B9 Animal Physiology Flashcards
Aerobic Respiration equation
glucose + oxygen –> CO2 + water + ATP
Anaerobic respiration in animals equation
glucose –> lactic acid + energy
What is the nervous system comprised of
brain and spinal cord
Sensory neurones function
connect receptors, which detect stimuli in the environment, with the central nervous system.
Sensory neurones function
connect receptors, which detect stimuli in the environment, with the central nervous system.
Has myelin sheaths
Relay neurones function
are found within the central nervous system. These connect the sensory as well as motor neurones and allow communication to and from the brain.
No myelin sheaths
Motor neurone function
connect the central nervous system to effectors. These are the parts of the body that produce a response to the electrical impulse. Effectors include muscles and glands.
Has myelin sheaths.
Function of myelin sheath
protects the axon and makes the impulse travel faster
What is a synapse?
A synapse is a small gap between two neurones.
Synapses allow neurones to transmit electrical impulses to each other.
What is a reflex arc used for
- These are designed to protect the body from harm and so they occur very rapidly.
- In order to make sure reflex reactions occur quickly, they do not require processing in the brain.
Parts of a reflex arc
Stimulus –> receptor –> sensory neurone –> relay neurone –> motor neurone –> effector
The function of the respiratory system
The main function of the respiratory system is to provide the body with sufficient oxygen for aerobic respiration
gas exchange occurs between…
the alveoli and blood
The cells lining the bronchi produce mucus to
trap any particles in the inhaled air,
eg pollen, dust, bacteria and viruses
Function of cilia (small hairs)
cilia on the cells then move the mucus up to the top of the trachea where it can be swallowed into the acid contents of the stomach in the digestive system.
Destroys them as they are removed from body.
One bronchus enters each lung and they then split into a number of narrow tubes called
bronchioles
At the end of the bronchioles are…
alveoli
Pathway of air into body
Mouth/nose -> larynx -> trachea (contains rings of cartilage) -> bronchus (contains cartilage) -> bronchioles (contains cartilage) -> alveoli
what is the diaphragm
sheet of muscle found under the lungs
Process of inhaling
- When we inhale, the intercostal muscles contract and pull the ribs up and outwards
- The diaphragm contracts and flattens downwards
- This increases the space (volume) within the thoracic cavity.
- This increases the space (volume) within the thoracic cavity.
- Air from outside the body enters the lungs via the trachea and bronchi to equalise the pressure.
Process of exhaling
- When we exhale, the intercostal muscles relax and pull the ribs down and inwards.
- The diaphragm relaxes and becomes domed (moves upwards towards the lungs).
- This decreases the space (volume) within the thoracic cavity.
- This reduced volume increases the air pressure inside the thoracic cavity compared to outside the body.
- Air from inside the lungs is forced out of the body through the bronchi and trachea to equalise the pressure.
How is the body adapted to allow efficient gas exchange
- The alveoli have a large surface area across which diffusion can occur.
- There are thousands of alveoli in each lung, increasing the surface for diffusion further.
- The alveoli and capillary walls are only one cell thick to ensure that the diffusion distance is short.
- The capillaries are wrapped around the alveoli, reducing the distance that the gases must diffuse.
- Blood constantly flows through the capillaries. This maintains the concentration gradients of each gas. This makes sure that both gases diffuse rapidly and in the correct direction.
Increasing the surface area to volume ratio will… (in lungs)
increase the rate at which gas exchange by diffusion occurs
Overall, this will result in a shorter gas exchange time relative to an organism with a larger volume or smaller surface area.
Blood vessel name for liver blood vessels
hepatic
Blood vessel name for kidney blood vessels
Renal
Vein features
Contains valves along its length to prevent blood flowing backwards.
Wide lumen (space inside vessel).
Relatively thin vessel walls with less muscle and elastic tissue.
Carries blood at lower pressure.
Usually carries deoxygenated blood (except pulmonary vein).
Artery features
No valves along the length of the vessel.
Narrow lumen (space inside vessel).
Thick walls made of muscle and elastic tissue to prevent bursting.
Carries higher pressure blood.
Usually carries oxygenated blood (except pulmonary artery).
Capillaries are…
Capillaries are very small vessels with walls made of a single layer of cells. These allow substances to pass easily from the blood into body cells.
ECG
The contraction of the heart muscle cells is coordinated using electrical impulses which pass between the different regions of the heart. These impulses can be recorded with an electrocardiogram (ECG) which detects the impulses using electrodes placed on the skin.
four major components of blood
red blood cells, white blood cells and platelets
Red blood cell function
Mature human red blood cells have a specially adapted shape called a biconcave disc. Their function is to transport oxygen around the body. To do this, oxygen binds to the protein haemoglobin in the cytoplasm of the red blood cells.
White blood cell function
help defend the body from disease. Two types of white blood cell are the lymphocytes and the phagocytes.