FirstRanker Logo

FirstRanker.com - FirstRanker's Choice is a hub of Question Papers & Study Materials for B-Tech, B.E, M-Tech, MCA, M.Sc, MBBS, BDS, MBA, B.Sc, Degree, B.Sc Nursing, B-Pharmacy, D-Pharmacy, MD, Medical, Dental, Engineering students. All services of FirstRanker.com are FREE

📱

Get the MBBS Question Bank Android App

Access previous years' papers, solved question papers, notes, and more on the go!

Install From Play Store

Download MBBS Integumentary System Skin Lecture PPT

Download MBBS (Bachelor of Medicine and Bachelor of Surgery) Latest Integumentary System Skin Lecture PPT

This post was last modified on 30 November 2021


INTEGUMENTARY SYSTEM(SKIN)
INTRODUCTION

? Integumentary System

--- Content provided by FirstRanker.com ---

? Skin and its derivatives (hair and nail).
Skin is outer covering of body.
Largest organ of body (16% of body weight).
? Consists of epidermis and dermis
? Epidermis is covered by keratinized stratified

--- Content provided by FirstRanker.com ---


squamous epithelium

? Dermis consists of irregular connective tissue
? Beneath the dermis is hypodermis or a subcutaneous

--- Content provided by FirstRanker.com ---


layer of connective tissue and adipose tissue that

forms the superficial fascia.

--- Content provided by FirstRanker.com ---

FUNCTION OF SKIN

? Protection- from injury.
? It provides a barrier to water.
? Thermoregulation-- sweating

--- Content provided by FirstRanker.com ---

? Sensory perception- like pain, touch,

temperature and pressure.

? Helps in production of vit.D.

--- Content provided by FirstRanker.com ---

? Excretions through sweat of water, sodium

salts, and nitrogenous waste.
? TYPES OF SKIN--
? Thick skin--Skin on the surface of palm and sole.

--- Content provided by FirstRanker.com ---

? Epidermis is thicker than elsewhere.
? Thick skin is hairless.
? Thin skin--present other places of body except

palm and sole.

--- Content provided by FirstRanker.com ---


? Thin and hairy.
? MICROSCOPIC STRUCTURE OF SKIN--
? Skin consist of two layers-
? Epidermis

--- Content provided by FirstRanker.com ---

? Dermis
? EPIDERMIS--
? It consist of stratified squamous epithelium.
? Five layers in thick skin from deep to superficial.
i)Stratum basale

--- Content provided by FirstRanker.com ---

ii)Stratum spinosum
iii)Stratum granulosum
iv)Stratum lucidum
v)Stratum corneum

--- Content provided by FirstRanker.com ---

? Stratum Basale (Germinativum)--
- Deepest layer of epidermis
-Single layer of cuboidal cells that rests on the

basement membrane.

--- Content provided by FirstRanker.com ---


- Cells attached by desmosomes and by

hemidesmosomes to basement membrane.

--- Content provided by FirstRanker.com ---

-The newly produced cells move towards

superficial layer

? Stratum spinosum--

--- Content provided by FirstRanker.com ---

? Consist of several layers of polygonal cells.

? During histological preparation, cells shrink

and intercellular spaces appear as spines

--- Content provided by FirstRanker.com ---


? This layer well developed in friction and

pressure area of skin.
? Stratum granulosum--

--- Content provided by FirstRanker.com ---

? Consists of 3-5 layers of flattened fusiform cells.
? These cells are filled with keratohyalin granules.

? Stratum lucidum--
? Seen only in thick skin.

--- Content provided by FirstRanker.com ---

? Cells are flattened, translucent.
? These cells are filled with protein called keratin

and eleidin.
? Stratum corneum--

--- Content provided by FirstRanker.com ---

? Most superficial layer of epidermis.
? Composed of dehydrated dead cells.
? Cells are filled with keratin.
? Thickness is much more in thick skin.
? This layer is continuously sloughed off, this

--- Content provided by FirstRanker.com ---


process takes 20-30 days.
? DERMIS--
? Made up of collagen bundles.
? It also contains elastic fibres, nerves, lymphatics

--- Content provided by FirstRanker.com ---


and blood vessels.

? It is divided into two layers.
? Papillary layer

--- Content provided by FirstRanker.com ---

? Reticular layer

? Papillary layer--
? Narrow band of loose connective tissue in

--- Content provided by FirstRanker.com ---

contact with basement membrane of st. basale.

? Shows finger-like processes (dermal papilla)

projecting into under surface of epidermis.

