Bahan Prof Rahmatina.

(1)

SIKLUS JANTUNG

(2)

The Cardiac Cycle

Definition:

The cardiac events that occur from the beginning

of one heartbeat to the beginning of the next

The cardiac cycle consists of:

- Diastole

:

period of relaxation, during

which the

heart fills with blood

- Systole

:

period of contraction, during

which

the heart ejects blood from its

(3)

Conductive System of Heart

SA Node (sinoatrial node)/ sinus node :

- located in the superior lateral wall of right atrium,

immediately below and slightly lateral to the opening of the superior vena cava

Internodal pathways:

- conductive system from SA node to AV node

AV node (atrioventricular node):

- located in the posterior septal wall of right atrium,

immediately behind tricuspid valve and adjacent to the opening of coronary sinus

AV bundle/ His bundle

(4)

(5)

(6)

(7)

(8)

Events of Cardiac Cycle

Generating and transmission of cardiac impulses:

1. Generating rhythmical impulses in SA node

2. Conducting the impulses rapidly throughout atria 

atria contract

3. Conducting impulses to AV node (delay 0,13 sec) 4. Conducting impulses through AV/ His bundle

(9)

…..Eve ts of Cardiac Cycle

Because of impulses generate in SA node and

delay i tra s issio to ve tricles → atria

contract (atrial systole) prior to ventricles

Ventricles still in relaxation period (

ventricular

diastole

), called

diastole



(10)

Filling of the ventricles during diastole

Rapid filling:

- Large amount of blood that accumulate in atria

because of closed of AV nodes, immediately push AV valves open and allow blood to flow rapidly into

ventricles; lasts for ± the first third of diastole Diastasis:

- During the middle third of diastole, only a small

amount of blood that continues to empty into atria from veins and passes directly into ventricles

Atrial systole:

- During the last third of diastole, atria contract and

give additional thrust to inflow of blood into ventricles

(11)

Emptying of the ventricles during systole

Period of isovolemic (isometric) contraction:

- When ventricular contraction begins, the

ventricular pressures build up and causing AV valves to close, but not sufficient to push semilunar valves open - There is no emptying of blood from ventricles

Period of ejection:

- Immediately after semilunar valves opened, blood begins to pour out of ventricles

Period of isovolemic (isometric) relaxation:

- When ventricular relaxation begins, the

ventricular pressures fall rapidly, allowing semilunar

valves to close, but not sufficient to cause AV valves open - There is no blood flow into ventricles

(12)

During ventricular contraction:

- Period of ejection

- Ventricular pressure rise cause blood to pour from ventricles into arterial system (aorta and pulmonary trunks)  - cardiac output (volume / minute) - stroke volume (volume/ contraction)

During atrial relaxation:

- Atrial pressure fall and allowing blood flow from veins into atria  venous return (volume/ minute)

(13)

The greater

venous return

, the greater the heart

muscle is stretched, the greater will be the force

of contraction and the greater

stroke volume

Within physiological limits, the heart pumps all

the blood that comes to it without allowing

excessive damming of blood in the veins

…..Eve ts of Cardiac Cycle

(14)

(15)

(16)

Ventricular Volume

End diastolic volume (EDV): 110

–

120 cc,

- Can be increased to

150

–

180 cc

Stroke volume (SV): 70 cc

- SV = EDV

–

ESV (110 cc

–

40 cc)

Ejection fraction: 60 %

- SV/EDV x 100%

End systolic volume (ESV): 40

–

50 cc,

- Can be decreased to

10

–

20 cc

(17)

(18)

Concepts of Preload and Afterload

Preload:

In assessing the contractile properties of

muscle, it is important to specify

the degree of

tension on muscle when it begins to contract

After load:

(19)

…..Co cepts of Preload a d Afterload

The importance of the concepts of preload and

afterload:

Many abnormal function states of the heart or

circulation, the pressure during

filling of

ventricle (the preload),

the

arterial pressure

(20)

(21)

FUNGSI

SEKRESI, ABSORBSI,

EKSKRESI

SISTEM PENCERNAAN

Rahmatina B. Herman Bagian Fisiologi

(22)

Introduction

The primary function of the digestive system is to transfer nutrients, water and electrolytes from the food e eat i to the ody’s i ter al e viro e t.

