GIT Anatomy and Physiology

• Human Anatomy and Physiology 1 covers the structure related to the physiology of mammalian body functions and processes.
• Includes cell and tissue structure and its relation to function.
• Explores the digestive, respiratory, cardiovascular, immune, and musculoskeletal systems.
• Discusses associated malfunctioning of these key systems.

Tissues: Definition and Classification

• Tissues are collections of similar cells performing specific roles in the body's structuring and functioning.
• Histology is the study of tissues.
• Tissue cells are separated and cohesively bound by a non-living intercellular matrix.
• The intercellular matrix secreted by the cells varies in composition across different tissues.
• The matrix can exist in liquid, semi-solid, or solid states.
• Blood has a liquid matrix allowing it to flow through vessels.
• Bone cells are separated by a solid matrix which enables them to support the body.
• The four main tissue groups are: Epithelial, Muscular, Connective, and Nervous.

Epithelial Tissues

• Epithelial tissues cover body and organ surfaces, line body and lumen cavities, and form glands.
• Muscle tissues contract to create movement.
• Connective tissues include blood, cartilage, bone, and cells of connective tissue.
• Nervous tissues initiate and transmit impulses throughout the body.
• Common characteristics of epithelia:
• Epithelium consists almost entirely of cells with little extracellular material.
• It covers body surfaces and lines the digestive tract, vessels, and body cavities; it forms structures such as salivary glands.
• They have one free surface not associated with other cells and a basal surface; the basal surface attaches to a basement membrane.
• The cells of some endocrine glands don't have a free surface or basal surface with a basement membrane..
• The basement membrane is extracellular material secreted by epithelial and connective tissue cells.
• Specialized cell contacts like tight junctions and desmosomes bind cells together.
• Blood vessels do not directly penetrate and reach the epithelium.
• Gases and nutrients reach it by diffusing across the basement membrane from connective tissues.
• Metabolically active epithelial cells with many layers are located near the basement membrane.
• Cells further from the basement membrane die.
• Epithelia are avascular but innervated.
• Epithelial cells regenerate through mitosis, replacing damaged cells.
• Some epithelia wear off due to friction, or are damaged by bacteria, acids and smoke.
• Epithelial cells replace lost cells by cell division as long as they receive sufficient nutrients.
• Epithelium are classified into membranous and glandular types.

Membranous Epithelia

• Membranous covers body surfaces, cavities and lumina (hollow portions of body tubes).
• Membranous epithelias are specialized for protection and absorption.
• One side of a membranous epithelium is exposed to a body, lumen, or skin surface.
• Ectoderm-derived membranous epithelia include the outer layer of skin.
• Mesoderm-derived membranous epithelia include the inside lining of blood vessels
• Endoderm-derived membranous epithelia include the inside lining of the gastrointestinal tract.
• Membrane thickness can vary.
• The upper surface is exposed to gases, liquids, or semi-solids, depending on the system (integumentary/respiratory, circulatory/urinary, digestive).
• Membranous epithelia are avascular, nourished via diffusion from underlying connective tissues.
• The cells are tightly packed with little intercellular matrix.
• Functions of membranous epithelia:
• Protection from pathogens.
• Absorption of digested products within the GIT lining.
• Filtration in the kidney
• Diffusion in the air sacs of the lungs
• Chemireception by specialized neuro-epithelial cells in taste buds and the nasal region.
• Membranous epithelia are classified by the number of cell layers and the shape of cells.
• Composed of a single layer of cells are called simple, while those that have layered cells are stratified.
• Squamous cells are flattened; cuboidal cells are cube-shaped; columnar cells are taller than wide.

Simple Epithelium

• Simple Epithelium contains tightly bound flattened, irregularly shaped cells.
• Each cell has a centrally located oval nucleus
• Cells may be thin, flattened or columnar, based on their function.

Simple squamous epithelium

• Made of flattened, scale-like, tightly bound, irregularly shaped cells
• Every cell features a centrally located nucleus.
• Adapted for diffusion, filtration, and absorption processes.
• It can be found in air sacs, kidney portions involved in blood filtration and the inside of blood vessels.
• Simple squamous epithelium lining lumina of blood and lymphatic vessels is called endothelium.
• Mesothelium covers visceral organs and lines body cavities.