--- Content provided by FirstRanker.com ---


? Papilla contain type III collagen, elastic fibres,

nerves, blood vessels and connective tissue cells.
? Reticular layer--

--- Content provided by FirstRanker.com ---

? It contains bundles of type I collagen, thick

elastic fibres, nerves, blood vessels and few

connective tissue cells

--- Content provided by FirstRanker.com ---

CELLS OF EPIDERMIS

? Keratinocytes--
? Most abundant cell (90%).
? Produces keratin

--- Content provided by FirstRanker.com ---

? Keratinocytes migrates from stratum basale

towards surface.
? Melanocytes--
? Derived from neural crest cells.

--- Content provided by FirstRanker.com ---

? Located between st. basale and st. Spinosum.
? Produce melanin pigments (responsible for skin

colour).

--- Content provided by FirstRanker.com ---

? Melanin darkens skin colour and protect it from

ultraviolet radiation.

? In white people melanin is degraded by

--- Content provided by FirstRanker.com ---


lysosomes.

? In black people this pigment is more stable.

--- Content provided by FirstRanker.com ---

? Langerhans Cells--
--Found in st. spinosum; part of immune system of

body

--- Content provided by FirstRanker.com ---

--Are antigen-presenting cells of the skin.

? Merkel's Cells--
--Sensory cells present in the st. Basale .
--Derived from neural crest.

--- Content provided by FirstRanker.com ---

--Function as mechanoreceptors.
--Abundant in fingertips, oral mucosa and hair follicle
DIFFERENCE BETWEEN THIN AND THICK SKIN

THIN SKIN

--- Content provided by FirstRanker.com ---


THICK SKIN

LAYERS OF EPIDERMIS ST. LUCIDUM ABSENT PRESENT

--- Content provided by FirstRanker.com ---

THICKNESS OF

0.10-0.15 mm

0.6-4.5 mm

--- Content provided by FirstRanker.com ---


EPIDERMIS
HAIR FOLLICLES

PRESENT

--- Content provided by FirstRanker.com ---


ABSENT

SWEAT GLAND

--- Content provided by FirstRanker.com ---

FEW

MANY

SENSORY RECEPTOR

--- Content provided by FirstRanker.com ---


LESS

MORE

--- Content provided by FirstRanker.com ---

DISTRIBUTION

COVERS ALL THE

PALM AND SOLE

--- Content provided by FirstRanker.com ---


PARTS OF THE BODY

EXCEPT PALM AND

--- Content provided by FirstRanker.com ---

SOLE


THIN SKIN

--- Content provided by FirstRanker.com ---


THICK SKIN


GLANDS OF SKIN

--- Content provided by FirstRanker.com ---


? Sebaceous Gland
? Present in the dermis of skin.
? Simple acinar gland whose

--- Content provided by FirstRanker.com ---

duct opens into the hair

follicle.

? It secretes oily substance

--- Content provided by FirstRanker.com ---


called sebum.

? Sebum keeps the skin smooth

--- Content provided by FirstRanker.com ---

to prevent it from drying

? Mode of secretion is

holocrine.

--- Content provided by FirstRanker.com ---



? Sweat Gland
? Present in the deeper part of

--- Content provided by FirstRanker.com ---

dermis and is widely distributed.

? Simple coiled, tubular gland

whose duct opens on the

--- Content provided by FirstRanker.com ---


epidermal surface.

? watery secretion helps in

--- Content provided by FirstRanker.com ---

maintaining body temperature.
? Two types of sweat glands

? Eccrine:
Widely distributed throughout skin.

--- Content provided by FirstRanker.com ---

Densely in the palms and soles.
Watery secretion.

? Apocrine:
Found in axilla, groin areola of breast.

--- Content provided by FirstRanker.com ---

Thick viscous secretion


RESPIRATOTY SYSTEM
INTRODUCTION

--- Content provided by FirstRanker.com ---


? Consists of nose, pharynx, larynx, trachea and

lungs.

--- Content provided by FirstRanker.com ---

? Functions:--
? Perception of smell
? Filtration of inhaled air
? Phonation
? Respiration

--- Content provided by FirstRanker.com ---

? Maintenance of blood pH
? Functionally respiratory system consists of two

parts.

--- Content provided by FirstRanker.com ---

? Conducting part--
? Nasal cavity
? Pharynx
? Larynx
? Trachea

--- Content provided by FirstRanker.com ---

? Bronchi
? Bronchioles & terminal bronchioles.
? Respiratory part--
? Respiratory bronchioles
? Alveolar duct

--- Content provided by FirstRanker.com ---

? Alveolar sac & alveoli.
Conducting part

? General structure of the conducting part
? Respiratory tract made of four coats--

--- Content provided by FirstRanker.com ---

1.Mucosa--epitehelial lining and underlying lamina

propria.