Ingested food is essential as:

- an energy source from which the cells can

generate ATP to carry out their particular energy-dependent activities

(23)

……I trodu tio

The digestive system performs 4 basic digestive processes:

1. Motility along gastrointestinal tract

2. Secretion of digestive juices

3. Digestion of food

4. Absorption the small absorbable units

Excretion of the waste materials

Regulation of digestive function through neural reflexes and hormonal pathways

(24)

Local changes in Digestive Tract (DT) External influences

Receptors in DT

Extrinsic (ANS) _{Intrinsic (ENS)} _{GI Hormones}

Smooth Muscle (self excitable)

Exocrine gland cells (digestive juices)

Endocrine gland cells (GI & Pancreatic Hormones

(25)

(26)

Daily Secretion of Digestive Juices

Daily Volume (ml)

pH

Saliva 1000 6.0 – 7.0

Gastric secretion 1500 1.0 – 3.5

Pancreatic secretion 1000 8.0 – 8.3

Bile 1000 7.8

Small intestine secretion 1800 7.5 – 8.0

Brunner’s gland secretion 200 8.0 – 8.9 Large intestine secretion 200 7.5 – 8.0

(27)

General Principles of Digestive Secretion

Type of digestive glands:

- Type of secretions: ◊ digestive enzymes

◊ digestive fluids ◊ mucus

- Anatomical type of glands:

◊ single cell mucous gland/ mucous cells (goblet cells) ◊ crypts of Lieberkuhn: small intestine

(28)

Basic Mechanism of Stimulation

Epithelial stimulation:

- tactile stimulation

- chemical irritation - distention of gut wall

Nervous stimulation

- Enteric nervous system - ENS (intrinsic)

- Autonomic nervous system – ANS (extrinsic): - parasympathetic stimulation

- sympathetic stimulation

(29)

Secretion in The Mouth

Saliva:

> Saliva glands:

- parotid gland: serous – ptyalin (-amylase) - submandibullar/ submaxillar gland: mix - sublingual: mix

- buccal: mucus

> Function:

- digestive process - oral hygiene:

◊ stream: flush away fine particles

◊ thiocyanate ion, lysozime, antibody, bicarbonate buffers

(30)

Esophageal Secretion

Mucoid

(entirely):

◊

Function:

- lubrication

- protection

◊

Glands:

- simple mucous glands:

lubrication

- compound mucous glands:

protection

(31)

Gastric Secretion

Oxyntic glands (gastric glands):

at corpus and fundus

- mucous neck cells: mucus & pepsinogen - peptic cells (chief cells): pepsinogen

- oxyntic cells (parietal cells): HCl & intrinsic factor

Pyloric glands:

at antrum

- mucus, hormone gastrin, pepsinogen

Mucus-secreting cells:

spread over the surface of the gastric mucosa

- mucus

(32)

Postulated Mechanism for Secretion of HCl

Extracellular

Fluid Oxyntic (Parietal) Cell

Lumen of Canaliculus

CO2 CO2

CO2 + OH- + H+ HCO3

-HCO3

-H2O

K+ _K+ Na+ P _Na+

K+ K+ (15 mEq/L) H+ (155 mEq/L P

Na+ _Na+ _(3mEq/L) P

Cl- Cl- Cl- Cl- (173 mEq/L) P

(33)

Regulation of Gastric Secretion

Acetylcholine:

excites secretion by all the secretory types in the gastric glands

Gastrin and histamine :

stimulate strongly the secretion of HCL

A few other substances such as circulating amino

acids, caffeine, and alcohol

also stimulate the gastric secretory cells but the

(34)

Phases of Gastric Secretion

1. Cephalic phase

: via vagus

2. Gastric phase :

- vagal reflexes

- local enteric reflexes - gastrin stimulation

3. Intestinal phase

:

(35)

Pancreatic Secretions

Digestive enzymes:

- carbohydrate: ◊ pancreatic amylase

- fat: ◊ pancreatic lipase ◊ cholesterol esterase ◊ phospholipase

- protein :

◊ trypsinogen

◊ chymotrypsinogen

◊ pro-carboxylpolypeptidase ◊ elastases & nucleases

Trypsin inhibitor

Bicarbonate ions

Entering duodenum via sphincter Oddi

Activated by

(36)

Regulation of Pancreatic Secretion

- Acetylcholine

- Gastrin

- Cholecystokinin

- Secretin

Na Bicarbonate solution

◊

Gastric acid

: Na B solution > enzymes

◊

Fat (soap) : Na B solution = enzymes

◊

Peptones

: Na B solution < enzymes

Phases of pancreatic secretion:

- Cephalic phase - Gastric phase - Intestinal phase

(37)

Secretion of Bile

Function:

- in fat digestion: emulsifying/ detergent function - in fat absorption: micelles