Simple Cuboidal

• Composed of a single layer of hexagonal cells, as tall as they are wide
• Some cells contain cilia (terminal bronchioles) and microvilli (kidney tubules)
• They found in small ducts and tubules and has excretory, secretory and absorptive functions.
• It occurs on the surface of the ovaries, terminal bronchioles, choroid plexus of the brain, smallest ducts of kidney tubules.

Simple columnar epithelium

• Composed of tall columnar cells, with height varying by tissue site and function.
• On occasion cells have cilia or microvilli on its free surface, which assists to move substances
• Each cell contains a single nucleus, located near the basement membrane.
• Goblet cells are specialized unicellular cells are dispersed throughout.
• They create a lubricative and protecting mucus membrane, along the free surface of the cells.
• It is found in the digestive tract (stomach to rectum), bronchioles, uterus, uterine tubes, gall bladder, bile ducts, and brain ventricles.

Simple ciliated columnar epithelium

• Simple ciliated columnar epithelium are defined by the presence of cilia along the free surface
• The cilia produce wave-like movements that transport materials through tubes
• It is located in the uterine tubes.

Pseudostratified ciliated columnar epithelium

• It is assembled from a single layer of cells, every of which are secured to the basement membrane.
• Some tall and thin reach the free surface of the cell while others do not
• Cells forming the nuclei of the epithelial has a stratified appearance, because the nuclei of these cells are at many different levels
• Consists of lots of goblet cells and a ciliated surface that is open and exposed
• It helps to move of mucous/fluids and transport particles of foreign matter from the lower part of the respiratory system.

Stratified Epithelia

• Stratified Epithelia contains two or more layers of cells
• The basal cell divides and pushes apically regenerating the older surface cells
• Stratified Epithelia are much more durable than simple epithelia
• They have protective purposes increased with fast mitotic activity
• Not well suited for absorbing or secretion due to the thickness present
• Classified via surface layer of cells shape since the cells connecting the epithelial layer is made of cuboidal/columnar cells

Stratified squamous epithelium

• Consists of cells arranged in variable amounts of layers.
• The free surface of the cells is made of squamos cells while the deeper layers consists of columnar cells
• Mitosis only arises in the deepest layer (stratum basale)
• Newly formed cell's develop then are pushed up to were the cells are removed
• There are two types keratinized and non-keratinized (moist)
• Keratinized stratified squamous forms the epidermis of the skin
  • Strengthened my Keratin a protein
  • withstands abrasion, desiccation and bacterial invasion
• Non-keratinized is called mucosa
  • withstanding moderate abrasion, it is not well adapted for fluid loss
  • are moistened and remain alive
  • occurs within the esophagus, mouth , throat throat, larynx, anus etc

Stratified Cuboidal

Consists of only 2 or 3 layers of cuboidal cells forming a lining around a lumen confined

• Located in the lining of main ducts containing sweat, pancreas and gland cells such as ovarian follicles
• This helps in secretion,absorption and protecting from infections

Stratified columnar

• Has multiple layers of with layers of cuboidal cell with multiple layers of tall and thin cells
• Cells can be ciliated within the larynx
• Helps to protect from sections

Transitional epithelium

• An unmatched stratified kind that lines the urinary bladder/ureters
• permits distension due to unique structures
• Its basal layer is composed of cuboidal/columnar cells
• Distention to the bladder that results to cells being reduced from 6 layers to 3
• Dome shaped cells in apical level begin to flatten

Body Membranes

• Thin tissues of Epithelial tissues
• Visceral organs can cover, seperate and support
• Thoracic/abdominal has a basic two with serous/mucous membrane

Mucous membranes

• Tubes that enter the body cavity or tubes oral/nasal cavities or respiratory,urinary or digestive
• Thick slimy mucus secreted is to protect/lubricate the organs

Serous membranes

Thoracic and abdominal tissues found within. covers the visceral organs Secrete which have lubrication fluid

• 1. Pleura: the serous membrane that connects to longs is the one we refer to as the pleura each pleura divides to two: Visceral: adheres to the lung surface parientalL:Lines the throacic wall with a diapraghm surface Fluid is stored within with in the pleural cavity
• 2. Pericardial serous membrane surrounding the heart A think viscous covers the surrounding of the core Parietal Pericardium
• 3. Peritoneal Membranes within the abdominal cavity This covers various visceral organs with abdominal well

