytes possessing half the normal complement of genetic material

• SPERMIOGENESIS: the spermatids begin to grow a tail, and develop a thickened mid-piece, where the mitochondria gather and form an axoneme

• OOGENESIS: process of meiosis in female organisms from an oogonium to a primary oocyte, to a secondary oocyte, and then to an ovum

• connective tissue covering developing oocytes: theca externa and theca interna

end of exam coverage