Tissues Flashcards
What are tissues?
A group of related cells that work/join together to carry out specific functions
What are the four main types of tissue?
Epithelial, connective, muscle, nervous
What is the general purpose of epithelial tissue?
- Is the lining of surfaces
- secretes parts of basement membranes
What is simple cuboidal tissue?
An epithelial tissue which lines ducts and tubes, allowing material to pass
(found in kidney tubules/sweat ducts/thyroid gland/breast tissue)
Structure of simple cuboidal tissue?
Single cellular, cube shaped with spherical nuclei
What is simple columnar tissue?
An epithelial tissue associated with cilia - Cilia transports the flow of dirty mucus to the exterior
(found in the trachea/bronchi/villi in the small intestine)
Structure of simple columnar tissue?
A tall and deep cell, single cell layered, with slightly oval nuclei, found near goblet cells (GC’s secrete mucus)
What is simple squamous tissue?
An epithelial tissue which allows materials to pass through via diffusion and osmosis
(found in lung alveoli/blood capillaries/bowman’s capsule of nephrons)
Structure of simple squamos tissue?
Very flat and scaly, single cell layer - delicate and thin cells where each nucleus forms a lump in the middle of the cell
What is simple ciliated tissue?
A type of epithelial tissue where the cilia are tiny hair like structures on the surface of the cell which sweep dust/hair/bacteria up to the back of the throat
What is compound simple tissue?
An epithelial tissue made up of multiple layers of cells which hamper the passage of material
(vagina/mouth/tongue are all lined by stratified epithelial layers of either squamous/cuboidal/columnar cells)
What is compound keratinised tissue?
A type of compound epithelial tissue which is the outer layer of skin cells that have died and hardened - the layer protects tissues underneath - make up external layer of skin and stomach lining
What is connective tissue?
The tough tissue binding internal structures together - providing support/elasticity.
Forms large parts of: skin/tendons/joints/ligaments/blood vessels/muscles
What are the 6 types of connective tissue?
Blood Cartilage Bone Lymph Areolar tissue Adipose tissue
What is cartilage?
Smooth/firm substance protecting bone ends from friction - forms major part of nose and ear flaps
What is bone?
A harder substance than cartilage which can be worn away - designed to weight bear and protect vital organs (limb bones are hollow)
What are the three major compartments of bone?
Calcium salts (form around collagen fibres to give bone its hardness) Collagen fibres (offer ability to bend under strain) Bone cells (osteocytes)
What do calcium salts do?
form around collagen fibres - giving the bone its hardness
What do collagen fibres do?
Offer some flexibility - allow the bone to bend under strain - preventing the bone being too brittle
What are bone cells called?
Oeteocytes
What is areolar tissue?
Most common connective tissue (also known as loose connective tissue)
It is a sticky white material which binds muscle groups together
Structure and elements of areolar tissue?
Semi fluid containing collagen fibres and elastic fibres - elastic fibres giving flexibility to the tissue
What is the dermis?
A deeper skin layer which is made of a denser type of areolar tissue with extra fibres and cells
What is adipose tissue?
Fatty tissue - loose connective tissue in which adipose(fat) cells have multiplied - usually under the skin and around organs
Purpose of adipose tissue?
Store energy in the form of fat, helps insulate body, protects against injury
What are the three types of muscle tissue?
Striated
Non-striated
Cardiac
What do all three types of muscle tissue have in common?
All muscles respond to stimuli
Each tissue is composed of muscle fibres capable of shortening (contracting) and returning to their original state (relaxing)
Contraction causes movement of the …
Skeleton, soft tissue, blood, also urine/faeces/food
What is striated muscle tissue?
Connective tissue attached to bones e.g. some facial muscles are attached to skin
How does striated muscle work?
Contracts when it receives impulses by conscious thought from the CNS
What does striated muscle consist of (structurally)?
Repeated individual fibres/elements (sacromeres) which show alternate dark and light banding (due to the muscle protein filaments from which it is made up of)
Each fibre is cylindrical and multinucleate
Contains lots of mitochondria
Why can striated muscle also be known as voluntary, striped or skeletal muscle?
Voluntary - movement of the muscle is conscious (CNS)
Striped - due to striations
Skeletal - it is attached to the bone of the skeleton
What is smooth muscle?
Involuntary muscle which requires nervous stimulation to contract (via autonomic NS)
It is not attached to bones but around hollow internal organs e.g. stomach/intestines/iris of the eye
What does smooth muscle consist of (structurally)?