Glandular epithelium

Specializes in tissues with secretive functions Contains connective tissue and epithelium Has a network of connects

• has ducts with are named exocrine and lined with epithelium tissue as well
• with ducts that have cellular called hormones in endocrine glands Most glands contains many cells known as multicellular where glands composed of single cells ares with respiratory Gland ducts that include branches are considered simple while those that with various branches are considered with compound where acini is in small sacs hollow sacs are described as avoeli Cells can leave classified known with 3 types

1. merocrine: secretion in actual cellular

• Exocytosis helps transported secretions like sweat

2. Apocrine help discharge fragments of secretion where products remain within retained within the cellular like glands
3. Holocene when Cells like in entire substances cells

• Connective tissues consist where cells sperate due to extracellular matrix with classification to its

Connective Tissues

• Tissues classification connective
• Except for mature cartilage this nourishing and vascular and replicates the body
• More intercellular than cell
• Doesn't occurs on open cavity or on surface of external of bodies

Cell types

Fibroblasts - forming fibrous tissue

• Chondrocytes are cells with a matrix strengthen with collagen cartilage

• osteoblasts form bone Matrix composed

• Protein fibres

• Ground substance (consisting of nonibrous protein and other molecules)

Types

• Collagen: accounts to the one third of total body protein consist of polypeptide chains
• reticular net- Like very thin branched
• strong
• Elatin flexible - Returns with to orgignal after compressed to classified with 1.) Embyronic before mesenchyme differentiates

Connective tissue proper

1. loose (areolar packs and binds

• bind muscles in skin or and blood tissues
• Contains cells such and fascia cells and produce histamine prevent clothing and vasodilation
• ground substance contains fibroblasts or collagen

2. densed connective tissues contains amounts of collagen of fibres

• strong supports
• tendons/ ligaments

3. dense irregular connective tissue

• amounts of densely packed interwoven to provide strength
• GIT in skin/ matrix is what it can use for bones

4 elastic connective tissue ( yellow color where elastic fibres Walls of a Large artery

5 Rectual Connective tissues with a network jelly lie Phagoctyic cells present Liver. bone marrow

6 Adipose tissue is a version that contains cells that store fats around body,hypodermis kidneys and such
Semi solids that has elastic properties can support/protect which perishes

Catillage

Hyaline -blue Support trachea / bronchi Fibro catrilage: durable in compression /tension with vertebrae and symphysis joint Elasric. Flexile giving it a yellowish color outer air way Bone tissue osseuous Hard. Contains calcium phyosphate 2 types Dense - outer area has periosteum

• and Provides attachemnt spongy - porous that aids bone marrow and lighter structure concentric layer contains blood vessels and nerves. nutrirents with inntercaniculi matrix despoited on concetric with lammalle called Vascular connective tissue fluid. Plasma for matrix mainting homoestais o2, co2 nurtitns Muscle Tissue main function on movement Cell / fibers elongated Three types from mesdoerm smooth catdiac or skeletel Voluntary functions

Muscle Tissue

Skelatal muscles are a bundle or fibers Responsible is movement elongate multinucleated paralell fascuili with bundle Control movemen

Smooth muscle

Lack striations GIT power with digestion of food Involuntary arteris or uterine tract

Cardiac muscles

Cylindrical and branching and linked with intercalated disks and involuntary

Nervous tissue

Abillity to transmt action potentiol Nuerons = send impulse Neurgloglia support bind Cell body contains dendrites receive stimuli axon

GIT

Divdes Alimentary canals and functions of accessory To prepare cells Motility :move digestion peristalsis secretion: exocrine water ENZYMES stomach 2-3 Litres each day and endocrine hormones

Digestion

Breakdown small Absorption passage lymph or blood to digest oral cavity the buccal and stomach large or small. Intestine 4 layers tunicis

Mucosa

Lumen absorption for secrets goblet cell simplescolumnar lamina propria:Contains connective tissue

Submucosa

Vascular that saves the mucosa and lymph Nerve plexus with innervation

Muscularis

Segmental contractions with muscles in outer / inner where is found the auerbaches plexus Serous Protective binding