- excretion of bilirubin and excesses cholesterol

Formation: in liver

- secreted by hepatocytes

- along the bile ducts: secretion of Na+ _{& HCO} 3

-Storage: in gallbladder

- re-absorption of water & electrolytes except Ca2+& K+

(38)

Composition of Bile

Liver Bile Gallbladder Bile

Water 97.5 gm/dl 92 gm/dl

Bile salts 1.1 gm/dl 6 gm/dl

Bilirubin 0.04 gm/dl 0.3 gm/dl

Cholesterol 0.1 gm/dl 0.3 – 0.9 gm/dl Fatty acids 0.12 gm/dl 0.3 – 1.2 gm/dl

Lecithin 0.04 gm/dl 0.3 gm/dl

Na+ _{145 mEq/L} _{130 mEq/L}

K+ _{5 mEq/L} _{12 mEq/L}

Ca++ _{5 mEq/L} _{23 mEq/L}

Cl- 100 mEq/L 25 mEq/L

(39)

Secretions of Small Intestine

Mucus:

- by Brunner glands especially at proximal

Digestive juices:

- extracellular fluids

- secreted by crypts of Lieberkuhn

- function: watery vehicles for absorption of substances from the chymes

Intestinal enzymes

- at brush border - peptidases

(40)

Regulation of Small Intestinal Secretion

Local enteric reflex mechanisms

-

in response to the presence of chyme in the intestine

- dominant role

Hormonal regulation

(41)

Secretions of Large Intestine

Mucus:

- function: ◊ protection (together with NaHCO3) ◊ lubrication

◊ adherent medium for holding fecal material together

- control: ◊ local

◊ parasympathetic

emotional disturbance: mucus stool

Water and electrolyte:

(42)

(43)

Basic Principles of Gastrointestinal Absorption

Basic mechanism: Transport across membrane

- active transport:

◊ primary ◊ secondary:

> co - transport

> counter - transport

- passive transport (diffusion):

◊ simple diffusion ◊ facilitated diffusion

(44)

…Basi Pri iples of Gastroi testi al

Absorption

Cell membrane consists of:

- lipid bilayer

- integral protein molecules:

◊

channel

(45)

Absorption in The Stomach

T

ight ju tio

Only a few:

●

fat-soluble material: alcohol

(46)

Absorption in The Small Intestines

Almost all of nutrient, water, and electrolytes

Nutrients:

◊ carbohydrate: ◊ protein:

◊ fat: - micelles - diffusion

- chylomicrons

Ions:

◊ positive ions: - active transport

◊ negative ions: - passive transport

Water:

- osmosis

- through intercellular spaces

-Active transport (Na co-transport)

(47)

………S all I testi es

Absorption facilities

Absorptive surface:

● Valvula of coniventes (Kerckring) : 3 x lipat ● Villi : 10 x lipat ● Microvilli (Brush border) : 20 x lipat

Transportation in villi:

● Vascular system  portal circulation

(48)

Large Intestines

Absorbing colon

◊ absorption almost all of water & electrolytes

◊ absorption capacity of colon: 5 – 7 L/day

◊ bacterial action:

- digesting small amounts of cellulose

- vit. K, B₁₂, thiamin, riboflavin - gases: CO₂, hydrogen, methan

(49)

…..Large I testi es

Composition of normal feces:

◊

three-fourths water and one-forth solid

material

◊

color: stercobilin dan urobilin

◊

odor: by products of bacterial action

- indol, skatol, mercaptan, H

₂

S

(50)

FUNGSI EKSKRESI

SALURAN PENCERNAAN

(51)

General Principles of

Gastrointestinal Motility

Characteristic of intestinal wall:

- mucosa, muscularis, serosa, peritonium

- smooth muscles:

> tunica muscularis, 2 muscle layers: - exterior: longitudinal

- interior: circular

> muscularis mucosae in the deeper layer of the mucosa

(52)

...General Principles of

Electrical activities in gastrointestinal smooth

muscles:



Slow waves: basic electrical rhythm

(BER)

- resting membrane potential (-50-60 mV) - because of activities of Na-K pump



S

pike potentials:

- a tio pote tial → us le o tra tio

(53)

...General Principles of

Functional types of movements in the GIT:



Propulsive movements:

peristalsis

- function of the myenteric plexus - peristaltic reflex/ myenteric reflex - law of gut: receptive relaxation



Mixing movements:

- quite different in difference parts of GIT - local constrictive contractions every few

centimeters in the gut wall

(54)

