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.
Lymphocytes definition
produce antibodies, proteins that target specific markers (antigens) on bacteria and viruses, destroying them. Some lymphocytes form memory cells (which are involved in a secondary immune response).
Phagocytes
ingest or engulf (take in) pathogens and digest them using enzymes to prevent damage to body cells.
Platelet function
Platelets are small fragments of cells. They contain no nucleus. Their role in the body is to help blood clot at a wound site. This stops blood loss and prevents microbes from entering the body.
Plasma function
involved with both the transport of blood components and other dissolves substances eg hormones, antibodies, urea and CO2. Also in distribution of heat.
Why do we need gas exchange and transport systems
In order to make the process faster, animals have a transport system which takes the oxygen close to a large number of cells throughout the body. This ensures that their cells are supplied with oxygen more rapidly.
The digestive system is the organ system that is involved in
the breakdown of large insoluble molecules found in food into their soluble products
the absorption of these products of digestion
Food passes through the digestive system in the following order:
1) mouth
2) oesophagus
3) stomach
4) small intestine
5) large intestine.
Peristalsis…
is waves of muscular contraction that move the bolus (ball of food) along.
How food moves through digestion.
The digestive system is the organ system that is involved in:
- the breakdown of large insoluble molecules found in food into their soluble products
- the absorption of these products of digestion.
Food passes through the digestive system in the following order
mouth -> oesophagus -> stomach -> small intestine -> large intestine
Why do the villi contain many blood capillaries
there is an excellent blood supply to carry away the products of digestion as soon as they have been absorbed
Why do the villi contain many blood capillaries
there is an excellent blood supply to carry away the products of digestion as soon as they have been absorbed
Absorbed nutrients are used by body cells to…
to make new macromolecules – carbohydrates, proteins, lipids
in aerobic respiration.
Absorbed nutrients are used by body cells to…
to make new macromolecules – carbohydrates, proteins, lipids
in aerobic respiration.
Most nutrients absorption occurs in the…
small intestine
Egestion is…
The expelling of waste products through the anus
function of the excretory system
the removal from organisms of toxic materials and substances in excess of requirements.
Organs include liver, lungs, skin and kidneys
function of the liver with amino acids
The body cannot store proteins or amino acids from digestion.
The liver breaks down the amino acids. The nitrogen component is converted to urea.
High concs of urea is bad. This is excreted by the kidneys.
Kidney’s function
The kidneys have three main roles, which all involve filtration of the blood:
- the removal of urea
- adjustment of the ion content
- adjustment of the water content.
The kidneys and the removal of urea:
Each kidney receives blood from the aorta via a renal artery. The blood is filtered to remove urea, excess water and salts. The filtered blood is returned to the vena cava via a renal vein.
The filtrate from the blood plasma (urine) the leaves to the bladder.
The kidneys also control the levels of […] in the blood
salts, acids and water
Homeostasis is
the maintenance of a constant internal environment
The kidneys maintain homeostasis by…
controlling the amount of water, ions, and other substances in the blood. Kidneys also secrete hormones that have other homeostatic functions
Role of insulin
- hormone which controlls the converting of glucose to glycogen in the liver when blood glucose concentrations are high
- Insulin also stimulates other body cells to take up more glucose for use in respiration.
Role of glucagon
hormone which controlls the converting of glycogen to glucose in the liver when blood glucose concentrations are low
Role of the pancreas in glucose regulation
Detects glucose changes, and excretes hormones which are delivered to the liver
Cause of type 1 diabetes
- caused by an inability of the pancreatic islet cells to secrete enough insulin to control blood glucose correctly.
- The disease can be inherited or be triggered by an event such as a viral infection. The infection causes the body’s immune system to attack the islet cells of the pancreas, so they stop producing sufficient insulin.
Symptoms of Type 1 Diabetes
These include feeling tired, feeling very thirsty, frequent urination and weight loss. There may be glucose present in the urine.
Treatment of Type 1 diabetes
- application of a carefully regulated diet to stop blood glucose levels from fluctuating too much.
- Regular blood tests are needed to monitor blood glucose levels.
- Regular injections of insulin are also required to control blood glucose levels.
Causes of Type 2 diabetes
- can be inherited, or a result of obesity, lack of exercise and an unhealthy diet
- can lead to insulin resistance, where the body does not use insulin properly
What is ADH
a hormone, carried in the blood, which signals to the kidneys how much water they should excrete or reabsorb.
(produced by the hypothalamus and extreted by the pituarity gland)
High levels of ADH leads to…
kidneys absorbing more water, so less urine excretes
Low levels of ADH leads to…
Kidneys absorb less water, so more urine excretes
arterioles dilating results in…
cooling of the skin (vasodilation)
Where are hormones released
from specific endocrine glands, and travel in the blood to the target structures.
What is thyroxine
a hormone produced in the thyroid
has an important role in regulating the basal metabolic rate
Where is adrenaline produced
In scary or stressful situations in the adrenal glands
What does adrenaline do
Stimulates the breakdown of glycogen to glucose, increases breathing rate, increases heart rate, and stimulates more blood flow to muscles
- increased supply of glucose and oxygen to the brain and muscles.
What is the main female reproductive hormone
estrogen produced in the ovaries
What is FSH (follicle stimulated hormone)
FSH stimulates an ovary:
- to develop a follicle containing an egg (ovum maturation)
- to produce oestrogen.
(produced in pituitary gland)
Role of oestrogen
stimulates the thickening of the uterine lining
(produced by ovaries)
Role of LH (luteinising hormone)
stimulates the mature follicle to release the egg/ovum (ovulation) in the middle of the cycle (around day 14).
(produced in the pituitary gland)
Role of Progesterone
maintains the lining of the uterus during the second half of the cycle so that a fertilised egg may implant.
(secreted by the empty follicle in the ovary)
What happens with decreasing progesterone
cause the thickened uterus lining to break down and be discharged (menstruation)
What would happen if oestrogen did not inhibit the production of FSH?
The ovaries would be stimulated to produce many follicles containing ova during the cycle. This could result in many ova being released and being fertilised during sexual reproduction.
How are hormones used in contraception
Oestrogen and progesterone prevent ovulation as they inhibit FSH production and egg maturation. Ovulation cannot take place.
What are communicable diseases caused by
pathogenic bacteria, viruses, protists and fungi
causes of non-communicable diseases
are not infectious – they cannot be passed from one person to another
are caused by the interaction of many different factors.
eg cardiovascular, cancers, nutrition realted
Treatment/management of CVD
i) using life-long medication
- eg statins, anti-coagulants abd anti-hyoertensive drugs
ii) surgical procedures
- stents and bypass for coronary heart disease
iii) lifestyle changes.
- reduced smoking, exercise, diets