Mouth/Pharynx

• Structures that initiate digestion such as in oral cavity by lips or cheeks or tongue Opening oral cavity and found to where digestive systems Ephithelium lining and mucus secretion

Tongue

Moving chewing during functions Tastes bud for tastes

Extrusic tongue mussels

Inserts where by the tounger 2/3 buccal 1/3 in 23 phayrnx posterior Surface elevator with food handler Tastes Buds on the elevator has 4 types of senses in taste

Salvary Glands

• Are accesspry digestion and glands

• Saliva acts as a solvent to break down

• Digiesting food and mucus for the pharynx

• Buccal membrane to make saliva 3 pairs

• parorits the biggest largest behind in the ear and becomes swollen

• located mandable on floor of the moth called wharthon

• 3 in tongue connected with Ruuvus ducts SEROUS is what has the watery fluid with enzymes and mucus in the gland

Pharynx

• has oral carvity with connection trachea and esophageal with respitory digestive functions Nasohx: respitory functions only Oro : the tounge from anterior all ( palatine tissue + lingual tissue) both respiratory and digestive functions Layrgo - lowest is esphous food moved esphousal and air is inhaled

Esphogus

It is 25 cm muscular tube

• it is posterior the trachea
• through diaphgram
• The opening called esphoucal hiatus with non - Keratinized epithelium
• upper contains 1/3 while middle has both while terminal only Smooth Muscled bag for food stores

Stomach

stores food with inititation of proteins

• it dived in 4 areas:
• 1. Cardia which directly lies to the sophigal to sphincter near diaphragm
• pylorus linked

The will contain 4

• mucus which throws rugs with pits lines cell and secterios to lining
• goblet : secrete mucus all intestinal
• amphiteroc neutalise acid allaki
• Parietal cells give with give -1 Mola final ph 2 digestive: protein ingestion ph to be to digestble
• week pepsingoen each get each and active

Argentaffin cellular

Serotonin and istamine gastrin/ Renin in young people Casin paracsein calcium Mucosa polypeptide Vitb 12

Small intestine

GIT sphincte valve opened. folded lumen with microvilla divided on region

Doidendum jejnum ileum shape

concave face with the bile secretion live pancrease

• 2 with hepato drains At this pont small
• histology differ brunners in Submicosae

jujum approximately meter and have slight

:

• small structure of tissue called tissue to the valce ILEUm Walls
• Aggregators with Peyer patches absortion that can occur
• carbids/ lipids poteim /
• bile salts are aborites with villi
• with cells columnr and goblet cells

Large innsetine : 15 meters with orifign in illium in the liver surerioir

• 90 persccner of that amount in faces by osomoic . sodium/pumsp Aldosterone - LIVER strutructre - largest interlao

Liver structure

Location: large underneath diaphgram to quadrate with cava Connects Ligamaneta with a porta by lymphatic It can have cells hepatocyte

• arrange the plates lobilies have central vein
• Portal blood mixes sinusiods. Blood biles do not mix

Goals Bladder

• Sac like organ
• stores and concentrates bile. for small 34- 100
• rug is inside which allows expansion

Contracts ejects to ampulla or bile forced cystic

Pancreas

• Can have endocrine and exocrine functions
• Endo: secrete insulin and units.
• Exochrine : acmini layer pancreatic juice which creates water /HCO3 -/ digestive enzymes

000Digestion and absorption of carbohydrates

starch broken in mouth salivary which moves stomach the stops and digests starch mainly

• Didoenum contains salivary disacharides released hydrozinzed glucose sucorse is glucoses and matlsos2 gluoceses with lactosed to galactosde

Protein Digestion

in stomach and peptide with protein / chrmotrpsin / bond in polymorphs with pepitides

• Exopipetide amino removes Amino termial polypeptide with result to amino acids pepti

Absorptin cells can abrobpt these with lipods stimulation bile salts

• action enzyme coats fat
• lipase hyrosys removing 3

Circulory System

Carvodasculer and Lymphatic Hearts/ vessels lymphatic tonsistion spleen Blood cell elements of matrix 97 water 3 percemt with dissolved presence color

• plasma
• ions sodium k+
• • protein plasm
• alumbin 150 that helps regulate pressure osmotic water Livers helps carry hormones metals and fibriongen
• clotting to testroesne was gases /enzuumes