...General Principles of

Basic mechanisms of stimulation

- distention (stretch) of the gut wall

- neural control

◊ enteric nervous system

- myenteric plexus (Auerbach) - submucosal plexus (Meissner)

◊ autonomic nervous system

- parasympathetic innervation - sympathetic innervation

(55)

Gastrointestinal Reflexes

Reflexes that occur entirely within the enteric nervous system

Reflexes from the gut to the prevertebral sympathetic ganglia and then back to the GIT

Reflexes from the gut to the spinal cord/ brain stem and then back to the GIT:

- Reflexes from stomach and duodenum to the brain stem and back to the GIT: gastrocolic, duodenocolic,

gastroileal, enterogastric

- pain reflexes that cause general inhibition of GIT

- defecation reflexes that travel to the spinal cord and back again to produce the powerful colonic, rectal, and

(56)

Defecation

Ordinarily, defecation is initiated by defecation

reflexes

Defecation reflexes:

- intrinsic reflex: relatively weak

mediated by the local enteric nervous system - extrinsic reflex: parasympathetic defecation

reflex

mediated by parasympathetic nervous system (sacral division)

(57)

…Defe atio

Whe fe es e ter the re tu → diste tio of the

re tal all → i itiated peristalti aves

As the peristaltic waves approach the anus:

- internal anal sphincter is relaxed (receptive relaxation by myenteric plexus

- if the external anal sphincter is consciously,

voluntarily relaxed at the same time, defecation will occur

To be effective in causing defecation, usually must

(58)

(59)

FISIOLOGI

REPRODUKSI

Rahmatina B. Herman

Bagian Fisiologi

(60)

Reproduction

Reproduction is process

to maintain

continuation of species

by which

- new individuals of a species are produced

- genetic material is passed from generation

to generation

Cell division in a multicellular organism is

necessary for growth and it involves passing of

genetic material from parent cells to daughter

cells

(61)

The Reproductive System

This system does not contribute to homeostasis

Is not essential for survival of an individual

But still plays a i porta t i a perso ’s life,

e.g. the manner:

- in which people relate as sexual beings

contributes in significant ways to

psychosocial behavior

- how people

view themselves

(62)

…..The Reprodu tive Syste

Reproductive function also has a profound

effect on society:

- universal organization of societies into family

units provide

a stable environment

that is

conducive for perpetuating

our species

- on other hand,

population explosion

and its

resultant drain on

dwindling resources

(63)

Reproductive capability depends on intricate

relationship

among

hypothalamus

,

reproductive organs

, and

target cells

of sex hormones

(64)

The organ of male and female may be grouped by

function

Testes and ovaries (called gonads), function in

production of gametes: sperm cells and ova Gonads also secrete hormones

The ducts of reproductive systems transport, receive, and store gametes

Accessory sex glands produce materials that support gametes

In females, the breasts are also considered accessory reproductive organs

(65)

Secondary Sexual Characteristic

Secondary sexual characteristic (SSC) are many

external characteristics

not directly involved in

reproduction

That

distinguish

male and female

Development and maintenance governed by

testosterone

in males and

estrogen

in females

Progesterone has no influence on SSC

(66)

…..Se o dary Se ual Chara teristi

In some species, secondary sexual

characteristic are great importance in courting

a d ati g ehavior (e.g. to attra t fe ale’s

attention)

In humans, attraction the opposite sex not

only influenced by secondary sexual

characteristic but also strongly affected by the

complexities of human society and cultural

(67)

Sex Determination and Differentiation

Reproductive cells each contain a

half set of

chromosomes

Gametogenesis is accomplished by

meiosis

The sex of and individual is determined by

combination of sex chromosomes

Sexual differentiation along male or female

lines depends on the presence/ absence of

(68)

Parents with diploid (46 chr) somatic cells

Mother

Father

Meiotic division of germ cells

Meiotic division of germ cells

Haploid Ovum Haploid Sperm

Fertilization

Diploid fertilized Ovum

Mitosis

(69)

Ovum with X sex chromosome

Fertilized by

Sperm with Y sc Sperm with X sc

Embryo with XY sc Genetic sex Embryo with XX sc

Sex-determining region of Y chr (SRY) stimulates Production of H-Y antigen

In plasma membrane of undifferentiated gonad

H-Y antigen directs differentiation of gonads into testes

No Y chr, so no SRY and no H-Y antigen

With no H-Y antigen, undifferentiated gonads

develop into ovaries

(70)