Epithelium is usually pseudostratified ciliated

--- Content provided by FirstRanker.com ---


columnar with goblet cells.

2.Submucosa--layer of loose connective tissue

--- Content provided by FirstRanker.com ---

containing mixed gland.

3.cartilage layer--mostly hyaline cartilage and

smooth muscle.

--- Content provided by FirstRanker.com ---


4.Adventitia--fibroelastic connective tissue.
? Epiglottis--
? Consists of a plate of elastic cartilage.
? On the both sides of cartilage there is

--- Content provided by FirstRanker.com ---


presence of lamina propria.

? Lamina propria contains seromucous gland.
? Anterior surface & upper part of posterior

--- Content provided by FirstRanker.com ---


surface lined by stratified squamous

epithelium.

--- Content provided by FirstRanker.com ---

? Posterior surface lined by pseudostratified

ciliated columnar epithelium with goblet cells.

? Trachea--

--- Content provided by FirstRanker.com ---

? The wall of the trachea consists of mucosa,

submucosa, hyaline cartilage, and adventitia.

? Trachea is kept patent (open) by 16-20 C-

--- Content provided by FirstRanker.com ---


shaped hyaline cartilage rings.

? The gap between the posterior ends of the

--- Content provided by FirstRanker.com ---

hyaline cartilage is filled by the smooth

trachealis muscle.

? The lumen of the trachea is lined by

--- Content provided by FirstRanker.com ---


pseudostratified ciliated columnar epithelium

with goblet cells.

--- Content provided by FirstRanker.com ---

Respiratory part

? Respiratory bronchioles--

? Transition from conducting part to respiratory part.

--- Content provided by FirstRanker.com ---

? Less than 0.5mm diameter.
? Lining epithelium is simple cuboidal with cilia.
? Alveoli--

? Thin walled polyhedral sacs about 200 um in

--- Content provided by FirstRanker.com ---


diameter.

? Alveoli are closlely packed, so the alveolar wall is a

--- Content provided by FirstRanker.com ---

partition or septum between two alveoli.

? Interalveolar septa contains network of capillaries.
? There may be opening in septa called as pores.
? Lined by simple squamous epithelium.

--- Content provided by FirstRanker.com ---


? Blood-air barrier--
? The air in alveolus is separated from blood in

capillary by three structures.

--- Content provided by FirstRanker.com ---


? Endothelium of capillary
? Lining epithelium of alveolus
? Fused basal lamina of endothelium and

--- Content provided by FirstRanker.com ---

epithelium.

? This is thin (1.5-2 um) and facilitates the

diffusion of oxygen and carbon dioxide.

--- Content provided by FirstRanker.com ---


? Cells of alveolar wall--
? Type I alveolar cells (pneumocyte I)
? Very thin squamous cells
? Cover 95% of alveolar surface

--- Content provided by FirstRanker.com ---

? Type II alveolar cells (pneumocyte II)
? Large rounded cells contains microvilli
? Secretory in nature and secretes pulmonary

surfactant, which lower surface tension and

--- Content provided by FirstRanker.com ---


prevents alveoli from collapsing during expiration

? Type II alveolar cells also gives type I alveolar cells
? It also produces surfactant protein A, B, C and D

--- Content provided by FirstRanker.com ---

? Brush cells--
? These cells found occasiniolly in alveolar epithelium.
? Serve as receptor to monitor the quality of air

entering in lung.

--- Content provided by FirstRanker.com ---


? Alveolar macrophage--
? Found in connective tissue of interalveolar septa
? First line defence against pulmonary infection.
? They phagocytes dust particles so called as dust cells.

--- Content provided by FirstRanker.com ---

? In patients of heart failure the erythrocytes

accumulate in alveoli which is phagocytosed by

macrophage and acquire brick red colour so called as

--- Content provided by FirstRanker.com ---


heart failure cells.
Difference between Bronchus & Bronchiole

BRONCHUS

--- Content provided by FirstRanker.com ---


BRONCHIOLE

DIAMETER > 1 MM

--- Content provided by FirstRanker.com ---

DIAMETER< 1 MM

PSEUDOSTRATIFIED CILIATED SIMPLE COLUMNAR OR

COLUMNAR

--- Content provided by FirstRanker.com ---


SIMPLE CUBOIDAL

SMOOTH MUSCLE

--- Content provided by FirstRanker.com ---

SMOOTH MUSCLE & ELASTIC

FIBRES

CARTILAGE PRESENT

--- Content provided by FirstRanker.com ---


CARTILAGE ABSENT

GLANDS PRESENT

--- Content provided by FirstRanker.com ---

NO GLANDS