The basic tissue and body layers Flashcards
Define tissue
-Tissues are groups of cells organised to perform one or more specific functions
Define organ
-Organs are made up of tissues and these are classified into 4 types
What are the 4 basic tissues of the body
-Epithelium (epithelial tissue)
-Connective tissue
-Muscle tissue
-Nerve tissue
Function of epithelial tissue
-covers body surfaces
-lines body cavities
-forms glands
Function of connective tissue
-underlines or supports other 3 tissues, both structurally and functionally
Function of muscle tissue
-made up of contractile cells
-responsible for movement
Function of nerve tissue
-receives, transmits and integrates information from outside and inside the body
-to control activities of the body
What layer of epithelial tissue? Location and function?
-Simple squamous
-Location: blood vessel, alveoli, body cavities
-Function: exchange diffusion
What layer of epithelial tissue? Location and function?
-Stratified squamous
-Location: epidermis, oral cavity, oesophagus, vagina
-Function: barrier protection
What layer of epithelial tissue? Location and function?
-Simple columnar
-Location: Small/large intestine, stomach lining
-Function: absorption, secretion
What layer of epithelial tissue? Location and function?
-Pseudostratified columnar
-Location: Respiratory tract
-Function: secretion
What layer of epithelial tissue? Location and function?
-Transitional (urothelium)
-Location: Urinary organs
-Function: distensible property
Classification of connective tissue
Structure/examples of dense connective tissue
Structure:
-More fibres
-Less cells
-Collagen fibres dominate the structure
E.g. tendons, ligaments
Structure/examples of loose connective tissue
Structure:
-Less fibres
-More fat cells
E.g. adipose, areolar
Classification of muscle tissue
Skeletal
-voluntary movement
-striated and red/white
Cardiac
-pumping of heart
-striated with centrally located nucleus
Smooth
-in walls of hollow organs for contraction
-non-striated with no sarcomeres
What is nerve tissue made of?
-Nerve cells (neurones) receive stimuli and conduct responsive impulses
-Neuroglia/Glial cells are supporting cells
What are the body layers?
Epidermis - Stratified squamous epithelium for protection
Dermis - Contains collagen and elastic fibres
Subcutaneous tissue (superficial fascia) -Loose connective tissue containing fat, sweat glands, superficial vessels and cutaneous nerves
Deep fascia
-Dense connective tissue
Skeletal muscle
-Movement
What tissue is the heart made up of?
-Cardiac muscle tissue
What tissue are blood vessels made up of?
-Epithelial
-Smooth muscle
-Connective tissue
What is the systemic circulation?
-Left ventricle
-To body
-To right atrium
What is the pulmonary circulation?
-Right ventricle
-To lungs
-To left atrium
What is portal circulation?
-Where a venous system links 2 capillary beds (e.g. hepatic portal vein)
What do capillaries link?
-Arterioles and venules
-Allow exchange of materials (oxygen and nutrients to cells of surrounding tissues)
How do we differentiate arteries from veins?
-If you squeeze an artery it recoils
-If you squeeze a vein it collapses
-Because arteries have a thicker smooth muscle tissue layer
-Veins have valves
How does blood in the venous system return to the heart?
-Gravity
-Musculovenous pump - skeletal muscles contract around veins
-Arteriovenous pump - when arteries fill with blood they push on surrounding veins which drives flow
What are anastomoses?
-Communications between small arterial branches of major arteries
-Providing detours for blood flow, offering a collateral route
What are end arteries?
-Arteries that are isolated from others
-Their branches do not anastomose with other arteries
-Territories supplied by an end artery is totally dependent on it
Anatomical end arteries vs Functional end arteries
Function of the lymphatic system
-Drainage of surplus tissue fluid and leaked plasma proteins
-Removal of debris from cellular decomposition and infection
What causes oedema?
-Build up of surplus fluid in extracellular space
-Causes reversal in osmotic pressure and retention of fluid
Parts of the lymphatic system?
Lymphatic capillaries (plexuses) - simple squamous epithelium
Lymphatic vessels - contains valve to direct lymph in one direction back into the venous system
Lymph - the tissue fluid (usually clear, watery and slightly yellow) found in lymphatic vessels
Lymph nodes - Small masses of lymphatic tissue that filter lymph (side of neck, axilla, inguinal)
Drainage of lymphatic system
-Thoracic duct responsible for draining 3/4 of lymph
-The rest drains through the right lymphatic duct
Lymphatic system and detecting cancer
-First set of lymph nodes draining a specific territory are called the sentinel nodes
-These help predict the source of cancer and infection
Lymphatic system against cancer
-Cancer cells metastasise and go into lymphatic system
-Lymph nodes filter lymph fluid and WBCs attack the cancer
-Lymph nodes become enlarged, making cancer easier to detect