Testosterone

Promotes development of undifferentiated external genitalia along male lines

(e.g. penis, scrotum)

Testes secrete hormone and factor

Phenotype sex Mullerian-inhibiting factor Dihydrotestosterone Converted to Degeneration of Mullerian ducts

Transforms Wolfian ducts into male reproductive tract

(e.g. epididymis, ductus deferens, ejaculatory duct,

(71)

Absence of testosterone

Undifferentiated external genitalia along female lines

(e.g. clitoris. labia)

Ovaries does not secrete hormone and factor

Phenotype sex

Absence of Mullerian- inhibiting factor

Degeneration of Wolfian ducts

(72)

(73)

(74)

FISIOLOGI

(75)

(76)

Reproductive Functions of Male

The essential reproductive functions of male are:

1. Production of sperm (

spermatogenesis

) by

testes

(in skin-covered sac:

scrotum

)

2. Delivery of sperm

to female

–

semen by

- male reproductive tract: epididymis, vas

deferens, ejaculatory duct

- urethra (in

penis

)

3. Male accessory sex glands

: providing bulk of

semen: seminal vesicle, prostate,

(77)

Testes

Primary male reproductive organs

Perform dual function:

- producing sperm (spermatogenesis)

- secreting male sex hormone: testosterone

Scrotal location provides a cooler environment

essential for spermatogenesis

Position of scrotum in relation to abdominal

cavity can be varied by spinal reflex mechanism

that plays important role in regulating

(78)

Development of Testes

In male embryo, testes develop from the genital ridge located at the rear of abdominal cavity

In last months of fetal life, testes begin a slow descent, passing out of abdominal cavity through inguinal canal into scrotum which is induced by testosterone

After testes descend into scrotum, the opening of abdominal wall through which inguinal canal passes

closes snugly around sperm-carrying duct

Incomplete closure or rupture of this opening permits

(79)

Functioning of Testis

During fetal life:

- stimulated by chorionic gonadotropin (hCG)

A few weeks after birth until puberty

(prepubertal period / childhood):

- dormant

Productive period:

- stimulated by gonadotropic hormone (GnH) - Spermatogenesis usually continues until death

Male climacteric:

(80)

Ductal System

Ductus epididymis

- Loosely attached to the rear surface of each testes - Sperm from seminiferous tubules are swept into

epididymis as a result of pressure created by continual secretion tubular fluid by Sertoli cells

Ductus (vas) deferens

- Formed from converged of epididymal ducts - Thick-walled, muscular duct

(81)

(82)

Accessory Sex Glands

Seminal vesicles:

- Empty secretions into the last portion of ductus deferens - Supply fructose to nourish the ejaculated sperm

- Secrete prostaglandin for sperm motility to help transport - Provide precursors for clotting of semen (fibrinogen)

Prostate gland:

- Completely surrounds urethra at bladder neck - Secretes alkaline fluid

- Provides clotting enzymes and fibrinolysin

Bulbourethral glands:

(83)

Spermatogenesis

Tubuli seminiferi

During active sexual life

As the result of stimulation by anterior

pituitary gonadotropic hormones

Beginning at age of ± 13 ys

(84)

…..Sper atoge esis

Steps of Spermatogenesis

1. Mitosis: spermatogonia A  spermatogonia B

2. Enlargement:  primary spermatocyte

3. Meiosis:

I. Primary spermatocyte  secondary spermatocyte II. Secondary spermatocyte  early spermatid

4. Physically reshaping: spermiogenesis

(85)

(86)

(87)

(88)

(89)

Sperms

(Normal and Mature)

Motile Fertile

Movement: 1 – 4 mm/min. Travel in a straight line

Activity: enhanced in neutral and slightly alkaline, depressed in mildly acidic media

Rapid death in strong acidic media

Temperature   activity   metabolism rate   shortened life

(90)

(91)

Semen

Fluid: - vas deferens (10 %)

- vesicula seminalis (60 %)

- prostat (30 %)

- mucous glands (bulbourethral)

pH: ± 7.5

Mucoid and milky

(92)

FISIOLOGI

(93)

(94)

Reproductive Functions of Female

Fe ale’s role i reprodu tio is ore o pli ated:

1. Production of ova (oogenesis) by ovaries

2. Reception of sperm: vagina-cervix

3. Reception of sperm and ovum to a common site for

union (fertilization or conception): Fallopian tube

4. Maintenance of the developing fetus until it can

survive in outside world (gestation or pregnancy),

including formation of placenta: uterus

5. Giving birth to the baby (parturition)

(95)