Erythrocytes haemtocrtit

Percentage value with rbcc in volume in range of 44 to 54 for male versus females

• disks 7 microns and 2 micrions thick
• each mililtire of blood contains 5-6 million rvvb Hb that contains polypeptide and iron Vitamin b12 is produced EPO formation Polycthernia over abundance viscocity leucocytes with amoeba nuclei mito can squeeze and infeciton
• 5k too the cells are spleen lymph notes bones

grouped in granules called granulocytes for cytolpasm

1-neturpholis 70 percentage with LOBES nuclei. enguof bacteris the the pos 2 Eosni 55 perscent red worms in blood. 5- 1.0 with

• 2 Lymphicoyctes and moncytess in Lymphitix . which to act as
• 3 percent 15 Micorns diatemtws in conjuciton

Platelets

Smallest made that breaks from bones

• contains 5-9 days vasocontrixting

Blood

vessels three layeres ( exterma/ media 3 intima artererirs and vients some important dervied cells are with intima arterty: aorta with elastic they Expand with contractions relx to prevent narrow small they are provide high resisitnaec venules direct with arteovenous Volume in blood Expade increase volume Low 22 mm with avegrage hundred

Capularies

Enodthelthilum 1 cell thick Types contain Conditonous conenctd the muscles channel moleuxjles only Fenstruated: intercellular porse kidney discontsious: sinusoirds

• heart structures between lings sternums thocractic called medistrunum Protected conective peracdaridum three layeres with picaruim

Epicardium/ visceral

2 . myocadium muscled Endocarium

• 4 chambers 4 atrima recieves vena cava. atrium and ventricals

• Left atrium receives branches to connect with left. and right atrium and prevents muscle

• Heart sound closing valves

• hear stethoscope - lub close with contrsact to the systoles

Diatstole - realcation hear activity

Electrical activity of the heart

• action myocrdials to atrima and a fiborous skeleton which impulses cant conduct and required

(AV node) on septum From. Bundle is to bundle

• fibers and causes contraction that ejects the heart to pulmonary

Lumpiathic System

1 Fluild 3 oliters cabbilores 3 passes back

• 2 Fats: that lactales with pass thorugh veins Defenses - filter sub
• Respiratpion with lung Resipiratrion with -3 ventilatio gas . exchange and otulitiation

Respitrory system

• lungs and brochinoles.

The nose - exteriaol protues air nasal bony and catrilage warm the air surface that are are moist The air. ciliated with pseudo lining Resonating voivce :pharyhnxy 3 types / naso

• Eustchian tisseues adeuouids.

• Oor: tounge the lYarngot

• triangeaular with catrliadged.

• with thyroid

• lrynaix to prevent and passage Rigns of cartliac

• membrane lined cuiliated Branches to 2 end branchiloles and and airwasy.

Muscles of the heart

With costal to help contact close

• diaphgram to expand. With exterrnl then abdomen compressin in .1 Contraction to contract musclies interrcostals

2. Evertes of msucles to Fiver is a non specific body setpoint secertions of endotixis bacteral Benficial aid intake of uptake

• interferes discovetr to protect for shrot viral three interferns to preotect to kill

Specific Imminity1

With Diteri aphtheria dose

• that can inject and second

Chemicals - Anti bodies that only

• Confferes act that antigenes with antiodes 2 ymotcites
• in bone narrow. produced B tissue functions : igm / ig with IGA IgE IGM
• is increased

Actie Immiutiy

Requires

• Exposed Antigen-
  • Inmune virucene vaccum
• Combats
  • pasive trnaserff immuns = A montsh After the birth
  • rehet and is. skelteal

-muslar

• bones tough contive tissues shortens. points attachment with insertion

• eye balled . 6 ocular reuces oblique

• masiucatition - 2 paris is stronhgesst is the temporal and pteroyd

• tounge mucle with out side

• muscle nervers

Neck

suporor head within struniod is sternum and clavile and to injurie to strunoid

• Ttratsuis is extened to p[osteior. The Spleniua Broad
• rotared

Thorax

rib during the exrertipon draphgram with

• Muscles and flat with abodmnal 3 quwue rabsominuos with
• appdneciular shleteiol shapuaclar and is connection - and action axial

non axilum

moves at leg and hamstrtign