tissues Flashcards
cells
Smallest functional unit of an organism (when grouped together create tissues).
tissues
Ensemble/collection of similar cells carrying out specific functions (when grouped together create organs).
organ
Group of tissues with specific functions (i.e. liver, stomach, brain, etc).
organ system
Collection of different organs that work together to do specific roles (i.e. digestive, circulatory, respiratory, etc).
epithelial tissues
Lining, protection, transport, secretion and absorption
muscle tissue
movement it contains cells which have the ability to shorten and contract muscle fibres
nervous tissue
Information, communication and control
endothelium
The epithelium lining the inside of the heart, blood vessels and lymph vessels
Epithelial tissue can be classified
depending on how many layers of cells it consists of and the shape of the cells
simple epithelium
a single layer of cells. it is found lining the blood vessels, lungs, kidneys, and lines the body cavities, and allows easy passage of materials by diffusion.
stratified epithelium.
When several layers of cells are present it is. The thicker the layer the greater the protection of the underlying structures.
pseudostratified epithelium.
It is a single layer of cells, however, the nuclei are organised in a way that makes them appear as stratified epithelium.
shapes of epithelium cell
Squamous cells: flattened in shape
Cuboidal cells: square or cubed in shape
Columnar cells: column shaped
summary of epithelial tissue
Epithelial tissue is supported by a basement. The basement membrane consists of a network of blood vessels, providing oxygen and nutrients to the cell and also allowing for absorption. Secretory epithelia are specialised to secrete substances such as proteins, for example, goblet cells and glandular cells.
Epithelial cells can be covered in small hair-like projections, called cilia. For example, ciliated epithelia in the upper respiratory tract helps to move dust and mucus.
epithelial tissue type simple cuboidal
lines the kidney tubules. it allows the diffusion and secretion of molecules
epithelial tissue type stratified squamous
This type of epithelium usually has protective functions, including protection against microorganisms from invading underlying tissue and/or protection against water loss. found on the outer layer of your skin
epithelial tissue type pseudostratified columnar
lines the trachea. it allows impurities to be swept toward the throat due to the secretion
three different muscle tissues
skeletal muscle
smooth muscle
cardiac muscle
smooth muscle
is located in the walls of hollow internal structures like the intestines and bladder to help urine get out of the body. it has 1 nucleus in the middle of the cell.
pupillary sphincter muscle
is located in the eye. it is a smooth muscle that shrinks with lots of light and expands for small amount of light
skeletal muscle
attached to the bone via tendons, several nuclei a large number of mitochondria. it is important for holding your bones together and preventing your joints from dislocating
cardiac muscle
makes up the heart. branching structure. 1 nucleus. never gets tire
the sliding filament theory
1)The message arrives at the neuromuscular (where the neuroses and muscles meet) junction
2) acetylcholine(lining of a bundle of fibres) gets released
3)this stimulates the sarcoplasmic reticulum
4) calcium is released and binds to troponin
5)so the tropomyosin changes shape so it can reveal the binding sites
6)the myosin head attaches to the binding site and attaches from a cross bright
7) ATP gets broken down into ADP
8)this allows the myosin’s head to pull the acting filament inwards this is called a power stroke. after this, the myosin lets go in the muscle.
slow twitch and fast twitch fibers
Slow-twitch muscle fibers support long distance endurance activities like marathon running, while fast-twitch muscle fibers support quick, powerful movements such as sprinting or weightlifting.
aerobic respiration
Is there a release of energy from the breakdown of glucose by combining with oxygen anaerobic respiration is more efficient than anaerobic respiration happens in the mitochondria of cells ag is used by animals to enable the muscle to contract and allow movement
anaerobic respiration
anaerobic respiration is respiration without oxygen it is a short-term energy production method that animals use when they cannot exchange enough oxygen to carry out aerobic respiration anaerobic respiration is less efficient than aerobic respiration and happens in the side pleasant the cell it leaves are poisonous chemical lactic acid in muscle discount stop muscle from working well and cause pain
how do nervous tissue work
The sensory neurones of the PNS receives stimuli from the internal/external environment
This information is transmitted to the CNS via sensory (afferent) neurones
The CNS (brain) processes the information and sends out a signal
This signal is transmitted to the muscle/organ via motor (efferent) neurones to execute an appropriate response
Sensory/Afferent Neuron
Receive sensory stimuli and send messages from PNS to CNS about the environment
Motor/Efferent Neuron
Cause a response (muscle contraction, etc.) in reaction to the environment
Interneuron/Relay
Situated in the spinal cord and receive impulse from afferent neurones and pass it to efferent neurones
Neuroglia Cells
Provide protection and support to nervous tissue. They are in direct contact with neurons and often surround them.
Neurons
Specialised cells that conduct information (electrical impulses)
glial cells provide production and support to nervous tissue. these cells are in direct contact with neurons and often surrounds them
Structure of a nerves
Dendrite – short fibres that branch out to receive information from other neurons or sensory organs
Cell body – contains a nucleus and acts as a control centre
Axon – Long slim trunk that conveys messages away from the cell to other neurons or to muscle/gland cells.
Myelin sheath – provides electrical insulation, made up of 20-30 layers of Schwann cell membrane
Node of Ranvier – uncovered segments of axon, allowing ion movements to take place
Synapse - site of transmission of electric nerve impulses between two nerve cells (neurons) or between a neuron and a gland or muscle cell (effector).
CENTRAL NERVOUS SYSTEM
ASTROCYTES
Provide support and exchange of materials between neurons and capillaries.
MICROGLIAL CELLS
Provide immune defence against invading microorganisms in CNS.
EPENDYMAL CELLS
Create, secrete and circulate cerebrospinal fluid.
OLIGODENDROCYTES
Wrap around neurons in CNS creating myelin sheath.
PERIPHERAL NERVOUS SYSTEM
glial cells
SATELLITE CELLS
Surround and support cell bodies
SCHWANN CELLS
Produce an insulating barrier called the myelin sheath by wrapping around axons.
How do messages pass from one neurone to another?
At the end of the axon there are multiple synapses
Between neurones there is a gap known as the synaptic cleft.
resting potential
at rest, inside a neuron, there is a negative charge compared to outside. This is caused by the distribution of Na+ and k+ ions which are regulated by the sodium-potassium pump.
the difference between the charges inside and outside the neuron gives the membrane a potential voltage of around - 70mv
action potential
when information gets sent through a neuron. during an action potential, there is a movement of ions across the membrane, initiating a nerve impulse
2 parts of the central nervous system
brain and spinal cord
the nervous system
responding to stimuli can be voluntary the brain is aware of the action - Somatic Nervous System (SNS). involuntary the brain is not in control of it
parasympathetic nervous system
rest to complete life processes to recharge the body
digestion to get nutrients and energy
degenerative myelopathy
is a disease that affects the spinal cord of older dogs, it gets worse over time
symptoms wobble as loss of coordination, and nerves damage
treatment - non
listeriosis
a bacterial infection causing swelling of the brain, and blood poisoning
symptoms collapse and involuntary movements
if untreated the consequence can be death
seizures
causes - brain injury, organ failure, and infection
symptoms - shaking, restlessness, nervous,
loss of consciousness and hallucinate
simple squamous
location alveoli
it allows substances to diffuse across
simple columnar
location lines the small intestine. it allows for nutrients to be absorbed