Ovaries

Primary female reproductive organs

Perform dual function:

- producing ova (oogenesis)

- secreting female sex hormones:

estrogen and progesterone which act together to: > promote fertilization of ovum

> prepare female reproductive system for pregnancy

Homologous to testes (in structure, position,

and origin)

(96)

Development of Ovaries

During fetal life, the outer surface of ovary is

covered by germinal epithelium

Cells that give rise to ova arise from endoderm

of yolk sac and migrate to ovaries during

embryonic development at 5-6 weeks of

gestation

Primordial (primitive) germ cells migrate from

endoderm of the yolk sac to ovaries during

(97)

Functioning of Ovaries

During fetal life:

- stimulated by chorionic gonadotropin (hCG)

A few weeks after birth until puberty

(prepubertal period / childhood):

- dormant

Productive period:

- stimulated by gonadotropic hormone (GnH) and ovarian hormone

(98)

Components of Female Reproductive Tract

Oviducts (Fallopian tubes)

- in close association with ovaries,

- pick up ova on ovulation and serve as fertilization site

Uterus

thick-walled hollow: responsible for

- maintaining fetus during development - expelling it at the end of pregnancy

Cervix

- lowest portion of uterus - projects into vagina

Cervical canal

(99)

…..Co po e ts of Fe ale Reprodu tive Tra t

Vagina

expandable tube, connects uterus to external environment

Vaginal opening

located in perineal region between urethral and anal opening

Hymen

thin mucus membrane partially covering vaginal opening

Labia minora and labia majora

skin folds surrounding vaginal and urethral openings Clitoris

(100)

Oogenesis

In the 3rd month of prenatal development: oogonia

divided mitotically into primary oocytes (diploid/ 2n) until 20-24 weeks  7 million (maximum)

7 month after conception, fetal oogonia cease dividing From this point on no new germ cells are generated

Almost from the start, attrition process occurs:

- by birth only 2 million primary oocytes remain - by puberty: 300.000 - 400.000

(101)

Primary oocytes enter reduction division (meiosis I), but do not complete the division in the fetus

Cells are said to be in a state meiotic arrest, and this state continues until puberty

Only primary oocytes destined for ovulation will ever complete the first meiotic division, for it occurs just before the egg is ovulated

The second meiotic division occurs in a fallopian tube after ovulation, but only if the secondary oocyte is

penetrated by a sperm (fertilized )

Daughter cell receive 23 chromosomes (haploid/ n) Each primary oocyte can produce only one ovum

(102)

(103)

Hormonal Control of Ovarian Function

Hypothalamus

GnRH

Anterior Pituitary

FSH and LH

(104)

Cycle: 28 days (20

–

45 days)

Ovarian cycle

1. The follicular phase: - ovarian follicle growth

- ovulation

2. The luteal phase: development of corpus luteum

Endometrial cycle (Uterine cycle)

1. Proliferative phase: - estrogen phase

- before ovulation

2. Secretory phase: - progestational phase

- after ovulation

3. Menstruation

(105)

(106)

(107)

(108)

(109)

(110)

(111)

(112)

ANATOMI FISIOLOGI SIRKULASI

FETUS, BAYI & DEWASA

Rahmatina B. Herman Bagian Fisiologi

(113)

Fetal Circulation

Differs from the postnatal (after birth) circulation,

because

Lungs, kidneys, and gastrointestinal tract are

nonfunctional

O2 and nutrients are derived from maternal

blood

(114)

Placenta

Is the fetal lu g

However cellular layers covering the villi are

thicker and less permeable

than the alveolar

membranes in the lungs and exchange is much

less efficient

Is also the route by which all nutritive materials

enter the fetus and wastes are discharged to

(115)

(116)

Arrangement of Fetal Circulation

55 % of fetal COP goes through placenta

Blood in umbilical vein (UV) ± 80 % saturated

with O2 (in arterial circulation of adult: ± 98 % )

Ductus venosus (DV) diverts some of the blood

directly to Inferior Vena Cava (IVC) and

remainders mixes with portal blood

- IVC blood is ± 67 % saturated with O2

(117)

….Arra ge e t of Fetal Cir ulatio

Most of the blood entering heart through IVC is

diverted directly to left atrium (LA) via

foramen

ovale



left ventricle (LV)

Most of blood from SVC enters right ventricle

(RV) and is expelled into pulmonary artery (PA)

Resistance of collapsed lungs is very high

Pressure in PA > aorta

Most of the blood from PA passes into aorta via

(118)