Made up of sheets/strands of muscle cells with singular central nuclei
These cells are composed of actin and myosin fibres along with other proteins
the protein filaments do not lie orderly and so do not have striations
What does peristalsis entail?
it is a series of wave-like (smooth) muscle contractions that move food to different processing stations in the digestive tract
Begins in the esophagus when a bolus of food is swallowed
What is cardiac muscle?
The muscle only found in the four chambers of the heart
It rhythmically contracts without any nervous stimulation but through an electrical stimulation at the Sinoatrial node
What does cardiac muscle consist of (structurally)?
Cardiac muscle fibers have a single nucleus, are branched, and joined to one another by intercalated discs that contain gap junctions (for depolarization between cells) and desmosomes to hold the fibres together when the heart contracts
What does the nervous system consist of?
The brain
The spinal cord
Nerves
What does the NS create?
Consistency, co-ordination and communication between parts of the body
What are organs?
The body’s essential structures which all carry out their own specific functions to keep the body running
What are organs made up of?
Several types of tissue and therefore several cell types
e.g the heart contains muscle tissue to pump the blood, fibrous tissue to make up heart valves and special cells to maintain rhythm and rate of HB
What are the 15 organs of the body?
Heart Lungs Brain Stomach Liver Pancreas Duodenum (part of small intestine) ileum (part of small intestine) Colon (large intestine) Kidneys Bladder Ovaries Testes Uterus Skin
Where is the heart situated in the body?
The heart is positioned in the chest behind the sternum (breastbone); in front of the trachea, esophagus, and aorta; and above the diaphragm
What is the structure of the heart?
The heart is divided into four chambers: two atria (upper chambers) and two ventricles (lower ventricles). The pulmonary trunk is a vessel that brings deoxygenated blood from the left ventricle into the lungs. Pulmonary veins return the oxygenated blood from the lungs back into the heart
What is the main function of the heart?
An organ that pumps blood throughout the body via the circulatory system, supplying oxygen and nutrients to the tissues and removing carbon dioxide and other wastes
Where are the lungs situated in the body?
On either side of the breastbone (sternum) in the chest cavity - divided into five main sections (lobes)
What is the structure of the lungs?
A pair of spongy, air-filled organs located on either side of the chest (thorax). The trachea (windpipe) conducts inhaled air into the lungs through its tubular branches, called bronchi. The bronchi then divide into smaller and smaller branches (bronchioles)
What is the main function of the lungs?
- Inhalation and Exhalation (Pulmonary Ventilation/breathing!)
- External Respiration Exchanges Gases Between the Lungs and the Bloodstream
- Internal Respiration Exchanges Gases Between the Bloodstream and Body Tissues
- Air Vibrating the Vocal Cords Creates Sound
- Olfaction, or Smelling, Is a Chemical Sensation
General cell shape associated with ‘squamous’ epithelium?
Flat
General cell shape associated with ‘cuboidal’ epithelium?
Square
General cell shape associated with ‘columnar’ epithelium?
Tall and deep
General structure of layering associated with ‘simple’ epithelium?
Single cellular layer - not protective but specialises in absorption/secretion/filtration
General structure of layering associated with ‘stratified’ epithelium?
Multiple layers
Keratinised meaning …
External parts of the body
Non-keratinised meaning …
Line wet areas of the body, such as: tongue/mouth
General structure of layering associated with ‘Pseudostratified’ epithelium?
Appears to have multiple layers but does not - only one
What is the blood made up of?
Plasma
RBC’s
Thrombocytes (platelets)
WBC’s
What are two types of nerve cells?
Neurones Neuroglial cells (glia)
What are neurones?
Highly specialised nerve cells that generate and conduct nerve impulses
What are neuroglial cells (glia)?
Supporting cells that provide support and nutrition within the NS, remove debris and provide electrical insulation
What is the general process of the NS?
NS interprets stimuli from sense organs so that sensations become apparent
What are all the 10 systems of the body?
Nervous system Immune s Digestive s Cardiovascular s Integumentary s Respiratory s Endocrine s Reproductive s Excretory s Musculoskeletal s
What is nervous tissue responsible for?
Controlling and co-ordinating many bodily activities and communicating things between different areas of the body
Where is nervous tissue found?
In the brain, spinal cord and nerves around the entire body
Where are simple cuboidal cells found?
In breast tissue
Where are simple columnar cells found?
In the trachea
Where is compound simple epithelial tissue found?
In mucous membranes
Most common tissue type in the body?
Areolar