….Arra ge e t of Fetal Cir ulatio

In this fashion:

Relatively unsaturated blood from

RV

is

diverted into

trunk and lower body

The

head

of fetus receives the

better-oxygenated blood from the

LV

(119)

(120)

(121)

(122)

Fetal Respiration

Tissues of fetal and newborn mammals have a

remark-able but poorly understood resistance to

hypoxia

O2 saturation of maternal blood in placenta is so

low that the fetus might suffer hypoxic damage if

fetal red cells did not have a greater O2 affinity

than adult

(123)

…..Fetal Respiratio

The fetal oxyhemoglobin dissociation curve is

shifted to the left → at e ual pressure of O2,

fetal blood carries significantly more O2 than

does maternal

In early fetal life, the high cardiac glycogen levels

that prevail may protect the heart from acute

periods of hypoxia

(124)

Umbilical Vessels

Umbilical vessels have thick muscular walls with a muscular sphincter

Hemorrhage of the newborn is prevented by

constriction of the umbilical vessels, because they are very reactive to trauma, sympathomimetic amines, bradykinin, angiotensin, and changes in PO2

Closure of the umbilical vessels increases the total peripheral resistance and the blood pressure

When blood flow ceases through the umbilical

(125)

Changes in

Fetal Circulation & Respiration at Birth

At birth, placental circulation is cut off and

peripheral resistance suddenly rises

Pressure in aorta rises until > in PA

Because of placental circulation has been cut off,

the infant becomes increasingly asphyxial and

ooli g of the ody → a tivates respiratory e ter

Finally, infant gasps several times and the lungs

e pa d → vas ular resista e de rease to

± 1/10

Markedly negative intrapleural pressure (-30 to -50

mmHg) during the gasps contributes to the

(126)

…..Cha ges i

The sucking action of the first breath plus

constriction umbilical veins (UV) squeezes 100 ml of

lood fro pla e ta (the pla e tal tra sfusio

Once the lungs are expanded, the pulmonary

vascular resistance falls to < 20% of utero value and

pulmonary blood flow increases markedly

Blood returning from the lungs raises the pressure

in the LA, closing

foramen ovale

by pushing the

(127)

…..Cha ges i

The LA pressure is raised > IVC and RA by:

1.

The de rease i pul o ary resista e → large

flow of blood through the lungs to the LA

2.

The redu tio of flo to the RA ← o lusio of

the UV

3.

The i reased resista e to LV output ←

occlusion of the UA

↓

Abruptly closes the valve over the

foramen ovale

(128)

…..Cha ges i

The de rease i pul o ary vas ular resista e →

the pressure in the PA fall to ± ½ (to ± 35 mmHg)

The slight i rease i aorti pressure → reverses

the blood flow through the

ductus arteriosus (DA)

↓

The large ductus arteriosus begin to constrict

↓

Manifested as a

murmur

in the newborn, because of

(129)

…..Cha ges i

DA constricts within a few hours after birth, producing functional closure, and permanent anatomic closure

follows in the next 24-48 hours due to extensive intimal thickening

Mechanism producing the initial constriction is not

completely understood, but the increase in arterial O2 tension plays an important role as follows:

1. The high O2 tension of the arterial blood that passes through the DA

2. The pulmonary ventilation with O2 that closes the DA. Ventilation with air low in O2 opens this shunt vessel Whether O2 acts directly on the DA, or through the

(130)

…..Cha ges i

Relatively high concentrations of vasodilators

(especially prostaglandin) are present in the DA

Synthesis of the prostaglandin is facilitated by

cyclooxygenase at birth

In many premature infants the ductus fails to

close spontaneously, but closure can be

(131)

(132)

(133)

The Walls of Cardiovascular System

At birth:

- The walls of the two ventricles are approximately of the same thickness, with a possibly slight

preponderance of the RV

- The muscle layer of the PA is thick, which is partly responsible for the high pulmonary vascular

resistance of the fetus

After birth:

- The thickness of the RV and PA walls diminishes - The LV walls become thicker

(134)

(135)

FISIOLOGI

HIDUNG DAN

SINUS PARANASAL

Rahmatina B. Herman

Bagian Fisiologi

(136)

Physiology of Nose

The interior of nose are specialized for 3

functions:

1. Incoming air

is warmed, moistened, and

filtered

2. Olfactory stimuli

are received

(137)

…………..Ph siolog of Nose

When air enters the nostrils, it passes:

Through vestibule which is lined by skin containing coarse hairs that filter out large dust particles

Then passes into upper nasal cavity :

- 3 conchae: superior, middle, inferior

- 3 meatuses: superior, middle, inferior

(138)

…………..Ph siolog of Nose

Olfactory receptors lie in the membrane lining

superior concha and adjacent septum, called olfactory epithelium

Below olfactory epithelium, mucous membrane contains capillaries; air which is whirls around

conchae and meatus warmed by blood in capillaries

Mucous membrane also contains epithelial cells with many goblet cells; mucus secreted by goblet cells

(139)

…………..Ph siolog of Nose

Drainage from the

nasolacrimal

ducts and

perhaps secretions from

paranasal sinuses

also

help

moistens

the air

The

cilia

move the mucus-dust packages to the

pharynx so they can be eliminated from

respiratory tract by

swallowing

or

(140)

(141)

(142)

Physiology of Paranasal Sinuses

Paired cavities in certain cranial and facial bones near nasal cavity:

frontal, sphenoid, ethmoid, maxillae

Lined with mucous membranes that are continuous with the lining of the nasal cavity

Producing mucus

Lighten the skull bones

(143)

(144)

(145)

Introduction

Smell and taste are generally classified as visceral sense because of their close association with

gastrointestinal function

Physiologically they are related to each other

Flavors of various foods are in large part a combination of their taste and smell

Food a taste differe t if o e has a old that

(146)

………..I trodu tio

Both smell and taste receptors are chemo-receptors that are stimulated by molecules in solution in mucus in the nose and saliva in the mouth

However, anatomically quite difference:

- Smell receptors are distance receptors (teleceptors), and its pathways have no relay in thalamus

(147)

Olfactory Mucous Membrane

Is specialized portion of nasal mucosa

With yellowish pigmented

In which olfactory receptor cells are located

Is constantly covered by mucus which is produced by

Bow a ’s gla ds

In dogs and other animals in which sense of smell is highly developed (macrosmatic animals)

(148)

Olfactory Receptors

Each olfactory receptor is a neuron

Each neuron has a short thick dendrite with expanded end called an olfactory rod

From the rods, cilia project to surface of mucus

Each receptor has 10-20 cilia

Axon of the neurons pierce cribriform plate of ethmoid bone and enter olfactory bulbs

(149)

(150)

(151)

Olfactory Bulbs

In olfactory bulbs, axons of receptors contact primary dendrites of mitral cells and tufted cells to form

complex globular synapses called olfactory glomeruli

Olfactory bulbs also contain periglomerular cells which are inhibitory neurons connecting one glomerolus to another

(152)

(153)

Olfactory Pathways

1. The very old olfactory system (medial olfactory area): concerning with basic olfactory reflexes to olfaction, such as licking the lips, salivation, and other feeding responses caused by smell of food

2. The less old olfactory system (lateral olfactory area): provides learned control of food intake (like / dislike certain foods)

3. The newer olfactory system: other cortical sensory systems and is used for conscious perception of

(154)

Olfactory Cortex

Axons of mitral and tufted cells pass posteriorly through intermediate olfactory stria and lateral olfactory stria to olfactory cortex

In humans, sniffing activates pyriform cortex

Smells activate lateral and anterior orbitofrontal gyri of frontal lobe

(155)

………Olfa tor Corte

Other fibers project:

- to

amygdala

, which is probably involved

with

emotional responses

to olfactory

stimuli,

(156)

Olfactory threshold & Discrimination

Olfactory receptors respond only to substances that are in contact with olfactory epithelium and are

dissolved in thin layer of mucus that covers it

Olfactory threshold remarkable sensitive to some substances

Olfactory discrimination is remarkable

(157)

….Olfa tor threshold & Dis ri i atio

Determination of differences in intensity of any given odor is poor

Concentration of odor-producing substance must be changed by about 30% before a difference can be detected

(158)

Role of Pain Fibers in Nose

Naked endings of many trigeminal pain fibers are found in olfactory mucous membrane

They are stimulated by irritating substances, and an irritative

Trigeminally mediated component is part of

hara teristi odor of su h su sta es as

peppermint, menthol, chlorine

These endings also responsible for initiating

(159)

Adaptation

When one is continuously exposed to even most

disagreeable odor, perception of odor decreases and eventually ceases

This phenomenon is due to fairly rapid adaptation, or desensitization that occurs in olfactory system

Mediated by Calcium ion acting via calmodulin on cyclic nucleotide-gated (CNG)

(160)

Abnormalities

Anosmia

: absence of sense of smell

Hyposmia

: diminished olfactory

sensitivity

(161)